git.libre-soc.org Git

c++: Normalize nested-requirements twice at parse time [PR97093]

The re-normalization performed from diagnose_nested_requirement doesn't
always work because we may have already lost the necessary template
context that determines the set of in-scope template parameters used by
the nested-requirement.  This leads to normalization producing atoms
that have incomplete/bogus parameter mappings, which breaks satisfaction.

To fix this, we could just use the normal form that we previously
computed at parse time, but this normal form lacks the diagnostic
information that leads to good error messages.

Instead, this patch makes diagnose_nested_requirement normalize twice at
parse time -- once without diagnostic information and once with -- so
that routines can use the "regular" normal form when performing
satisfaction quietly and the "diagnostic" normal form when performing
satisfaction noisily.  Moreover, this patch makes tsubst_nested_requirement
always first perform satisfaction quietly so that the satisfaction cache
can get consistently utilized.

This patch also adds some sanity checks to build_parameter_mapping that
would have caught the underlying bug sooner (and deterministically).

gcc/cp/ChangeLog:

PR c++/97093
* constraint.cc (parameter_mapping_equivalent_p): Add some
sanity checks.  Clarify comment.
(tsubst_nested_requirement): Always perform satisfaction
quietly first.  If that yields an erroneous result, emit a
context message and replay satisfaction noisily with the
diagnostic normal form.
(finish_nested_requirement): Normalize the constraint-expression
twice, once with diagnostic information and once without.  Store
them in a TREE_LIST within the TREE_TYPE.
(diagnose_nested_requirement): When replaying satisfaction, use
the diagnostic normal form instead of renormalizing on the spot.

gcc/testsuite/ChangeLog:

PR c++/97093
* g++.dg/cpp2a/concepts-requires22.C: New test.

c++: Distinguish unsatisfaction vs errors during satisfaction [PR97093]

During satisfaction, the flag info.noisy() controls three things:
whether to diagnose ill-formed satisfaction (such as the satisfaction
value of an atom being non-bool or non-constant); whether to diagnose
unsatisfaction; and whether to bypass the satisfaction cache.

The flag turns out to be too coarse however, because in some cases we
want to diagnose ill-formed satisfaction (and bypass the satisfaction
cache) but not diagnose unsatisfaction, for instance when replaying an
erroneous satisfaction result from constraint_satisfaction_value,
evaluate_concept_check and tsubst_nested_requirement.

And when noisily evaluating a disjunction, we want to first evaluate its
branches noisily (bypassing the satisfaction cache) but suppress
unsatisfaction diagnostics.  We currently work around this by instead
first evaluating each branch quietly, but that means the recursive calls
to satisfy_atom will use the satisfaction cache.

To fix this, this patch adds the info.diagnose_unsatisfaction_p() flag,
which refines the info.noisy() flag as part of a new sat_info class that
derives from subst_info.  During satisfaction, info.noisy() now controls
whether to diagnose ill-formed satisfaction, and
info.diagnose_unsatisfaction_p() controls whether to additionally
diagnose unsatisfaction.  This enables us to address the above two
issues straightforwardly.

Incidentally, the change to satisfy_disjunction suppresses the ICE in
the PR97093 testcase because we no longer insert atoms into the
satisfaction cache that have been incorrectly re-normalized in
diagnose_nested_requirement (after losing the necessary template
context).  But the underlying re-normalization issue remains, and will
be fixed in a subsequent patch.

gcc/cp/ChangeLog:

PR c++/97093
* constraint.cc (struct sat_info): Define.
(tsubst_nested_requirement): Pass a sat_info object to
satisfy_constraint.
(satisfy_constraint_r): Take a sat_info argument instead of
subst_info.
(satisfy_conjunction): Likewise.
(satisfy_disjunction): Likewise.  Instead of first evaluating
each branch quietly, evaluate each branch only with
unsatisfaction diagnostics disabled.  Exit early if evaluation
of a branch returns error_mark_node.
(satisfy_atom): Take a sat_info argument instead of subst_info.
Fix a comment.  Check diagnose_unsatisfaction_p() instead of
noisy() before replaying a substitution failure.
(satisfy_constraint): Take a sat_info argument instead of
subst_info.
(satisfy_associated_constraints): Likewise.
(satisfy_constraint_expression): Likewise.
(satisfy_declaration_constraints): Likewise.
(constraint_satisfaction_value): Likewise and adjust
accordingly.  Fix formatting.
(constraints_satisfied_p): Pass a sat_info object to
constraint_satisfaction_value.
(evaluate_concept_check): Pass a sat_info object to
satisfy_constraint_expression.
(diagnose_nested_requirement): Likewise.
(diagnose_constraints): Pass an appropriate sat_info object to
constraint_satisfaction_value.

gcc/testsuite/ChangeLog:

PR c++/97093
* g++.dg/concepts/pr94252.C: Verify we no longer issue a
spurious unsatisfaction note when diagnosing ill-formed
satisfaction.
* g++.dg/cpp2a/concepts-requires18.C: No longer expect a
spurious unsatisfaction diagnostic when evaluating the
nested-requirement subst<void&> of a requires-expression that
appears outside of a template.
* g++.dg/cpp2a/concepts-requires21.C: Verify we no longer issue
a spurious unsatisfaction note when evaluating a
nested-requirement of a requires-expression that appears outside
of a template.
* g++.dg/cpp2a/concepts-nonbool3.C: New test.
* g++.dg/cpp2a/concepts-pr97093.C: New test.

PR target/95294: VAX: Add test cases for MODE_CC representation

gcc/testsuite/
PR target/95294
* gcc.target/vax/cmpelim-eq-adddf.c: New test.
* gcc.target/vax/cmpelim-eq-addhi.c: New test.
* gcc.target/vax/cmpelim-eq-addqi.c: New test.
* gcc.target/vax/cmpelim-eq-addsf.c: New test.
* gcc.target/vax/cmpelim-eq-addsi.c: New test.
* gcc.target/vax/cmpelim-eq-andhi.c: New test.
* gcc.target/vax/cmpelim-eq-andqi.c: New test.
* gcc.target/vax/cmpelim-eq-andsi.c: New test.
* gcc.target/vax/cmpelim-eq-ashlsi.c: New test.
* gcc.target/vax/cmpelim-eq-ashrsi.c: New test.
* gcc.target/vax/cmpelim-eq-divdf.c: New test.
* gcc.target/vax/cmpelim-eq-divhi.c: New test.
* gcc.target/vax/cmpelim-eq-divqi.c: New test.
* gcc.target/vax/cmpelim-eq-divsf.c: New test.
* gcc.target/vax/cmpelim-eq-divsi.c: New test.
* gcc.target/vax/cmpelim-eq-extendhisi.c: New test.
* gcc.target/vax/cmpelim-eq-extendqisi.c: New test.
* gcc.target/vax/cmpelim-eq-extvsi.c: New test.
* gcc.target/vax/cmpelim-eq-extzvsi.c: New test.
* gcc.target/vax/cmpelim-eq-fixdfhi.c: New test.
* gcc.target/vax/cmpelim-eq-fixdfqi.c: New test.
* gcc.target/vax/cmpelim-eq-fixdfsi.c: New test.
* gcc.target/vax/cmpelim-eq-fixsfhi.c: New test.
* gcc.target/vax/cmpelim-eq-fixsfqi.c: New test.
* gcc.target/vax/cmpelim-eq-fixsfsi.c: New test.
* gcc.target/vax/cmpelim-eq-floatsisf.c: New test.
* gcc.target/vax/cmpelim-eq-insvsi.c: New test.
* gcc.target/vax/cmpelim-eq-iorhi.c: New test.
* gcc.target/vax/cmpelim-eq-iorqi.c: New test.
* gcc.target/vax/cmpelim-eq-iorsi.c: New test.
* gcc.target/vax/cmpelim-eq-mova.c: New test.
* gcc.target/vax/cmpelim-eq-movdf.c: New test.
* gcc.target/vax/cmpelim-eq-movhi.c: New test.
* gcc.target/vax/cmpelim-eq-movqi.c: New test.
* gcc.target/vax/cmpelim-eq-movsf.c: New test.
* gcc.target/vax/cmpelim-eq-movsi.c: New test.
* gcc.target/vax/cmpelim-eq-muldf.c: New test.
* gcc.target/vax/cmpelim-eq-mulhi.c: New test.
* gcc.target/vax/cmpelim-eq-mulqi.c: New test.
* gcc.target/vax/cmpelim-eq-mulsf.c: New test.
* gcc.target/vax/cmpelim-eq-mulsi.c: New test.
* gcc.target/vax/cmpelim-eq-nothi.c: New test.
* gcc.target/vax/cmpelim-eq-notqi.c: New test.
* gcc.target/vax/cmpelim-eq-notsi.c: New test.
* gcc.target/vax/cmpelim-eq-rotlsi.c: New test.
* gcc.target/vax/cmpelim-eq-rotrsi.c: New test.
* gcc.target/vax/cmpelim-eq-subdf.c: New test.
* gcc.target/vax/cmpelim-eq-subhi.c: New test.
* gcc.target/vax/cmpelim-eq-subqi.c: New test.
* gcc.target/vax/cmpelim-eq-subsf.c: New test.
* gcc.target/vax/cmpelim-eq-subsi.c: New test.
* gcc.target/vax/cmpelim-eq-truncdfsf.c: New test.
* gcc.target/vax/cmpelim-eq-trunchiqi.c: New test.
* gcc.target/vax/cmpelim-eq-truncsihi.c: New test.
* gcc.target/vax/cmpelim-eq-truncsiqi.c: New test.
* gcc.target/vax/cmpelim-eq-zextendhisi.c: New test.
* gcc.target/vax/cmpelim-eq-zextendqihi.c: New test.
* gcc.target/vax/cmpelim-eq-zextendqisi.c: New test.
* gcc.target/vax/cmpelim-le-adddf.c: New test.
* gcc.target/vax/cmpelim-le-addhi.c: New test.
* gcc.target/vax/cmpelim-le-addqi.c: New test.
* gcc.target/vax/cmpelim-le-addsf.c: New test.
* gcc.target/vax/cmpelim-le-addsi.c: New test.
* gcc.target/vax/cmpelim-le-andhi.c: New test.
* gcc.target/vax/cmpelim-le-andqi.c: New test.
* gcc.target/vax/cmpelim-le-andsi.c: New test.
* gcc.target/vax/cmpelim-le-ashlsi.c: New test.
* gcc.target/vax/cmpelim-le-ashrsi.c: New test.
* gcc.target/vax/cmpelim-le-divdf.c: New test.
* gcc.target/vax/cmpelim-le-divhi.c: New test.
* gcc.target/vax/cmpelim-le-divqi.c: New test.
* gcc.target/vax/cmpelim-le-divsf.c: New test.
* gcc.target/vax/cmpelim-le-divsi.c: New test.
* gcc.target/vax/cmpelim-le-extendhisi.c: New test.
* gcc.target/vax/cmpelim-le-extendqisi.c: New test.
* gcc.target/vax/cmpelim-le-extvsi.c: New test.
* gcc.target/vax/cmpelim-le-extzvsi.c: New test.
* gcc.target/vax/cmpelim-le-fixdfhi.c: New test.
* gcc.target/vax/cmpelim-le-fixdfqi.c: New test.
* gcc.target/vax/cmpelim-le-fixdfsi.c: New test.
* gcc.target/vax/cmpelim-le-fixsfhi.c: New test.
* gcc.target/vax/cmpelim-le-fixsfqi.c: New test.
* gcc.target/vax/cmpelim-le-fixsfsi.c: New test.
* gcc.target/vax/cmpelim-le-floatsisf.c: New test.
* gcc.target/vax/cmpelim-le-insvsi.c: New test.
* gcc.target/vax/cmpelim-le-iorhi.c: New test.
* gcc.target/vax/cmpelim-le-iorqi.c: New test.
* gcc.target/vax/cmpelim-le-iorsi.c: New test.
* gcc.target/vax/cmpelim-le-movdf.c: New test.
* gcc.target/vax/cmpelim-le-movhi.c: New test.
* gcc.target/vax/cmpelim-le-movqi.c: New test.
* gcc.target/vax/cmpelim-le-movsf.c: New test.
* gcc.target/vax/cmpelim-le-movsi.c: New test.
* gcc.target/vax/cmpelim-le-muldf.c: New test.
* gcc.target/vax/cmpelim-le-mulhi.c: New test.
* gcc.target/vax/cmpelim-le-mulqi.c: New test.
* gcc.target/vax/cmpelim-le-mulsf.c: New test.
* gcc.target/vax/cmpelim-le-mulsi.c: New test.
* gcc.target/vax/cmpelim-le-nothi.c: New test.
* gcc.target/vax/cmpelim-le-notqi.c: New test.
* gcc.target/vax/cmpelim-le-notsi.c: New test.
* gcc.target/vax/cmpelim-le-rotlsi.c: New test.
* gcc.target/vax/cmpelim-le-rotrsi.c: New test.
* gcc.target/vax/cmpelim-le-subdf.c: New test.
* gcc.target/vax/cmpelim-le-subhi.c: New test.
* gcc.target/vax/cmpelim-le-subqi.c: New test.
* gcc.target/vax/cmpelim-le-subsf.c: New test.
* gcc.target/vax/cmpelim-le-subsi.c: New test.
* gcc.target/vax/cmpelim-le-truncdfsf.c: New test.
* gcc.target/vax/cmpelim-le-xorhi.c: New test.
* gcc.target/vax/cmpelim-le-xorqi.c: New test.
* gcc.target/vax/cmpelim-le-xorsi.c: New test.
* gcc.target/vax/cmpelim-leu-subhi.c: New test.
* gcc.target/vax/cmpelim-leu-subqi.c: New test.
* gcc.target/vax/cmpelim-leu-subsi.c: New test.
* gcc.target/vax/cmpelim-lt-adddf.c: New test.
* gcc.target/vax/cmpelim-lt-addhi.c: New test.
* gcc.target/vax/cmpelim-lt-addqi.c: New test.
* gcc.target/vax/cmpelim-lt-addsf.c: New test.
* gcc.target/vax/cmpelim-lt-addsi.c: New test.
* gcc.target/vax/cmpelim-lt-andhi.c: New test.
* gcc.target/vax/cmpelim-lt-andqi.c: New test.
* gcc.target/vax/cmpelim-lt-andsi.c: New test.
* gcc.target/vax/cmpelim-lt-ashlsi.c: New test.
* gcc.target/vax/cmpelim-lt-ashrsi.c: New test.
* gcc.target/vax/cmpelim-lt-divdf.c: New test.
* gcc.target/vax/cmpelim-lt-divhi.c: New test.
* gcc.target/vax/cmpelim-lt-divqi.c: New test.
* gcc.target/vax/cmpelim-lt-divsf.c: New test.
* gcc.target/vax/cmpelim-lt-divsi.c: New test.
* gcc.target/vax/cmpelim-lt-extendhisi.c: New test.
* gcc.target/vax/cmpelim-lt-extendqisi.c: New test.
* gcc.target/vax/cmpelim-lt-extvsi.c: New test.
* gcc.target/vax/cmpelim-lt-extzvsi.c: New test.
* gcc.target/vax/cmpelim-lt-fixdfhi.c: New test.
* gcc.target/vax/cmpelim-lt-fixdfqi.c: New test.
* gcc.target/vax/cmpelim-lt-fixdfsi.c: New test.
* gcc.target/vax/cmpelim-lt-fixsfhi.c: New test.
* gcc.target/vax/cmpelim-lt-fixsfqi.c: New test.
* gcc.target/vax/cmpelim-lt-fixsfsi.c: New test.
* gcc.target/vax/cmpelim-lt-floatsisf.c: New test.
* gcc.target/vax/cmpelim-lt-insvsi.c: New test.
* gcc.target/vax/cmpelim-lt-iorhi.c: New test.
* gcc.target/vax/cmpelim-lt-iorqi.c: New test.
* gcc.target/vax/cmpelim-lt-iorsi.c: New test.
* gcc.target/vax/cmpelim-lt-movdf.c: New test.
* gcc.target/vax/cmpelim-lt-movhi.c: New test.
* gcc.target/vax/cmpelim-lt-movqi.c: New test.
* gcc.target/vax/cmpelim-lt-movsf.c: New test.
* gcc.target/vax/cmpelim-lt-movsi.c: New test.
* gcc.target/vax/cmpelim-lt-muldf.c: New test.
* gcc.target/vax/cmpelim-lt-mulhi.c: New test.
* gcc.target/vax/cmpelim-lt-mulqi.c: New test.
* gcc.target/vax/cmpelim-lt-mulsf.c: New test.
* gcc.target/vax/cmpelim-lt-mulsi.c: New test.
* gcc.target/vax/cmpelim-lt-nothi.c: New test.
* gcc.target/vax/cmpelim-lt-notqi.c: New test.
* gcc.target/vax/cmpelim-lt-notsi.c: New test.
* gcc.target/vax/cmpelim-lt-rotlsi.c: New test.
* gcc.target/vax/cmpelim-lt-rotrsi.c: New test.
* gcc.target/vax/cmpelim-lt-subdf.c: New test.
* gcc.target/vax/cmpelim-lt-subhi.c: New test.
* gcc.target/vax/cmpelim-lt-subqi.c: New test.
* gcc.target/vax/cmpelim-lt-subsf.c: New test.
* gcc.target/vax/cmpelim-lt-subsi.c: New test.
* gcc.target/vax/cmpelim-lt-truncdfsf.c: New test.
* gcc.target/vax/cmpelim-lt-xorhi.c: New test.
* gcc.target/vax/cmpelim-lt-xorqi.c: New test.
* gcc.target/vax/cmpelim-lt-xorsi.c: New test.
* gcc.target/vax/cmpelim-ltu-subhi.c: New test.
* gcc.target/vax/cmpelim-ltu-subqi.c: New test.
* gcc.target/vax/cmpelim-ltu-subsi.c: New test.
* gcc.target/vax/cmpelim-xx-addsi.c: New test.
* gcc.target/vax/cmpelim-xx-insvsi.c: New test.
* gcc.target/vax/cmpelim-xxu-subsi.c: New test.
* gcc.target/vax/peephole2-eq-andhi.c: New test.
* gcc.target/vax/peephole2-eq-andqi.c: New test.
* gcc.target/vax/peephole2-eq-andsi.c: New test.
* gcc.target/vax/peephole2-eq-cmpvsi.c: New test.
* gcc.target/vax/peephole2-eq-cmpzvsi.c: New test.
* gcc.target/vax/peephole2-eq-ctzhi-0.c: New test.
* gcc.target/vax/peephole2-eq-ctzhi-1.c: New test.
* gcc.target/vax/peephole2-eq-ctzqi-0.c: New test.
* gcc.target/vax/peephole2-eq-ctzqi-1.c: New test.
* gcc.target/vax/peephole2-eq-ctzsi-0.c: New test.
* gcc.target/vax/peephole2-eq-ctzsi-1.c: New test.
* gcc.target/vax/peephole2-eq-ffshi.c: New test.
* gcc.target/vax/peephole2-eq-ffsqi.c: New test.
* gcc.target/vax/peephole2-eq-ffssi.c: New test.
* gcc.target/vax/peephole2-le-andhi.c: New test.
* gcc.target/vax/peephole2-le-andqi.c: New test.
* gcc.target/vax/peephole2-le-andsi.c: New test.
* gcc.target/vax/peephole2-le-cmpvsi.c: New test.
* gcc.target/vax/peephole2-le-cmpzvsi.c: New test.
* gcc.target/vax/peephole2-leu-cmpvsi.c: New test.
* gcc.target/vax/peephole2-leu-cmpzvsi.c: New test.
* gcc.target/vax/peephole2-lt-andhi.c: New test.
* gcc.target/vax/peephole2-lt-andqi.c: New test.
* gcc.target/vax/peephole2-lt-andsi.c: New test.
* gcc.target/vax/peephole2-lt-cmpvsi.c: New test.
* gcc.target/vax/peephole2-lt-cmpzvsi.c: New test.
* gcc.target/vax/peephole2-ltu-cmpvsi.c: New test.
* gcc.target/vax/peephole2-ltu-cmpzvsi.c: New test.

PR target/95294: VAX: Convert backend to MODE_CC representation

In the VAX ISA INSV bit-field insert instruction is the only computational
operation that keeps the condition codes, held in the PSL or Processor
Status Longword register, intact.  The instruction is flexible enough it
could potentially be used for data moves post-reload, but then reportedly
it is not the best choice performance-wise, and then we have no addition
operation available that would keep the condition codes unchanged.

Futhermore, as usually with a complex CISC ISA, for many operations we
have several machine instructions or instruction sequences to choose
from that set condition codes in a different manner.

Use the approach then where the condition codes only get introduced by
reload, by definining instruction splitters for RTL insns that change
condition codes in some way, by default considering them clobbered.

Then to prevent code generated from regressing too much provide insns
that include a `compare' operation setting the condition codes in
parallel to the main operation.  The manner condition codes are set by
each insn is supposed to be provided by the whatever the SELECT_CC_MODE
macro expands to.

Given that individual patterns provided for the same RTL basic operation
may set the condion codes differently keeping the information away from
the insn patterns themselves would cause a maintenance nightmare and
would be bound to fail in a horrible way sooner or later.  Therefore
instead let the patterns themselves choose which condition modes they
support, by having one or more subst iterators applied and then have
individual comparison operators require the specific condition mode each
according to the codes used by the operation.

While subst iterators only support one alternative each, there is
actually no problem with applying multiple ones to a single insn with
the result as intended, and if the corresponding subst attribute
supplies an empty NO-SUBST-VALUE, then no mess results even.  Make use
of this observation.

Add appropriate subst iterators to all the computational patterns then,
according to the condition codes they usably set, including DImode ones
and a substitute DImode comparison instruction in the absence of a CMPQ
machine instruction, however do not provide a `cbranchdi4' named pattern
as without a further development it regresses code quality by resorting
to the `__cmpdi2' libcall where a simpler operation would do, e.g. to
check for negativity the TSTL machine instruction may be executed over
the upper longword only.  This is good material for further work.

Do not apply subst iterators to the increment- or decrement-and-branch
patterns at this time; these may yet have to be reviewed, in particular
whether `*jsobneq_minus_one' is still relevant in the context of the
recent integer constant cost review.

Also add a couple of peepholes to help eliminating comparisons in some
problematic cases, such as with the BIT instruction which is bitwise-AND
for condition codes only that has no direct counterpart for the actual
calculation, because the BIC instruction which does do bitwise-AND and
produces a result implements the operation with a bitwise negation of
its input `mask' operand.  Or the FFS instruction which sets the Z
condition code according to its `field' input operand rather than the
result produced.  Or the bit-field comparisons we don't have generic
middle-end support for.

Code size stats are as follows, obtained from 17640 and 9086 executables
built in `check-c' and `check-c++' GCC testing respectively:

                      check-c                 check-c++
              samples average  median  samples average  median
---------------------------------------------------------------
regressions      1813  0.578%  0.198%      289  0.349%  0.175%
unchanged       15160  0.000%  0.000%     8662  0.000%  0.000%
progressions      667 -0.589% -0.194%      135 -0.944% -0.191%
----------------------------------------------------------------
total           17640  0.037%  0.000%     9086 -0.003%  0.000%

Outliers:

old     new     change  %change filename
----------------------------------------------------
2406    2950    +544    +22.610 20111208-1.exe
4314    5329    +1015   +23.528 pr39417.exe
2235    3055    +820    +36.689 990404-1.exe
2631    4213    +1582   +60.129 pr57521.exe
3063    5579    +2516   +82.142 20000422-1.exe

and:

old     new     change  %change filename
----------------------------------------------------
6317    4845    -1472   -23.302 vector-compare-1.exe
6313    4845    -1468   -23.254 vector-compare-1.exe
6474    5002    -1472   -22.737 vector-compare-1.exe
6470    5002    -1468   -22.689 vector-compare-1.exe

We have some code quality regressions like:

    10861: 9e ef d9 12 movab 11b40 <p>,r0
    10865: 00 00 50
    10868: 90 a0 03 a0 movb 0x3(r0),0x2(r0)
    1086c: 02
    1086d: d1 60 8f 61 cmpl (r0),$0x64646261
    10871: 62 64 64
    10874: 13 07        beql 1087d <main_test+0x21>

to:

    10861: 9e ef e1 12 movab 11b48 <p>,r0
    10865: 00 00 50
    10868: 90 a0 03 a0 movb 0x3(r0),0x2(r0)
    1086c: 02
    1086d: d1 ef d5 12 cmpl 11b48 <p>,$0x64646261
    10871: 00 00 8f 61
    10875: 62 64 64
    10878: 13 07        beql 10881 <main_test+0x25>

(from `memmove-2.x2') due to the constant propagation passes eagerly
replacing pseudo registers with direct symbol references where possible,
which does not happen with CC0 even though the passes do run regardless.

There are further code quality regressions due to earlier compilation
stages trying to push expression evaluation earlier where possible so
as to make data dependencies further apart from each other.  This works
well for computations and architectures that do not involve condition
codes set as a side effect of calculations.  However for integer
negation that makes assembly code produced like:

movb *8(%ap),%r0
mnegb %r0,%r1
tstb %r0
jeql .L2

the RTL equibvalent of which the comparison elimination pass cannot
really do anything about, because the comparison is made on the source
rather than the target operand of the negation (we could add a peephole
for this, but this seems futile an effort, as one'd have to iterate over
all the possible such cases), even though this is really equivalent to:

movb *8(%ap),%r0
mnegb %r0,%r1
jeql .L2

or, if R0 is dead at the conclusion of the branch, even:

mnegb *8(%ap),%r1
jeql .L2

Since the compiler insists on doing the comparison on the source of the
negation it obviously has to load it into a temporary so as to avoid
accessing the original memory location twice, hence the sequence of
three instructions rather than just a single one.  A similar phenomenon
can be observed with the XOR operation and in other cases.

In some cases a comparison does get eliminated, however useless moves
into registers done in preparation to it remain, such as with:

movb *8(%ap),%r2
movb *12(%ap),%r1
subb3 %r1,%r2,%r0
jlssu .L2

where R1 and R2 are both dead at conclusion and therefore:

subb3 *12(%ap),*8(%ap),%r0
jlssu .L2

would obviously do, but there was to be a comparison before the branch:

cmpb %r2,%r1

All this looks like material for future improvement.

Test cases for comparison elimination and the peepholes will be supplied
separately.

gcc/
PR target/95294
* config/vax/elf.h (REGISTER_NAMES): Append `%psl'.
* config/vax/vax-modes.def (CCN, CCNZ, CCZ): New modes.
* config/vax/vax-protos.h (vax_select_cc_mode): New prototype.
(vax_maybe_split_dimode_move): Likewise.
(vax_notice_update_cc): Remove prototype.
* config/vax/vax.c (TARGET_FLAGS_REGNUM): New macro.
(TARGET_CC_MODES_COMPATIBLE): Likewise.
(TARGET_MD_ASM_ADJUST): Likewise.
(vax_select_cc_mode): New function
(vax_cc_modes_compatible): Likewise.
(vax_md_asm_adjust): Likewise.
(vax_notice_update_cc): Remove function.
(vax_output_int_move): Factor out code checking if a DImode move
may have to be split...
(vax_maybe_split_dimode_move): ... into this new function.
* config/vax/vax.h (FIRST_PSEUDO_REGISTER): Bump up.
(FIXED_REGISTERS): Append an entry for PSL.
(CALL_USED_REGISTERS): Likewise.
(NOTICE_UPDATE_CC, OUTPUT_JUMP): Remove macros.
(SELECT_CC_MODE): New macro.
(REGISTER_NAMES): Append `psl'.
* config/vax/predicates.md (const_zero_operand)
(vax_cc_comparison_operator, vax_ccn_comparison_operator)
(vax_ccnz_comparison_operator, vax_ccz_comparison_operator):
New predicates.
* config/vax/builtins.md: Rewrite for MODE_CC representation.
* config/vax/vax.md: Likewise.

VAX: Fix the LTO compiler downgrading code to non-PIC model

Fix a testsuite failure:

/tmp/ccL65Mmt.s: Assembler messages:
/tmp/ccL65Mmt.s:36: Warning: Symbol n used as immediate operand in PIC mode.
FAIL: gcc.dg/lto/pr55660 c_lto_pr55660_0.o-c_lto_pr55660_1.o link, -O0 -flto -flto-partition=none -fuse-linker-plugin

where non-PIC code is substituted by the LTO compiler at the link stage
for what used to be PIC code in the original compilation.  This happens
because in the de-facto VAX ELF psABI we rely on code being PIC for GOT
support in dynamic executables and arrange that by having `-fPIC' passed
to the compiler by default by means of a specs recipe.

That is however canceled where the LTO wrapper is used, by an internal
arrangement in the LTO compiler that clears the PIC flag whenever the
`-flinker-output=exec' option has been used.  This has been deliberately
introduced with commit 1ff9ed6fb282 ("re PR lto/67548 (LTO drops weak
binding with "ld -r")")[1]:

"In the log of PR67548 HJ actually pointed out that we do have API at
linker plugin side which says what type of output is done.  This is cool
because we can also use it to drop -fpic when building static binary.
This is common in Firefox, where some objects are built with -fpic and
linked to both binaries and libraries."

with this code:

    case LTO_LINKER_OUTPUT_EXEC: /* Normal executable */
      flag_pic = 0;
      flag_pie = 0;
      flag_shlib = 0;
      break;

Consequently code like:

.L6:
addl3 -8(%fp),$n,%r0
pushl %r0
calls $1,foo
addl2 %r0,-12(%fp)
incl -8(%fp)
.L5:

is produced by the LTO compiler, where a reference to `n' is used that
is invalid in PIC code, because it uses the immediate addressing mode,
denoted by the `$' prefix.

For that not to happen we must never pass `-flinker-output=exec' to the
LTO compiler unless non-PIC code has been explicitly requested.  Using
`-flinker-output=dyn' except for relocatable output would seem the
simplest approach, as it does not fiddle with any of the internal code
model settings beyond what the command-line options have arranged and
therefore lets them remain the same as with the original compilation,
but it breaks as well causing PR lto/69866 to retrigger, as that code
seems sensitive to `flag_shlib':

lto1: internal compiler error: in add_symbol_to_partition_1, at lto/lto-partition.c:152
0x105be1cb add_symbol_to_partition_1
.../gcc/lto/lto-partition.c:152
0x105be443 add_symbol_to_partition_1
.../gcc/lto/lto-partition.c:194
0x105be80f add_symbol_to_partition
.../gcc/lto/lto-partition.c:270
0x105bee6f add_sorted_nodes
.../gcc/lto/lto-partition.c:395
0x105c0903 lto_balanced_map(int, int)
.../gcc/lto/lto-partition.c:815
0x105aa91f do_whole_program_analysis
.../gcc/lto/lto.c:499
0x105aac97 lto_main()
.../gcc/lto/lto.c:637
Please submit a full bug report,
with preprocessed source if appropriate.
Please include the complete backtrace with any bug report.
See <https://gcc.gnu.org/bugs/> for instructions.
lto-wrapper: fatal error: .../gcc/xgcc returned 1 exit status
compilation terminated.
.../usr/bin/vax-netbsdelf-ld: error: lto-wrapper failed
collect2: error: ld returned 1 exit status
compiler exited with status 1
FAIL: gcc.dg/lto/pr69866 c_lto_pr69866_0.o-c_lto_pr69866_1.o link, -O0 -flto -fuse-linker-plugin -fno-fat-lto-objects  (internal compiler error)

Substitute `-flinker-output=pie' for `-flinker-output=exec' in the specs
then unless `-no-pie' has also been used, preserving the original intent
of emitting PIC code by default for executables while keeping the linker
arrangement unchanged.  The LTO compiler uses the `cc1' spec, so keep
`cc1plus' unmodified.

This makes code like:

.L6:
movab n,%r0
addl2 -8(%fp),%r0
pushl %r0
calls $1,foo
addl2 %r0,-12(%fp)
incl -8(%fp)
.L5:

be produced instead corresponding to the fragment quoted above, which is
valid PIC code as it uses the PC-relative addressing mode denoted by the
absence of a prefix to `n' (which can be redirected to GOT as required,
by changing the addressing mode to PC-relative indirect in the operand
specifier).

Ideally we would instead default to the PIE model for executables, but
that triggers a BFD bug where for a change the LTO wrapper is not used:

.../usr/bin/vax-netbsdelf-ld: /tmp/ccV2sWQt.ltrans0.ltrans.o: warning: GOT addend of 3 to `n' does not match previous GOT addend of 0
FAIL: gcc.dg/lto/pr55660 c_lto_pr55660_0.o-c_lto_pr55660_1.o link, -O2 -flto -flto-partition=1to1 -fno-use-linker-plugin

which is due to assembly code like:

main:
.word 0
subl2 $4,%sp
movab n,%r0
movab n+3,%r2
clrl %r3
movb $98,%r1
.L4:

and consequently object code like:

00000000 <main>:
   0: 00 00        .word 0x0000 # Entry mask: < >
   2: c2 04 5e     subl2 $0x4,sp
   5: 9e ef 00 00 movab b <main+0xb>,r0
   9: 00 00 50
7: R_VAX_GOT32 n
   c: 9e ef 00 00 movab 12 <main+0x12>,r2
  10: 00 00 52
e: R_VAX_GOT32 n+0x3
  13: d4 53        clrf r3
  15: 90 8f 62 51 movb $0x62,r1

being produced.  This would be problematic for external `n', because we
do not support multiple GOT entries for the same symbol referred to with
different offsets in a single link unit.  In this case however the LTO
compiler correctly observes that `n' is defined by the executable and
not preemptible and therefore no GOT entry will be made for it.

Indeed a valid executable is produced:

00010548 <main>:
   10548: 00 00        .word 0x0000 # Entry mask: < >
   1054a: c2 04 5e     subl2 $0x4,sp
   1054d: 9e ef dd 14 movab 11a30 <n>,r0
   10551: 00 00 50
   10554: 9e ef d9 14 movab 11a33 <__bss_start>,r2
   10558: 00 00 52
   1055b: d4 53        clrf r3
   1055d: 90 8f 62 51 movb $0x62,r1

despite the warning, but it would be rather bad to have users annoyed
with this message from BFD, however harmless, especially as it triggers
outside LTO compilations as well.

Therefore this change is the best we can do until binutils have been
fixed.

References:

[1] Jan Hubicka, "Getting LTO incremental linking work",
    <https://gcc.gnu.org/ml/gcc-patches/2015-11/msg02986.html>

gcc/
* config/vax/elf.h (VAX_CC1_SPEC, VAX_CC1PLUS_SPEC): New macros.
* config/vax/netbsd-elf.h (CC1_SPEC): Use VAX_CC1_SPEC rather
than VAX_CC1_AND_CC1PLUS_SPEC.
(CC1PLUS_SPEC): Use VAX_CC1PLUS_SPEC rather than
VAX_CC1_AND_CC1PLUS_SPEC.

PDP11: Use `const_double_zero' to express double zero constant

We do not define a comparison operation between floating-point and
integer data, including integer zero constant. Consequently the RTL
instruction stream presented to the post-reload comparison elimination
pass will include, where applicable, floating-point comparison insns
against `const_double:DF 0.0 [0x0.0p+0]' rather than `const_int 0 [0]',
meaning that the latter expression will not match when used in machine
description.

Use `const_double_zero' then for the relevant patterns to match the
intended RTL instructions.

gcc/
* config/pdp11/pdp11.md (fcc_cc, fcc_ccnz): Use
`const_double_zero' to express double zero constant.

RTL: Add `const_double_zero' syntactic rtx

The use of a constant double zero is required for post-reload compare
elimination to be able to discard redundant floating-point comparisons,
for example with a VAX RTL instruction stream like:

(insn 34 4 3 2 (parallel [
            (set (reg/v:DF 0 %r0 [orig:24 x ] [24])
                (mem/c:DF (plus:SI (reg/f:SI 12 %ap)
                        (const_int 4 [0x4])) [1 x+0 S8 A32]))
            (clobber (reg:CC 16 %psl))
        ]) ".../gcc/testsuite/gcc.target/vax/cmpelim-eq-movdf.c":9:1 37 {*movdf}
     (nil))
(note 3 34 35 2 NOTE_INSN_FUNCTION_BEG)
(insn 35 3 36 2 (set (reg:CCZ 16 %psl)
        (compare:CCZ (reg/v:DF 0 %r0 [orig:24 x ] [24])
            (const_double:DF 0.0 [0x0.0p+0]))) ".../gcc/testsuite/gcc.target/vax/cmpelim-eq-movdf.c":10:6 21 {*cmpdf_ccz}
     (nil))
(jump_insn 36 35 9 2 (set (pc)
        (if_then_else (eq (reg:CCZ 16 %psl)
                (const_int 0 [0]))
            (label_ref 11)
            (pc))) ".../gcc/testsuite/gcc.target/vax/cmpelim-eq-movdf.c":10:6 537 {*branch_ccz}
     (int_list:REG_BR_PROB 536870916 (nil))
-> 11)

that we want to transform into:

(insn 34 4 3 2 (parallel [
            (set (reg:CCZ 16 %psl)
                (compare:CCZ (mem/c:DF (plus:SI (reg/f:SI 12 %ap)
                            (const_int 4 [0x4])) [1 x+0 S8 A32])
                    (const_double:DF 0.0 [0x0.0p+0])))
            (set (reg/v:DF 0 %r0 [orig:24 x ] [24])
                (mem/c:DF (plus:SI (reg/f:SI 12 %ap)
                        (const_int 4 [0x4])) [1 x+0 S8 A32]))
        ]) ".../gcc/testsuite/gcc.target/vax/cmpelim-eq-movdf.c":9:1 40 {*movdf_ccz}
     (nil))
(note 3 34 36 2 NOTE_INSN_FUNCTION_BEG)
(jump_insn 36 3 9 2 (set (pc)
        (if_then_else (eq (reg:CCZ 16 %psl)
                (const_int 0 [0]))
            (label_ref 11)
            (pc))) ".../gcc/testsuite/gcc.target/vax/cmpelim-eq-movdf.c":10:6 537 {*branch_ccz}
     (int_list:REG_BR_PROB 536870916 (nil))
-> 11)

with the upcoming MODE_CC representation.

For this we need to express the `const_double:DF 0.0 [0x0.0p+0]' rtx as
recorded above in the relevant pattern(s) in machine description.  The
way we represent double constants, as a host-dependent number of wide
integers, however means that we currently have no portable way to encode
a double zero constant in machine description.

Define a syntactic rtx alias then to represent `(const_double 0 0 ...)'
as if the suitable number of zeros have been supplied according to the
host-specific definition of CONST_DOUBLE_FORMAT.

gcc/
* read-rtl.c (rtx_reader::read_rtx_code): Handle syntactic
`const_double_zero' rtx.
* doc/rtl.texi (Constant Expression Types): Document it.

VAX: Make the `divmoddisi4' and `*amulsi4' comment notation consistent

Use a double colon to introduce the comments like elsewhere throughout
the VAX machine description.

gcc/
* config/vax/vax.md (divmoddisi4, *amulsi4): Make the comment
notation consistent with the rest of the file.

VAX: Correct issues with commented-out insns

Correct issues with commented-out insns, which fail to build if enabled:

.../gcc/config/vax/vax.md:503:1: repeated operand number 1
.../gcc/config/vax/vax.md:503:1: repeated operand number 2

and then when the issue with the repeated operands has been corrected:

.../gcc/config/vax/vax.md:107:1: destination operand 0 allows non-lvalue
.../gcc/config/vax/vax.md:503:1: destination operand 0 allows non-lvalue
.../gcc/config/vax/vax.md:503:1: destination operand 3 allows non-lvalue
.../gcc/config/vax/vax.md:744:1: destination operand 0 allows non-lvalue

Fix the RTL with the repeated operands and change the relevant output
operand predicates not to allow immediates.

Also emit MOVO rather than MOVH assembly instruction with the `movti'
insn so that the condition codes are set according to the integer rather
than floating-point interpretation of the datum moved, as expected with
the operation associated with the pattern.

Finally give `*amulsi4' a name, for easier reference here and elsewhere.

We may eventually want to have some of these insns enabled at `-Os'.

gcc/
* config/vax/vax.md (movti): Fix output predicate. Emit `movo'
rather than `movh'.
(divmoddisi4): Fix output predicates, correct RTL.
(*amulsi4): Name insn. Fix output predicate.

VAX: Fix predicates for widening multiply and multiply-add insns

It makes no sense for insn operand predicates, as long as they accept a
register operand, to be more restrictive than the set of the associated
constraints, because expand will choose the insn based on the relevant
operand being a pseudo register then and reload will keep it happily as
an immediate if a constraint permits it.  So the restriction posed by
such a predicate will be happily ignored, and moreover if a splitter is
added, such as required for MODE_CC support, the new instructions will
reject the original operands supplied, causing an ICE like below:

.../gcc/testsuite/gfortran.dg/graphite/PR67518.f90:44:0: Error: could not split insn
(insn 90 662 663 (set (reg:DI 10 %r10 [orig:97 _235 ] [97])
        (mult:DI (sign_extend:DI (mem/c:SI (plus:SI (reg/f:SI 13 %fp)
                        (const_int -800 [0xfffffffffffffce0])) [14 %sfp+-800 S4 A32]))
            (sign_extend:DI (const_int -51 [0xffffffffffffffcd])))) 299 {mulsidi3}
     (expr_list:REG_EQUAL (mult:DI (sign_extend:DI (subreg:SI (mem/c:DI (plus:SI (reg/f:SI 13 %fp)
                            (const_int -800 [0xfffffffffffffce0])) [14 %sfp+-800 S8 A32]) 0))
            (const_int -51 [0xffffffffffffffcd]))
        (nil)))
during RTL pass: final
.../gcc/testsuite/gfortran.dg/graphite/PR67518.f90:44:0: internal compiler error: in final_scan_insn_1, at final.c:3073
Please submit a full bug report,
with preprocessed source if appropriate.
See <https://gcc.gnu.org/bugs/> for instructions.

Change the predicates used with the widening multiply and multiply-add
insns to allow immediates then, just as the constraints and the machine
instructions produced permit.

Also give the insns names, for easier reference here and elsewhere.

gcc/
* config/vax/vax.md (mulsidi3): Fix the multiplicand predicates.
(*maddsidi4, *maddsidi4_const): Likewise.  Name insns.

VAX: Fix predicates and constraints for bit-field comparison insns

It makes no sense for insn operand predicates, as long as they accept a
register operand, to be more restrictive than the set of the associated
constraints, because expand will choose the insn based on the relevant
operand being a pseudo register then and reload keep it happily as a
memory reference if a constraint permits it.  So the restriction posed
by such a predicate will be happily ignored, and moreover if a splitter
is added, such as required for MODE_CC support, the new instructions
will reject the original operands supplied, causing an ICE.  An actual
example will be given with a subsequent change.

Therefore, similarly to EXTV/EXTZV/INSV insns, remove inconsistencies
with predicates and constraints of bit-field comparison insns, observing
that a bit-field located in memory is byte-addressed by the respective
machine instructions and therefore SImode may only be used with a
register or an offsettable memory operand (i.e. not an indexed,
pre-decremented, or post-incremented one).

Also give the insns names, for easier reference here and elsewhere.

gcc/
* config/vax/vax.md (*cmpv_2): Name insn.
(*cmpv, *cmpzv, *cmpzv_2): Likewise.  Fix location predicate and
constraint.

VAX: Make `extv' an expander matching the remaining bit-field operations

We have matching insns defined for `sign_extract' and `zero_extract'
expressions, so make the three named patterns for bit-field operations
consistent and make `extv' an expander rather than an insn taking a
SImode, a QImode, and a SImode general operand for the LOC, SIZE, and
POS operands respectively, like with the `extzv' and `insv' patterns,
matching the machine instructions and giving the middle end more choice
as to which actual insn to choose in a given situation.

Given this program:

typedef struct
{
  int f0:1;
  int f1:7;
  int f8:8;
  int f16:16;
} bit_t;

typedef struct
{
  unsigned int f0:1;
  unsigned int f1:7;
  unsigned int f8:8;
  unsigned int f16:16;
} ubit_t;

typedef union
{
  bit_t b;
  int i;
} bit_u;

typedef union
{
  ubit_t b;
  unsigned int i;
} ubit_u;

int
ins1 (bit_u x, int y)
{
  asm volatile ("" : "+r" (x), "+r" (y));
  x.b.f1 = y;
  return x.i;
}

int
ext1 (bit_u x)
{
  asm volatile ("" : "+r" (x));
  return x.b.f1;
}

unsigned int
extz1 (ubit_u x)
{
  asm volatile ("" : "+r" (x));
  return x.b.f1;
}

int
ins8 (bit_u x, int y)
{
  asm volatile ("" : "+r" (x), "+r" (y));
  x.b.f8 = y;
  return x.i;
}

int
ext8 (bit_u x)
{
  asm volatile ("" : "+r" (x));
  return x.b.f8;
}

unsigned int
extz8 (ubit_u x)
{
  asm volatile ("" : "+r" (x));
  return x.b.f8;
}

int
ins16 (bit_u x, int y)
{
  asm volatile ("" : "+r" (x), "+r" (y));
  x.b.f16 = y;
  return x.i;
}

int
ext16 (bit_u x)
{
  asm volatile ("" : "+r" (x));
  return x.b.f16;
}

unsigned int
extz16 (ubit_u x)
{
  asm volatile ("" : "+r" (x));
  return x.b.f16;
}

this results in the following code change:

@@ -16,12 +16,12 @@ ins1:
.globl ext1
.type ext1, @function
ext1:
- .word 0 # 19 [c=0]  procedure_entry_mask
- subl2 $4,%sp # 20 [c=32]  addsi3
+ .word 0 # 18 [c=0]  procedure_entry_mask
+ subl2 $4,%sp # 19 [c=32]  addsi3
movl 4(%ap),%r0 # 2 [c=16]  movsi_2
- cvtbl %r0,%r0 # 7 [c=4]  extendqisi2
- ashl $-1,%r0,%r0 # 14 [c=40]  *vax.md:624
- ret # 24 [c=0]  return
+ extv $1,$7,%r0,%r0 # 7 [c=60]  *extv_non_const
+ cvtbl %r0,%r0 # 13 [c=4]  extendqisi2
+ ret # 23 [c=0]  return
.size ext1, .-ext1
.align 1
.globl extz1
@@ -49,12 +49,12 @@ ins8:
.globl ext8
.type ext8, @function
ext8:
- .word 0 # 20 [c=0]  procedure_entry_mask
- subl2 $4,%sp # 21 [c=32]  addsi3
+ .word 0 # 18 [c=0]  procedure_entry_mask
+ subl2 $4,%sp # 19 [c=32]  addsi3
movl 4(%ap),%r0 # 2 [c=16]  movsi_2
- cvtwl %r0,%r0 # 7 [c=4]  extendhisi2
- ashl $-8,%r0,%r0 # 15 [c=40]  *vax.md:624
- ret # 25 [c=0]  return
+ rotl $24,%r0,%r0 # 13 [c=60]  *extv_non_const
+ cvtbl %r0,%r0
+ ret # 23 [c=0]  return
.size ext8, .-ext8
.align 1
.globl extz8

If there is a performance degradation with the replacement sequences,
then it can and should be sorted within `extv_non_const'.

gcc/
* config/vax/vax.md (extv): Rename insn to...
(*extv): ... this.
(extv): New expander.

VAX: Ensure PIC mode address is adjustable with aligned bit-field insns

With the `*insv_aligned', `*extzv_aligned' and `*extv_aligned' insns we
are going to adjust the bit-field location if it is in memory, so only
allow such location addresses that can be offset, excluding external
symbol references in the PIC mode in particular.

This fixes an ICE like:

during RTL pass: final
In file included from .../gcc/testsuite/gcc.dg/torture/vshuf-v16qi.c:11:
.../gcc/testsuite/gcc.dg/torture/vshuf-main.inc: In function 'test_13':
.../gcc/testsuite/gcc.dg/torture/vshuf-main.inc:27:1: internal compiler error: in change_address_1, at emit-rtl.c:2275
.../gcc/testsuite/gcc.dg/torture/vshuf-16.inc:16:1: note: in expansion of macro 'T'
.../gcc/testsuite/gcc.dg/torture/vshuf-main.inc:28:1: note: in expansion of macro 'TESTS'
0x10a34b33 change_address_1
.../gcc/emit-rtl.c:2275
0x10a358af adjust_address_1(rtx_def*, machine_mode, poly_int<1u, long>, int, int, int, poly_int<1u, long>)
.../gcc/emit-rtl.c:2409
0x11d2505f output_97
.../gcc/config/vax/vax.md:806
0x10adec4b get_insn_template(int, rtx_insn*)
.../gcc/final.c:2070
0x10ae1c5b final_scan_insn_1
.../gcc/final.c:3039
0x10ae2257 final_scan_insn(rtx_insn*, _IO_FILE*, int, int, int*)
.../gcc/final.c:3152
0x10ade9a3 final_1
.../gcc/final.c:2020
0x10ae6157 rest_of_handle_final
.../gcc/final.c:4658
0x10ae6697 execute
.../gcc/final.c:4736
Please submit a full bug report,
with preprocessed source if appropriate.
Please include the complete backtrace with any bug report.
See <https://gcc.gnu.org/bugs/> for instructions.
compiler exited with status 1
FAIL: gcc.dg/torture/vshuf-v16qi.c   -O2  (internal compiler error)

triggered by an RTL instruction like:

(insn 97 96 98 (set (reg:SI 5 %r5 [88])
        (zero_extract:SI (mem/c:SI (symbol_ref:SI ("b") <var_decl 0x7ffff7f801b0 b>) [0 b+0 S4 A128])
            (const_int 8 [0x8])
            (const_int 24 [0x18]))) ".../gcc/testsuite/gcc.dg/torture/vshuf-main.inc":28:1 97 {*extzv_aligned}
     (nil))

and removes these regressions:

FAIL: gcc.dg/torture/vshuf-v16qi.c   -O2  (internal compiler error)
FAIL: gcc.dg/torture/vshuf-v16qi.c   -O2  (test for excess errors)
FAIL: gcc.dg/torture/vshuf-v4hi.c   -O2  (internal compiler error)
FAIL: gcc.dg/torture/vshuf-v4hi.c   -O2  (test for excess errors)
FAIL: gcc.dg/torture/vshuf-v8hi.c   -O2  (internal compiler error)
FAIL: gcc.dg/torture/vshuf-v8hi.c   -O2  (test for excess errors)
FAIL: gcc.dg/torture/vshuf-v8qi.c   -O2  (internal compiler error)
FAIL: gcc.dg/torture/vshuf-v8qi.c   -O2  (test for excess errors)

However expand typically presents pseudo-registers rather than memory
references to these insns, so a further rework is required to make a
better use of the code variant they are supposed to produce.  This at
least fixes the problem at hand.

gcc/
* config/vax/vax.md (*insv_aligned, *extzv_aligned)
(*extv_aligned): Also make sure the memory address of a bit-field
location can be adjusted in the PIC mode.

VAX: Remove EXTV/EXTZV/INSV instruction use from aligned case insns

The INSV machine instruction is the only computational operation in the
VAX ISA that keeps condition codes intact.  In preparation to MODE_CC
transition keep patterns apart then that make or do not make use of said
instruction.  For consistency update EXTV and EXTZV instruction uses
accordingly.  In expand SUBREGs will be presented as operands, so handle
that possibility in the insn condition.

This actually yields better code by avoiding EXTV/EXTZV instructions in
pseudo-aligned register cases previously resorting to those instructions:

@@ -42,7 +42,7 @@ ins8:
subl2 $4,%sp # 21 [c=32]  addsi3
movl 4(%ap),%r0 # 2 [c=16]  movsi_2
movl 8(%ap),%r1 # 17 [c=16]  movsi_2
- insv %r1,$8,$8,%r0 # 9 [c=4]  *insv_aligned
+ insv %r1,$8,$8,%r0 # 9 [c=4]  *insv_2
ret # 25 [c=0]  return
.size ins8, .-ins8
.align 1
@@ -60,12 +60,12 @@ ext8:
.globl extz8
.type extz8, @function
extz8:
- .word 0 # 19 [c=0]  procedure_entry_mask
- subl2 $4,%sp # 20 [c=32]  addsi3
+ .word 0 # 18 [c=0]  procedure_entry_mask
+ subl2 $4,%sp # 19 [c=32]  addsi3
movl 4(%ap),%r0 # 2 [c=16]  movsi_2
- extzv $8,$8,%r0,%r1 # 13 [c=60]  *extzv_aligned
- movl %r1,%r0 # 18 [c=4]  movsi_2
- ret # 24 [c=0]  return
+ rotl $24,%r0,%r0 # 13 [c=60]  *extzv_non_const
+ movzbl %r0,%r0
+ ret # 23 [c=0]  return
.size extz8, .-extz8
.align 1
.globl ins16
@@ -75,7 +75,7 @@ ins16:
subl2 $4,%sp # 21 [c=32]  addsi3
movl 4(%ap),%r0 # 2 [c=16]  movsi_2
movl 8(%ap),%r1 # 17 [c=16]  movsi_2
- insv %r1,$16,$16,%r0 # 9 [c=4]  *insv_aligned
+ insv %r1,$16,$16,%r0 # 9 [c=4]  *insv_2
ret # 25 [c=0]  return
.size ins16, .-ins16
.align 1
@@ -94,8 +94,9 @@ ext16:
extz16:
.word 0 # 18 [c=0]  procedure_entry_mask
subl2 $4,%sp # 19 [c=32]  addsi3
- movl 4(%ap),%r1 # 2 [c=16]  movsi_2
- extzv $16,$16,%r1,%r0 # 7 [c=60]  *extzv_aligned
+ movl 4(%ap),%r0 # 2 [c=16]  movsi_2
+ rotl $16,%r0,%r0 # 7 [c=60]  *extzv_non_const
+ movzwl %r0,%r0
movzwl %r0,%r0 # 13 [c=4]  zero_extendhisi2
ret # 23 [c=0]  return
.size extz16, .-extz16

demonstrated with this program:

typedef struct
{
  int f0:1;
  int f1:7;
  int f8:8;
  int f16:16;
} bit_t;

typedef struct
{
  unsigned int f0:1;
  unsigned int f1:7;
  unsigned int f8:8;
  unsigned int f16:16;
} ubit_t;

typedef union
{
  bit_t b;
  int i;
} bit_u;

typedef union
{
  ubit_t b;
  unsigned int i;
} ubit_u;

int
ins1 (bit_u x, int y)
{
  asm volatile ("" : "+r" (x), "+r" (y));
  x.b.f1 = y;
  return x.i;
}

int
ext1 (bit_u x)
{
  asm volatile ("" : "+r" (x));
  return x.b.f1;
}

unsigned int
extz1 (ubit_u x)
{
  asm volatile ("" : "+r" (x));
  return x.b.f1;
}

int
ins8 (bit_u x, int y)
{
  asm volatile ("" : "+r" (x), "+r" (y));
  x.b.f8 = y;
  return x.i;
}

int
ext8 (bit_u x)
{
  asm volatile ("" : "+r" (x));
  return x.b.f8;
}

unsigned int
extz8 (ubit_u x)
{
  asm volatile ("" : "+r" (x));
  return x.b.f8;
}

int
ins16 (bit_u x, int y)
{
  asm volatile ("" : "+r" (x), "+r" (y));
  x.b.f16 = y;
  return x.i;
}

int
ext16 (bit_u x)
{
  asm volatile ("" : "+r" (x));
  return x.b.f16;
}

unsigned int
extz16 (ubit_u x)
{
  asm volatile ("" : "+r" (x));
  return x.b.f16;
}

It also papers over a regression:

FAIL: gcc.dg/pr83623.c (internal compiler error)
FAIL: gcc.dg/pr83623.c (test for excess errors)

from an ICE like:

during RTL pass: final
.../gcc/testsuite/gcc.dg/pr83623.c: In function 'foo':
.../gcc/testsuite/gcc.dg/pr83623.c:13:1: internal compiler error: in change_address_1, at emit-rtl.c:2275
0x10a056e3 change_address_1
.../gcc/emit-rtl.c:2275
0x10a0645f adjust_address_1(rtx_def*, machine_mode, poly_int<1u, long>, int, int, int, poly_int<1u, long>)
.../gcc/emit-rtl.c:2409
0x11cb588f output_97
.../gcc/config/vax/vax.md:808
0x10aafb2f get_insn_template(int, rtx_insn*)
.../gcc/final.c:2070
0x10ab2b3f final_scan_insn_1
.../gcc/final.c:3039
0x10ab313b final_scan_insn(rtx_insn*, _IO_FILE*, int, int, int*)
.../gcc/final.c:3152
0x10aaf887 final_1
.../gcc/final.c:2020
0x10ab703b rest_of_handle_final
.../gcc/final.c:4658
0x10ab757b execute
.../gcc/final.c:4736
Please submit a full bug report,
with preprocessed source if appropriate.
Please include the complete backtrace with any bug report.
See <https://gcc.gnu.org/bugs/> for instructions.
compiler exited with status 1
FAIL: gcc.dg/pr83623.c (internal compiler error)

triggered by an RTL instruction like:

(insn 17 14 145 (set (reg:SI 1 %r1)
        (zero_extract:SI (mem/c:SI (symbol_ref:SI ("x") <var_decl 0x7ffff7f80120 x>) [1 x+0 S4 A128])
            (const_int 16 [0x10])
            (const_int 16 [0x10]))) ".../gcc/testsuite/gcc.dg/pr83623.c":12:9 97 {*extzv_aligned}
     (nil))

(where the address cannot be adjusted by 2 for PIC code as requested
here as it would create an offset external symbol reference) otherwise
caused by the patterns modified here, addressed next.  This indicates
a further rework is warranted here, but at least problems at hand have
been fixed.

gcc/
* config/vax/vax.md (*insv_aligned, *extzv_aligned)
(*extv_aligned): Reject register bit-field locations that are not
aligned to the least significant bit; update output statement
accordingly.

VAX: Fix predicates and constraints for EXTV/EXTZV/INSV insns

It makes no sense for insn operand predicates, as long as they accept a
register operand, to be more restrictive than the set of the associated
constraints, because expand will choose the insn based on the relevant
operand being a pseudo register then and reload keep it happily as a
memory reference if a constraint permits it.  So the restriction posed
by such a predicate will be happily ignored, and moreover if a splitter
is added, such as required for MODE_CC support, the new instructions
will reject the original operands supplied, causing an ICE.  An actual
example will be given with a subsequent change.

Remove such inconsistencies we have with the EXTV/EXTZV/INSV insns then,
observing that a bit-field located in memory is byte-addressed by the
respective machine instructions and therefore SImode may only be used
with a register or an offsettable memory operand (i.e. not an indexed,
pre-decremented, or post-incremented one), which has already been taken
into account with the constraints currently used, except for `*insv_2'.
The QI machine mode may be used for the bit-field location with any kind
of memory operand, but we got the constraint wrong, although harmlessly
in reality, with `*insv'.  Fix that for consistency though.

Also give the insns names, for easier reference here and elsewhere.

gcc/
* config/vax/vax.md (*insv_aligned, *extzv_aligned)
(*extv_aligned, *extv_non_const, *extzv_non_const): Name insns.
Fix location predicate.
(*extzv): Name insn.
(*insv): Likewise.  Fix location constraint.
(*insv_2): Likewise, and the predicate.

VAX: Add the `movmemhi' instruction

The MOVC3 machine instruction has `memmove' semantics[1]:

"The operation of the instruction is such that overlap of the source and
destination strings does not affect the result."

so use it to provide the `movmemhi' instruction as well.

References:

[1] DEC STD 032-0 "VAX Architecture Standard", Digital Equipment
    Corporation, A-DS-EL-00032-00-0 Rev J, December 15, 1989, Section
    3.10 "Character-String Instructions", p. 3-162

gcc/
* config/vax/vax.md (cpymemhi1): Rename insn to...
(movmemhi1): ... this.
(cpymemhi): Update accordingly.  Remove constraints.
(movmemhi): New expander.

gcc/testsuite/
* gcc.target/vax/movmem.c: New test.

VAX: Add a test for the `cpymemhi' instruction

gcc/testsuite/
* gcc.target/vax/cpymem.c: New test.

VAX: Actually produce QImode and HImode `ctz' operations

The middle end does not refer to `ctzqi2'/`ctzhi2' or `ffsqi2'/`ffshi2'
patterns by name where `__builtin_ctz' or `__builtin_ffs' respectively
is invoked for an argument of the QImode or HImode type, and instead it
extends the data type before passing it to `ctzsi2' or `ffssi2'.

Avoid the redundant operation and use a peephole2 to convert it to the
right RTL expression that will collapse the two operations into a single
machine instruction instead unless we need the extended intermediate
result for another purpose.

gcc/
* config/vax/builtins.md: Add a peephole2 for QImode and HImode
`ctz' operations.
(any_extend): New code iterator.

gcc/testsuite/
* gcc.target/vax/ctzhi.c: New test.
* gcc.target/vax/ctzqi.c: New test.
* gcc.target/vax/ffshi.c: New test.
* gcc.target/vax/ffsqi.c: New test.

VAX: Also provide QImode and HImode `ctz' and `ffs' operations

The FFS machine instruction provides for arbitrary input bit-field widths
so take advantage of this and convert `ffssi2' and `ctzsi2' to templates
for all the three of QI, HI, SI machine modes.

Test cases will be added separately.

gcc/
* config/vax/builtins.md (width): New mode attribute.
(ffssi2): Rework expander into...
(ffs<mode>2): ... this.
(ctzsi2): Rework insn into...
(ctz<mode>2): ... this.

VAX: Provide the `ctz' operation

Our `ffssi2_internal' pattern and the machine FFS instruction, which
technically is a bit-field operation, match the `ctz' operation exactly,
with the result produced for the bit-field source operand of zero equal
to its width as specified with another machine instruction operand, not
directly expressed in RTL and currently hardcoded in the assembly code
produced. In our terms this is the bit size of the machine mode used,
and although it's SImode now let's be flexible for an upcoming change.

The operation also sets the Z condition code according to the value of
the source operand.

gcc/
* config/vax/builtins.md (ffssi2_internal): Rename insn to...
(ctzsi2): ... this. Update the RTL operation.
(ffssi2): Update accordingly.
* config/vax/vax.c (vax_notice_update_cc): Handle CTZ.
* config/vax/vax.h (CTZ_DEFINED_VALUE_AT_ZERO): New macro.

gcc/testsuite/
* gcc.target/vax/ctzsi.c: New test.

VAX: Add tests for `sync_lock_test_and_set' and `sync_lock_release'

Based on gcc.dg/pr61756.c.

gcc/testsuite/
* gcc.target/vax/bbcci.c: New test.
* gcc.target/vax/bbssi.c: New test.

VAX: Add a test for the SImode `ffs' operation

gcc/testsuite/
* gcc.target/vax/ffssi.c: New test.

VAX: Actually enable `builtins.md' now that it is fully functional

Test cases will follow.

gcc/
* config/vax/vax.md: Include `builtins.md'.

VAX: Correct `sync_lock_test_and_set' and `sync_lock_release' builtins

Remove an ICE like:

during RTL pass: expand
.../libatomic/tas_n.c: In function 'libat_test_and_set_1':
.../libatomic/tas_n.c:39:1: internal compiler error: in patch_jump_insn, at cfgrtl.c:1298
   39 | }
      | ^
0x108a09ff patch_jump_insn
.../gcc/cfgrtl.c:1298
0x108a0b07 redirect_branch_edge
.../gcc/cfgrtl.c:1325
0x108a124b rtl_redirect_edge_and_branch
.../gcc/cfgrtl.c:1458
0x1087f6d3 redirect_edge_and_branch(edge_def*, basic_block_def*)
.../gcc/cfghooks.c:373
0x11d6264b try_forward_edges
.../gcc/cfgcleanup.c:562
0x11d6b0eb try_optimize_cfg
.../gcc/cfgcleanup.c:2960
0x11d6ba4f cleanup_cfg(int)
.../gcc/cfgcleanup.c:3174
0x10870b3f execute
.../gcc/cfgexpand.c:6763

triggered with an RTL pattern like:

(jump_insn 8 7 20 2 (parallel [
            (set (pc)
                (if_then_else (ne (zero_extract:SI (mem/v:QI (mem/f/c:SI (reg/f:SI 16 virtual-incoming-args) [1 mptr+0 S4 A32]) [-1  S1 A8])
                            (const_int 1 [0x1])
                            (const_int 0 [0]))
                        (const_int 0 [0]))
                    (label_ref 10)
                    (pc)))
            (set (zero_extract:SI (mem/v:QI (mem/f/c:SI (reg/f:SI 16 virtual-incoming-args) [1 mptr+0 S4 A32]) [-1  S1 A8])
                    (const_int 1 [0x1])
                    (const_int 0 [0]))
                (const_int 1 [0x1]))
        ]) ".../libatomic/tas_n.c":38:12 -1
     (nil)
-> 10)

caused by a volatile memory reference used that is not accepted by the
`memory_operand' predicate of the `jbbssiqi' insn explicitly referred
from the `sync_lock_test_and_setqi' expander.  Also seen with:

FAIL: gcc.dg/pr61756.c (internal compiler error)

Define a new `any_memory_operand' predicate accepting both ordinary and
volatile memory references and use it with the `jbb<ccss>i<mode>' insn,
so as to address the ICE.

Also remove useless operations from the `sync_lock_test_and_set<mode>'
and `sync_lock_release<mode>' expanders as those always either complete
or fail and therefore never fall through to using their template other
than to match operands.  Wrap `jbb<ccss>i<mode>' into `unspec_volatile'
instead so that the jump does not get removed or reordered.  Share one
index to avoid a complication around the iterators since the index is
nowhere referred to anyway and the pattern required pulled by its name.

Test cases will be added separately.

gcc/
* config/vax/predicates.md (volatile_mem_operand)
(any_memory_operand): New predicates.
* config/vax/builtins.md (VUNSPEC_UNLOCK): Remove constant.
(sync_lock_test_and_set<mode>): Remove `set' and `unspec'
operations, match operands only.  Reformat.
(sync_lock_release<mode>): Likewise.  Remove cruft.
(jbb<ccss>i<mode>): Wrap into `unspec_volatile', use
`any_memory_operand' predicate.

VAX: Use an int iterator to produce individual interlocked branches

With mode-specific interlocked branch insns already folded into iterated
templates now fold the two templates into one too, observing that the
only difference between them is the value of the bit branched on, which
is of course reflected both in the RTL expression and the instruction
produced. Use an int iterator to iterate over the bit value, making use
of the newly-added wide integer support, and substituting patterns as
necessary to produce equivalent individual insns. No functional change.

gcc/
* config/vax/builtins.md (bit): New int iterator.
(ccss): New int attribute.
(jbbssi<mode>, jbbcci<mode>): Fold insns into...
(jbb<ccss>i<mode>): ... this.

VAX: Use a mode iterator to produce individual interlocked branches

Regardless of the machine mode all the interlocked branches of the same
kind, one of the two provided by the ISA, use the same RTL patterns and
machine instructions, except for the memory operand's constraint.

Remove code duplication then and make use of a mode iterator combined
with an attribute to expand the same insn patterns with the constraint
suitably substituted from a single template. No functional change.

gcc/
* config/vax/builtins.md (bb_mem): New mode attribute.
(jbbssiqi, jbbssihi, jbbssisi): Fold insns into...
(jbbssi<mode>): ... this.
(jbbcciqi, jbbccihi, jbbccisi): Likewise...
(jbbcci<mode>): ... this.

jump: Also handle jumps wrapped in UNSPEC or UNSPEC_VOLATILE

VAX has interlocked branch instructions used for atomic operations and
we want to have them wrapped in UNSPEC_VOLATILE so as not to have code
carried across.  This however breaks with jump optimization and leads
to an ICE in the build of libbacktrace like:

.../libbacktrace/mmap.c:190:1: internal compiler error: in fixup_reorder_chain, at cfgrtl.c:3934
  190 | }
      | ^
0x1087d46b fixup_reorder_chain
.../gcc/cfgrtl.c:3934
0x1087f29f cfg_layout_finalize()
.../gcc/cfgrtl.c:4447
0x1087c74f execute
.../gcc/cfgrtl.c:3662

on RTL like:

(jump_insn 18 17 150 4 (unspec_volatile [
            (set (pc)
                (if_then_else (eq (zero_extract:SI (mem/v:SI (reg/f:SI 23 [ _2 ]) [-1  S4 A32])
                            (const_int 1 [0x1])
                            (const_int 0 [0]))
                        (const_int 1 [0x1]))
                    (label_ref 20)
                    (pc)))
            (set (zero_extract:SI (mem/v:SI (reg/f:SI 23 [ _2 ]) [-1  S4 A32])
                    (const_int 1 [0x1])
                    (const_int 0 [0]))
                (const_int 1 [0x1]))
        ] 101) ".../libbacktrace/mmap.c":135:14 158 {jbbssisi}
     (nil)
-> 20)

when those branches are enabled with a follow-up change.  Also showing
with:

FAIL: gcc.dg/pr61756.c (internal compiler error)

Handle branches wrapped in UNSPEC_VOLATILE then and, for consistency,
also in UNSPEC.  The presence of UNSPEC_VOLATILE will prevent such
branches from being removed as they won't be accepted by `onlyjump_p',
we just need to let them through.

gcc/
* jump.c (pc_set): Also accept a jump wrapped in UNSPEC or
UNSPEC_VOLATILE.
(any_uncondjump_p, any_condjump_p): Update comment accordingly.

loop-doloop: Add missing call to `onlyjump_p'

Keep any jump that has side effects as those must not be removed.

gcc/
* loop-doloop.c (add_test): Only remove the jump if `onlyjump_p'.

cfgrtl: Add missing call to `onlyjump_p'

If any unconditional jumps within a block have side effects then the
block cannot be considered empty.

gcc/
* cfgrtl.c (rtl_block_empty_p): Return false if `!onlyjump_p'
too.

sel-sched-ir: Add missing call to `onlyjump_p'

Do not try to remove a conditional jump if it has side effects.

gcc/
* sel-sched-ir.c (maybe_tidy_empty_bb): Only try to remove a
conditional jump if `onlyjump_p'.

loop-iv: Add missing calls to `onlyjump_p'

Ignore jumps that have side effects in loop processing as pasting the
body of a loop multiple times within is semantically equivalent to jump
deletion (between the iterations unrolled) even if we do not physically
delete the jump RTL insn.

gcc/
* loop-iv.c (simplify_using_initial_values): Only process jumps
that match `onlyjump_p'.
(check_simple_exit): Likewise.

ifcvt: Add missing call to `onlyjump_p'

Do not convert a conditional jump into conditional execution (and remove
the jump as a consequence) if the jump has side effects.

gcc/
* ifcvt.c (dead_or_predicable) [!IFCVT_MODIFY_TESTS]: Bail out
if `!onlyjump_p'.

RTL: Also support HOST_WIDE_INT with int iterators

Add wide integer aka 'w' rtx format support to int iterators so that
machine description can iterate over `const_int' expressions.

This is made by expanding standard integer aka 'i' format support,
observing that any standard integer already present in any of our
existing RTL code will also fit into HOST_WIDE_INT, so there is no need
for a separate handler.  Any truncation of the number parsed is made by
the caller.  An assumption is made however that no place relies on
capping out of range values to INT_MAX.

Now the 'p' format is handled explicitly rather than being implied by
rtx being a SUBREG, so actually assert that it is, just to play safe.

gcc/
* read-rtl.c: Add a page-feed separator at the start of iterator
code.
(struct iterator_group): Change the return type to HOST_WIDE_INT
for the `find_builtin' member.  Likewise the second parameter
type for the `apply_iterator' member.
(atoll) [!HAVE_ATOQ]: Reorder.
(find_mode, find_code): Change the return type to HOST_WIDE_INT.
(apply_mode_iterator, apply_code_iterator)
(apply_subst_iterator): Change the second parameter type to
HOST_WIDE_INT.
(find_int): Handle input suitable for HOST_WIDE_INT output.
(apply_int_iterator): Rewrite in terms of explicit format
interpretation.
(rtx_reader::read_rtx_operand) <'w'>: Fold into...
<'i', 'n', 'p'>: ... this.
* doc/md.texi (Int Iterators): Document 'w' rtx format support.

VAX: Correct fatal issues with the `ffs' builtin

The `builtins.md' machine description fragment is not included anywhere
and is therefore dead code, which has become bitrotten due to non-use.

If actually enabled, it does not build due to the use of an unknown `t'
constraint:

.../gcc/config/vax/builtins.md:42:1: error: undefined machine-specific constraint at this point: "t"
.../gcc/config/vax/builtins.md:42:1: note:  in operand 1

which came from commit becb93d02cc1 ("builtins.md (ffssi2_internal):
Correct constraint."), which was not applied as posted and reviewed; `T'
was meant to be used instead.

Once this has been fixed this code still fails building:

.../gcc/config/vax/builtins.md: In function 'rtx_def* gen_ffssi2(rtx, rtx)':
.../gcc/config/vax/builtins.md:35:19: error: 'gen_bne' was not declared in this
scope; did you mean 'gen_use'?
   35 |   emit_jump_insn (gen_bne (label));
      |                   ^~~~~~~
      |                   gen_use
make[2]: *** [Makefile:1122: insn-emit.o] Error 1

Finally the FFS machine instruction sets the Z condition code according
to the comparison of the value held in the source operand against zero
rather than the value held in the target operand.  If the source operand
is found hold zero, then the target operand is set to the width of the
source operand, 32 for SImode (FFS supports arbitrary widths).

Correct the build issues then and update RTL to match the operation of
the machine instruction.  A test case will be added separately.

gcc/
* config/vax/builtins.md (ffssi2): Make preparation statements
actually buildable.
(ffssi2_internal): Fix input constraints; make the RTL pattern
match reality for `cc0'.

VAX: Rationalize expression and address costs

Expression costs are required to be given in terms of COSTS_N_INSNS (n),
which is defined to stand for the count of single fast instructions, and
actually returns `n * 4'.  The VAX backend however instead operates on
naked numbers, causing an anomaly for the integer const zero rtx, where
the cost given is 4 as opposed to 1 for integers in the [1:63] range, as
well as -1 for comparisons.  This is because the value of 0 returned by
`vax_rtx_costs' is converted to COSTS_N_INSNS (1) in `pattern_cost':

  return cost > 0 ? cost : COSTS_N_INSNS (1);

Consequently, where feasible, 1 or -1 are preferred over 0 by the middle
end causing code pessimization, e.g. rather than producing this:

subl2 $4,%sp
movl 4(%ap),%r0
jgtr .L2
addl2 $2,%r0
.L2:
ret

or this:

subl2 $4,%sp
addl3 4(%ap),8(%ap),%r0
jlss .L6
addl2 $2,%r0
.L6:
ret

code is produced like this:

subl2 $4,%sp
movl 4(%ap),%r0
cmpl %r0,$1
jgeq .L2
addl2 $2,%r0
.L2:
ret

or this:

subl2 $4,%sp
addl3 4(%ap),8(%ap),%r0
cmpl %r0,$-1
jleq .L6
addl2 $2,%r0
.L6:
ret

from this:

int
compare_mov (int x)
{
  if (x > 0)
    return x;
  else
    return x + 2;
}

and this:

int
compare_add (int x, int y)
{
  int z;

  z = x + y;
  if (z < 0)
    return z;
  else
    return z + 2;
}

respectively, which is slower and larger both at a time.

Furthermore once the backend is converted to MODE_CC this anomaly makes
it usually impossible to remove redundant comparisons in the comparison
elimination pass, because most VAX instructions set the condition codes
as per the relation of the instruction's result to 0 and not -1.

The middle end has some other assumptions as to rtx costs being given in
terms of COSTS_N_INSNS, so wrap all the VAX rtx costs then as they stand
into COSTS_N_INSNS invocations, effectively scaling the costs by 4 while
preserving their relative values, except for the integer const zero rtx
given the value of `COSTS_N_INSNS (1) / 2', half of a fast instruction
(this can be further halved if needed in the future).

Adjust address costs likewise so that they remain proportional to the
new absolute values of rtx costs.

Code size stats are as follows, collected from 17639 executables built
in `check-c' GCC testing:

              samples average  median
--------------------------------------
regressions      1420  0.400%  0.195%
unchanged       13811  0.000%  0.000%
progressions     2408 -0.504% -0.201%
--------------------------------------
total           17639 -0.037%  0.000%

with a small number of outliers only (over 5% size change):

old     new     change  %change filename
----------------------------------------------------
4991    5249     258     5.1693 981001-1.exe
2637    2777     140     5.3090 interchange-6.exe
2187    2307     120     5.4869 sprintf.x7
3969    4197     228     5.7445 pr28982a.exe
8264    8816     552     6.6795 vector-compare-1.exe
5199    5575     376     7.2321 pr28982b.exe
2113    2411     298    14.1031 20030323-1.exe
2113    2411     298    14.1031 20030323-1.exe
2113    2411     298    14.1031 20030323-1.exe

so it seems we are looking good, and we have complementing reductions
to compensate:

old     new     change  %change filename
----------------------------------------------------
2919    2631    -288    -9.8663 pr57521.exe
3427    3167    -260    -7.5868 sabd_1.exe
2985    2765    -220    -7.3701 ssad-run.exe
2985    2765    -220    -7.3701 ssad-run.exe
2985    2765    -220    -7.3701 usad-run.exe
2985    2765    -220    -7.3701 usad-run.exe
4509    4253    -256    -5.6775 vshuf-v2sf.exe
4541    4285    -256    -5.6375 vshuf-v2si.exe
4673    4417    -256    -5.4782 vshuf-v2df.exe
2993    2841    -152    -5.0785 abs-2.x4
2993    2841    -152    -5.0785 abs-3.x4

This actually causes `loop-8.c' to regress:

FAIL: gcc.dg/loop-8.c scan-rtl-dump-times loop2_invariant "Decided" 1
FAIL: gcc.dg/loop-8.c scan-rtl-dump-not loop2_invariant "without introducing a new temporary register"

but upon a closer inspection this is a red herring.  Old code looks as
follows:

.file "loop-8.c"
.text
.align 1
.globl f
.type f, @function
f:
.word 0
subl2 $4,%sp
movl 4(%ap),%r2
movl 8(%ap),%r3
movl $42,(%r2)
clrl %r0
movl $42,%r1
movl %r1,%r4
jbr .L2
.L5:
movl %r4,%r1
.L2:
movl %r1,(%r3)[%r0]
incl %r0
cmpl %r0,$100
jeql .L6
movl $42,(%r2)[%r0]
bicl3 $-2,%r0,%r1
jeql .L5
movl %r0,%r1
jbr .L2
.L6:
ret
.size f, .-f

while new one is like below:

.file "loop-8.c"
.text
.align 1
.globl f
.type f, @function
f:
.word 0
subl2 $4,%sp
movl 4(%ap),%r2
movl $42,(%r2)+
movl 8(%ap),%r1
clrl %r0
movl $42,%r3
movzbl $100,%r4
movl %r3,%r5
jbr .L2
.L5:
movl %r5,%r3
.L2:
movl %r3,(%r1)+
incl %r0
cmpl %r0,%r4
jeql .L6
movl $42,(%r2)+
bicl3 $-2,%r0,%r3
jeql .L5
movl %r0,%r3
jbr .L2
.L6:
ret
.size f, .-f

and is clearly better: not only it is smaller, but it also uses the
post-increment rather than indexed addressing mode in the loop, of
which the former comes for free in terms of both performance and code
size while the latter causes an extra byte per operand to be produced
for the index register and also incurs an execution penalty for the
extra address calculation.

Exclude the case from VAX testing then, as already done for some other
targets and discussed with commit d242fdaec186 ("gcc.dg/loop-8.c: Skip
for mmix.").

gcc/
* config/vax/vax.c (vax_address_cost): Express the cost in terms
of COSTS_N_INSNS.
(vax_rtx_costs): Likewise.

gcc/testsuite/
* gcc.dg/loop-8.c: Exclude for `vax-*-*'.
* gcc.target/vax/compare-add-zero.c: New test.
* gcc.target/vax/compare-mov-zero.c: New test.

VAX/testsuite: Run target testing over all the usual optimization levels

It makes sense to use what other targets do and run all the VAX test
cases over all the usual optimization levels, so make `vax.exp' use our
`gcc-dg-runtest' rather than the generic `dg-runtest' test driver.

This breaks `pr56875.c' however, which is optimized away at levels above
`-O0' as a result of how it has been written for calculations to make no
effect:

FAIL: gcc.target/vax/pr56875.c   -O1   scan-assembler ashq .*,\\$0xffffffffffffffff,
FAIL: gcc.target/vax/pr56875.c   -O2   scan-assembler ashq .*,\\$0xffffffffffffffff,
FAIL: gcc.target/vax/pr56875.c   -O3 -g   scan-assembler ashq .*,\\$0xffffffffffffffff,
FAIL: gcc.target/vax/pr56875.c   -Os   scan-assembler ashq .*,\\$0xffffffffffffffff,
FAIL: gcc.target/vax/pr56875.c   -O2 -flto -fno-use-linker-plugin -flto-partition=none   scan-assembler ashq .*,\\$0xffffffffffffffff,
FAIL: gcc.target/vax/pr56875.c   -O2 -flto -fuse-linker-plugin -fno-fat-lto-objects   scan-assembler ashq .*,\\$0xffffffffffffffff,

Rather than keeping it at `-O0' update the test case for its code to do
make effect while retaining its sense.  Also reformat it according to
our requirements.

gcc/testsuite/
* gcc.target/vax/vax.exp: Use `gcc-dg-runtest' rather than
`dg-runtest'.
* gcc.target/vax/pr56875.c (dg-options): Make empty.
(a): Rewrite for calculations to make effect.  Reformat.

VAX: Define LEGITIMATE_PIC_OPERAND_P

The VAX ELF psABI does not permit the use of all hardware operand modes
for PIC symbol references due to the need to use PC-relative addressing
for symbols that end up local and the need to make references indirect
symbols that end up global.

Therefore symbols referred as immediates may only be used with the move
and push address (MOVA and PUSHA) instructions and their PC-relative
displacement address mode, as there is no genuine PC-relative immediate
available that all the other instructions would have to use.

Furthermore global symbol references must not have an offset applied,
which has to be added with a separate instruction, because there is no
support now for GOT entries for external `symbol+offset' references, so
any indirect GOT references made by the static linker from the original
direct symbol references must not have an addend applied.  Consequently
no addend is allowed even if a given external symbol turns out local,
for whatever reason, at the static link time.

Define the LEGITIMATE_PIC_OPERAND_P macro then, a corresponding function
and predicate to exclude the relevant expressions as required, and then
a constraint so that reloads are produced where needed, and use the new
facilities in the machine description, folding corresponding duplicated
patterns for local and external symbols together.  Rewrite predicates to
make use of the new function, rename them to match their sense and also
remove ones no longer used.

All this fixing an ICE like this:

during RTL pass: postreload
.../gcc/testsuite/gcc.c-torture/execute/20040709-2.c: In function 'testE':
.../gcc/testsuite/gcc.c-torture/execute/20040709-2.c:89:1: internal compiler error: in reload_combine_note_use, at postreload.c:1559
.../gcc/testsuite/gcc.c-torture/execute/20040709-2.c:96:65: note: in expansion of macro 'T'
0x10fe84cb reload_combine_note_use
.../gcc/postreload.c:1559
0x10fe8857 reload_combine_note_use
.../gcc/postreload.c:1621
0x10fe8303 reload_combine_note_use
.../gcc/postreload.c:1517
0x10fe7c7b reload_combine
.../gcc/postreload.c:1408
0x10fe3417 reload_cse_regs
.../gcc/postreload.c:67
0x10feaf9f execute
.../gcc/postreload.c:2358

due to the presence of a pseudo register post-reload:

(insn 435 228 229 13 (set (reg:SI 1 %r1)
        (mem/c:SI (reg/f:SI 341) [25 sE+12 S4 A8])) ".../gcc/testsuite/gcc.c-torture/execute/20040709-2.c":96:65 12 {movsi_2}
     (nil))

(due to the use of an offset `sE+12' symbol reference) and removing
these regressions:

FAIL: gcc.c-torture/execute/20040709-2.c   -O2  (internal compiler error)
FAIL: gcc.c-torture/execute/20040709-2.c   -O2  (test for excess errors)
FAIL: gcc.c-torture/execute/20040709-2.c   -O3 -fomit-frame-pointer -funroll-loops -fpeel-loops -ftracer -finline-functions  (internal compiler error)
FAIL: gcc.c-torture/execute/20040709-2.c   -O3 -fomit-frame-pointer -funroll-loops -fpeel-loops -ftracer -finline-functions  (test for excess errors)
FAIL: gcc.c-torture/execute/20040709-2.c   -O3 -g  (internal compiler error)
FAIL: gcc.c-torture/execute/20040709-2.c   -O3 -g  (test for excess errors)
FAIL: gcc.c-torture/execute/20040709-2.c   -Os  (internal compiler error)
FAIL: gcc.c-torture/execute/20040709-2.c   -Os  (test for excess errors)
FAIL: gcc.c-torture/execute/20040709-2.c   -O2 -flto -fno-use-linker-plugin -flto-partition=none  (internal compiler error)
FAIL: gcc.c-torture/execute/20040709-2.c   -O2 -flto -fno-use-linker-plugin -flto-partition=none  (test for excess errors)
FAIL: gcc.c-torture/execute/20040709-3.c   -O2  (internal compiler error)
FAIL: gcc.c-torture/execute/20040709-3.c   -O2  (test for excess errors)
FAIL: gcc.c-torture/execute/20040709-3.c   -O3 -g  (internal compiler error)
FAIL: gcc.c-torture/execute/20040709-3.c   -O3 -g  (test for excess errors)
FAIL: gcc.c-torture/execute/20040709-3.c   -Os  (internal compiler error)
FAIL: gcc.c-torture/execute/20040709-3.c   -Os  (test for excess errors)
FAIL: gcc.c-torture/execute/20040709-3.c   -O2 -flto -fno-use-linker-plugin -flto-partition=none  (internal compiler error)
FAIL: gcc.c-torture/execute/20040709-3.c   -O2 -flto -fno-use-linker-plugin -flto-partition=none  (test for excess errors)
FAIL: gcc.dg/torture/pr52028.c   -O2 -flto -fuse-linker-plugin -fno-fat-lto-objects  (internal compiler error)
FAIL: gcc.dg/torture/pr52028.c   -O2 -flto -fuse-linker-plugin -fno-fat-lto-objects  (test for excess errors)

gcc/
* config/vax/constraints.md (A): New constraint.
* config/vax/predicates.md (external_symbolic_operand)
(external_const_operand): Remove predicates.
(local_symbolic_operand): Rename to...
(pic_symbolic_operand): ... this, and rework.
(external_memory_operand): Rename to...
(non_pic_external_memory_operand): ... this, and rework.
(illegal_blk_memory_operand, illegal_addsub_di_memory_operand):
Update accordingly.
* config/vax/vax-protos.h (vax_acceptable_pic_operand_p): New
prototype.
* config/vax/vax.c (vax_acceptable_pic_operand_p): New function.
(vax_output_int_add): Update according to predicate rework.
* config/vax/vax.h (LEGITIMATE_PIC_OPERAND_P): New macro.
* config/vax/vax.md (pushlclsymreg, pushextsymreg): Fold
together, and rename to...
(*pushsymreg): ... this.  Use the `pic_symbolic_operand'
predicate and the `A' constraint for the displacement operand.
(movlclsymreg, movextsymreg): Fold together, and rename to...
(*movsymreg): ... this.  Use the `pic_symbolic_operand'
predicate and the `A' constraint for the displacement operand.
(pushextsym, pushlclsym): Fold together, and rename to...
(*pushsym): ... this.  Use the `pic_symbolic_operand' predicate
and the `A' constraint for the displacement operand.
(movextsym, movlclsym): Fold together, and rename to...
(*movsym): ... this.  Use the `pic_symbolic_operand' predicate
and the `A' constraint for the displacement operand.

VAX: Remove `c' operand format specifier overload

The `c' operand format specifier is handled directly by the middle end
in `output_asm_insn':

   %cN means require operand N to be a constant
      and print the constant expression with no punctuation.

however it resorts to the target for constants that are not valid
addresses:

    else if (letter == 'c')
      {
if (CONSTANT_ADDRESS_P (operands[opnum]))
  output_addr_const (asm_out_file, operands[opnum]);
else
  output_operand (operands[opnum], 'c');
      }

The VAX backend expects the fallback never to happen and overloads `c'
with the branch condition code.  This is confusing however and it is not
like we are short of letters, so instead make the branch condition code
use `k', and then for consistency make `K' the reverse branch condition
code format specifier.  This is safe to do as we provide no means to use
a computed branch condition code in user `asm'.

gcc/
* config/vax/vax.c (print_operand): Replace `c' and `C' with
`k' and `K' respectively.
* config/vax/vax.md (*branch, *branch_reversed): Update
accordingly.

PR target/58901: reload: Handle SUBREG of MEM with a mode-dependent address

Fix an ICE with the handling of RTL expressions like:

(subreg:QI (mem/c:SI (plus:SI (plus:SI (mult:SI (reg/v:SI 0 %r0 [orig:67 i ] [67])
                    (const_int 4 [0x4]))
                (reg/v/f:SI 7 %r7 [orig:59 doacross ] [59]))
            (const_int 40 [0x28])) [1 MEM[(unsigned int *)doacross_63 + 40B + i_106 * 4]+0 S4 A32]) 0)

that causes the compilation of libgomp to fail:

during RTL pass: reload
.../libgomp/ordered.c: In function 'GOMP_doacross_wait':
.../libgomp/ordered.c:507:1: internal compiler error: in change_address_1, at emit-rtl.c:2275
  507 | }
      | ^
0x10a3462b change_address_1
.../gcc/emit-rtl.c:2275
0x10a353a7 adjust_address_1(rtx_def*, machine_mode, poly_int<1u, long>, int, int, int, poly_int<1u, long>)
.../gcc/emit-rtl.c:2409
0x10ae2993 alter_subreg(rtx_def**, bool)
.../gcc/final.c:3368
0x10ae25cf cleanup_subreg_operands(rtx_insn*)
.../gcc/final.c:3322
0x110922a3 reload(rtx_insn*, int)
.../gcc/reload1.c:1232
0x10de2bf7 do_reload
.../gcc/ira.c:5812
0x10de3377 execute
.../gcc/ira.c:5986

in a `vax-netbsdelf' build, where an attempt is made to change the mode
of the contained memory reference to the mode of the containing SUBREG.
Such RTL expressions are produced by the VAX shift and rotate patterns
(`ashift', `ashiftrt', `rotate', `rotatert') where the count operand
always has the QI mode regardless of the mode, either SI or DI, of the
datum shifted or rotated.

Such a mode change cannot work where the memory reference uses the
indexed addressing mode, where a multiplier is implied that in the VAX
ISA depends on the width of the memory access requested and therefore
changing the machine mode would change the address calculation as well.

Avoid the attempt then by forcing the reload of any SUBREGs containing
a mode-dependent memory reference, also fixing these regressions:

FAIL: gcc.c-torture/compile/pr46883.c   -Os  (internal compiler error)
FAIL: gcc.c-torture/compile/pr46883.c   -Os  (test for excess errors)
FAIL: gcc.c-torture/execute/20120808-1.c   -O2  (internal compiler error)
FAIL: gcc.c-torture/execute/20120808-1.c   -O2  (test for excess errors)
FAIL: gcc.c-torture/execute/20120808-1.c   -O3 -fomit-frame-pointer -funroll-loops -fpeel-loops -ftracer -finline-functions  (internal compiler error)
FAIL: gcc.c-torture/execute/20120808-1.c   -O3 -fomit-frame-pointer -funroll-loops -fpeel-loops -ftracer -finline-functions  (test for excess errors)
FAIL: gcc.c-torture/execute/20120808-1.c   -O3 -g  (internal compiler error)
FAIL: gcc.c-torture/execute/20120808-1.c   -O3 -g  (test for excess errors)
FAIL: gcc.c-torture/execute/20120808-1.c   -O2 -flto -fno-use-linker-plugin -flto-partition=none  (internal compiler error)
FAIL: gcc.c-torture/execute/20120808-1.c   -O2 -flto -fno-use-linker-plugin -flto-partition=none  (test for excess errors)
FAIL: gcc.c-torture/execute/20120808-1.c   -O2 -flto -fuse-linker-plugin -fno-fat-lto-objects  (internal compiler error)
FAIL: gcc.c-torture/execute/20120808-1.c   -O2 -flto -fuse-linker-plugin -fno-fat-lto-objects  (test for excess errors)
FAIL: gcc.dg/20050629-1.c (internal compiler error)
FAIL: gcc.dg/20050629-1.c (test for excess errors)
FAIL: c-c++-common/torture/pr53505.c   -Os  (internal compiler error)
FAIL: c-c++-common/torture/pr53505.c   -Os  (test for excess errors)
FAIL: gfortran.dg/coarray_failed_images_1.f08   -Os  (internal compiler error)
FAIL: gfortran.dg/coarray_stopped_images_1.f08   -Os  (internal compiler error)

With test case #0 included it causes a reload with:

(insn 15 14 16 4 (set (reg:SI 31)
        (ashift:SI (const_int 1 [0x1])
            (subreg:QI (reg:SI 30 [ MEM[(int *)s_8(D) + 4B + _5 * 4] ]) 0))) "pr58901-0.c":15:12 94 {ashlsi3}
     (expr_list:REG_DEAD (reg:SI 30 [ MEM[(int *)s_8(D) + 4B + _5 * 4] ])
        (nil)))

as follows:

Reloads for insn # 15
Reload 0: reload_in (SI) = (reg:SI 30 [ MEM[(int *)s_8(D) + 4B + _5 * 4] ])
ALL_REGS, RELOAD_FOR_INPUT (opnum = 2)
reload_in_reg: (reg:SI 30 [ MEM[(int *)s_8(D) + 4B + _5 * 4] ])
reload_reg_rtx: (reg:SI 5 %r5)

resulting in:

(insn 37 14 15 4 (set (reg:SI 5 %r5)
        (mem/c:SI (plus:SI (plus:SI (mult:SI (reg/v:SI 1 %r1 [orig:25 i ] [25])
                        (const_int 4 [0x4]))
                    (reg/v/f:SI 4 %r4 [orig:29 s ] [29]))
                (const_int 4 [0x4])) [1 MEM[(int *)s_8(D) + 4B + _5 * 4]+0 S4 A32])) "pr58901-0.c":15:12 12 {movsi_2}
     (nil))
(insn 15 37 16 4 (set (reg:SI 2 %r2 [31])
        (ashift:SI (const_int 1 [0x1])
            (reg:QI 5 %r5))) "pr58901-0.c":15:12 94 {ashlsi3}
     (nil))

and assembly like:

.L3:
movl 4(%r4)[%r1],%r5
ashl %r5,$1,%r2
xorl2 %r2,%r0
incl %r1
cmpl %r1,%r3
jneq .L3

produced for the loop, providing optimization has been enabled.

Likewise with test case #1 the reload of:

(insn 17 16 18 4 (set (reg:SI 34)
        (and:SI (subreg:SI (reg/v:DI 27 [ t ]) 4)
            (const_int 1 [0x1]))) "pr58901-1.c":18:20 77 {*andsi_const_int}
     (expr_list:REG_DEAD (reg/v:DI 27 [ t ])
        (nil)))

is as follows:

Reloads for insn # 17
Reload 0: reload_in (DI) = (reg/v:DI 27 [ t ])
reload_out (SI) = (reg:SI 2 %r2 [34])
ALL_REGS, RELOAD_OTHER (opnum = 0)
reload_in_reg: (reg/v:DI 27 [ t ])
reload_out_reg: (reg:SI 2 %r2 [34])
reload_reg_rtx: (reg:DI 4 %r4)

resulting in:

(insn 40 16 17 4 (set (reg:DI 4 %r4)
        (mem/c:DI (plus:SI (mult:SI (reg/v:SI 1 %r1 [orig:26 i ] [26])
                    (const_int 8 [0x8]))
                (reg/v/f:SI 3 %r3 [orig:30 s ] [30])) [1 MEM[(const struct s *)s_13(D) + _7 * 8]+0 S8 A32])) "pr58901-1.c":18:20 11 {movdi}
     (nil))
(insn 17 40 41 4 (set (reg:SI 4 %r4)
        (and:SI (reg:SI 5 %r5 [+4 ])
            (const_int 1 [0x1]))) "pr58901-1.c":18:20 77 {*andsi_const_int}
     (nil))

and assembly like:

.L3:
movq (%r3)[%r1],%r4
bicl3 $-2,%r5,%r4
addl2 %r4,%r0
jaoblss %r0,%r1,.L3

First posted at: <https://gcc.gnu.org/ml/gcc/2014-06/msg00060.html>.

2020-12-05  Matt Thomas  <matt@3am-software.com>
    Maciej W. Rozycki  <macro@linux-mips.org>

gcc/
PR target/58901
* reload.c (push_reload): Also reload the inner expression of a
SUBREG for pseudos associated with a mode-dependent memory
reference.
(find_reloads): Force a reload likewise.

2020-12-05  Maciej W. Rozycki  <macro@linux-mips.org>

gcc/testsuite/
PR target/58901
* gcc.c-torture/compile/pr58901-0.c: New test.
* gcc.c-torture/compile/pr58901-1.c: New test.

modulo-sched: Carefully process loop counter initialization [PR97421]

Do not allow direct adjustment of pre-header initialization instruction for
count register if is read in some instruction below in that basic block.

gcc/ChangeLog:

PR rtl-optimization/97421
* modulo-sched.c (generate_prolog_epilog): Remove forward
declaration, adjust last argument name and type.
(const_iteration_count): Add bool pointer parameter to return
whether count register is read in pre-header after its
initialization.
(sms_schedule): Fix count register initialization adjustment
procedure according to what const_iteration_count said.

gcc/testsuite/ChangeLog:

PR rtl-optimization/97421
* gcc.c-torture/execute/pr97421-1.c: New test.
* gcc.c-torture/execute/pr97421-2.c: New test.
* gcc.c-torture/execute/pr97421-3.c: New test.

Fortran: flag formal argument before resolving an array spec [PR98016].

2020-12-05 Paul Thomas <pault@gcc.gnu.org>

gcc/fortran
PR fortran/98016
* resolve.c (resolve_symbol): Set formal_arg_flag before
resolving an array spec and restore value afterwards.

gcc/testsuite/
PR fortran/98016
* gfortran.dg/pr98016.f90: New test.

Darwin : Update libtool and dependencies for Darwin20 [PR97865]

The change in major version (and the increment from Darwin19 to 20)
caused libtool tests to fail which resulted in incorrect build settings
for shared libraries.

We take this opportunity to sort out the shared undefined symbols state
rather than propagating the current unsound behaviour into a new rev.

This change means that we default to the case that missing symbols are
considered an error, and if one wants to allow this intentionally, the
confiuration for that case should be set appropriately.

Three existing cases need undefined dynamic lookup:
libitm, where there is already a configuration mechanism to add the
flags.
libcc1, where we add simple configuration to add the flags for Darwin.
libsanitizer, where we can add to the existing extra flags.

libcc1/ChangeLog:

PR target/97865
* Makefile.am: Add dynamic_lookup to LD flags for Darwin.
* configure.ac: Test for Darwin host and set a flag.
* Makefile.in: Regenerate.
* configure: Regenerate.

libitm/ChangeLog:

PR target/97865
* configure.tgt: Add dynamic_lookup to XLDFLAGS for Darwin.
* configure: Regenerate.

libsanitizer/ChangeLog:

PR target/97865
* configure.tgt: Add dynamic_lookup to EXTRA_CXXFLAGS for
Darwin.
* configure: Regenerate.

ChangeLog:

PR target/97865
* libtool.m4: Update handling of Darwin platform link flags
for Darwin20.

gcc/ChangeLog:

PR target/97865
* configure: Regenerate.

libatomic/ChangeLog:

PR target/97865
* configure: Regenerate.

libbacktrace/ChangeLog:

PR target/97865
* configure: Regenerate.

libffi/ChangeLog:

PR target/97865
* configure: Regenerate.

libgfortran/ChangeLog:

PR target/97865
* configure: Regenerate.

libgomp/ChangeLog:

PR target/97865
* configure: Regenerate.

libhsail-rt/ChangeLog:

PR target/97865
* configure: Regenerate.

libobjc/ChangeLog:

PR target/97865
* configure: Regenerate.

libphobos/ChangeLog:

PR target/97865
* configure: Regenerate.

libquadmath/ChangeLog:

PR target/97865
* configure: Regenerate.

libssp/ChangeLog:

PR target/97865
* configure: Regenerate.

libstdc++-v3/ChangeLog:

PR target/97865
* configure: Regenerate.

libvtv/ChangeLog:

PR target/97865
* configure: Regenerate.

zlib/ChangeLog:

PR target/97865
* configure: Regenerate.

X86_64: Enable support for next generation AMD Zen3 CPU.

2020-12-03 Venkataramanan Kumar <Venkataramanan.Kumar@amd.com>
Sharavan Kumar <Shravan.Kumar@amd.com>

gcc/ChangeLog:

* common/config/i386/cpuinfo.h (get_amd_cpu) recognize znver3.
* common/config/i386/i386-common.c (processor_names): Add
znver3.
(processor_alias_table): Add znver3 and AMDFAM19H entry.
* common/config/i386/i386-cpuinfo.h (processor_types): Add
AMDFAM19H.
(processor_subtypes): AMDFAM19H_ZNVER3.
* config.gcc (i[34567]86-*-linux* | ...): Likewise.
* config/i386/driver-i386.c: (host_detect_local_cpu): Let
-march=native recognize znver3 processors.
* config/i386/i386-c.c (ix86_target_macros_internal): Add
znver3.
* config/i386/i386-options.c (m_znver3): New definition.
(m_ZNVER): Include m_znver3.
(processor_cost_table): Add znver3.
* config/i386/i386.c (ix86_reassociation_width): Likewise.
* config/i386/i386.h (TARGET_znver3): New definition.
(enum processor_type): Add PROCESSOR_ZNVER3.
* config/i386/i386.md (define_attr "cpu"): Add znver3.
* config/i386/x86-tune-sched.c: (ix86_issue_rate): Likewise.
(ix86_adjust_cost): Likewise.
* config/i386/x86-tune.def (X86_TUNE_AVOID_256FMA_CHAINS:
Likewise.
* config/i386/znver1.md: Add new reservations for znver3.
* doc/extend.texi: Add details about znver3.
* doc/invoke.texi: Likewise.

gcc/testsuite/ChangeLog:

* gcc.target/i386/funcspec-56.inc: Handle new march.
* g++.target/i386/mv29.C: New file.

i386: Combine splitters followup [PR96226]

Here is the patch to simplify the newly added combine splitters,
when we split into 2 insns anyway, no reason to split into the masking
define_insn_and_split we'd be splitting shortly after.

2020-12-05 Jakub Jelinek <jakub@redhat.com>

PR target/96226
* config/i386/i386.md (splitter after *<rotate_insn><mode>3_mask,
splitter after *<rotate_insn><mode>3_mask_1): Drop the masking from
the patterns to split into.

c++: Fix constexpr access to union member through pointer-to-member [PR98122]

We currently incorrectly reject the first testcase, because
cxx_fold_indirect_ref_1 doesn't attempt to handle UNION_TYPEs.
As the second testcase shows, it isn't that easy, because I believe we need
to take into account the active member and prefer that active member over
other members, because if we pick a non-active one, we might reject valid
programs.

2020-12-05 Jakub Jelinek <jakub@redhat.com>

PR c++/98122
* constexpr.c (cxx_union_active_member): New function.
(cxx_fold_indirect_ref_1): Add ctx argument, pass it through to
recursive call. Handle UNION_TYPE.
(cxx_fold_indirect_ref): Add ctx argument, pass it to recursive calls
and cxx_fold_indirect_ref_1.
(cxx_eval_indirect_ref): Adjust cxx_fold_indirect_ref calls.

* g++.dg/cpp1y/constexpr-98122.C: New test.
* g++.dg/cpp2a/constexpr-98122.C: New test.

Daily bump.

runtime: update type descriptor name in fieldtrack C support code

We were using the old name, but nothing noticed because it is a weak
reference that is permitted to be nil, so that it works with code that
does not use the field tracking library.

Reviewed-on: https://go-review.googlesource.com/c/gofrontend/+/275449

c++: Fix deduction from auto template parameter [PR93083]

The check in do_class_deduction to handle passing one class placeholder
template parm as an argument for itself needed to be extended to also handle
equivalent parms from other templates.

gcc/cp/ChangeLog:

PR c++/93083
* pt.c (convert_template_argument): Handle equivalent placeholders.
(do_class_deduction): Look through EXPR_PACK_EXPANSION, too.

gcc/testsuite/ChangeLog:

PR c++/93083
* g++.dg/cpp2a/nontype-class40.C: New test.

vec: Simplify use with C++11 range-based 'for'.

It looks cleaner if we can use a vec* directly as a range for the C++11
range-based 'for' loop, without needing to indirect from it, and also works
with null pointers.

The change in cp_parser_late_parsing_default_args is an example of how this
can be used to simplify a simple loop over a vector. Reverse or subset
iteration will require adding range adaptors.

I deliberately didn't format the new overloads for etags since they are
trivial.

gcc/ChangeLog:

* vec.h (begin, end): Add overloads for vec*.
* tree.c (build_constructor_from_vec): Remove *.

gcc/cp/ChangeLog:

* decl2.c (clear_consteval_vfns): Remove *.
* pt.c (do_auto_deduction): Remove *.
* parser.c (cp_parser_late_parsing_default_args): Change loop
to use range 'for'.

rs6000: fix PTR_SIZE in rs6000.c

The recent change to rs6000.c for DWARF in AIX references the macro
PTR_SIZE that only is defined in dwarf2out.c. This patch changes the
reference to the equivalent POINTER_SIZE_UNITS defined in defaults.h.

gcc/ChangeLog:

* config/rs6000/rs6000.c (rs6000_option_override_internal):
Change PTR_SIZE to POINTER_SIZE_UNITS.

doc/implement-c.texi: About same-as-scalar-type volatile aggregate accesses, PR94600

We say very little about reads and writes to aggregate /
compound objects, just scalar objects (i.e. assignments don't
cause reads).  Let's lets say something safe about aggregate
objects, but only for those that are the same size as a scalar
type.

There's an equal-sounding section (Volatiles) in extend.texi,
but this seems a more appropriate place, as specifying the
behavior of a standard qualifier.

gcc:

2020-12-04  Hans-Peter Nilsson  <hp@axis.com>
    Martin Sebor  <msebor@redhat.com>

PR middle-end/94600
* doc/implement-c.texi (Qualifiers implementation): Add blurb
about access to the whole of a volatile aggregate object, only for
same-size as a scalar object.

gimple: Return fnspec only for replaceable new/delete operators called from new/delete [PR98130]

As mentioned in the PR, we shouldn't treat non-replaceable operator
new/delete (e.g. with the placement new) as replaceable ones.

There is some pending discussion that perhaps operator delete called from
delete if not replaceable should return some other fnspec, but can we handle
that incrementally, fix this wrong-code and then deal with a missed
optimization? I really don't know what exactly should be returned.

2020-12-04 Jakub Jelinek <jakub@redhat.com>

PR c++/98130
* gimple.c (gimple_call_fnspec): Only return ".co " for replaceable
operator delete or ".mC" for replaceable operator new called from
new/delete.

* g++.dg/opt/pr98130.C: New test.

i386: Add combine splitters to allow combining multiple insns into reg1 = const; reg2 = rotate (reg1, reg3 & cst) [PR96226]

As mentioned in the PR, we can combine ~(1 << x) into -2 r<< x, but we give
up in the ~(1 << (x & 31)) cases, as *<rotate_insn><mode>3_mask* don't allow
immediate operand 1 and find_split_point prefers to split (x & 31) instead
of the constant.

With these combine splitters we help combine decide how to split those
insns.

2020-12-04 Jakub Jelinek <jakub@redhat.com>

PR target/96226
* config/i386/i386.md (splitter after *<rotate_insn><mode>3_mask,
splitter after *<rotate_insn><mode>3_mask_1): New combine splitters.

* gcc.target/i386/pr96226.c: New test.

fold-const: Don't use build_constructor for non-aggregate types in native_encode_initializer [PR93121]

The following testcase is rejected, because when trying to encode a zeroing
CONSTRUCTOR, the code was using build_constructor to build initializers for
the elements but when recursing the function handles CONSTRUCTOR only for
aggregate types.

The following patch fixes that by using build_zero_cst instead for
non-aggregates.  Another option would be add handling CONSTRUCTOR for
non-aggregates in native_encode_initializer.  Or we can do both, I guess
the middle-end generally doesn't like CONSTRUCTORs for scalar variables, but
am not 100% sure if the FE doesn't produce those sometimes.

2020-12-04  Jakub Jelinek  <jakub@redhat.com>

PR libstdc++/93121
* fold-const.c (native_encode_initializer): Use build_zero_cst
instead of build_constructor.

* g++.dg/cpp2a/bit-cast6.C: New test.

c++: Revert dependent-array changes [PR 98116]

The changes reverted here are exposing an existing problem with alias
template comparisons. The typename_type changes are also incomplete,
possibly for similar reasons. It seems safer to revert them, fix the
underlying issue and then move forwards.

The testcases is adjusted to more robustly check the specialization
table, and ICEs with and without the c++ changes.

Revert:
62fb1b9e0da c++: Fix array type dependency [PR 98107]
07589ca2b2c c++: typename_type structural comparison
29ae1d7751 c++: Extend build_array_type API

PR c++/98116
gcc/cp/
* cp-tree.h (comparing_typenames): Delete.
(cplus_build_array_type): Remove default parm.
* pt.c (comparing_typenames): Delete.
(spec_hasher::equal): Don't increment it.
* tree.c (set_array_type_canon): Remove dep parm.
(build_cplus_array_type): Remove dep parm changes.
(cp_build_qualified_type_real): Remove dependent array type
changes.
(strip_typedefs): Likewise.
* typeck.c (structural_comptypes): Revert comparing_typename
changes.
gcc/testsuite/
* g++.dg/template/pr98116.C: Enable robust checking.

c++: Module API declarations

This provides the inline predicates about module state, and declares
the functions to be provided.

gcc/cp/
* cp-tree.h: Add various inline module state predicates, and
declare the API that will be provided by modules.cc

debug: Fix another vector DECL_MODE ICE [PR98100]

The PR88587 fix changes DECL_MODE of vars with vector type during inlining/cloning
when the vars are copied, so that their DECL_MODE matches their TYPE_MODE in
the new function.  Unfortunately, the following testcase still ICEs, the var
isn't really used in the new function and so it isn't copied, but becomes
just a nonlocalized var.  So we can't adjust its DECL_MODE because it
appears in multiple functions and needs different modes in between them.
The following patch changes the DEBUG_INSN creation to use TYPE_MODE instead
of DECL_MODE for vars with vector types.

2020-12-04  Jakub Jelinek  <jakub@redhat.com>

PR target/98100
* cfgexpand.c (expand_gimple_basic_block): For vars with
vector type, use TYPE_MODE rather than DECL_MODE.

* gcc.target/i386/pr98100.c: New test.

dwarf: Add -gdwarf{32,64} options

The following patch makes the choice between 32-bit and 64-bit DWARF formats
selectable by command line switch, rather than being hardcoded through
DWARF_OFFSET_SIZE macro.

The options themselves don't turn on debug info themselves, so one needs
to use -g -gdwarf64 or similar.

2020-12-04 Jakub Jelinek <jakub@redhat.com>

* common.opt (-gdwarf32, -gdwarf64): New options.
* config/rs6000/rs6000.c (rs6000_option_override_internal): Default
dwarf_offset_size to 8 if not overridden from the command line.
* dwarf2out.c: Change all occurrences of DWARF_OFFSET_SIZE to
dwarf_offset_size.
* doc/invoke.texi (-gdwarf32, -gdwarf64): Document.

testsuite: use param for if-to-switch tests

gcc/testsuite/ChangeLog:

PR testsuite/98123
* gcc.dg/tree-ssa/if-to-switch-4.c: Add param to make the test
stable on all architectures.
* gcc.dg/tree-ssa/if-to-switch-6.c: Likewise.
* gcc.dg/tree-ssa/if-to-switch-8.c: Likewise.

Add target selector to gcc.dg/pr98099.c

gcc/testsuite/ChangeLog:
* gcc.dg/pr98099.c: Compile only for dfp targets.

Refactor -frecord-gcc-switches.

gcc/ChangeLog:

* doc/tm.texi: Change argument of the record_gcc_switches
hook and remove SWITCH_TYPE_* enum values.
* dwarf2out.c (gen_producer_string): Move to opts.c and remove
handling of the dwarf_record_gcc_switches option.
(dwarf2out_early_finish): Use moved gen_producer_string
function.
* opts.c (gen_producer_string): New.
* opts.h (gen_producer_string): New.
* target.def: Change type of record_gcc_switches.
* target.h (enum print_switch_type): Remove.
(elf_record_gcc_switches): Change first argument.
* toplev.c (MAX_LINE): Remove.
(print_to_asm_out_file): Likewise.
(print_to_stderr): Likewise.
(print_single_switch): Likewise.
(print_switch_values): Likewise.
(init_asm_output): Use new gen_producer_string function.
(process_options): Likewise.
* varasm.c (elf_record_gcc_switches): Just save the string argument
to the ELF container.

Fix checking failure in IPA-SRA

This is a regression present on the mainline and 10 branch: on the one
hand, IPA-SRA does *not* disqualify accesses with zero size but, on the
other hand, it checks that accesses present in the tree have a (strictly)
positive size, thus trivially yielding an ICE in some cases.

gcc/ChangeLog:
* ipa-sra.c (verify_access_tree_1): Relax assertion on the size.

gcc/testsuite/ChangeLog:
* gnat.dg/opt91.ads, gnat.dg/opt91.adb: New test.
* gnat.dg/opt91_pkg.ads, gnat.dg/opt91_pkg.adb: New helper.

Document missing params.

contrib/ChangeLog:

* check-params-in-docs.py: use flake8 and add some
tweaks to ignore aarch64 params.

gcc/ChangeLog:

* doc/invoke.texi: Add missing params.

c++: Change __builtin_source_location to use __PRETTY_FUNCTION__ instead of __FUNCTION__ [PR80780]

On Tue, Dec 01, 2020 at 01:03:52PM +0000, Jonathan Wakely via Gcc-patches wrote:
> I mentioned in PR 80780 that a __builtin__PRETTY_FUNCTION would have
> been nice, because __FUNCTION__ isn't very useful for C++, because of
> overloading and namespace/class scopes. There are an unlimited number
> of functions that have __FUNCTION__ == "s", e.g. "ns::s(int)" and
> "ns::s()" and "another_scope::s::s<T...>(T...)" etc.
>
> Since __builtin_source_location() can do whatever it wants (without
> needing to add __builtin__PRETTY_FUNCTION) it might be nice to use the
> __PRETTY_FUNCTION__ string. JeanHeyd's tests would still need changes,
> because the name would be "s::s(void*)" not "s::s" but that still
> seems better for users.

When I've added template tests for the previous patch, I have noticed that
the current __builtin_source_location behavior is not really __FUNCTION__,
just close, because e.g. in function template __FUNCTION__ is still
"bar" but __builtin_source_location gave "bar<0>".

Anyway, this patch implements above request to follow __PRETTY_FUNCTION__
(on top of the earlier posted patch).

2020-12-04  Jakub Jelinek  <jakub@redhat.com>

PR c++/80780
* cp-gimplify.c (fold_builtin_source_location): Use 2 instead of 0
as last argument to cxx_printable_name.

* g++.dg/cpp2a/srcloc1.C (quux): Use __PRETTY_FUNCTION__ instead of
function.
* g++.dg/cpp2a/srcloc2.C (quux): Likewise.
* g++.dg/cpp2a/srcloc15.C (S::S): Likewise.
(bar): Likewise.  Adjust expected column.
* g++.dg/cpp2a/srcloc17.C (S::S): Likewise.
(bar): Likewise.  Adjust expected column.

* testsuite/18_support/source_location/1.cc (main): Adjust for
__builtin_source_location using __PRETTY_FUNCTION__-like names instead
__FUNCTION__-like.
* testsuite/18_support/source_location/consteval.cc (main): Likewise.

Daily bump.

c++: XFAIL testcase for PR98019

Apparently it isn't actually fixed on trunk yet, was just passing because of
some WIP in my tree. So XFAIL for now.

gcc/testsuite/ChangeLog:

* g++.dg/cpp2a/concepts-nodiscard1.C: XFAIL.

c++: Fix bootstrap on 32-bit hosts [PR91828]

Using the releasing_vec op[] with an int index was breaking on 32-bit hosts
because of ambiguity with the built-in operator and the conversion
function. Since the built-in operator has a ptrdiff_t, this was fine on
64-bit targets where ptrdiff_t is larger than int, but broke on 32-bit
targets where it's the same as int, making the conversion for that argument
better than the member function. Fixed by changing the member function to
also use ptrdiff_t for the index.

gcc/cp/ChangeLog:

* cp-tree.h (releasing_vec::operator[]): Change parameter type to
ptrdiff_t.

Add support for detecting mismatched allocation/deallocation calls.

PR c++/90629 - Support for -Wmismatched-new-delete
PR middle-end/94527 - Add an __attribute__ that marks a function as freeing an object

gcc/ChangeLog:

PR c++/90629
PR middle-end/94527
* builtins.c (access_ref::access_ref): Initialize new member.
(compute_objsize): Use access_ref::deref. Handle simple pointer
assignment.
(expand_builtin): Remove handling of the free built-in.
(call_dealloc_argno): Same.
(find_assignment_location): New function.
(fndecl_alloc_p): Same.
(gimple_call_alloc_p): Same.
(call_dealloc_p): Same.
(matching_alloc_calls_p): Same.
(warn_dealloc_offset): Same.
(maybe_emit_free_warning): Same.
* builtins.h (struct access_ref): Declare new member.
(maybe_emit_free_warning): Make extern. Make use of access_ref.
Handle -Wmismatched-new-delete.
* calls.c (initialize_argument_information): Call
maybe_emit_free_warning.
* doc/extend.texi (attribute malloc): Update.
* doc/invoke.texi (-Wfree-nonheap-object): Expand documentation.
(-Wmismatched-new-delete): Document new option.
(-Wmismatched-dealloc): Document new option.

gcc/c-family/ChangeLog:

PR c++/90629
PR middle-end/94527
* c-attribs.c (handle_dealloc_attribute): New function.
(handle_malloc_attribute): Handle argument forms of attribute.
* c.opt (-Wmismatched-dealloc): New option.
(-Wmismatched-new-delete): New option.

gcc/testsuite/ChangeLog:

PR c++/90629
PR middle-end/94527
* g++.dg/asan/asan_test.cc: Fix a bug.
* g++.dg/warn/delete-array-1.C: Add expected warning.
* g++.old-deja/g++.other/delete2.C: Add expected warning.
* g++.dg/warn/Wfree-nonheap-object-2.C: New test.
* g++.dg/warn/Wfree-nonheap-object.C: New test.
* g++.dg/warn/Wmismatched-new-delete.C: New test.
* g++.dg/warn/Wmismatched-dealloc-2.C: New test.
* g++.dg/warn/Wmismatched-dealloc.C: New test.
* gcc.dg/Wmismatched-dealloc.c: New test.
* gcc.dg/analyzer/malloc-1.c: Prune out expected warning.
* gcc.dg/attr-malloc.c: New test.
* gcc.dg/free-1.c: Adjust text of expected warning.
* gcc.dg/free-2.c: Same.
* gcc.dg/torture/pr71816.c: Prune out expected warning.
* gcc.dg/tree-ssa/pr19831-2.c: Add an expected warning.
* gcc.dg/Wfree-nonheap-object-2.c: New test.
* gcc.dg/Wfree-nonheap-object-3.c: New test.
* gcc.dg/Wfree-nonheap-object.c: New test.

libstdc++-v3/ChangeLog:

* testsuite/ext/vstring/modifiers/clear/56166.cc: Suppress a false
positive warning.

c++: Exported using decls

With modules we need to record whethe a (namespace-scope) using decl
is exporting the named entities. Record this on the OVERLOAD marking
the used decl.

gcc/cp/
* cp-tree.h (OVL_EXPORT): New.
(class ovl_iterator): Add get_using, exporting_p.
* tree.c (ovl_insert): Extend using_or_hidden meaning to include
an exported using.

c++: uninstantiated template friends

template friends need to be recognized by module streaming and
associated with the befriending class. but their context is that of
the friend (a namespace or other class). This adds a flag to mark
such templates, and uses their DECL_CHAIN to point at the befriender.

gcc/cp
* cp-tree.h (DECL_UNINSTANTIATED_TEMPLATE_FRIEND): New.
* pt.c (push_template_decl): Set it.
(tsubst_friend_function): Clear it.

Go testsuite: update new tests to version in source repo

PowerPC: PR libgcc/97543 and libgcc/97643, fix long double issues

If you use a compiler with long double defaulting to 64-bit instead of 128-bit
with IBM extended double, you get linker warnings about mis-matches in the gnu
attributes for long double (PR libgcc/97543).  Even if the compiler is
configured to have long double be 64 bit as the default with the configuration
option '--without-long-double-128' you get the warnings.

You also get the same issues if you use a compiler with long double defaulting
to IEEE 128-bit instead of IBM extended double (PR libgcc/97643).

The issue is the way libgcc.a/libgcc.so is built.  Right now when building
libgcc under Linux, the long double size is set to 128-bits when building
libgcc.  However, the gnu attributes are set, leading to the warnings.

One feature of the current GNU attribute implementation is if you have a shared
library (such as libgcc_s.so), the GNU attributes for the shared library is an
inclusive OR of all of the objects within the library.  This means if any
object file that uses the -mlong-double-128 option and uses long double, the GNU
attributes for the library will indicate that it uses 128-bit IBM long
doubles.  If you have a static library, you will get the warning only if you
actually reference an object file  with the attribute set.

This patch does two things:

    1) All of the object files that support IBM 128-bit long doubles
explicitly set the ABI to IBM extended double.

    2) I turned off GNU attributes for building the shared library or for
        building the IBM 128-bit long double support.

libgcc/
2020-12-03  Michael Meissner  <meissner@linux.ibm.com>

PR libgcc/97543
PR libgcc/97643
* config/rs6000/t-linux (IBM128_STATIC_OBJS): New make variable.
(IBM128_SHARED_OBJS): New make variable.
(IBM128_OBJS): New make variable.  Set all objects to use the
explicit IBM format, and disable gnu attributes.
(IBM128_CFLAGS): New make variable.
(gcc_s_compile): Add -mno-gnu-attribute to all shared library
modules.

PR fortran/95342 - ICE in gfc_match_subroutine, at fortran/decl.c:7913

Add checks for NULL pointers before dereferencing them.

gcc/fortran/ChangeLog:

PR fortran/95342
* decl.c (gfc_match_function_decl): Avoid NULL pointer dereference.
(gfc_match_subroutine): Likewise.

gcc/testsuite/ChangeLog:

PR fortran/95342
* gfortran.dg/pr95342.f90: New test.

libstdc++: Fix typos in #error strings

libstdc++-v3/ChangeLog:

* testsuite/26_numerics/bit/bit.cast/bit_cast.cc: Remove stray
word from copy&paste.
* testsuite/26_numerics/bit/bit.cast/version.cc: Likewise.

fix __builtin___clear_cache overrider fallout

Machines that had CLEAR_CACHE_INSN and that would thus issue calls to
__clear_cache with the default call expander, would fail on languages
that did not set up the __clear_cache builtin.  This patch arranges
for all languages to set up this builtin.

Machines or multilibs that had ptr_mode != Pmode, such as aarch64 with
-mabi=ilp32, would fail the RTL mode test of the arguments passed to
__clear_cache, because we'd insist on ptr_mode.  This patch arranges
for Pmode to be accepted as well.

for  gcc/ChangeLog

* tree.c (build_common_builtin_nodes): Declare
__builtin___clear_cache for all languages.
* builtins.c (maybe_emit_call_builtin___clear_cache): Accept
Pmode arguments.

libstdc++: Update C++20 library implementation status

libstdc++-v3/ChangeLog:

* doc/xml/manual/status_cxx2020.xml: Update C++20 status.
* doc/html/*: Regenerate.

libtdc++: Define std::source_location for C++20

This doesn't define a new _GLIBCXX_HAVE_BUILTIN_SOURCE_LOCATION macro.
because using __has_builtin(__builtin_source_location) is sufficient.
Currently only GCC supports it, but if/when Clang and Intel add it the
__has_builtin check should for them too.

Co-authored-by: Jonathan Wakely <jwakely@redhat.com>
libstdc++-v3/ChangeLog:

* doc/doxygen/user.cfg.in (INPUT): Add <source_location>.
* include/Makefile.am: Add <source_location>.
* include/Makefile.in: Regenerate.
* include/std/version (__cpp_lib_source_location): Define.
* include/std/source_location: New file.
* testsuite/18_support/source_location/1.cc: New test.
* testsuite/18_support/source_location/consteval.cc: New test.
* testsuite/18_support/source_location/srcloc.h: New test.
* testsuite/18_support/source_location/version.cc: New test.

libstdc++: Add std::bit_cast for C++20 [PR 93121]

Thanks to Jakub's addition of the built-in, we can add this to the
library now. The compiler tests for the built-in are quite extensive,
including verifying the constraints, so this only adds minimal tests to
the library testsuite.

This doesn't add a new _GLIBCXX_HAVE_BUILTIN_BIT_CAST because using
__has_builtin(__builtin_bit_cast) works for GCC and versions of Clang
that provide the built-in.

libstdc++-v3/ChangeLog:

PR libstdc++/93121
* include/std/bit (__cpp_lib_bit_cast, bit_cast): Define.
* include/std/version (__cpp_lib_bit_cast): Define.
* testsuite/26_numerics/bit/bit.cast/bit_cast.cc: New test.
* testsuite/26_numerics/bit/bit.cast/version.cc: New test.

Go testsuite: add a bunch of new tests from source repo

go-test.exp: add -I. when compiling in directory

* go.test/go-test.exp (go-gc-tests): Add -I. when building all
sources in a directory (errorcheckdir, compiledir, rundir,
rundircmpout).

c++: Add testcase for PR98019

This has already been fixed on trunk, but I don't see a testcase for it.

gcc/testsuite/ChangeLog:

PR c++/98019
* g++.dg/cpp2a/concepts-nodiscard1.C: New test.

testsuite: update existing Go tests to source repo

This updates a bunch of existing Go tests to the contents of the
source repo. This does not add any of the newer tests.

RTEMS: Add Cortex-R52 multilib

gcc/
* config/arm/t-rtems: Add "-mthumb -mcpu=cortex-r52
-mfloat-abi=hard" multilib.

libstdc++: Update powerpc-linux baselines for GCC 10.1

This should have been done before the GCC 10.1 release.

libstdc++-v3/ChangeLog:

* config/abi/post/powerpc-linux-gnu/baseline_symbols.txt:
Update.
* config/abi/post/powerpc64-linux-gnu/32/baseline_symbols.txt:
Update.

libstdc++: Disable std::array assertions for C++11 constexpr

The recent changes to add assertions to std::array broke the functions
that need to be constexpr in C++11, because of the restrictive rules for
constexpr functions in C++11.

This simply disables the assertions for C++11 mode, so the functions can
be constexpr again.

libstdc++-v3/ChangeLog:

* include/std/array (array::operator[](size_t) const, array::front() const)
(array::back() const) [__cplusplus == 201103]: Disable
assertions.
* testsuite/23_containers/array/element_access/constexpr_element_access.cc:
Check for correct values.
* testsuite/23_containers/array/tuple_interface/get_neg.cc:
Adjust dg-error line numbers.
* testsuite/23_containers/array/debug/constexpr_c++11.cc: New test.

c++:  templatey type creation

This patch makes a couple of type-creation routines available to
modules.  That needs to create unbound template parms, and canonical
template parms.

gcc/cp/
* cp-tree.h (make_unbound_class_template_raw): Declare.
(canonical_type_parameter): Declare.
* decl.c (make_unbound_class_template_raw): Break out of ...
(make_unboud_class_template): ... here.  Call it.
* pt.c (canonical_type_parameter): Externalize.  Refactor & set
structural_equality for type parms.

i386: Fix up ix86_md_asm_adjust for TImode [PR98086]

ix86_md_asm_adjust assumes that dest_mode can be only [QHSD]Imode
and nothing else.  The patch rewrites zero-extension part to use
convert_to_mode to handle TImode and hypothetically even wider modes.

2020-12-03  Uroš Bizjak  <ubizjak@gmail.com>
    Jakub Jelinek  <jakub@redhat.com>

gcc/
PR target/98086
* config/i386/i386.c (ix86_md_asm_adjustmd): Rewrite
zero-extension part to use convert_to_mode.

gcc/testsuite/
PR target/98086
* gcc.target/i386/pr98086.c: New test.

c++: Testcases [PR 98115]

These two testcases provide coverage for 98115, which doesn't trigger on all hosts.

PR c++/98115
PR c++/98116
gcc/testsuite/
* g++.dg/template/pr98115.C: New.
* g++.dg/template/pr98116.C: New.

compiler: cast comparison function result to expected bool type

Otherwise cases like
type mybool bool
var b mybool = [10]string{} == [10]string{}
get an incorrect type checking error.

Reviewed-on: https://go-review.googlesource.com/c/gofrontend/+/274446

compiler: defer to middle-end for complex division

Go used to use slightly different semantics than C99 for complex division,
so we used runtime routines to handle the different. The gc compiler
has changes its behavior to match C99, so changes ours as well.

For golang/go#14644

Reviewed-on: https://go-review.googlesource.com/c/gofrontend/+/274213

IBM Z: Fix mode in probe_stack pattern

The probe pattern uses Pmode but the middle-end wants to emit a
word_mode probe check. This - as usual - breaks on Z with -m31
-mzarch were word_mode doesn't match Pmode.

gcc/ChangeLog:

* config/s390/s390.md ("@probe_stack2<mode>"): Change mode
iterator to W.

gcc/testsuite/ChangeLog:

* gcc.target/s390/stack-clash-4.c: New test.

c++: Fix array type dependency [PR 98107]

I'd missed some paths through build_cplus_array_type, plus, some
arrays come via the C-type builder. This propagates dependency in
more places and asserts that in the cases where TYPE_DEPENDENT_P_VALID
is unset, the type is non-dependent.

PR c++/98107
gcc/cp/
* tree.c (build_cplus_array_type): Mark dependency of new variant.
(cp_build_qualified_type_real, strip_typedefs): Assert
TYPE_DEPENDENT_P_VALID, or not a dependent type.

aarch64: Don't fold svundef* at the gimple level

As the testcase shows, folding svundef*() at the gimple level
has the unfortunate side-effect of introducing -Wuninitialized
or -Wmaybe-uninitialized warnings. We don't have a testcase
that relies on the fold, so the easiest fix seems to be to
remove it.

gcc/
* config/aarch64/aarch64-sve-builtins-base.cc (svundef_impl::fold):
Delete.

gcc/testsuite/
* gcc.target/aarch64/sve/acle/general/undef_1.c: New test.

Fix PR middle-end/98099

this replaces the ICE by a sorry message for the use of reverse scalar
storage order with 128-bit decimal floating-point type on 32-bit targets.

gcc/ChangeLog:
PR middle-end/98099
* expmed.c (flip_storage_order): In the case of a non-integer mode,
sorry out if the integer mode to be used instead is not supported.

gcc/testsuite/ChangeLog:
* gcc.dg/pr98099.c: New test.

Fix PR middle-end/98082

this fixes an ICE introduced by the fix for PR middle-end/97078 where
use_register_for_decl was changed to return true at -O0 for a parameter
of a thunk. It turns out that we need to do the same for a result in
this case.

gcc/ChangeLog:
PR middle-end/98082
* function.c (use_register_for_decl): Also return true for a result
if cfun->tail_call_marked is true.

gcc/testsuite/ChangeLog:
* g++.dg/cpp2a/pr98082.C: New test.

c++: Add __builtin_bit_cast to implement std::bit_cast [PR93121]

The following patch adds __builtin_bit_cast builtin, similarly to
clang or MSVC which implement std::bit_cast using such an builtin too.
It checks the various std::bit_cast requirements, when not constexpr
evaluated acts pretty much like VIEW_CONVERT_EXPR of the source argument
to the destination type and the hardest part is obviously the constexpr
evaluation.
I've left out PDP11 handling of those, couldn't figure out how exactly are
bitfields laid out there

2020-12-03  Jakub Jelinek  <jakub@redhat.com>

PR libstdc++/93121
* fold-const.h (native_encode_initializer): Add mask argument
defaulted to nullptr.
(find_bitfield_repr_type): Declare.
(native_interpret_aggregate): Declare.
* fold-const.c (find_bitfield_repr_type): New function.
(native_encode_initializer): Add mask argument and support for
filling it.  Handle also some bitfields without integral
DECL_BIT_FIELD_REPRESENTATIVE.
(native_interpret_aggregate): New function.
* gimple-fold.h (clear_type_padding_in_mask): Declare.
* gimple-fold.c (struct clear_padding_struct): Add clear_in_mask
member.
(clear_padding_flush): Handle buf->clear_in_mask.
(clear_padding_union): Copy clear_in_mask.  Don't error if
buf->clear_in_mask is set.
(clear_padding_type): Don't error if buf->clear_in_mask is set.
(clear_type_padding_in_mask): New function.
(gimple_fold_builtin_clear_padding): Set buf.clear_in_mask to false.
* doc/extend.texi (__builtin_bit_cast): Document.

* c-common.h (enum rid): Add RID_BUILTIN_BIT_CAST.
* c-common.c (c_common_reswords): Add __builtin_bit_cast.

* cp-tree.h (cp_build_bit_cast): Declare.
* cp-tree.def (BIT_CAST_EXPR): New tree code.
* cp-objcp-common.c (names_builtin_p): Handle RID_BUILTIN_BIT_CAST.
(cp_common_init_ts): Handle BIT_CAST_EXPR.
* cxx-pretty-print.c (cxx_pretty_printer::postfix_expression):
Likewise.
* parser.c (cp_parser_postfix_expression): Handle
RID_BUILTIN_BIT_CAST.
* semantics.c (cp_build_bit_cast): New function.
* tree.c (cp_tree_equal): Handle BIT_CAST_EXPR.
(cp_walk_subtrees): Likewise.
* pt.c (tsubst_copy): Likewise.
* constexpr.c (check_bit_cast_type, cxx_eval_bit_cast): New functions.
(cxx_eval_constant_expression): Handle BIT_CAST_EXPR.
(potential_constant_expression_1): Likewise.
* cp-gimplify.c (cp_genericize_r): Likewise.

* g++.dg/cpp2a/bit-cast1.C: New test.
* g++.dg/cpp2a/bit-cast2.C: New test.
* g++.dg/cpp2a/bit-cast3.C: New test.
* g++.dg/cpp2a/bit-cast4.C: New test.
* g++.dg/cpp2a/bit-cast5.C: New test.

c++: consteval-defarg1.C test variant for templates

We weren't recognizing a default argument for a consteval member function as
being in immediate function context because there was no function parameter
scope to look at.

The following testcase is an attempt to test it with templates, both
non-dependent and dependent consteval calls in both function and class
templates, and with r11-5694 it now passes.

2020-12-03 Jakub Jelinek <jakub@redhat.com>

* g++.dg/cpp2a/consteval-defarg2.C: New test.

tree-ssa-threadedge.c (record_temporary_equivalences_from_stmts_at_dest): Do not allow __builtin_constant_p.

This is the same as commit 70a62009181f ("tree-ssa-threadbackward.c
(profitable_jump_thread_path): Do not allow __builtin_constant_p."), but
for the old forward threader.

gcc/ChangeLog:

2020-12-03 Ilya Leoshkevich <iii@linux.ibm.com>

* tree-ssa-threadedge.c (record_temporary_equivalences_from_stmts_at_dest):
Do not allow __builtin_constant_p on a threading path.

Fix division by 0 in printf_strlen_execute when dumping

gcc/ChangeLog:

2020-12-03 Ilya Leoshkevich <iii@linux.ibm.com>

* tree-ssa-strlen.c (printf_strlen_execute): Avoid division by
0.

RISC-V: Canonicalize --with-arch

- We would like to canonicalize the arch string for --with-arch for
easier handling multilib, so split canonicalization part to a stand
along script to shared the logic.

gcc/ChangeLog:

* config/riscv/multilib-generator (arch_canonicalize): Move
code to arch-canonicalize, and call that script to canonicalize arch
string.
(canonical_order): Move code to arch-canonicalize.
(LONG_EXT_PREFIXES): Ditto.
(IMPLIED_EXT): Ditto.
* config/riscv/arch-canonicalize: New.
* config.gcc (riscv*-*-*): Canonicalize --with-arch.