VAX: Define LEGITIMATE_PIC_OPERAND_P

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.