i386: Fix up handling of OPTION_MASK_ISA_MMX builtins [PR94461]
In https://gcc.gnu.org/ml/gcc-patches/2017-10/msg00576.html the builtin
handling was changed so that OPTION_MASK_ISA_MMX | OPTION_MASK_ISA_SSE
etc. in i386-builtin.def means we require both mmx and sse, not just one of
those, and later on for other option combinations very similar rule has
been clarified, with a few exceptions that ix86_expand_builtin lists
(SSE | 3DNOW_A, SSE4_2 | CRC32 and FMA | FMA4 are one or the other).
The above mentioned patch also added OPTION_MASK_ISA_MMX to a few insns
that in the ISA documents are documented e.g. only requiring SSE2 or SSSE3
etc. CPUID, but because those builtins take or return V2SI or similar
MMX-ish arguments, we can't really support those builtins in functions that
have MMX disabled.
Now, during the TARGET_MMX_WITH_SSE changes,
https://gcc.gnu.org/ml/gcc-patches/2019-02/msg01479.html
and
https://gcc.gnu.org/ml/gcc-patches/2019-05/msg01084.html
actually changed this; it added | OPTION_MASK_ISA_SSE2 to builtins
that were formerly OPTION_MASK_ISA_MMX only, but didn't touch the builtins
that were already using OPTION_MASK_ISA_SSE2 | OPTION_MASK_ISA_MMX
for something different (both options must be enabled).
This causes e.g. ICE on the following testcase, because the builtins are
now enabled even with just -mmmx -mno-sse2, even when they (those changed in
2017) require SSE2.
The following patch instead reverts the above two 2019-ish changes (except
for header/testsuite changes), and instead treats OPTION_MASK_ISA_MMX
requirement in bdesc/.isa specially, as being satisfied by either
TARGET_MMX (no changes really needed for that), or by TARGET_MMX_WITH_SSE.
This achieves what the two 2019-ish patches want to do, that the
OPTION_MASK_ISA_MMX only builtins are enabled not just with -mmmx, but also
with -m64 -msse2, and for the other builtins that require MMX and something
else will either require -mmmx and that some other ISA, or -m64 -msse2 and
that other ISA, but -mmmx will not enable builtins that need something more
than OPTION_MASK_ISA_MMX only.
The i386-builtins.c changes that aren't reversion of the two patches try to
make sure that in .isa we still record OPTION_MASK_ISA_MMX for builtins that
have that requirement, so that it is in the end only ix86_expand_builtin
that decides if the builtin is ok or not and the rest of code just decides
if it is the right time to declare the builtin already or if it should be
deferred.
2020-04-03 Jakub Jelinek <jakub@redhat.com>
PR target/94461
* config/i386/i386-expand.c (ix86_expand_builtin): If
TARGET_MMX_WITH_SSE without TARGET_MMX and bisa contains
OPTION_MASK_ISA_MMX, clear OPTION_MASK_ISA_MMX and set
OPTION_MASK_ISA_SSE2 in bisa. Revert 2019-05-17 and 2019-05-15
changes.
* config/i386/i386-builtins.c (def_builtin): If mask includes
OPTION_MASK_ISA_MMX and TARGET_MMX_WITH_SSE, consider it satisfied.
(ix86_add_new_builtins): For TARGET_64BIT, consider
OPTION_MASK_ISA_SSE2 enabled in isa as satisfying OPTION_MASK_ISA_MMX
requirement.
(ix86_init_tm_builtins): If TARGET_MMX_WITH_SSE consider
OPTION_MASK_ISA_MMX as satisfied.
(bdesc_tm): Revert 2019-05-15 changes.
(ix86_init_mmx_sse_builtins): Likewise.
* config/i386/i386-builtin.def: Likewise.
* gcc.target/i386/pr94461.c: New test.
projects / gcc.git / commit