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| author | Jakub Jelinek <jakub@redhat.com> | 2023-03-28 10:43:08 +0200 |
|---|---|---|
| committer | Jakub Jelinek <jakub@redhat.com> | 2023-03-28 10:43:08 +0200 |
| commit | 4b5ef857f5faf09f274c0a95c67faaa80d198124 (patch) | |
| tree | 548066d9669ab3225dbbf31fb3536ea825958e70 /gcc | |
| parent | a21bd7faba67997a6da457dbda16f15bca1a9156 (diff) | |
| download | gcc-4b5ef857f5faf09f274c0a95c67faaa80d198124.zip gcc-4b5ef857f5faf09f274c0a95c67faaa80d198124.tar.gz gcc-4b5ef857f5faf09f274c0a95c67faaa80d198124.tar.bz2 | |
i386: Require just 32-bit alignment for SLOT_FLOATxFDI_387 -m32 -mpreferred-stack-boundary=2 DImode temporaries [PR109276]
The following testcase ICEs since r11-2259 because assign_386_stack_local
-> assign_stack_local -> ix86_local_alignment now uses 64-bit alignment
for DImode temporaries rather than 32-bit as before.
Most of the spots in the backend which ask for DImode temporaries are during
expansion and those apparently are handled fine with -m32
-mpreferred-stack-boundary=2, we dynamically realign the stack in that case
(most of the spots actually don't need that alignment but at least one
does), then 2 spots are in STV which I assume also work correctly.
But during splitting we can create a DImode slot which doesn't need to be
64-bit alignment (it is nicer for performance though), when we apparently
aren't able to detect it for dynamic stack realignment purposes.
The following patch just makes the slot 32-bit aligned in that rare case.
2023-03-28 Jakub Jelinek <jakub@redhat.com>
PR target/109276
* config/i386/i386.cc (assign_386_stack_local): For DImode
with SLOT_FLOATxFDI_387 and -m32 -mpreferred-stack-boundary=2 pass
align 32 rather than 0 to assign_stack_local.
* gcc.target/i386/pr109276.c: New test.
Diffstat (limited to 'gcc')
| -rw-r--r-- | gcc/config/i386/i386.cc | 10 | ||||
| -rw-r--r-- | gcc/testsuite/gcc.target/i386/pr109276.c | 13 |
2 files changed, 22 insertions, 1 deletions
diff --git a/gcc/config/i386/i386.cc b/gcc/config/i386/i386.cc index 6a8734c..2cc8e95 100644 --- a/gcc/config/i386/i386.cc +++ b/gcc/config/i386/i386.cc @@ -16682,10 +16682,18 @@ assign_386_stack_local (machine_mode mode, enum ix86_stack_slot n) if (s->mode == mode && s->n == n) return validize_mem (copy_rtx (s->rtl)); + int align = 0; + /* For DImode with SLOT_FLOATxFDI_387 use 32-bit + alignment with -m32 -mpreferred-stack-boundary=2. */ + if (mode == DImode + && !TARGET_64BIT + && n == SLOT_FLOATxFDI_387 + && ix86_preferred_stack_boundary < GET_MODE_ALIGNMENT (DImode)) + align = 32; s = ggc_alloc<stack_local_entry> (); s->n = n; s->mode = mode; - s->rtl = assign_stack_local (mode, GET_MODE_SIZE (mode), 0); + s->rtl = assign_stack_local (mode, GET_MODE_SIZE (mode), align); s->next = ix86_stack_locals; ix86_stack_locals = s; diff --git a/gcc/testsuite/gcc.target/i386/pr109276.c b/gcc/testsuite/gcc.target/i386/pr109276.c new file mode 100644 index 0000000..5d0827a --- /dev/null +++ b/gcc/testsuite/gcc.target/i386/pr109276.c @@ -0,0 +1,13 @@ +/* PR target/109276 */ +/* { dg-do compile } */ +/* { dg-options "-march=x86-64" } */ +/* { dg-additional-options "-mpreferred-stack-boundary=2" { target ia32 } } */ + +long long a; +long double b; + +void +foo (void) +{ + b += a; +} |