There's a typo in the way we compute opts->x_ix86_move_max:
if (opts_set->x_ix86_move_max == PVW_NONE)
{
/* Set the maximum number of bits can be moved from memory to
memory efficiently. */
if (opts_set->x_prefer_vector_width_type != PVW_NONE)
opts->x_ix86_move_max = opts->x_prefer_vector_width_type;
else if (ix86_tune_features[X86_TUNE_AVX512_MOVE_BY_PIECES])
opts->x_ix86_move_max = PVW_AVX512;
else if (ix86_tune_features[X86_TUNE_AVX256_MOVE_BY_PIECES])
opts->x_ix86_move_max = PVW_AVX256;
else
{
opts->x_ix86_move_max = opts->x_prefer_vector_width_type;
/* */ if (opts_set->x_ix86_move_max == PVW_NONE)
{
if (TARGET_AVX512F_P (opts->x_ix86_isa_flags))
opts->x_ix86_move_max = PVW_AVX512;
/* Align with vectorizer to avoid potential STLF issue. */
else if (TARGET_AVX_P (opts->x_ix86_isa_flags))
opts->x_ix86_move_max = PVW_AVX256;
else
opts->x_ix86_move_max = PVW_AVX128;
}
}
}
as written the /* */ condition is redundant with the outermost one.
But intended is (IMO) that the earlier set opts->x_prefer_vector_width_type
via X86_TUNE_{AVX128,AVX256}_OPTIMAL takes precedence over the ISA
based setup that follows. So instead of checking opts_set we want
to check whether the previous assignment left us with still PVW_NONE.
The issue makes us ignore X86_TUNE_AVX128_OPTIMAL/X86_TUNE_AVX256_OPTIMAL
when determining opts->x_ix86_move_max.
Bootstrap and regtest ongoing on x86_64-unknown-linux-gnu. The
issue seems to be present on branches as well.
OK for trunk (and branches)?
Thanks,
Richard.
* config/i386/i386-options.cc (ix86_option_override_internal):
Fix check during opts->x_ix86_move_max initialization.
---
gcc/config/i386/i386-options.cc | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/gcc/config/i386/i386-options.cc b/gcc/config/i386/i386-options.cc
index dadcf7664c6..ba598a817f3 100644
--- a/gcc/config/i386/i386-options.cc
+++ b/gcc/config/i386/i386-options.cc
@@ -2917,7 +2917,7 @@ ix86_option_override_internal (bool main_args_p,
else
{
opts->x_ix86_move_max = opts->x_prefer_vector_width_type;
- if (opts_set->x_ix86_move_max == PVW_NONE)
+ if (opts->x_ix86_move_max == PVW_NONE)
{
if (TARGET_AVX512F_P (opts->x_ix86_isa_flags))
opts->x_ix86_move_max = PVW_AVX512;
--
2.51.0
