https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88889
jseward at acm dot org changed:
What |Removed |Added
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CC| |jseward at acm dot org
--- Comment #4 from jseward at acm dot org ---
This seems to me to be another rerun of the movie where a program does
integer equality on partially defined operands, and still produces a
defined result. Memcheck can already deal with this, but doesn't do so
for 64-bit compares on amd64 by default, since it's expensive.
In memcheck/mc_translate.c, around line 8354, find this
# if defined(VGA_x86)
mce.dlbo.dl_Add32 = DLauto;
mce.dlbo.dl_CmpEQ32_CmpNE32 = DLexpensive;
# elif defined(VGA_amd64)
mce.dlbo.dl_Add64 = DLauto;
mce.dlbo.dl_CmpEQ32_CmpNE32 = DLexpensive;
# elif defined(VGA_ppc64le)
// Needed by (at least) set_AV_CR6() in the front end.
mce.dlbo.dl_CmpEQ64_CmpNE64 = DLexpensive;
# endif
and add to the VGA_amd64 case:
mce.dlbo.dl_CmpEQ64_CmpNE64 = DLexpensive;
That should make it run clean even without using
--expensive-definedness-checks=yes. Does it?
