http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52323
--- Comment #4 from Steven Bosscher <steven at gcc dot gnu.org> 2012-10-09
22:16:34 UTC ---
IMHO -fgcse should just be disabled on ix86.
Index: i386.c
===================================================================
--- i386.c (revision 192273)
+++ i386.c (working copy)
@@ -3264,6 +3264,15 @@ ix86_option_override_internal (bool main
SUBSUBTARGET_OVERRIDE_OPTIONS;
#endif
+ /* RTL lazy code motion (-fgcse) causes nothing but trouble on
+ non-X32 32-bits targets. Most profitable code transformation
+ opportunities have already been performed by GIMPLE PRE. The
+ remaining cases at the RTL stage are address arithmetic exprs
+ in loops, and loop-invariant.c handles those much better than
+ lazy code motion. */
+ if (! (TARGET_X32 || TARGET_64BIT))
+ flag_gcse = 0;
+
/* -fPIC is the default for x86_64. */
if (TARGET_MACHO && TARGET_64BIT)
flag_pic = 2;
Patch needs a foster parent, I don't care enough about old 32-bits i386 :-)
