Hi,
This is a patch which fixes a latent bug in RTL GCSE/PRE, described
more fully in:
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=57159
I haven't been able to reproduce the problem on mainline (nor on a
supported target). Maybe someone more familiar with the code in question
than I am can tell if the patch is correct nonetheless?
Thanks,
Julian
ChangeLog
gcc/
* gcse.c (compute_ld_motion_mems): Invalidate non-simple mem refs
in REG_EQUAL notes.
Index: gcc/gcse.c
===================================================================
--- gcc/gcse.c (revision 198175)
+++ gcc/gcse.c (working copy)
@@ -3888,6 +3888,13 @@ compute_ld_motion_mems (void)
{
rtx src = SET_SRC (PATTERN (insn));
rtx dest = SET_DEST (PATTERN (insn));
+ rtx note = find_reg_equal_equiv_note (insn);
+ rtx src_eq;
+
+ if (note != 0 && REG_NOTE_KIND (note) == REG_EQUAL)
+ src_eq = XEXP (note, 0);
+ else
+ src_eq = NULL_RTX;
/* Check for a simple LOAD... */
if (MEM_P (src) && simple_mem (src))
@@ -3904,6 +3911,12 @@ compute_ld_motion_mems (void)
invalidate_any_buried_refs (src);
}
+ /* Also invalidate any buried loads which may be present in
+ REG_EQUAL notes. */
+ if (src_eq != NULL_RTX
+ && !(MEM_P (src_eq) && simple_mem (src_eq)))
+ invalidate_any_buried_refs (src_eq);
+
/* Check for stores. Don't worry about aliased ones, they
will block any movement we might do later. We only care
about this exact pattern since those are the only
