re PR rtl-optimization/24257 (ICE: in extract_insn with -O -fgcse -fgcse-sm)

2006-01-14  Steven Bosscher  <stevenb.gcc@gmail.com>
	Richard Guenther  <rguenther@suse.de>

	PR rtl-optimization/24257
	* gcse.c (find_moveable_store): Only consider a store movable
	when the SET_SRC of the insn can be assigned to a register.

	* gcc.dg/torture/pr24257.c: New testcase.

Co-Authored-By: Richard Guenther <rguenther@suse.de>

From-SVN: r109701

1 files changed, 8 insertions, 0 deletions

diff --git a/gcc/gcse.c b/gcc/gcse.c
index 5966694..290f70e 100644
--- a/gcc/gcse.c
+++ b/gcc/gcse.c
@@ -5664,6 +5664,14 @@ find_moveable_store (rtx insn, int *regs_set_before, int *regs_set_after)
   if (find_reg_note (insn, REG_EH_REGION, NULL_RTX))
     return;
 
+  /* Make sure that the SET_SRC of this store insns can be assigned to
+     a register, or we will fail later on in replace_store_insn, which
+     assumes that we can do this.  But sometimes the target machine has
+     oddities like MEM read-modify-write instruction.  See for example
+     PR24257.  */
+  if (!can_assign_to_reg_p (SET_SRC (set)))
+    return;
+
   ptr = ldst_entry (dest);
   if (!ptr->pattern_regs)
     ptr->pattern_regs = extract_mentioned_regs (dest);