emit-rtl.c (set_unique_reg_note): Don't set a REG_EQUAL or REG_EQUIV note if…

emit-rtl.c (set_unique_reg_note): Don't set a REG_EQUAL or REG_EQUIV note if multiple sets are present.

	* emit-rtl.c (set_unique_reg_note): Don't set
	a REG_EQUAL or REG_EQUIV note if multiple sets
	are present.

From-SVN: r47657

gcc/ChangeLog

+Wed Dec  5 00:42:16 EST 2001  John Wehle  (john@feith.com)
+
+	* emit-rtl.c (set_unique_reg_note): Don't set
+	a REG_EQUAL or REG_EQUIV note if multiple sets
+	are present.
+
 2001-12-04  John David Anglin  <dave@hiauly1.hia.nrc.ca>
 
 	* cfgrtl.c (verify_flow_info): Allow jump table data in fallthru if

gcc/emit-rtl.c

@@ -4068,11 +4068,30 @@ set_unique_reg_note (insn, kind, datum)
 {
   rtx note = find_reg_note (insn, kind, NULL_RTX);
 
-  /* Don't add ASM_OPERAND REG_EQUAL/REG_EQUIV notes.
-     It serves no useful purpose and breaks eliminate_regs.  */
-  if ((kind == REG_EQUAL || kind == REG_EQUIV)
-      && GET_CODE (datum) == ASM_OPERANDS)
-    return NULL_RTX;
+  switch (kind)
+    {
+    case REG_EQUAL:
+    case REG_EQUIV:
+      /* Don't add REG_EQUAL/REG_EQUIV notes if the insn
+	 has multiple sets (some callers assume single_set
+	 means the insn only has one set, when in fact it
+	 means the insn only has one * useful * set).  */
+      if (GET_CODE (PATTERN (insn)) == PARALLEL && multiple_sets (insn))
+	{
+	  if (note)
+	    abort ();
+	  return NULL_RTX;
+	}
+
+      /* Don't add ASM_OPERAND REG_EQUAL/REG_EQUIV notes.
+	 It serves no useful purpose and breaks eliminate_regs.  */
+      if (GET_CODE (datum) == ASM_OPERANDS)
+	return NULL_RTX;
+      break;
+
+    default:
+      break;
+    }
 
   if (note)
     {