re PR rtl-optimization/21767 (if-convert leaves invalid REG_EQUAL notes)

	PR rtl-optimization/21767
	* rtl.h (function_invariant_p): Re-add declaration.
	* reload1.c (function_invariant_p): No longer static.
	* ifcvt.c (dead_or_predicable): Remove REG_EQUAL notes that
	might have become invalid.

From-SVN: r100448

gcc/ChangeLog

+2005-06-01  J"orn Rennecke <joern.rennecke@st.com>
+
+	PR rtl-optimization/21767
+	* rtl.h (function_invariant_p): Re-add declaration.
+	* reload1.c (function_invariant_p): No longer static.
+	* ifcvt.c (dead_or_predicable): Remove REG_EQUAL notes that
+	might have become invalid.
+
 2005-06-01  Jakub Jelinek  <jakub@redhat.com>
 
 	PR c/21536

gcc/ifcvt.c

@@ -3430,12 +3430,31 @@ dead_or_predicable (basic_block test_bb, basic_block merge_bb,
   /* Move the insns out of MERGE_BB to before the branch.  */
   if (head != NULL)
     {
+      rtx insn;
+
       if (end == BB_END (merge_bb))
 	BB_END (merge_bb) = PREV_INSN (head);
 
       if (squeeze_notes (&head, &end))
 	return TRUE;
 
+      /* PR 21767: When moving insns above a conditional branch, REG_EQUAL
+	 notes might become invalid.  */
+      insn = head;
+      do
+	{
+	  rtx note, set;
+
+	  if (! INSN_P (insn))
+	    continue;
+	  note = find_reg_note (insn, REG_EQUAL, NULL_RTX);
+	  if (! note)
+	    continue;
+	  set = single_set (insn);
+	  if (!set || !function_invariant_p (SET_SRC (set)))
+	    remove_note (insn, note);
+	} while (insn != end && (insn = NEXT_INSN (insn)));
+
       reorder_insns (head, end, PREV_INSN (earliest));
     }
 

gcc/reload1.c

@@ -405,7 +405,6 @@ static int reload_reg_free_for_value_p (int, int, int, enum reload_type,
 					rtx, rtx, int, int);
 static int free_for_value_p (int, enum machine_mode, int, enum reload_type,
 			     rtx, rtx, int, int);
-static int function_invariant_p (rtx);
 static int reload_reg_reaches_end_p (unsigned int, int, enum reload_type);
 static int allocate_reload_reg (struct insn_chain *, int, int);
 static int conflicts_with_override (rtx);
@@ -4984,7 +4983,7 @@ free_for_value_p (int regno, enum machine_mode mode, int opnum,
    pic_offset_table_rtx is not, and we must not spill these things to
    memory.  */
 
-static int
+int
 function_invariant_p (rtx x)
 {
   if (CONSTANT_P (x))

gcc/rtl.h

@@ -2062,6 +2062,9 @@ extern void dbr_schedule (rtx, FILE *);
 extern void dump_local_alloc (FILE *);
 extern int local_alloc (void);
 
+/* In reload1.c */
+extern int function_invariant_p (rtx);
+
 /* In reg-stack.c */
 extern bool reg_to_stack (FILE *);