re PR target/11052 ([arm] noce_process_if_block() can loose REG_INC notes)

PR target/11052
* ifcvt.c (noce_process_if_block): Fail if the destination has
side-effects.

gcc.c-torture/execute/20030606-1.c: New.

From-SVN: r67558

gcc/ChangeLog

+2003-06-06  Richard Earnshaw  <rearnsha@arm.com>
+
+	PR target/11052
+	* ifcvt.c (noce_process_if_block): Fail if the destination has
+	side-effects.
+
 2003-06-06  Jason Merrill  <jason@redhat.com>
 
 	* stmt.c (resolve_asm_operand_names): Rename from

gcc/ifcvt.c

@@ -1821,6 +1821,15 @@ noce_process_if_block (ce_info)
 	  || modified_between_p (x, PREV_INSN (if_info.cond_earliest), jump))
 	insn_b = set_b = NULL_RTX;
     }
+
+  /* If x has side effects then only the if-then-else form is safe to
+     convert.  But even in that case we would need to restore any notes
+     (such as REG_INC) at then end.  That can be tricky if 
+     noce_emit_move_insn expands to more than one insn, so disable the
+     optimization entirely for now if there are side effects.  */
+  if (side_effects_p (x))
+    return FALSE;
+
   b = (set_b ? SET_SRC (set_b) : x);
 
   /* Only operate on register destinations, and even then avoid extending

gcc/testsuite/ChangeLog

+2003-06-06  Richard Earnshaw  <rearnsha@arm.com>
+
+	gcc.c-torture/execute/20030606-1.c: New.
+
 2003-06-06  Roger Sayle  <roger@eyesopen.com>
 
 	* gcc.dg/builtins-2.c: Correct check-in of incorrect version.

gcc/testsuite/gcc.c-torture/execute/20030606-1.c

+
+int * foo (int *x, int b)
+{
+
+  *(x++) = 55;
+  if (b)
+    *(x++) = b;
+
+  return x;
+}
+
+main()
+{
+  int a[5];
+
+  memset (a, 1, sizeof (a));
+
+  if (foo(a, 0) - a != 1 || a[0] != 55 || a[1] != a[4])
+    abort();
+
+  memset (a, 1, sizeof (a));
+
+  if (foo(a, 2) - a != 2 || a[0] != 55 || a[1] != 2)
+    abort();
+
+  exit (0);
+}