arc.c (arc_loop_hazard): Don't convert the jump label rtx to an rtx_insn until…

arc.c (arc_loop_hazard): Don't convert the jump label rtx to an rtx_insn until we confirm it's not a...

2015-12-17  Andrew Burgess  <andrew.burgess@embecosm.com>
gcc:
        * config/arc/arc.c (arc_loop_hazard): Don't convert the jump label
        rtx to an rtx_insn until we confirm it's not a return rtx.
gcc/testsuite:
        * gcc.target/arc/loop-hazard-1.c: New file

From-SVN: r231752

gcc/ChangeLog

+2015-12-17  Andrew Burgess  <andrew.burgess@embecosm.com>
+
+	* config/arc/arc.c (arc_loop_hazard): Don't convert the jump label
+	rtx to an rtx_insn until we confirm it's not a return rtx.
+
 2015-12-17  Richard Biener  <rguenther@suse.de>
 
 	* gimple-ssa.h (struct gimple_df): Remove modified_noreturn_calls

gcc/config/arc/arc.c

@@ -8041,6 +8041,7 @@ static bool
 arc_loop_hazard (rtx_insn *pred, rtx_insn *succ)
 {
   rtx_insn *jump  = NULL;
+  rtx label_rtx = NULL_RTX;
   rtx_insn *label = NULL;
   basic_block succ_bb;
 
@@ -8067,22 +8068,22 @@ arc_loop_hazard (rtx_insn *pred, rtx_insn *succ)
   else
     return false;
 
-  label = JUMP_LABEL_AS_INSN (jump);
-  if (!label)
-    return false;
-
   /* Phase 2b: Make sure is not a millicode jump.  */
   if ((GET_CODE (PATTERN (jump)) == PARALLEL)
       && (XVECEXP (PATTERN (jump), 0, 0) == ret_rtx))
     return false;
 
-  /* Phase 2c: Make sure is not a simple_return.  */
-  if ((GET_CODE (PATTERN (jump)) == SIMPLE_RETURN)
-      || (GET_CODE (label) == SIMPLE_RETURN))
+  label_rtx = JUMP_LABEL (jump);
+  if (!label_rtx)
+    return false;
+
+  /* Phase 2c: Make sure is not a return.  */
+  if (ANY_RETURN_P (label_rtx))
     return false;
 
   /* Pahse 2d: Go to the target of the jump and check for aliveness of
      LP_COUNT register.  */
+  label = safe_as_a <rtx_insn *> (label_rtx);
   succ_bb = BLOCK_FOR_INSN (label);
   if (!succ_bb)
     {

gcc/testsuite/ChangeLog

@@ -12,6 +12,10 @@
 
 2015-12-17  Andrew Burgess  <andrew.burgess@embecosm.com>
 
+	* gcc.target/arc/loop-hazard-1.c: New file.
+
+2015-12-17  Andrew Burgess  <andrew.burgess@embecosm.com>
+
 	* gcc.target/arc/jump-around-jump.c (rtc_set_time): Declare.
 
 2015-12-17  Thomas Preud'homme  <thomas.preudhomme@arm.com>

gcc/testsuite/gcc.target/arc/loop-hazard-1.c

+/* { dg-do compile } */
+/* { dg-options "-Os" } */
+
+/* This caused an assertion within arc_loop_hazard.  */
+
+unsigned a, b;
+
+long fn1()
+{
+  long c = 1, d = 0;
+  while (a && c && b)
+    c <<= 1;
+  while (c)
+    d |= c;
+  return d;
+}