[RTL ifcvt] PR 67786, 67787: Check that intermediate instructions in the basic…

[RTL ifcvt] PR 67786, 67787: Check that intermediate instructions in the basic block don't clobber a reg used in condition

        PR rtl-optimization/67786
        PR rtl-optimization/67787
        * ifcvt.c (bb_valid_for_noce_process_p): Reject basic block if
        it modifies a reg used in the condition calculation.

        * gcc.dg/pr67786.c: New test.
        * gcc.dg/pr67787.c: Likewise.

From-SVN: r228375

gcc/ChangeLog

+2015-10-02  Kyrylo Tkachov  <kyrylo.tkachov@arm.com>
+
+	PR rtl-optimization/67786
+	PR rtl-optimization/67787
+	* ifcvt.c (bb_valid_for_noce_process_p): Reject basic block if
+	it modifies a reg used in the condition calculation.
+
 2015-10-02  James Greenhalgh  <james.greenhalgh@arm.com>
 
 	* config/aarch64/aarch64-simd.md (*aarch64_combinez<mode>): Add

gcc/ifcvt.c

@@ -3003,7 +3003,8 @@ bb_valid_for_noce_process_p (basic_block test_bb, rtx cond,
 	  gcc_assert (sset);
 
 	  if (contains_mem_rtx_p (SET_SRC (sset))
-	      || !REG_P (SET_DEST (sset)))
+	      || !REG_P (SET_DEST (sset))
+	      || reg_overlap_mentioned_p (SET_DEST (sset), cond))
 	    goto free_bitmap_and_fail;
 
 	  potential_cost += insn_rtx_cost (sset, speed_p);

gcc/testsuite/ChangeLog

+2015-10-02  Kyrylo Tkachov  <kyrylo.tkachov@arm.com>
+
+	PR rtl-optimization/67786
+	PR rtl-optimization/67787
+	* gcc.dg/pr67786.c: New test.
+	* gcc.dg/pr67787.c: Likewise.
+
 2015-10-02  James Greenhalgh  <james.greenhalgh@arm.com>
 
 	* gcc.target/aarch64/vect_combine_zeroes_1.c: New.

gcc/testsuite/gcc.dg/pr67786.c

+/* { dg-do run } */
+/* { dg-options "-O3" } */
+
+int a, b = 10;
+char c;
+
+int
+main ()
+{
+  char d;
+  int e = 5;
+  for (a = 0; a; a--)
+    e = 0;
+  c = (b & 15) ^ e;
+  d = c > e ? c : c << e;
+  __builtin_printf ("%d\n", d);
+  return 0;
+}
+
+/* { dg-output "15" } */

gcc/testsuite/gcc.dg/pr67787.c

+/* { dg-do run } */
+/* { dg-options "-O3" } */
+
+int a, c, f, g;
+char b;
+
+static int
+fn1 ()
+{
+  char h;
+  int k = -1, i, j;
+  for (; b < 16; b++)
+    ;
+  __builtin_printf (" ");
+  if (b < 5)
+    k++;
+  if (k)
+    {
+      int l = 2;
+      a = h = b < 0 || b > (127 >> l) ? b : b << 1;
+      return 0;
+    }
+  for (i = 0; i < 1; i++)
+    for (j = 0; j < 7; j++)
+      f = 0;
+  for (c = 0; c; c++)
+    ;
+  if (g)
+    for (;;)
+      ;
+  return 0;
+}
+
+int
+main ()
+{
+  fn1 ();
+
+  if (a != 32)
+    __builtin_abort ();
+
+  return 0;
+}