re PR tree-optimization/68026 (Regression in GCC-6.0.0's optimizer)

2015-10-21  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/68026
	* tree-ssa-ccp.c (get_value_for_expr): Zero-extend mask for
	unsigned VARYING values.

	* gcc.dg/tree-ssa/ssa-ccp-39.c: New testcase.

From-SVN: r229117

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 2b15977437a4c4a9381c7a13c0ed218030a6d5dc..20c272d9edc3f7261d85de30a0cd50369cb6ec12 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+2015-10-21  Richard Biener  <rguenther@suse.de>
+
+       PR tree-optimization/68026
+       * tree-ssa-ccp.c (get_value_for_expr): Zero-extend mask for
+       unsigned VARYING values.
+
 2015-10-21  Maxim Ostapenko  <m.ostapenko@partner.samsung.com>
 
        * asan.c (asan_emit_stack_protection): Don't pass local stack to

diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index df804352bd3e38acbbacf35e9b523ed0e0d43119..1809ddfcce380aa33ee9abdd0c2b4125160c3b2e 100644 (file)
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2015-10-21  Richard Biener  <rguenther@suse.de>
+
+       PR tree-optimization/68026
+       * gcc.dg/tree-ssa/ssa-ccp-39.c: New testcase.
+
 2015-10-21  Maxim Ostapenko  <m.ostapenko@partner.samsung.com>
 
        * c-c++-common/ubsan/float-cast-overflow-10.c: Adjust test.

diff --git a/gcc/testsuite/gcc.dg/tree-ssa/ssa-ccp-39.c b/gcc/testsuite/gcc.dg/tree-ssa/ssa-ccp-39.c
new file mode 100644 (file)
index 0000000..21af559
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/tree-ssa/ssa-ccp-39.c
@@ -0,0 +1,19 @@
+/* { dg-do run } */
+/* { dg-options "-O -fdump-tree-ccp1" } */
+
+int main (void)
+{
+  volatile int x1 = 1;
+  volatile int x2 = 1;
+  int x3 = 2;
+  int t = 1;
+
+  t = 3<=(x2|1|x3|x1-1U);
+
+  if (t == 1) {} 
+  else { __builtin_abort(); }
+
+  return 0;
+}
+
+/* { dg-final { scan-tree-dump-not "abort" "ccp1" } } */

diff --git a/gcc/tree-ssa-ccp.c b/gcc/tree-ssa-ccp.c
index ed5fe1e3cea52189fd52d118e0d9f91cb3476c3c..2c69178a0ae5a21831188c13d4e365e29374d85c 100644 (file)
--- a/gcc/tree-ssa-ccp.c
+++ b/gcc/tree-ssa-ccp.c
@@ -629,6 +629,11 @@ get_value_for_expr (tree expr, bool for_bits_p)
       val.mask = -1;
       val.value = NULL_TREE;
     }
+
+  if (val.lattice_val == VARYING
+      && TYPE_UNSIGNED (TREE_TYPE (expr)))
+    val.mask = wi::zext (val.mask, TYPE_PRECISION (TREE_TYPE (expr)));
+
   return val;
 }