From: Richard Biener <rguenther@suse.de>
Date: Wed, 21 Oct 2015 07:56:54 +0000 (+0000)
Subject: re PR tree-optimization/68026 (Regression in GCC-6.0.0's optimizer)
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=33b35c280747d60086dc2cc640a3c15239ec3e8d;p=gcc.git

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 2b15977437a..20c272d9edc 100644
--- 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 df804352bd3..1809ddfcce3 100644
--- 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
index 00000000000..21af5593f50
--- /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 ed5fe1e3cea..2c69178a0ae 100644
--- 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;
 }