From bb0249cbb7500772af1bfcc68f8929d60f6cb51f Mon Sep 17 00:00:00 2001
From: Marc Glisse <marc.glisse@inria.fr>
Date: Tue, 25 Apr 2017 08:51:44 +0200
Subject: [PATCH] Let tree_single_nonzero_warnv_p use range information

2017-04-25  Marc Glisse  <marc.glisse@inria.fr>

gcc/
	* fold-const.c (tree_single_nonzero_warnv_p): Handle SSA_NAME.

gcc/testsuite/
	* gcc.dg/tree-ssa/cmpmul-1.c: New file.
	* gcc.dg/Wstrict-overflow-18.c: Xfail.

From-SVN: r247123
---
 gcc/ChangeLog                              |  4 ++++
 gcc/fold-const.c                           |  5 +++++
 gcc/testsuite/ChangeLog                    |  5 +++++
 gcc/testsuite/gcc.dg/Wstrict-overflow-18.c |  3 ++-
 gcc/testsuite/gcc.dg/tree-ssa/cmpmul-1.c   | 11 +++++++++++
 5 files changed, 27 insertions(+), 1 deletion(-)
 create mode 100644 gcc/testsuite/gcc.dg/tree-ssa/cmpmul-1.c

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 95bb4152c25..5b59d793850 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,7 @@
+2017-04-25  Marc Glisse  <marc.glisse@inria.fr>
+
+	* fold-const.c (tree_single_nonzero_warnv_p): Handle SSA_NAME.
+
 2017-04-25  Julian Brown  <julian@codesourcery.com>
 	    Naveen H.S  <Naveen.Hurugalawadi@cavium.com>
 
diff --git a/gcc/fold-const.c b/gcc/fold-const.c
index 4ae21fb0d2f..f0b8e7a3f1b 100644
--- a/gcc/fold-const.c
+++ b/gcc/fold-const.c
@@ -13412,6 +13412,11 @@ tree_single_nonzero_warnv_p (tree t, bool *strict_overflow_p)
 	}
       break;
 
+    case SSA_NAME:
+      if (!INTEGRAL_TYPE_P (TREE_TYPE (t)))
+	break;
+      return expr_not_equal_to (t, wi::zero (TYPE_PRECISION (TREE_TYPE (t))));
+
     default:
       break;
     }
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 824a8a11f0e..4fb111ebe90 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2017-04-25  Marc Glisse  <marc.glisse@inria.fr>
+
+	* gcc.dg/tree-ssa/cmpmul-1.c: New file.
+	* gcc.dg/Wstrict-overflow-18.c: Xfail.
+
 2017-04-22  Janus Weil  <janus@gcc.gnu.org>
 
 	PR fortran/80121
diff --git a/gcc/testsuite/gcc.dg/Wstrict-overflow-18.c b/gcc/testsuite/gcc.dg/Wstrict-overflow-18.c
index bab91ce3889..8c8ddcf2b26 100644
--- a/gcc/testsuite/gcc.dg/Wstrict-overflow-18.c
+++ b/gcc/testsuite/gcc.dg/Wstrict-overflow-18.c
@@ -14,7 +14,8 @@ foo (struct c *p)
 
   for (i = 0; i < p->a - p->b; ++i)
     {
-      if (i > 0)  /* { dg-warning "signed overflow" "" } */
+      /* See PR80511 for the XFAIL.  */
+      if (i > 0)  /* { dg-warning "signed overflow" "" { xfail *-*-* } } */
 	sum += 2;
       bar (p);
     }
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/cmpmul-1.c b/gcc/testsuite/gcc.dg/tree-ssa/cmpmul-1.c
new file mode 100644
index 00000000000..1e303b19690
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/tree-ssa/cmpmul-1.c
@@ -0,0 +1,11 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -fdump-tree-optimized-raw" } */
+
+int f(int a, int b, int c){
+  c |= 1; // c cannot be 0
+  a *= c;
+  b *= c;
+  return a == b;
+}
+
+/* { dg-final { scan-tree-dump-not "bit_ior_expr" "optimized" } } */
-- 
2.11.4.GIT