From: Richard Biener <rguenther@suse.de>
Date: Mon, 14 Nov 2016 10:33:15 +0000 (+0000)
Subject: re PR tree-optimization/78312 (wrong code due to ssa-backprop)
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=5129b43be675171c2e4742ae4b1e073249314818;p=gcc.git

re PR tree-optimization/78312 (wrong code due to ssa-backprop)

2016-11-14  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/78312
	* gimple-ssa-backprop.c (backprop::prepare_change): Reset
	flow-sensitive info.

	* gcc.dg/torture/pr78312.c: New testcase.

From-SVN: r242380
---

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 5c53b9bf271..a4f6a34f8f1 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+2016-11-14  Richard Biener  <rguenther@suse.de>
+
+	PR tree-optimization/78312
+	* gimple-ssa-backprop.c (backprop::prepare_change): Reset
+	flow-sensitive info.
+
 2016-11-14  Georg-Johann Lay  <avr@gjlay.de>
 
 	PR target/78093
diff --git a/gcc/gimple-ssa-backprop.c b/gcc/gimple-ssa-backprop.c
index 53349e89658..6ef221817f9 100644
--- a/gcc/gimple-ssa-backprop.c
+++ b/gcc/gimple-ssa-backprop.c
@@ -728,6 +728,7 @@ backprop::prepare_change (tree var)
 {
   if (MAY_HAVE_DEBUG_STMTS)
     insert_debug_temp_for_var_def (NULL, var);
+  reset_flow_sensitive_info (var);
 }
 
 /* STMT has been changed.  Give the fold machinery a chance to simplify
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index b87788eaf16..bf99ab981b9 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2016-11-14  Richard Biener  <rguenther@suse.de>
+
+	PR tree-optimization/78312
+	* gcc.dg/torture/pr78312.c: New testcase.
+
 2016-11-14  Georg-Johann Lay  <avr@gjlay.de>
 
 	PR target/78093
diff --git a/gcc/testsuite/gcc.dg/torture/pr78312.c b/gcc/testsuite/gcc.dg/torture/pr78312.c
new file mode 100644
index 00000000000..470e5b2ea0a
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/torture/pr78312.c
@@ -0,0 +1,23 @@
+/* { dg-do run } */
+
+typedef unsigned short u16;
+
+static u16 a;
+
+u16 __attribute__ ((noinline, noclone))
+foo (int p1)
+{
+  a = -(p1 > 0);
+  a *= 0 != a;
+  a *= (unsigned)a;
+  return a;
+}
+
+int
+main ()
+{
+  u16 x = foo (1);
+  if (x != 1)
+    __builtin_abort();
+  return 0;
+}