From: Eric Botcazou <ebotcazou@adacore.com>
Date: Thu, 28 Feb 2019 23:03:01 +0000 (+0000)
Subject: re PR tree-optimization/89536 (wrong code at -Os and above on x86_64-linux-gnu)
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=85222504cc447607d81183e77a6c450351c20ff7;p=gcc.git

re PR tree-optimization/89536 (wrong code at -Os and above on x86_64-linux-gnu)

	PR tree-optimization/89536
	* tree-ssa-dom.c (edge_info::derive_equivalences) <BIT_NOT_EXPR>: Test
	only whether bit #0 of the value is 0 instead of the entire value.

From-SVN: r269289
---

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 3ee63704fd5..4c57ead4d61 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+2019-02-28  Eric Botcazou  <ebotcazou@adacore.com>
+
+	PR tree-optimization/89536
+	* tree-ssa-dom.c (edge_info::derive_equivalences) <BIT_NOT_EXPR>: Test
+	only whether bit #0 of the value is 0 instead of the entire value.
+
 2019-02-28  Marek Polacek  <polacek@redhat.com>
 
 	PR c++/87068 - missing diagnostic with fallthrough statement.
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 423591d3a8d..cf4f06eb88d 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,7 @@
+2019-02-28  Eric Botcazou  <ebotcazou@adacore.com>
+
+	* gcc.c-torture/execute/20190228-1.c: New test.
+
 2019-02-28  Marek Polacek  <polacek@redhat.com>
 
 	PR c++/87068 - missing diagnostic with fallthrough statement.
diff --git a/gcc/testsuite/gcc.c-torture/execute/20190228-1.c b/gcc/testsuite/gcc.c-torture/execute/20190228-1.c
new file mode 100644
index 00000000000..e71f33a279b
--- /dev/null
+++ b/gcc/testsuite/gcc.c-torture/execute/20190228-1.c
@@ -0,0 +1,16 @@
+/* PR tree-optimization/89536 */
+/* Testcase by Zhendong Su <su@cs.ucdavis.edu> */
+
+int a = 1;
+
+int main (void)
+{
+  a = ~(a && 1); 
+  if (a < -1)
+    a = ~a;
+  
+  if (!a)
+    __builtin_abort ();
+
+  return 0;
+}
diff --git a/gcc/tree-ssa-dom.c b/gcc/tree-ssa-dom.c
index 4f4b7db2189..aa4e24bc358 100644
--- a/gcc/tree-ssa-dom.c
+++ b/gcc/tree-ssa-dom.c
@@ -348,7 +348,7 @@ edge_info::derive_equivalences (tree name, tree value, int recursion_limit)
 		&& TREE_CODE (rhs) == SSA_NAME
 		&& ssa_name_has_boolean_range (rhs))
 	      {
-		if (integer_zerop (value))
+		if ((TREE_INT_CST_LOW (value) & 1) == 0)
 		  res = build_one_cst (TREE_TYPE (rhs));
 		else
 		  res = build_zero_cst (TREE_TYPE (rhs));