PR tree-optimization/56559

	* tree-ssa-reassoc.c (zero_one_operation): When looking at rhs2,
	check that it has only a single use.

	* gcc.dg/tree-ssa/reassoc-26.c: New test.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@196520 138bc75d-0d04-0410-961f-82ee72b054a4

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index af3dd81..ff171e2 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+2013-03-07  Jakub Jelinek  <jakub@redhat.com>
+
+       PR tree-optimization/56559
+       * tree-ssa-reassoc.c (zero_one_operation): When looking at rhs2,
+       check that it has only a single use.
+
 2013-03-07  Richard Biener  <rguenther@suse.de>
 
        * doc/invoke.texi (fwhole-program): Discourage use in combination

diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 3c456e2..ee5c580 100644 (file)
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2013-03-07  Jakub Jelinek  <jakub@redhat.com>
+
+       PR tree-optimization/56559
+       * gcc.dg/tree-ssa/reassoc-26.c: New test.
+
 2013-03-07  Andreas Schwab  <schwab@suse.de>
 
        * gcc.dg/pr31490.c: Fix last change.

diff --git a/gcc/testsuite/gcc.dg/tree-ssa/reassoc-26.c b/gcc/testsuite/gcc.dg/tree-ssa/reassoc-26.c
new file mode 100644 (file)
index 0000000..ae4bdaa
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/tree-ssa/reassoc-26.c
@@ -0,0 +1,12 @@
+/* PR tree-optimization/56559 */
+/* { dg-do compile } */
+/* { dg-options "-O2 -ffast-math" } */
+
+double a, b, c, d, e;
+
+void
+foo ()
+{
+  a = e * e;
+  b = d * e + c * e * a;
+}

diff --git a/gcc/tree-ssa-reassoc.c b/gcc/tree-ssa-reassoc.c
index f53526b..27161cd 100644 (file)
--- a/gcc/tree-ssa-reassoc.c
+++ b/gcc/tree-ssa-reassoc.c
@@ -1107,7 +1107,8 @@ zero_one_operation (tree *def, enum tree_code opcode, tree op)
         the operand might be hiding in the rightmost one.  */
       if (opcode == MULT_EXPR
          && gimple_assign_rhs_code (stmt) == opcode
-         && TREE_CODE (gimple_assign_rhs2 (stmt)) == SSA_NAME)
+         && TREE_CODE (gimple_assign_rhs2 (stmt)) == SSA_NAME
+         && has_single_use (gimple_assign_rhs2 (stmt)))
        {
          gimple stmt2 = SSA_NAME_DEF_STMT (gimple_assign_rhs2 (stmt));
          if (stmt_is_power_of_op (stmt2, op))