Add check for overflow after MUL operations in side-effect free int32 expressions.

BUG=http://code.google.com/p/v8/issues/detail?id=927
TEST=test/mjsunit/regress/regress-927.js

Review URL: http://codereview.chromium.org/4746001

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@5793 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

diff --git a/src/ia32/codegen-ia32.cc b/src/ia32/codegen-ia32.cc
index 7295340..6f4ef87 100644 (file)
--- a/src/ia32/codegen-ia32.cc
+++ b/src/ia32/codegen-ia32.cc
@@ -8578,9 +8578,11 @@ void CodeGenerator::Int32BinaryOperation(BinaryOperation* node) {
       }
       right.Unuse();
       frame_->Push(&left);
-      if (!node->to_int32()) {
-        // If ToInt32 is called on the result of ADD, SUB, or MUL, we don't
+      if (!node->to_int32() || op == Token::MUL) {
+        // If ToInt32 is called on the result of ADD, SUB, we don't
         // care about overflows.
+        // Result of MUL can be non-representable precisely in double so
+        // we have to check for overflow.
         unsafe_bailout_->Branch(overflow);
       }
       break;

diff --git a/test/mjsunit/regress/regress-927.js b/test/mjsunit/regress/regress-927.js
new file mode 100644 (file)
index 0000000..c671f7d
--- /dev/null
+++ b/test/mjsunit/regress/regress-927.js
@@ -0,0 +1,33 @@
+// Copyright 2010 the V8 project authors. All rights reserved.
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+//       notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+//       copyright notice, this list of conditions and the following
+//       disclaimer in the documentation and/or other materials provided
+//       with the distribution.
+//     * Neither the name of Google Inc. nor the names of its
+//       contributors may be used to endorse or promote products derived
+//       from this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+function a1() {
+    var a2 = -1756315459;
+    return ((((a2 & a2) ^ 1) * a2) << -10);
+}
+
+assertEquals(a1(), -2147483648);