Take all uses into account to clear int32 truncation.

R=jkummerow@chromium.org

Review URL: https://chromiumcodereview.appspot.com/16656002

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@15017 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/hydrogen.cc

@@ -3195,9 +3195,8 @@ void HGraph::InsertRepresentationChanges() {
       HValue* use = it.value();
       Representation input_representation =
           use->RequiredInputRepresentation(it.index());
-      if ((input_representation.IsInteger32() &&
-           !use->CheckFlag(HValue::kTruncatingToInt32)) ||
-          input_representation.IsDouble()) {
+      if (!input_representation.IsInteger32() ||
+          !use->CheckFlag(HValue::kTruncatingToInt32)) {
         if (FLAG_trace_representation) {
           PrintF("#%d Phi is not truncating because of #%d %s\n",
                  phi->id(), it.value()->id(), it.value()->Mnemonic());

test/mjsunit/regress/regress-int32-truncation.js

+// Copyright 2013 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.
+
+// Flags: --allow-natives-syntax
+
+function f(i, b) {
+  var a = 0;
+  if (b) {
+    var c = 1 << i;
+    a = c + c;
+  }
+  var x = a >> 3;
+  return a;
+}
+
+f(1, false);
+f(1, true);
+%OptimizeFunctionOnNextCall(f);
+assertEquals((1 << 30) * 2, f(30, true));
+
+
+var global = 1;
+
+function f2(b) {
+  var a = 0;
+  if (b) {
+    a = global;
+  }
+  var x = a >> 3;
+  return a;
+}
+
+f2(false);
+f2(true);
+%OptimizeFunctionOnNextCall(f2);
+global = 2.5;
+assertEquals(global, f2(true));