ia32: Fix comparisons of two constant double operands when exactly one of them is...

R=titzer@chromium.org

Review URL: https://codereview.chromium.org/46883008

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@17428 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

diff --git a/src/ia32/lithium-ia32.cc b/src/ia32/lithium-ia32.cc
index 0800823..b4ebe6d 100644 (file)
--- a/src/ia32/lithium-ia32.cc
+++ b/src/ia32/lithium-ia32.cc
@@ -1728,9 +1728,12 @@ LInstruction* LChunkBuilder::DoCompareNumericAndBranch(
     ASSERT(instr->right()->representation().IsDouble());
     LOperand* left;
     LOperand* right;
-    if (instr->left()->IsConstant() && instr->right()->IsConstant()) {
-      left = UseRegisterOrConstantAtStart(instr->left());
-      right = UseRegisterOrConstantAtStart(instr->right());
+    if (CanBeImmediateConstant(instr->left()) &&
+        CanBeImmediateConstant(instr->right())) {
+      // The code generator requires either both inputs to be constant
+      // operands, or neither.
+      left = UseConstant(instr->left());
+      right = UseConstant(instr->right());
     } else {
       left = UseRegisterAtStart(instr->left());
       right = UseRegisterAtStart(instr->right());

diff --git a/test/mjsunit/regress/regress-compare-constant-doubles.js b/test/mjsunit/regress/regress-compare-constant-doubles.js
new file mode 100644 (file)
index 0000000..0f8ffe3
--- /dev/null
+++ b/test/mjsunit/regress/regress-compare-constant-doubles.js
@@ -0,0 +1,58 @@
+// 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
+
+var left = 1.5;
+var right;
+
+var keepalive;
+
+function foo() {
+  // Fill XMM registers with cruft.
+  var a1 = Math.sin(1) + 10;
+  var a2 = a1 + 1;
+  var a3 = a2 + 1;
+  var a4 = a3 + 1;
+  var a5 = a4 + 1;
+  var a6 = a5 + 1;
+  keepalive = [a1, a2, a3, a4, a5, a6];
+
+  // Actual test.
+  if (left < right) return "ok";
+  return "bad";
+}
+
+function prepare(base) {
+  right = 0.5 * base;
+}
+
+prepare(21);
+assertEquals("ok", foo());
+assertEquals("ok", foo());
+%OptimizeFunctionOnNextCall(foo);
+assertEquals("ok", foo());