Revision: 18737
Author: [email protected]
Date: Wed Jan 22 11:54:51 2014 UTC
Log: Fixed floor-of-div optimization.
We removed an HDiv by hand which was still used by an HChange. The
solution is letting dead code removal do the cleanup.
Removed a fragile "optimization" (looking through an HChange), too,
this obviously never triggered and is hard to get right given all our
global invariants and state/type/... changes.
The repro is a bit tricky, because you need inlining to make our
representations and types disagree in this case.
LOG=y
BUG=334708
[email protected]
Review URL: https://codereview.chromium.org/143903016
http://code.google.com/p/v8/source/detail?r=18737
Added:
/branches/bleeding_edge/test/mjsunit/regress/regress-334708.js
Modified:
/branches/bleeding_edge/src/hydrogen-instructions.cc
=======================================
--- /dev/null
+++ /branches/bleeding_edge/test/mjsunit/regress/regress-334708.js Wed Jan
22 11:54:51 2014 UTC
@@ -0,0 +1,42 @@
+// Copyright 2014 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 foo(x, y) {
+ return Math.floor(x / y);
+}
+
+function bar(x, y) {
+ return foo(x + 1, y + 1);
+}
+
+foo(16, "4");
+
+bar(64, 2);
+%OptimizeFunctionOnNextCall(bar);
+bar(64, 2);
=======================================
--- /branches/bleeding_edge/src/hydrogen-instructions.cc Mon Jan 20
19:00:11 2014 UTC
+++ /branches/bleeding_edge/src/hydrogen-instructions.cc Wed Jan 22
11:54:51 2014 UTC
@@ -1442,7 +1442,6 @@
if (op() == kMathFloor) {
HValue* val = value();
- if (val->IsChange()) val = HChange::cast(val)->value();
if (val->IsDiv() && (val->UseCount() == 1)) {
HDiv* hdiv = HDiv::cast(val);
HValue* left = hdiv->left();
@@ -1481,17 +1480,8 @@
}
HMathFloorOfDiv* instr =
HMathFloorOfDiv::New(block()->zone(), context(), new_left,
new_right);
- // Replace this HMathFloor instruction by the new HMathFloorOfDiv.
instr->InsertBefore(this);
- ReplaceAllUsesWith(instr);
- Kill();
- // We know the division had no other uses than this HMathFloor.
Delete it.
- // Dead code elimination will deal with |left| and |right| if
- // appropriate.
- hdiv->DeleteAndReplaceWith(NULL);
-
- // Return NULL to remove this instruction from the graph.
- return NULL;
+ return instr;
}
}
return this;
--
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