Reviewers: Sven Panne,
Message:
Patch from Hirofumi Mako. Please take a look.
Description:
Fix pattern detection for replacing shifts by rotation.
BUG=2499
[email protected]
Please review this at https://chromiumcodereview.appspot.com/12047015/
SVN Base: https://v8.googlecode.com/svn/branches/bleeding_edge
Affected files:
M src/hydrogen.cc
A + test/mjsunit/regress/regress-2499.js
Index: src/hydrogen.cc
diff --git a/src/hydrogen.cc b/src/hydrogen.cc
index
335a40c65ef21cac7328c5fcff4606d1532cba00..eb72a3d5c10421ea09eee9427344ff29d21d3622
100644
--- a/src/hydrogen.cc
+++ b/src/hydrogen.cc
@@ -8464,6 +8464,7 @@ static bool ShiftAmountsAllowReplaceByRotate(HValue*
sa,
HValue* const32_minus_sa) {
if (!const32_minus_sa->IsSub()) return false;
HSub* sub = HSub::cast(const32_minus_sa);
+ if (sa != sub->right()) return false;
HValue* const32 = sub->left();
if (!const32->IsConstant() ||
HConstant::cast(const32)->Integer32Value() != 32) {
@@ -8492,6 +8493,7 @@ bool HOptimizedGraphBuilder::MatchRotateRight(HValue*
left,
} else {
return false;
}
+ if (shl->left() != shr->left()) return false;
if (!ShiftAmountsAllowReplaceByRotate(shl->right(), shr->right()) &&
!ShiftAmountsAllowReplaceByRotate(shr->right(), shl->right())) {
Index: test/mjsunit/regress/regress-2499.js
diff --git a/test/mjsunit/regress/regress-110509.js
b/test/mjsunit/regress/regress-2499.js
similarity index 85%
copy from test/mjsunit/regress/regress-110509.js
copy to test/mjsunit/regress/regress-2499.js
index
132bd233bee32f6c84061049224ea43901dae06a..52aad874db6fcdc89f5ee1ae4db45304e64b0e77
100644
--- a/test/mjsunit/regress/regress-110509.js
+++ b/test/mjsunit/regress/regress-2499.js
@@ -1,4 +1,4 @@
-// Copyright 2012 the V8 project authors. All rights reserved.
+// 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:
@@ -27,15 +27,14 @@
// Flags: --allow-natives-syntax
-// Verify that LRandom preserves rsi correctly.
-
-function foo() {
- Math.random();
- new Function("");
+function foo(word, nBits) {
+ return (word[1] >>> nBits) | (word[0] << (32 - nBits));
}
-foo();
-foo();
-foo();
+word = [0x1001, 0];
+
+var expected = foo(word, 1);
+foo(word, 1);
%OptimizeFunctionOnNextCall(foo);
-foo();
+var optimized = foo(word, 1);
+assertEquals(expected, optimized)
--
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