Revision: 10321
Author: [email protected]
Date: Tue Jan 3 02:45:28 2012
Log: Improve performance of Math.min and Math.max for the case of two
arguments.
BUG=v8:1325
TEST=
Review URL: http://codereview.chromium.org/9065008
http://code.google.com/p/v8/source/detail?r=10321
Modified:
/branches/bleeding_edge/src/math.js
=======================================
--- /branches/bleeding_edge/src/math.js Fri Nov 25 05:15:31 2011
+++ /branches/bleeding_edge/src/math.js Tue Jan 3 02:45:28 2012
@@ -1,4 +1,4 @@
-// Copyright 2006-2008 the V8 project authors. All rights reserved.
+// Copyright 2012 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:
@@ -119,6 +119,19 @@
// ECMA 262 - 15.8.2.11
function MathMax(arg1, arg2) { // length == 2
var length = %_ArgumentsLength();
+ if (length == 2) {
+ if (!IS_NUMBER(arg1)) arg1 = NonNumberToNumber(arg1);
+ if (!IS_NUMBER(arg2)) arg2 = NonNumberToNumber(arg2);
+ if (arg2 > arg1) return arg2;
+ if (arg1 > arg2) return arg1;
+ if (arg1 == arg2) {
+ // Make sure -0 is considered less than +0. -0 is never a Smi, +0
can be
+ // a Smi or a heap number.
+ return (arg1 == 0 && !%_IsSmi(arg1) && 1 / arg1 < 0) ? arg2 : arg1;
+ }
+ // All comparisons failed, one of the arguments must be NaN.
+ return 0/0; // Compiler constant-folds this to NaN.
+ }
if (length == 0) {
return -1/0; // Compiler constant-folds this to -Infinity.
}
@@ -131,7 +144,7 @@
if (NUMBER_IS_NAN(n)) return n;
// Make sure +0 is considered greater than -0. -0 is never a Smi, +0
can be
// a Smi or heap number.
- if (n > r || (r === 0 && n === 0 && !%_IsSmi(r) && 1 / r < 0)) r = n;
+ if (n > r || (r == 0 && n == 0 && !%_IsSmi(r) && 1 / r < 0)) r = n;
}
return r;
}
@@ -139,6 +152,19 @@
// ECMA 262 - 15.8.2.12
function MathMin(arg1, arg2) { // length == 2
var length = %_ArgumentsLength();
+ if (length == 2) {
+ if (!IS_NUMBER(arg1)) arg1 = NonNumberToNumber(arg1);
+ if (!IS_NUMBER(arg2)) arg2 = NonNumberToNumber(arg2);
+ if (arg2 > arg1) return arg1;
+ if (arg1 > arg2) return arg2;
+ if (arg1 == arg2) {
+ // Make sure -0 is considered less than +0. -0 is never a Smi, +0
can be
+ // a Smi or a heap number.
+ return (arg1 == 0 && !%_IsSmi(arg1) && 1 / arg1 < 0) ? arg1 : arg2;
+ }
+ // All comparisons failed, one of the arguments must be NaN.
+ return 0/0; // Compiler constant-folds this to NaN.
+ }
if (length == 0) {
return 1/0; // Compiler constant-folds this to Infinity.
}
@@ -149,9 +175,9 @@
var n = %_Arguments(i);
if (!IS_NUMBER(n)) n = NonNumberToNumber(n);
if (NUMBER_IS_NAN(n)) return n;
- // Make sure -0 is considered less than +0. -0 is never a Smi, +0 can
b a
+ // Make sure -0 is considered less than +0. -0 is never a Smi, +0 can
be a
// Smi or a heap number.
- if (n < r || (r === 0 && n === 0 && !%_IsSmi(n) && 1 / n < 0)) r = n;
+ if (n < r || (r == 0 && n == 0 && !%_IsSmi(n) && 1 / n < 0)) r = n;
}
return r;
}
--
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