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Implemented fast case for NumberToString where the result is a single character string.

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Review URL: http://codereview.chromium.org/126189

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@2175 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
This commit is contained in:
bak@chromium.org 2009-06-16 06:44:09 +00:00
parent 97482a43bf
commit 03356a0e60
1 changed files with 13 additions and 0 deletions
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13
src/runtime.cc
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@ -2416,6 +2416,19 @@ static Object* Runtime_NumberToRadixString(Arguments args) {
NoHandleAllocation ha;
ASSERT(args.length() == 2);
// Fast case where the result is a one character string.
if (args[0]->IsSmi() && args[1]->IsSmi()) {
int value = Smi::cast(args[0])->value();
int radix = Smi::cast(args[1])->value();
if (value >= 0 && value < radix) {
RUNTIME_ASSERT(radix <= 36);
// Character array used for conversion.
static const char kCharTable[] = "0123456789abcdefghijklmnopqrstuvwxyz";
return Heap::LookupSingleCharacterStringFromCode(kCharTable[value]);
}
}
// Slow case.
CONVERT_DOUBLE_CHECKED(value, args[0]);
if (isnan(value)) {
return Heap::AllocateStringFromAscii(CStrVector("NaN"));