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Speed up raw_ostream::<<(unsigned long long) for 32-bit systems by doing most

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div/mods in 32-bits.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@79375 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Daniel Dunbar 2009-08-18 22:24:00 +00:00
parent c0823fe7c6
commit 3b3de924f5
1 changed files with 15 additions and 10 deletions
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25
lib/Support/raw_ostream.cpp
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@ -125,19 +125,24 @@ raw_ostream &raw_ostream::operator<<(long N) {
}
raw_ostream &raw_ostream::operator<<(unsigned long long N) {
// Output using 32-bit div/mod when possible.
// Handle simple case when value fits in long already.
if (N == static_cast<unsigned long>(N))
return this->operator<<(static_cast<unsigned long>(N));
char NumberBuffer[20];
char *EndPtr = NumberBuffer+sizeof(NumberBuffer);
char *CurPtr = EndPtr;
while (N) {
*--CurPtr = '0' + char(N % 10);
N /= 10;
}
return write(CurPtr, EndPtr-CurPtr);
// Otherwise divide into at two or three 10**9 chunks and write out using
// long div/mod, this is substantially faster on a 32-bit system.
unsigned long Top = 0, Mid = 0, Bot = N % 1000000000;
N /= 1000000000;
if (N > 1000000000) {
Mid = N % 1000000000;
Top = N / 1000000000;
} else
Mid = N;
if (Top)
this->operator<<(static_cast<unsigned long>(Top));
this->operator<<(static_cast<unsigned long>(Mid));
return this->operator<<(static_cast<unsigned long>(Bot));
}
raw_ostream &raw_ostream::operator<<(long long N) {