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

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

View File

@ -125,19 +125,24 @@ raw_ostream &raw_ostream::operator<<(long N) {
} }
raw_ostream &raw_ostream::operator<<(unsigned long 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)) if (N == static_cast<unsigned long>(N))
return this->operator<<(static_cast<unsigned long>(N)); return this->operator<<(static_cast<unsigned long>(N));
char NumberBuffer[20]; // Otherwise divide into at two or three 10**9 chunks and write out using
char *EndPtr = NumberBuffer+sizeof(NumberBuffer); // long div/mod, this is substantially faster on a 32-bit system.
char *CurPtr = EndPtr; unsigned long Top = 0, Mid = 0, Bot = N % 1000000000;
N /= 1000000000;
while (N) { if (N > 1000000000) {
*--CurPtr = '0' + char(N % 10); Mid = N % 1000000000;
N /= 10; Top = N / 1000000000;
} } else
return write(CurPtr, EndPtr-CurPtr); 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) { raw_ostream &raw_ostream::operator<<(long long N) {