Lexer: Don't throw away the hard work SSE did to find a slash.
We can reuse the information and avoid looping over all the bytes again.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@145070 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Lex/Lexer.cpp b/lib/Lex/Lexer.cpp
index 796110a..a115579 100644
--- a/lib/Lex/Lexer.cpp
+++ b/lib/Lex/Lexer.cpp
@@ -1916,11 +1916,18 @@
if (C == '/') goto FoundSlash;
#ifdef __SSE2__
- __m128i Slashes = _mm_set_epi8('/', '/', '/', '/', '/', '/', '/', '/',
- '/', '/', '/', '/', '/', '/', '/', '/');
- while (CurPtr+16 <= BufferEnd &&
- _mm_movemask_epi8(_mm_cmpeq_epi8(*(__m128i*)CurPtr, Slashes)) == 0)
+ __m128i Slashes = _mm_set1_epi8('/');
+ while (CurPtr+16 <= BufferEnd) {
+ int cmp = _mm_movemask_epi8(_mm_cmpeq_epi8(*(__m128i*)CurPtr, Slashes));
+ if (cmp != 0) {
+ // Adjust the pointer to the first '/' that was found.
+ CurPtr += llvm::CountTrailingZeros_32(cmp);
+ C = *CurPtr++;
+ assert(C == '/');
+ goto FoundSlash;
+ }
CurPtr += 16;
+ }
#elif __ALTIVEC__
__vector unsigned char Slashes = {
'/', '/', '/', '/', '/', '/', '/', '/',
@@ -1948,8 +1955,8 @@
while (C != '/' && C != '\0')
C = *CurPtr++;
- FoundSlash:
if (C == '/') {
+ FoundSlash:
if (CurPtr[-2] == '*') // We found the final */. We're done!
break;