In OutputString, avoid calling memcpy for really tiny strings.
This speeds up -E on 447.dealII by 5.8%
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@40423 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/Driver/PrintPreprocessedOutput.cpp b/Driver/PrintPreprocessedOutput.cpp
index d1f1cef..e5f4491 100644
--- a/Driver/PrintPreprocessedOutput.cpp
+++ b/Driver/PrintPreprocessedOutput.cpp
@@ -87,7 +87,20 @@
#else
if (OutBufCur+Size >= OutBufEnd)
FlushBuffer();
- memcpy(OutBufCur, Ptr, Size);
+
+ switch (Size) {
+ default:
+ memcpy(OutBufCur, Ptr, Size);
+ break;
+ case 3:
+ OutBufCur[2] = Ptr[2];
+ case 2:
+ OutBufCur[1] = Ptr[1];
+ case 1:
+ OutBufCur[0] = Ptr[0];
+ case 0:
+ break;
+ }
OutBufCur += Size;
#endif
}