[llvm-commits] [llvm] r92896 - /llvm/trunk/lib/Support/StringRef.cpp
Douglas Gregor
dgregor at apple.com
Wed Jan 6 18:24:07 PST 2010
Author: dgregor
Date: Wed Jan 6 20:24:06 2010
New Revision: 92896
URL: http://llvm.org/viewvc/llvm-project?rev=92896&view=rev
Log:
More trivial optimizations to a function well outside the critical path
Modified:
llvm/trunk/lib/Support/StringRef.cpp
Modified: llvm/trunk/lib/Support/StringRef.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Support/StringRef.cpp?rev=92896&r1=92895&r2=92896&view=diff
==============================================================================
--- llvm/trunk/lib/Support/StringRef.cpp (original)
+++ llvm/trunk/lib/Support/StringRef.cpp Wed Jan 6 20:24:06 2010
@@ -8,7 +8,6 @@
//===----------------------------------------------------------------------===//
#include "llvm/ADT/StringRef.h"
-#include <cstring>
using namespace llvm;
@@ -52,21 +51,18 @@
size_type m = size();
size_type n = Other.size();
- unsigned SmallPrevious[32];
- unsigned SmallCurrent[32];
-
- unsigned *previous = SmallPrevious;
- unsigned *current = SmallCurrent;
- if (n + 1 > 32) {
- previous = new unsigned [n+1];
- current = new unsigned [n+1];
- }
+ const unsigned SmallBufferSize = 64;
+ unsigned SmallBuffer[SmallBufferSize];
+ unsigned *Allocated = 0;
+ unsigned *previous = SmallBuffer;
+ if (2*(n + 1) > SmallBufferSize)
+ Allocated = previous = new unsigned [2*(n+1)];
+ unsigned *current = previous + (n + 1);
for (unsigned i = 0; i <= n; ++i)
previous[i] = i;
for (size_type y = 1; y <= m; ++y) {
- std::memset(current, 0, (n + 1) * sizeof(unsigned));
current[0] = y;
for (size_type x = 1; x <= n; ++x) {
if (AllowReplacements) {
@@ -85,10 +81,7 @@
}
unsigned Result = previous[n];
- if (n + 1 > 32) {
- delete [] previous;
- delete [] current;
- }
+ delete [] Allocated;
return Result;
}
More information about the llvm-commits
mailing list