[llvm-commits] CVS: llvm/lib/Transforms/Scalar/SimplifyCFG.cpp

[Chris Lattner]

Changes in directory llvm/lib/Transforms/Scalar:

SimplifyCFG.cpp updated: 1.19 -> 1.20
---
Log message:

switch MarkAliveBlocks over to using SmallPtrSet instead of std::set, speeding
up simplifycfg by 20%



---
Diffs of the changes:  (+5 -5)

 SimplifyCFG.cpp |   10 +++++-----
 1 files changed, 5 insertions(+), 5 deletions(-)


Index: llvm/lib/Transforms/Scalar/SimplifyCFG.cpp
diff -u llvm/lib/Transforms/Scalar/SimplifyCFG.cpp:1.19 llvm/lib/Transforms/Scalar/SimplifyCFG.cpp:1.20
--- llvm/lib/Transforms/Scalar/SimplifyCFG.cpp:1.19	Mon Feb  5 17:32:05 2007
+++ llvm/lib/Transforms/Scalar/SimplifyCFG.cpp	Sat Mar  3 22:20:48 2007
@@ -27,8 +27,8 @@
 #include "llvm/Support/CFG.h"
 #include "llvm/Support/Compiler.h"
 #include "llvm/Pass.h"
+#include "llvm/ADT/SmallPtrSet.h"
 #include "llvm/ADT/Statistic.h"
-#include <set>
 using namespace llvm;
 
 STATISTIC(NumSimpl, "Number of blocks simplified");
@@ -45,9 +45,9 @@
   return new CFGSimplifyPass();
 }
 
-static bool MarkAliveBlocks(BasicBlock *BB, std::set<BasicBlock*> &Reachable) {
-  if (Reachable.count(BB)) return false;
-  Reachable.insert(BB);
+static bool MarkAliveBlocks(BasicBlock *BB,
+                            SmallPtrSet<BasicBlock*, 16> &Reachable) {
+  if (!Reachable.insert(BB)) return false;
 
   // Do a quick scan of the basic block, turning any obviously unreachable
   // instructions into LLVM unreachable insts.  The instruction combining pass
@@ -85,7 +85,7 @@
 // simplify the CFG.
 //
 bool CFGSimplifyPass::runOnFunction(Function &F) {
-  std::set<BasicBlock*> Reachable;
+  SmallPtrSet<BasicBlock*, 16> Reachable;
   bool Changed = MarkAliveBlocks(F.begin(), Reachable);
 
   // If there are unreachable blocks in the CFG...