Use a depth-first iteratation in CorrelatedValuePropagation to avoid wasting time trying

to optimize unreachable blocks.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@114105 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Owen Anderson 2010-09-16 18:35:07 +00:00
parent 677c6ecd08
commit ceb9a95957

View File

@ -19,6 +19,7 @@
#include "llvm/Analysis/LazyValueInfo.h"
#include "llvm/Support/CFG.h"
#include "llvm/Transforms/Utils/Local.h"
#include "llvm/ADT/DepthFirstIterator.h"
#include "llvm/ADT/Statistic.h"
using namespace llvm;
@ -166,7 +167,10 @@ bool CorrelatedValuePropagation::runOnFunction(Function &F) {
bool FnChanged = false;
for (Function::iterator FI = F.begin(), FE = F.end(); FI != FE; ++FI) {
// Perform a depth-first walk of the CFG so that we don't waste time
// optimizing unreachable blocks.
for (df_iterator<BasicBlock*> FI = df_begin(&F.getEntryBlock()),
FE = df_end(&F.getEntryBlock()); FI != FE; ++FI) {
bool BBChanged = false;
for (BasicBlock::iterator BI = FI->begin(), BE = FI->end(); BI != BE; ) {
Instruction *II = BI++;
@ -191,7 +195,7 @@ bool CorrelatedValuePropagation::runOnFunction(Function &F) {
// Propagating correlated values might leave cruft around.
// Try to clean it up before we continue.
if (BBChanged)
SimplifyInstructionsInBlock(FI);
SimplifyInstructionsInBlock(*FI);
FnChanged |= BBChanged;
}