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Promoting allocas with the 'single store' fastpath is 

faster than with the 'local to a block' fastpath.  This speeds
up PR1432 from 2.1232 to 2.0686s (2.6%)

llvm-svn: 40818
This commit is contained in:
Chris Lattner 2007-08-04 20:03:23 +00:00
parent 4a930f9444
commit 6b04ecbaf9
1 changed files with 9 additions and 10 deletions
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19
llvm/lib/Transforms/Utils/PromoteMemoryToRegister.cpp
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@ -273,16 +273,6 @@ void PromoteMem2Reg::run() {
// analogous to finding the 'uses' and 'definitions' of each variable.
Info.AnalyzeAlloca(AI);
// If the alloca is only read and written in one basic block, just perform a
// linear sweep over the block to eliminate it.
if (Info.OnlyUsedInOneBlock) {
LocallyUsedAllocas[Info.OnlyBlock].push_back(AI);
// Remove the alloca from the Allocas list, since it will be processed.
RemoveFromAllocasList(AllocaNum);
continue;
}
// If there is only a single store to this value, replace any loads of
// it that are directly dominated by the definition with the value stored.
if (Info.DefiningBlocks.size() == 1) {
@ -303,6 +293,15 @@ void PromoteMem2Reg::run() {
}
}
// If the alloca is only read and written in one basic block, just perform a
// linear sweep over the block to eliminate it.
if (Info.OnlyUsedInOneBlock) {
LocallyUsedAllocas[Info.OnlyBlock].push_back(AI);
// Remove the alloca from the Allocas list, since it will be processed.
RemoveFromAllocasList(AllocaNum);
continue;
}
if (AST)
PointerAllocaValues[AllocaNum] = Info.AllocaPointerVal;