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Fix an obvious typo in the loop vectorizer where the cost model uses the wrong variable. The variable BlockCost is ignored.

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We don't have tests for the effect of if-conversion loops because it requires a big test (that includes if-converted loops) and it is difficult to find and balance a loop to do the right thing.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186845 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Nadav Rotem 2013-07-22 17:10:48 +00:00
parent 6303ef1fb7
commit b987c40548
1 changed files with 2 additions and 2 deletions
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4
lib/Transforms/Vectorize/LoopVectorize.cpp
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@ -4390,7 +4390,7 @@ unsigned LoopVectorizationCostModel::expectedCost(unsigned VF) {
continue; continue;
unsigned C = getInstructionCost(it, VF); unsigned C = getInstructionCost(it, VF);
Cost += C; BlockCost += C;
DEBUG(dbgs() << "LV: Found an estimated cost of "<< C <<" for VF " << DEBUG(dbgs() << "LV: Found an estimated cost of "<< C <<" for VF " <<
VF << " For instruction: "<< *it << "\n"); VF << " For instruction: "<< *it << "\n");
} }
@ -4398,7 +4398,7 @@ unsigned LoopVectorizationCostModel::expectedCost(unsigned VF) {
// We assume that if-converted blocks have a 50% chance of being executed. // We assume that if-converted blocks have a 50% chance of being executed.
// When the code is scalar then some of the blocks are avoided due to CF. // When the code is scalar then some of the blocks are avoided due to CF.
// When the code is vectorized we execute all code paths. // When the code is vectorized we execute all code paths.
if (Legal->blockNeedsPredication(*bb) && VF == 1) if (VF == 1 && Legal->blockNeedsPredication(*bb))
BlockCost /= 2; BlockCost /= 2;
Cost += BlockCost; Cost += BlockCost;