diff options
Diffstat (limited to 'lib/Transforms')
| -rw-r--r-- | lib/Transforms/Scalar/LoopUnrollPass.cpp | 15 |
1 files changed, 0 insertions, 15 deletions
diff --git a/lib/Transforms/Scalar/LoopUnrollPass.cpp b/lib/Transforms/Scalar/LoopUnrollPass.cpp index 90eb857c85..80b263a30c 100644 --- a/lib/Transforms/Scalar/LoopUnrollPass.cpp +++ b/lib/Transforms/Scalar/LoopUnrollPass.cpp @@ -99,21 +99,6 @@ static unsigned ApproximateLoopSize(const Loop *L, unsigned &NumCalls) { unsigned LoopSize = Metrics.NumInsts; - // If we can identify the induction variable, we know that it will become - // constant when we unroll the loop, so factor that into our loop size - // estimate. - // FIXME: We have to divide by InlineConstants::InstrCost because the - // measure returned by CountCodeReductionForConstant is not an instruction - // count, but rather a weight as defined by InlineConstants. It would - // probably be a good idea to standardize on a single weighting scheme by - // pushing more of the logic for weighting into CodeMetrics. - if (PHINode *IndVar = L->getCanonicalInductionVariable()) { - unsigned SizeDecrease = Metrics.CountCodeReductionForConstant(IndVar); - // NOTE: Because SizeDecrease is a fuzzy estimate, we don't want to allow - // it to totally negate the cost of unrolling a loop. - SizeDecrease = SizeDecrease > LoopSize / 2 ? LoopSize / 2 : SizeDecrease; - } - // Don't allow an estimate of size zero. This would allows unrolling of loops // with huge iteration counts, which is a compile time problem even if it's // not a problem for code quality. |