diff options
| -rw-r--r-- | llvm/include/llvm/Support/MathExtras.h | 5 | ||||
| -rw-r--r-- | llvm/lib/Transforms/Utils/LoopUtils.cpp | 14 |
2 files changed, 12 insertions, 7 deletions
diff --git a/llvm/include/llvm/Support/MathExtras.h b/llvm/include/llvm/Support/MathExtras.h index 004a6f5f6eb..37b9669cbee 100644 --- a/llvm/include/llvm/Support/MathExtras.h +++ b/llvm/include/llvm/Support/MathExtras.h @@ -732,6 +732,11 @@ inline uint64_t divideCeil(uint64_t Numerator, uint64_t Denominator) { return alignTo(Numerator, Denominator) / Denominator; } +/// Returns the integer nearest(Numerator / Denominator). +inline uint64_t divideNearest(uint64_t Numerator, uint64_t Denominator) { + return (Numerator + (Denominator / 2)) / Denominator; +} + /// Returns the largest uint64_t less than or equal to \p Value and is /// \p Skew mod \p Align. \p Align must be non-zero inline uint64_t alignDown(uint64_t Value, uint64_t Align, uint64_t Skew = 0) { diff --git a/llvm/lib/Transforms/Utils/LoopUtils.cpp b/llvm/lib/Transforms/Utils/LoopUtils.cpp index b7dd3d75e45..c4c40189fda 100644 --- a/llvm/lib/Transforms/Utils/LoopUtils.cpp +++ b/llvm/lib/Transforms/Utils/LoopUtils.cpp @@ -714,19 +714,19 @@ Optional<unsigned> llvm::getLoopEstimatedTripCount(Loop *L) { // To estimate the number of times the loop body was executed, we want to // know the number of times the backedge was taken, vs. the number of times // we exited the loop. - uint64_t TrueVal, FalseVal; - if (!LatchBR->extractProfMetadata(TrueVal, FalseVal)) + uint64_t BackedgeTakenWeight, LatchExitWeight; + if (!LatchBR->extractProfMetadata(BackedgeTakenWeight, LatchExitWeight)) return None; - if (!TrueVal || !FalseVal) + if (LatchBR->getSuccessor(0) != L->getHeader()) + std::swap(BackedgeTakenWeight, LatchExitWeight); + + if (!BackedgeTakenWeight || !LatchExitWeight) return 0; // Divide the count of the backedge by the count of the edge exiting the loop, // rounding to nearest. - if (LatchBR->getSuccessor(0) == L->getHeader()) - return (TrueVal + (FalseVal / 2)) / FalseVal; - else - return (FalseVal + (TrueVal / 2)) / TrueVal; + return llvm::divideNearest(BackedgeTakenWeight, LatchExitWeight); } bool llvm::hasIterationCountInvariantInParent(Loop *InnerLoop, |
