[LoopUnroll] Fix truncation bug in canUnrollCompletely.
Summary:
canUnrollCompletely takes `unsigned` values for `UnrolledCost` and
`RolledDynamicCost` but is passed in `uint64_t`s that are silently
truncated. Because of this, when `UnrolledSize` is a large integer
that has a small remainder with UINT32_MAX, LLVM tries to completely
unroll loops with high trip counts.
Reviewers: mzolotukhin, chandlerc
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D10293
llvm-svn: 239218
diff --git a/llvm/lib/Transforms/Scalar/LoopUnrollPass.cpp b/llvm/lib/Transforms/Scalar/LoopUnrollPass.cpp
index d8ba964..e831d83 100644
--- a/llvm/lib/Transforms/Scalar/LoopUnrollPass.cpp
+++ b/llvm/lib/Transforms/Scalar/LoopUnrollPass.cpp
@@ -227,7 +227,7 @@
bool canUnrollCompletely(Loop *L, unsigned Threshold,
unsigned PercentDynamicCostSavedThreshold,
unsigned DynamicCostSavingsDiscount,
- unsigned UnrolledCost, unsigned RolledDynamicCost);
+ uint64_t UnrolledCost, uint64_t RolledDynamicCost);
};
}
@@ -768,8 +768,8 @@
bool LoopUnroll::canUnrollCompletely(Loop *L, unsigned Threshold,
unsigned PercentDynamicCostSavedThreshold,
unsigned DynamicCostSavingsDiscount,
- unsigned UnrolledCost,
- unsigned RolledDynamicCost) {
+ uint64_t UnrolledCost,
+ uint64_t RolledDynamicCost) {
if (Threshold == NoThreshold) {
DEBUG(dbgs() << " Can fully unroll, because no threshold is set.\n");