Inlining and unrolling heuristics should be aware of free truncs.
We want heuristics to be based on accurate data, but more importantly
we don't want llvm to behave randomly. A benign trunc inserted by an
upstream pass should not cause a wild swings in optimization
level. See PR11034. It's a general problem with threshold-based
heuristics, but we can make it less bad.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@140919 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/Scalar/LoopUnrollPass.cpp b/lib/Transforms/Scalar/LoopUnrollPass.cpp
index cca7ba0..91395b2 100644
--- a/lib/Transforms/Scalar/LoopUnrollPass.cpp
+++ b/lib/Transforms/Scalar/LoopUnrollPass.cpp
@@ -22,6 +22,7 @@
#include "llvm/Support/Debug.h"
#include "llvm/Support/raw_ostream.h"
#include "llvm/Transforms/Utils/UnrollLoop.h"
+#include "llvm/Target/TargetData.h"
#include <climits>
using namespace llvm;
@@ -107,11 +108,12 @@
}
/// ApproximateLoopSize - Approximate the size of the loop.
-static unsigned ApproximateLoopSize(const Loop *L, unsigned &NumCalls) {
+static unsigned ApproximateLoopSize(const Loop *L, unsigned &NumCalls,
+ const TargetData *TD) {
CodeMetrics Metrics;
for (Loop::block_iterator I = L->block_begin(), E = L->block_end();
I != E; ++I)
- Metrics.analyzeBasicBlock(*I);
+ Metrics.analyzeBasicBlock(*I, TD);
NumCalls = Metrics.NumInlineCandidates;
unsigned LoopSize = Metrics.NumInsts;
@@ -174,8 +176,9 @@
// Enforce the threshold.
if (Threshold != NoThreshold) {
+ const TargetData *TD = getAnalysisIfAvailable<TargetData>();
unsigned NumInlineCandidates;
- unsigned LoopSize = ApproximateLoopSize(L, NumInlineCandidates);
+ unsigned LoopSize = ApproximateLoopSize(L, NumInlineCandidates, TD);
DEBUG(dbgs() << " Loop Size = " << LoopSize << "\n");
if (NumInlineCandidates != 0) {
DEBUG(dbgs() << " Not unrolling loop with inlinable calls.\n");