#include "llvm/ADT/Statistic.h"
#include "llvm/Analysis/AssumptionCache.h"
#include "llvm/Analysis/LoopInfo.h"
-#include "llvm/Analysis/OptimizationRemarkEmitter.h"
#include "llvm/Analysis/ScalarEvolution.h"
#include "llvm/Analysis/ScalarEvolutionExpander.h"
#include "llvm/Analysis/TargetTransformInfo.h"
STATISTIC(NumHWLoops, "Number of loops converted to hardware loops");
-#ifndef NDEBUG
-static void debugHWLoopFailure(const StringRef DebugMsg,
- Instruction *I) {
- dbgs() << "HWLoops: " << DebugMsg;
- if (I)
- dbgs() << ' ' << *I;
- else
- dbgs() << '.';
- dbgs() << '\n';
-}
-#endif
-
-static OptimizationRemarkAnalysis
-createHWLoopAnalysis(StringRef RemarkName, Loop *L, Instruction *I) {
- Value *CodeRegion = L->getHeader();
- DebugLoc DL = L->getStartLoc();
-
- if (I) {
- CodeRegion = I->getParent();
- // If there is no debug location attached to the instruction, revert back to
- // using the loop's.
- if (I->getDebugLoc())
- DL = I->getDebugLoc();
- }
-
- OptimizationRemarkAnalysis R(DEBUG_TYPE, RemarkName, DL, CodeRegion);
- R << "hardware-loop not created: ";
- return R;
-}
-
namespace {
- void reportHWLoopFailure(const StringRef Msg, const StringRef ORETag,
- OptimizationRemarkEmitter *ORE, Loop *TheLoop, Instruction *I = nullptr) {
- LLVM_DEBUG(debugHWLoopFailure(Msg, I));
- ORE->emit(createHWLoopAnalysis(ORETag, TheLoop, I) << Msg);
- }
-
using TTI = TargetTransformInfo;
class HardwareLoops : public FunctionPass {
AU.addRequired<ScalarEvolutionWrapperPass>();
AU.addRequired<AssumptionCacheTracker>();
AU.addRequired<TargetTransformInfoWrapperPass>();
- AU.addRequired<OptimizationRemarkEmitterWrapperPass>();
}
// Try to convert the given Loop into a hardware loop.
ScalarEvolution *SE = nullptr;
LoopInfo *LI = nullptr;
const DataLayout *DL = nullptr;
- OptimizationRemarkEmitter *ORE = nullptr;
const TargetTransformInfo *TTI = nullptr;
DominatorTree *DT = nullptr;
bool PreserveLCSSA = false;
public:
HardwareLoop(HardwareLoopInfo &Info, ScalarEvolution &SE,
- const DataLayout &DL,
- OptimizationRemarkEmitter *ORE) :
- SE(SE), DL(DL), ORE(ORE), L(Info.L), M(L->getHeader()->getModule()),
+ const DataLayout &DL) :
+ SE(SE), DL(DL), L(Info.L), M(L->getHeader()->getModule()),
ExitCount(Info.ExitCount),
CountType(Info.CountType),
ExitBranch(Info.ExitBranch),
private:
ScalarEvolution &SE;
const DataLayout &DL;
- OptimizationRemarkEmitter *ORE = nullptr;
Loop *L = nullptr;
Module *M = nullptr;
const SCEV *ExitCount = nullptr;
DT = &getAnalysis<DominatorTreeWrapperPass>().getDomTree();
TTI = &getAnalysis<TargetTransformInfoWrapperPass>().getTTI(F);
DL = &F.getParent()->getDataLayout();
- ORE = &getAnalysis<OptimizationRemarkEmitterWrapperPass>().getORE();
auto *TLIP = getAnalysisIfAvailable<TargetLibraryInfoWrapperPass>();
LibInfo = TLIP ? &TLIP->getTLI(F) : nullptr;
PreserveLCSSA = mustPreserveAnalysisID(LCSSAID);
// converted and the parent loop doesn't support containing a hardware loop.
bool HardwareLoops::TryConvertLoop(Loop *L) {
// Process nested loops first.
- for (Loop::iterator I = L->begin(), E = L->end(); I != E; ++I) {
- if (TryConvertLoop(*I)) {
- reportHWLoopFailure("nested hardware-loops not supported", "HWLoopNested",
- ORE, L);
+ for (Loop::iterator I = L->begin(), E = L->end(); I != E; ++I)
+ if (TryConvertLoop(*I))
return true; // Stop search.
- }
- }
HardwareLoopInfo HWLoopInfo(L);
- if (!HWLoopInfo.canAnalyze(*LI)) {
- reportHWLoopFailure("cannot analyze loop, irreducible control flow",
- "HWLoopCannotAnalyze", ORE, L);
+ if (!HWLoopInfo.canAnalyze(*LI))
return false;
- }
- if (!ForceHardwareLoops &&
- !TTI->isHardwareLoopProfitable(L, *SE, *AC, LibInfo, HWLoopInfo)) {
- reportHWLoopFailure("it's not profitable to create a hardware-loop",
- "HWLoopNotProfitable", ORE, L);
- return false;
- }
+ if (TTI->isHardwareLoopProfitable(L, *SE, *AC, LibInfo, HWLoopInfo) ||
+ ForceHardwareLoops) {
+
+ // Allow overriding of the counter width and loop decrement value.
+ if (CounterBitWidth.getNumOccurrences())
+ HWLoopInfo.CountType =
+ IntegerType::get(M->getContext(), CounterBitWidth);
- // Allow overriding of the counter width and loop decrement value.
- if (CounterBitWidth.getNumOccurrences())
- HWLoopInfo.CountType =
- IntegerType::get(M->getContext(), CounterBitWidth);
+ if (LoopDecrement.getNumOccurrences())
+ HWLoopInfo.LoopDecrement =
+ ConstantInt::get(HWLoopInfo.CountType, LoopDecrement);
- if (LoopDecrement.getNumOccurrences())
- HWLoopInfo.LoopDecrement =
- ConstantInt::get(HWLoopInfo.CountType, LoopDecrement);
+ MadeChange |= TryConvertLoop(HWLoopInfo);
+ return MadeChange && (!HWLoopInfo.IsNestingLegal && !ForceNestedLoop);
+ }
- MadeChange |= TryConvertLoop(HWLoopInfo);
- return MadeChange && (!HWLoopInfo.IsNestingLegal && !ForceNestedLoop);
+ return false;
}
bool HardwareLoops::TryConvertLoop(HardwareLoopInfo &HWLoopInfo) {
LLVM_DEBUG(dbgs() << "HWLoops: Try to convert profitable loop: " << *L);
if (!HWLoopInfo.isHardwareLoopCandidate(*SE, *LI, *DT, ForceNestedLoop,
- ForceHardwareLoopPHI)) {
- // TODO: there can be many reasons a loop is not considered a
- // candidate, so we should let isHardwareLoopCandidate fill in the
- // reason and then report a better message here.
- reportHWLoopFailure("loop is not a candidate", "HWLoopNoCandidate", ORE, L);
+ ForceHardwareLoopPHI))
return false;
- }
assert(
(HWLoopInfo.ExitBlock && HWLoopInfo.ExitBranch && HWLoopInfo.ExitCount) &&
if (!Preheader)
return false;
- HardwareLoop HWLoop(HWLoopInfo, *SE, *DL, ORE);
+ HardwareLoop HWLoop(HWLoopInfo, *SE, *DL);
HWLoop.Create();
++NumHWLoops;
return true;
void HardwareLoop::Create() {
LLVM_DEBUG(dbgs() << "HWLoops: Converting loop..\n");
-
+
Value *LoopCountInit = InitLoopCount();
- if (!LoopCountInit) {
- reportHWLoopFailure("could not safely create a loop count expression",
- "HWLoopNotSafe", ORE, L);
+ if (!LoopCountInit)
return;
- }
InsertIterationSetup(LoopCountInit);
projects / llvm / commitdiff