From 14cc2e25c51a4188b263d01c2e8c2ae976587b83 Mon Sep 17 00:00:00 2001 From: Adam Nemet Date: Wed, 18 Feb 2015 03:42:57 +0000 Subject: [PATCH] [LoopAccesses] Cache the result of canVectorizeMemory LAA will be an on-demand analysis pass, so we need to cache the result of the analysis. canVectorizeMemory is renamed to analyzeLoop which computes the result. canVectorizeMemory becomes the query function for the cached result. This is part of the patchset that converts LoopAccessAnalysis into an actual analysis pass. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@229624 91177308-0d34-0410-b5e6-96231b3b80d8 --- include/llvm/Analysis/LoopAccessAnalysis.h | 12 ++++++-- lib/Analysis/LoopAccessAnalysis.cpp | 33 +++++++++++++--------- lib/Transforms/Vectorize/LoopVectorize.cpp | 4 +-- 3 files changed, 31 insertions(+), 18 deletions(-) diff --git a/include/llvm/Analysis/LoopAccessAnalysis.h b/include/llvm/Analysis/LoopAccessAnalysis.h index 93ee959bfa7..0cdde4c2564 100644 --- a/include/llvm/Analysis/LoopAccessAnalysis.h +++ b/include/llvm/Analysis/LoopAccessAnalysis.h @@ -134,11 +134,14 @@ public: const TargetLibraryInfo *TLI, AliasAnalysis *AA, DominatorTree *DT) : TheLoop(L), SE(SE), DL(DL), TLI(TLI), AA(AA), DT(DT), NumLoads(0), - NumStores(0), MaxSafeDepDistBytes(-1U) {} + NumStores(0), MaxSafeDepDistBytes(-1U), CanVecMem(false) {} + + /// \brief Analyze the loop. Replaces symbolic strides using Strides. + void analyzeLoop(ValueToValueMap &Strides); /// Return true we can analyze the memory accesses in the loop and there are - /// no memory dependence cycles. Replaces symbolic strides using Strides. - bool canVectorizeMemory(ValueToValueMap &Strides); + /// no memory dependence cycles. + bool canVectorizeMemory() { return CanVecMem; } RuntimePointerCheck *getRuntimePointerCheck() { return &PtrRtCheck; } @@ -182,6 +185,9 @@ private: unsigned MaxSafeDepDistBytes; + /// \brief Cache the result of analyzeLoop. + bool CanVecMem; + /// \brief The diagnostics report generated for the analysis. E.g. why we /// couldn't analyze the loop. Optional Report; diff --git a/lib/Analysis/LoopAccessAnalysis.cpp b/lib/Analysis/LoopAccessAnalysis.cpp index 927ae494548..6ebb0eff812 100644 --- a/lib/Analysis/LoopAccessAnalysis.cpp +++ b/lib/Analysis/LoopAccessAnalysis.cpp @@ -812,7 +812,7 @@ bool MemoryDepChecker::areDepsSafe(AccessAnalysis::DepCandidates &AccessSets, return true; } -bool LoopAccessInfo::canVectorizeMemory(ValueToValueMap &Strides) { +void LoopAccessInfo::analyzeLoop(ValueToValueMap &Strides) { typedef SmallVector ValueVector; typedef SmallPtrSet ValueSet; @@ -855,7 +855,8 @@ bool LoopAccessInfo::canVectorizeMemory(ValueToValueMap &Strides) { emitAnalysis(VectorizationReport(Ld) << "read with atomic ordering or volatile read"); DEBUG(dbgs() << "LV: Found a non-simple load.\n"); - return false; + CanVecMem = false; + return; } NumLoads++; Loads.push_back(Ld); @@ -869,13 +870,15 @@ bool LoopAccessInfo::canVectorizeMemory(ValueToValueMap &Strides) { if (!St) { emitAnalysis(VectorizationReport(it) << "instruction cannot be vectorized"); - return false; + CanVecMem = false; + return; } if (!St->isSimple() && !IsAnnotatedParallel) { emitAnalysis(VectorizationReport(St) << "write with atomic ordering or volatile write"); DEBUG(dbgs() << "LV: Found a non-simple store.\n"); - return false; + CanVecMem = false; + return; } NumStores++; Stores.push_back(St); @@ -891,7 +894,8 @@ bool LoopAccessInfo::canVectorizeMemory(ValueToValueMap &Strides) { // care if the pointers are *restrict*. if (!Stores.size()) { DEBUG(dbgs() << "LV: Found a read-only loop!\n"); - return true; + CanVecMem = true; + return; } AccessAnalysis::DepCandidates DependentAccesses; @@ -914,7 +918,8 @@ bool LoopAccessInfo::canVectorizeMemory(ValueToValueMap &Strides) { VectorizationReport(ST) << "write to a loop invariant address could not be vectorized"); DEBUG(dbgs() << "LV: We don't allow storing to uniform addresses\n"); - return false; + CanVecMem = false; + return; } // If we did *not* see this pointer before, insert it to the read-write @@ -937,7 +942,8 @@ bool LoopAccessInfo::canVectorizeMemory(ValueToValueMap &Strides) { DEBUG(dbgs() << "LV: A loop annotated parallel, ignore memory dependency " << "checks.\n"); - return true; + CanVecMem = true; + return; } for (I = Loads.begin(), IE = Loads.end(); I != IE; ++I) { @@ -972,7 +978,8 @@ bool LoopAccessInfo::canVectorizeMemory(ValueToValueMap &Strides) { // other reads in this loop then is it safe to vectorize. if (NumReadWrites == 1 && NumReads == 0) { DEBUG(dbgs() << "LV: Found a write-only loop!\n"); - return true; + CanVecMem = true; + return; } // Build dependence sets and check whether we need a runtime pointer bounds @@ -1013,12 +1020,13 @@ bool LoopAccessInfo::canVectorizeMemory(ValueToValueMap &Strides) { DEBUG(dbgs() << "LV: We can't vectorize because we can't find " << "the array bounds.\n"); PtrRtCheck.reset(); - return false; + CanVecMem = false; + return; } PtrRtCheck.Need = NeedRTCheck; - bool CanVecMem = true; + CanVecMem = true; if (Accesses.isDependencyCheckNeeded()) { DEBUG(dbgs() << "LV: Checking memory dependencies\n"); CanVecMem = DepChecker.areDepsSafe( @@ -1051,7 +1059,8 @@ bool LoopAccessInfo::canVectorizeMemory(ValueToValueMap &Strides) { << " dependent memory operations checked at runtime"); DEBUG(dbgs() << "LV: Can't vectorize with memory checks\n"); PtrRtCheck.reset(); - return false; + CanVecMem = false; + return; } CanVecMem = true; @@ -1064,8 +1073,6 @@ bool LoopAccessInfo::canVectorizeMemory(ValueToValueMap &Strides) { DEBUG(dbgs() << "LV: We" << (NeedRTCheck ? "" : " don't") << " need a runtime memory check.\n"); - - return CanVecMem; } bool LoopAccessInfo::blockNeedsPredication(BasicBlock *BB) { diff --git a/lib/Transforms/Vectorize/LoopVectorize.cpp b/lib/Transforms/Vectorize/LoopVectorize.cpp index abb38d19ea1..1def103d970 100644 --- a/lib/Transforms/Vectorize/LoopVectorize.cpp +++ b/lib/Transforms/Vectorize/LoopVectorize.cpp @@ -3825,11 +3825,11 @@ void LoopVectorizationLegality::collectLoopUniforms() { } bool LoopVectorizationLegality::canVectorizeMemory() { - bool Success = LAI.canVectorizeMemory(Strides); + LAI.analyzeLoop(Strides); auto &OptionalReport = LAI.getReport(); if (OptionalReport) emitAnalysis(*OptionalReport); - return Success; + return LAI.canVectorizeMemory(); } static bool hasMultipleUsesOf(Instruction *I, -- 2.34.1