From 75277b9f70a086b0dcdf5c71cdca6d58e9d29941 Mon Sep 17 00:00:00 2001 From: Hal Finkel Date: Tue, 14 Oct 2014 22:59:49 +0000 Subject: [PATCH] [LoopVectorize] Ignore @llvm.assume for cost estimates and legality A few minor changes to prevent @llvm.assume from interfering with loop vectorization. First, treat @llvm.assume like the lifetime intrinsics, which are scalarized (but don't otherwise interfere with the legality checking). Second, ignore the cost of ephemeral instructions in the loop (these will go away anyway during CodeGen). Alignment assumptions and other uses of @llvm.assume can often end up inside of loops that should be vectorized (this is not uncommon for assumptions generated by __attribute__((align_value(n))), for example). git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219741 91177308-0d34-0410-b5e6-96231b3b80d8 --- include/llvm/Transforms/Utils/VectorUtils.h | 2 +- lib/Transforms/Vectorize/LoopVectorize.cpp | 35 ++++++- test/Transforms/LoopVectorize/X86/assume.ll | 100 ++++++++++++++++++++ 3 files changed, 133 insertions(+), 4 deletions(-) create mode 100644 test/Transforms/LoopVectorize/X86/assume.ll diff --git a/include/llvm/Transforms/Utils/VectorUtils.h b/include/llvm/Transforms/Utils/VectorUtils.h index 44a7149eee9..f796e570184 100644 --- a/include/llvm/Transforms/Utils/VectorUtils.h +++ b/include/llvm/Transforms/Utils/VectorUtils.h @@ -99,7 +99,7 @@ getIntrinsicIDForCall(CallInst *CI, const TargetLibraryInfo *TLI) { if (IntrinsicInst *II = dyn_cast(CI)) { Intrinsic::ID ID = II->getIntrinsicID(); if (isTriviallyVectorizable(ID) || ID == Intrinsic::lifetime_start || - ID == Intrinsic::lifetime_end) + ID == Intrinsic::lifetime_end || ID == Intrinsic::assume) return ID; else return Intrinsic::not_intrinsic; diff --git a/lib/Transforms/Vectorize/LoopVectorize.cpp b/lib/Transforms/Vectorize/LoopVectorize.cpp index d45b8d8a72b..f3bd96c028c 100644 --- a/lib/Transforms/Vectorize/LoopVectorize.cpp +++ b/lib/Transforms/Vectorize/LoopVectorize.cpp @@ -55,7 +55,9 @@ #include "llvm/ADT/StringExtras.h" #include "llvm/Analysis/AliasAnalysis.h" #include "llvm/Analysis/AliasSetTracker.h" +#include "llvm/Analysis/AssumptionTracker.h" #include "llvm/Analysis/BlockFrequencyInfo.h" +#include "llvm/Analysis/CodeMetrics.h" #include "llvm/Analysis/LoopInfo.h" #include "llvm/Analysis/LoopIterator.h" #include "llvm/Analysis/LoopPass.h" @@ -884,8 +886,12 @@ public: LoopVectorizationLegality *Legal, const TargetTransformInfo &TTI, const DataLayout *DL, const TargetLibraryInfo *TLI, - const Function *F, const LoopVectorizeHints *Hints) - : TheLoop(L), SE(SE), LI(LI), Legal(Legal), TTI(TTI), DL(DL), TLI(TLI), TheFunction(F), Hints(Hints) {} + AssumptionTracker *AT, const Function *F, + const LoopVectorizeHints *Hints) + : TheLoop(L), SE(SE), LI(LI), Legal(Legal), TTI(TTI), DL(DL), TLI(TLI), + AT(AT), TheFunction(F), Hints(Hints) { + CodeMetrics::collectEphemeralValues(L, AT, EphValues); + } /// Information about vectorization costs struct VectorizationFactor { @@ -954,6 +960,9 @@ private: *TheFunction, DL, Message.str()); } + /// Values used only by @llvm.assume calls. + SmallPtrSet EphValues; + /// The loop that we evaluate. Loop *TheLoop; /// Scev analysis. @@ -968,6 +977,8 @@ private: const DataLayout *DL; /// Target Library Info. const TargetLibraryInfo *TLI; + /// Tracker for @llvm.assume. + AssumptionTracker *AT; const Function *TheFunction; // Loop Vectorize Hint. const LoopVectorizeHints *Hints; @@ -1251,6 +1262,7 @@ struct LoopVectorize : public FunctionPass { BlockFrequencyInfo *BFI; TargetLibraryInfo *TLI; AliasAnalysis *AA; + AssumptionTracker *AT; bool DisableUnrolling; bool AlwaysVectorize; @@ -1266,6 +1278,7 @@ struct LoopVectorize : public FunctionPass { BFI = &getAnalysis(); TLI = getAnalysisIfAvailable(); AA = &getAnalysis(); + AT = &getAnalysis(); // Compute some weights outside of the loop over the loops. Compute this // using a BranchProbability to re-use its scaling math. @@ -1384,7 +1397,8 @@ struct LoopVectorize : public FunctionPass { } // Use the cost model. - LoopVectorizationCostModel CM(L, SE, LI, &LVL, *TTI, DL, TLI, F, &Hints); + LoopVectorizationCostModel CM(L, SE, LI, &LVL, *TTI, DL, TLI, AT, F, + &Hints); // Check the function attributes to find out if this function should be // optimized for size. @@ -1471,6 +1485,7 @@ struct LoopVectorize : public FunctionPass { } void getAnalysisUsage(AnalysisUsage &AU) const override { + AU.addRequired(); AU.addRequiredID(LoopSimplifyID); AU.addRequiredID(LCSSAID); AU.addRequired(); @@ -3361,6 +3376,7 @@ void InnerLoopVectorizer::vectorizeBlockInLoop(BasicBlock *BB, PhiVector *PV) { Intrinsic::ID ID = getIntrinsicIDForCall(CI, TLI); assert(ID && "Not an intrinsic call!"); switch (ID) { + case Intrinsic::assume: case Intrinsic::lifetime_end: case Intrinsic::lifetime_start: scalarizeInstruction(it); @@ -5457,6 +5473,10 @@ unsigned LoopVectorizationCostModel::getWidestType() { for (BasicBlock::iterator it = BB->begin(), e = BB->end(); it != e; ++it) { Type *T = it->getType(); + // Ignore ephemeral values. + if (EphValues.count(it)) + continue; + // Only examine Loads, Stores and PHINodes. if (!isa(it) && !isa(it) && !isa(it)) continue; @@ -5719,6 +5739,10 @@ LoopVectorizationCostModel::calculateRegisterUsage() { // Ignore instructions that are never used within the loop. if (!Ends.count(I)) continue; + // Ignore ephemeral values. + if (EphValues.count(I)) + continue; + // Remove all of the instructions that end at this location. InstrList &List = TransposeEnds[i]; for (unsigned int j=0, e = List.size(); j < e; ++j) @@ -5759,6 +5783,10 @@ unsigned LoopVectorizationCostModel::expectedCost(unsigned VF) { if (isa(it)) continue; + // Ignore ephemeral values. + if (EphValues.count(it)) + continue; + unsigned C = getInstructionCost(it, VF); // Check if we should override the cost. @@ -6059,6 +6087,7 @@ static const char lv_name[] = "Loop Vectorization"; INITIALIZE_PASS_BEGIN(LoopVectorize, LV_NAME, lv_name, false, false) INITIALIZE_AG_DEPENDENCY(TargetTransformInfo) INITIALIZE_AG_DEPENDENCY(AliasAnalysis) +INITIALIZE_PASS_DEPENDENCY(AssumptionTracker) INITIALIZE_PASS_DEPENDENCY(BlockFrequencyInfo) INITIALIZE_PASS_DEPENDENCY(DominatorTreeWrapperPass) INITIALIZE_PASS_DEPENDENCY(ScalarEvolution) diff --git a/test/Transforms/LoopVectorize/X86/assume.ll b/test/Transforms/LoopVectorize/X86/assume.ll new file mode 100644 index 00000000000..a94e24dd7e9 --- /dev/null +++ b/test/Transforms/LoopVectorize/X86/assume.ll @@ -0,0 +1,100 @@ +; RUN: opt < %s -loop-vectorize -mtriple=x86_64-apple-macosx10.8.0 -mcpu=corei7 -S | FileCheck %s +target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128" +target triple = "x86_64-unknown-linux-gnu" + +; Function Attrs: nounwind uwtable +define void @test1(float* noalias nocapture %a, float* noalias nocapture readonly %b) #0 { +entry: + br label %for.body + +; CHECK-LABEL: @test1 +; CHECK: vector.body: +; CHECK: @llvm.assume +; CHECK: @llvm.assume +; CHECK: @llvm.assume +; CHECK: @llvm.assume +; CHECK: @llvm.assume +; CHECK: @llvm.assume +; CHECK: @llvm.assume +; CHECK: @llvm.assume +; CHECK: for.body: +; CHECK: ret void + +for.body: ; preds = %for.body, %entry + %indvars.iv = phi i64 [ 0, %entry ], [ %indvars.iv.next, %for.body ] + %arrayidx = getelementptr inbounds float* %b, i64 %indvars.iv + %0 = load float* %arrayidx, align 4 + %cmp1 = fcmp ogt float %0, 1.000000e+02 + tail call void @llvm.assume(i1 %cmp1) + %add = fadd float %0, 1.000000e+00 + %arrayidx5 = getelementptr inbounds float* %a, i64 %indvars.iv + store float %add, float* %arrayidx5, align 4 + %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1 + %exitcond = icmp eq i64 %indvars.iv, 1599 + br i1 %exitcond, label %for.end, label %for.body + +for.end: ; preds = %for.body + ret void +} + +; Function Attrs: nounwind +declare void @llvm.assume(i1) #1 + +attributes #0 = { nounwind uwtable } +attributes #1 = { nounwind } + +%struct.data = type { float*, float* } + +; Function Attrs: nounwind uwtable +define void @test2(%struct.data* nocapture readonly %d) #0 { +entry: + %b = getelementptr inbounds %struct.data* %d, i64 0, i32 1 + %0 = load float** %b, align 8 + %ptrint = ptrtoint float* %0 to i64 + %maskedptr = and i64 %ptrint, 31 + %maskcond = icmp eq i64 %maskedptr, 0 + %a = getelementptr inbounds %struct.data* %d, i64 0, i32 0 + %1 = load float** %a, align 8 + %ptrint2 = ptrtoint float* %1 to i64 + %maskedptr3 = and i64 %ptrint2, 31 + %maskcond4 = icmp eq i64 %maskedptr3, 0 + br label %for.body + +; CHECK-LABEL: @test2 +; CHECK: vector.body: +; CHECK: @llvm.assume +; CHECK: @llvm.assume +; CHECK: @llvm.assume +; CHECK: @llvm.assume +; CHECK: @llvm.assume +; CHECK: @llvm.assume +; CHECK: @llvm.assume +; CHECK: @llvm.assume +; CHECK: @llvm.assume +; CHECK: @llvm.assume +; CHECK: @llvm.assume +; CHECK: @llvm.assume +; CHECK: @llvm.assume +; CHECK: @llvm.assume +; CHECK: @llvm.assume +; CHECK: @llvm.assume +; CHECK: for.body: +; CHECK: ret void + +for.body: ; preds = %for.body, %entry + %indvars.iv = phi i64 [ 0, %entry ], [ %indvars.iv.next, %for.body ] + tail call void @llvm.assume(i1 %maskcond) + %arrayidx = getelementptr inbounds float* %0, i64 %indvars.iv + %2 = load float* %arrayidx, align 4 + %add = fadd float %2, 1.000000e+00 + tail call void @llvm.assume(i1 %maskcond4) + %arrayidx5 = getelementptr inbounds float* %1, i64 %indvars.iv + store float %add, float* %arrayidx5, align 4 + %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1 + %exitcond = icmp eq i64 %indvars.iv, 1599 + br i1 %exitcond, label %for.end, label %for.body + +for.end: ; preds = %for.body + ret void +} + -- 2.34.1