From a8958769ea5583d58ae51931d8b1271c23fd20ea Mon Sep 17 00:00:00 2001 From: Pekka Jaaskelainen Date: Tue, 23 Apr 2013 08:08:51 +0000 Subject: Refuse to (even try to) vectorize loops which have uniform writes, even if erroneously annotated with the parallel loop metadata. Fixes Bug 15794: "Loop Vectorizer: Crashes with the use of llvm.loop.parallel metadata" git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@180081 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/Transforms/Vectorize/LoopVectorize.cpp | 18 +++---- .../X86/illegal-parallel-loop-uniform-write.ll | 58 ++++++++++++++++++++++ 2 files changed, 67 insertions(+), 9 deletions(-) create mode 100644 test/Transforms/LoopVectorize/X86/illegal-parallel-loop-uniform-write.ll diff --git a/lib/Transforms/Vectorize/LoopVectorize.cpp b/lib/Transforms/Vectorize/LoopVectorize.cpp index 0c88ba7835..2e42585e35 100644 --- a/lib/Transforms/Vectorize/LoopVectorize.cpp +++ b/lib/Transforms/Vectorize/LoopVectorize.cpp @@ -2548,13 +2548,6 @@ LoopVectorizationLegality::hasPossibleGlobalWriteReorder( bool LoopVectorizationLegality::canVectorizeMemory() { - if (TheLoop->isAnnotatedParallel()) { - DEBUG(dbgs() - << "LV: A loop annotated parallel, ignore memory dependency " - << "checks.\n"); - return true; - } - typedef SmallVector ValueVector; typedef SmallPtrSet ValueSet; // Holds the Load and Store *instructions*. @@ -2577,7 +2570,7 @@ bool LoopVectorizationLegality::canVectorizeMemory() { if (it->mayReadFromMemory()) { LoadInst *Ld = dyn_cast(it); if (!Ld) return false; - if (!Ld->isSimple()) { + if (!Ld->isSimple() && !TheLoop->isAnnotatedParallel()) { DEBUG(dbgs() << "LV: Found a non-simple load.\n"); return false; } @@ -2589,7 +2582,7 @@ bool LoopVectorizationLegality::canVectorizeMemory() { if (it->mayWriteToMemory()) { StoreInst *St = dyn_cast(it); if (!St) return false; - if (!St->isSimple()) { + if (!St->isSimple() && !TheLoop->isAnnotatedParallel()) { DEBUG(dbgs() << "LV: Found a non-simple store.\n"); return false; } @@ -2636,6 +2629,13 @@ bool LoopVectorizationLegality::canVectorizeMemory() { ReadWrites.insert(std::make_pair(Ptr, ST)); } + if (TheLoop->isAnnotatedParallel()) { + DEBUG(dbgs() + << "LV: A loop annotated parallel, ignore memory dependency " + << "checks.\n"); + return true; + } + for (I = Loads.begin(), IE = Loads.end(); I != IE; ++I) { LoadInst *LD = cast(*I); Value* Ptr = LD->getPointerOperand(); diff --git a/test/Transforms/LoopVectorize/X86/illegal-parallel-loop-uniform-write.ll b/test/Transforms/LoopVectorize/X86/illegal-parallel-loop-uniform-write.ll new file mode 100644 index 0000000000..bc606f3ebd --- /dev/null +++ b/test/Transforms/LoopVectorize/X86/illegal-parallel-loop-uniform-write.ll @@ -0,0 +1,58 @@ +; RUN: opt < %s -loop-vectorize -force-vector-unroll=1 -force-vector-width=4 -dce -instcombine -S | FileCheck %s + +target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64-S128" +target triple = "x86_64-unknown-linux-gnu" + +;CHECK: @foo +;CHECK-NOT: <4 x + +; Function Attrs: nounwind uwtable +define void @foo(i32* nocapture %a, i32* nocapture %b, i32 %k, i32 %m) #0 { +entry: + %cmp27 = icmp sgt i32 %m, 0 + br i1 %cmp27, label %for.body3.lr.ph.us, label %for.end15 + +for.end.us: ; preds = %for.body3.us + %arrayidx9.us = getelementptr inbounds i32* %b, i64 %indvars.iv33 + %0 = load i32* %arrayidx9.us, align 4, !tbaa !0, !llvm.mem.parallel_loop_access !3 + %add10.us = add nsw i32 %0, 3 + store i32 %add10.us, i32* %arrayidx9.us, align 4, !tbaa !0, !llvm.mem.parallel_loop_access !3 + %indvars.iv.next34 = add i64 %indvars.iv33, 1 + %lftr.wideiv35 = trunc i64 %indvars.iv.next34 to i32 + %exitcond36 = icmp eq i32 %lftr.wideiv35, %m + br i1 %exitcond36, label %for.end15, label %for.body3.lr.ph.us, !llvm.loop.parallel !5 + +for.body3.us: ; preds = %for.body3.us, %for.body3.lr.ph.us + %indvars.iv29 = phi i64 [ 0, %for.body3.lr.ph.us ], [ %indvars.iv.next30, %for.body3.us ] + %1 = trunc i64 %indvars.iv29 to i32 + %add4.us = add i32 %add.us, %1 + %idxprom.us = sext i32 %add4.us to i64 + %arrayidx.us = getelementptr inbounds i32* %a, i64 %idxprom.us + %2 = load i32* %arrayidx.us, align 4, !tbaa !0, !llvm.mem.parallel_loop_access !3 + %add5.us = add nsw i32 %2, 1 + store i32 %add5.us, i32* %arrayidx7.us, align 4, !tbaa !0, !llvm.mem.parallel_loop_access !3 + %indvars.iv.next30 = add i64 %indvars.iv29, 1 + %lftr.wideiv31 = trunc i64 %indvars.iv.next30 to i32 + %exitcond32 = icmp eq i32 %lftr.wideiv31, %m + br i1 %exitcond32, label %for.end.us, label %for.body3.us, !llvm.loop.parallel !4 + +for.body3.lr.ph.us: ; preds = %for.end.us, %entry + %indvars.iv33 = phi i64 [ %indvars.iv.next34, %for.end.us ], [ 0, %entry ] + %3 = trunc i64 %indvars.iv33 to i32 + %add.us = add i32 %3, %k + %arrayidx7.us = getelementptr inbounds i32* %a, i64 %indvars.iv33 + br label %for.body3.us + +for.end15: ; preds = %for.end.us, %entry + ret void +} + +attributes #0 = { nounwind uwtable "less-precise-fpmad"="false" "no-frame-pointer-elim"="false" "no-frame-pointer-elim-non-leaf"="false" "no-infs-fp-math"="false" "no-nans-fp-math"="false" "unsafe-fp-math"="false" "use-soft-float"="false" } + +!0 = metadata !{metadata !"int", metadata !1} +!1 = metadata !{metadata !"omnipotent char", metadata !2} +!2 = metadata !{metadata !"Simple C/C++ TBAA"} +!3 = metadata !{metadata !4, metadata !5} +!4 = metadata !{metadata !4} +!5 = metadata !{metadata !5} + -- cgit v1.2.3