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author | Bill Wendling <isanbard@gmail.com> | 2013-11-20 06:28:12 +0000 |
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committer | Bill Wendling <isanbard@gmail.com> | 2013-11-20 06:28:12 +0000 |
commit | dd9c5e98c87a33eae1fe0ec9e03bc41f6f3a731d (patch) | |
tree | 848344455baa0d30359ff05aa8c181466261eac0 | |
parent | 8e5b91849a39173b1ce1c15e0e279b94562204b5 (diff) | |
download | llvm-dd9c5e98c87a33eae1fe0ec9e03bc41f6f3a731d.tar.gz llvm-dd9c5e98c87a33eae1fe0ec9e03bc41f6f3a731d.tar.bz2 llvm-dd9c5e98c87a33eae1fe0ec9e03bc41f6f3a731d.tar.xz |
Merging r195162:
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r195162 | arnolds | 2013-11-19 14:20:20 -0800 (Tue, 19 Nov 2013) | 12 lines
SLPVectorizer: Fix stale for Value pointer array
We are slicing an array of Value pointers and process those slices in a loop.
The problem is that we might invalidate a later slice by vectorizing a former
slice.
Use a WeakVH to track the pointer. If the pointer is deleted or RAUW'ed we can
tell.
The test case will only fail when running with libgmalloc.
radar://15498655
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git-svn-id: https://llvm.org/svn/llvm-project/llvm/branches/release_34@195222 91177308-0d34-0410-b5e6-96231b3b80d8
-rw-r--r-- | lib/Transforms/Vectorize/SLPVectorizer.cpp | 30 | ||||
-rw-r--r-- | test/Transforms/LoopVectorize/X86/rauw-bug.ll | 33 |
2 files changed, 63 insertions, 0 deletions
diff --git a/lib/Transforms/Vectorize/SLPVectorizer.cpp b/lib/Transforms/Vectorize/SLPVectorizer.cpp index 0c962d68a9..2b498a88f5 100644 --- a/lib/Transforms/Vectorize/SLPVectorizer.cpp +++ b/lib/Transforms/Vectorize/SLPVectorizer.cpp @@ -1833,6 +1833,21 @@ private: StoreListMap StoreRefs; }; +/// \brief Check that the Values in the slice in VL array are still existant in +/// the WeakVH array. +/// Vectorization of part of the VL array may cause later values in the VL array +/// to become invalid. We track when this has happened in the WeakVH array. +static bool hasValueBeenRAUWed(ArrayRef<Value *> &VL, + SmallVectorImpl<WeakVH> &VH, + unsigned SliceBegin, + unsigned SliceSize) { + for (unsigned i = SliceBegin; i < SliceBegin + SliceSize; ++i) + if (VH[i] != VL[i]) + return true; + + return false; +} + bool SLPVectorizer::vectorizeStoreChain(ArrayRef<Value *> Chain, int CostThreshold, BoUpSLP &R) { unsigned ChainLen = Chain.size(); @@ -1845,11 +1860,19 @@ bool SLPVectorizer::vectorizeStoreChain(ArrayRef<Value *> Chain, if (!isPowerOf2_32(Sz) || VF < 2) return false; + // Keep track of values that were delete by vectorizing in the loop below. + SmallVector<WeakVH, 8> TrackValues(Chain.begin(), Chain.end()); + bool Changed = false; // Look for profitable vectorizable trees at all offsets, starting at zero. for (unsigned i = 0, e = ChainLen; i < e; ++i) { if (i + VF > e) break; + + // Check that a previous iteration of this loop did not delete the Value. + if (hasValueBeenRAUWed(Chain, TrackValues, i, VF)) + continue; + DEBUG(dbgs() << "SLP: Analyzing " << VF << " stores at offset " << i << "\n"); ArrayRef<Value *> Operands = Chain.slice(i, VF); @@ -1990,6 +2013,9 @@ bool SLPVectorizer::tryToVectorizeList(ArrayRef<Value *> VL, BoUpSLP &R) { bool Changed = false; + // Keep track of values that were delete by vectorizing in the loop below. + SmallVector<WeakVH, 8> TrackValues(VL.begin(), VL.end()); + for (unsigned i = 0, e = VL.size(); i < e; ++i) { unsigned OpsWidth = 0; @@ -2001,6 +2027,10 @@ bool SLPVectorizer::tryToVectorizeList(ArrayRef<Value *> VL, BoUpSLP &R) { if (!isPowerOf2_32(OpsWidth) || OpsWidth < 2) break; + // Check that a previous iteration of this loop did not delete the Value. + if (hasValueBeenRAUWed(VL, TrackValues, i, OpsWidth)) + continue; + DEBUG(dbgs() << "SLP: Analyzing " << OpsWidth << " operations " << "\n"); ArrayRef<Value *> Ops = VL.slice(i, OpsWidth); diff --git a/test/Transforms/LoopVectorize/X86/rauw-bug.ll b/test/Transforms/LoopVectorize/X86/rauw-bug.ll new file mode 100644 index 0000000000..4284fbacfa --- /dev/null +++ b/test/Transforms/LoopVectorize/X86/rauw-bug.ll @@ -0,0 +1,33 @@ +; RUN: opt -slp-vectorizer -S %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-n32:64-S128" +target triple = "x86_64-apple-macosx" + +; This test used to fail under libgmalloc. Because we would try to access a +; pointer that was already deleted. +; +; llvm-lit -v --param use_gmalloc=1 --param +; gmalloc_path=/usr/lib/libgmalloc.dylib +; test/Transforms/LoopVectorize/X86/rauw-bug.ll +; +; radar://15498655 + +; CHECK: reduced +define void @reduced() { +entry: + br i1 undef, label %while.body, label %while.cond63.preheader.while.end76_crit_edge + +while.cond63.preheader.while.end76_crit_edge: + ret void + +while.body: + %d2_fx.015 = phi double [ %sub52, %while.body ], [ undef, %entry ] + %d2_fy.014 = phi double [ %sub58, %while.body ], [ undef, %entry ] + %d3_fy.013 = phi double [ %div56, %while.body ], [ undef, %entry ] + %d3_fx.012 = phi double [ %div50, %while.body ], [ undef, %entry ] + %div50 = fmul double %d3_fx.012, 1.250000e-01 + %sub52 = fsub double 0.000000e+00, %div50 + %div56 = fmul double %d3_fy.013, 1.250000e-01 + %sub58 = fsub double 0.000000e+00, %div56 + br label %while.body +} |