[llvm] 9c3a75e - [SLP]Fix a crash when preparing a mask for external scalars.

[Alexey Bataev via llvm-commits]

Author: Alexey Bataev
Date: 2022-05-09T07:59:34-07:00
New Revision: 9c3a75eabf577f0e0e372be95ec4861600a5acdb

URL: https://github.com/llvm/llvm-project/commit/9c3a75eabf577f0e0e372be95ec4861600a5acdb
DIFF: https://github.com/llvm/llvm-project/commit/9c3a75eabf577f0e0e372be95ec4861600a5acdb.diff

LOG: [SLP]Fix a crash when preparing a mask for external scalars.

Need to use actual index instead of the tree entry position, since the
insert index may be different than 0. It mean, that we vectorized part
of the buildvector starting from not initial insertelement instruction
beause of some reason.

Added: 
    llvm/test/Transforms/SLPVectorizer/X86/buildvector-shuffle.ll

Modified: 
    llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp

Removed: 
    


################################################################################
diff  --git a/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp b/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp
index 23af4360eaafd..ce58d839fd64b 100644
--- a/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp
+++ b/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp
@@ -6559,6 +6559,9 @@ InstructionCost BoUpSLP::getTreeCost(ArrayRef<Value *> VectorizedVals) {
           int VecId = -1;
           if (It == FirstUsers.end()) {
             (void)ShuffleMasks.emplace_back();
+            SmallVectorImpl<int> &Mask = ShuffleMasks.back()[ScalarTE];
+            if (Mask.empty())
+              Mask.assign(FTy->getNumElements(), UndefMaskElem);
             // Find the insertvector, vectorized in tree, if any.
             Value *Base = VU;
             while (auto *IEBase = dyn_cast<InsertElementInst>(Base)) {
@@ -6566,12 +6569,12 @@ InstructionCost BoUpSLP::getTreeCost(ArrayRef<Value *> VectorizedVals) {
               if (const TreeEntry *E = getTreeEntry(IEBase)) {
                 VU = IEBase;
                 do {
-                  int Idx = E->findLaneForValue(Base);
-                  SmallVectorImpl<int> &Mask = ShuffleMasks.back()[ScalarTE];
-                  if (Mask.empty())
-                    Mask.assign(FTy->getNumElements(), UndefMaskElem);
+                  IEBase = cast<InsertElementInst>(Base);
+                  int Idx = *getInsertIndex(IEBase);
+                  assert(Mask[Idx] == UndefMaskElem &&
+                         "InsertElementInstruction used already.");
                   Mask[Idx] = Idx;
-                  Base = cast<InsertElementInst>(Base)->getOperand(0);
+                  Base = IEBase->getOperand(0);
                 } while (E == getTreeEntry(Base));
                 break;
               }

diff  --git a/llvm/test/Transforms/SLPVectorizer/X86/buildvector-shuffle.ll b/llvm/test/Transforms/SLPVectorizer/X86/buildvector-shuffle.ll
new file mode 100644
index 0000000000000..92762dd28174f
--- /dev/null
+++ b/llvm/test/Transforms/SLPVectorizer/X86/buildvector-shuffle.ll
@@ -0,0 +1,43 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
+; RUN: opt -S -slp-vectorizer -mtriple=x86_64-unknown-linux-gnu < %s | FileCheck %s
+
+define void @b() {
+; CHECK-LABEL: @b(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    [[TMP0:%.*]] = insertelement <4 x float> poison, float 0x7FF8000000000000, i32 0
+; CHECK-NEXT:    [[TMP1:%.*]] = shufflevector <4 x float> [[TMP0]], <4 x float> <float 0xFFF8000000000000, float 0xFFF8000000000000, float undef, float undef>, <4 x i32> <i32 0, i32 4, i32 5, i32 3>
+; CHECK-NEXT:    [[TMP2:%.*]] = insertelement <4 x float> [[TMP1]], float 0x7FF8000000000000, i32 3
+; CHECK-NEXT:    [[TMP3:%.*]] = call <4 x float> @llvm.fmuladd.v4f32(<4 x float> [[TMP2]], <4 x float> zeroinitializer, <4 x float> zeroinitializer)
+; CHECK-NEXT:    [[TMP4:%.*]] = fmul <4 x float> [[TMP3]], <float undef, float undef, float undef, float 2.000000e+00>
+; CHECK-NEXT:    [[TMP5:%.*]] = fdiv <4 x float> [[TMP4]], zeroinitializer
+; CHECK-NEXT:    store <4 x float> [[TMP5]], ptr undef, align 4
+; CHECK-NEXT:    ret void
+;
+entry:
+  %mul = fmul float undef, 2.000000e+00
+  %i = tail call float @llvm.fmuladd.f32(float %mul, float 0.000000e+00, float 0.000000e+00)
+  %mul2 = fmul float undef, %i
+  %add = fadd float undef, 1.000000e+00
+  %neg = fneg float %add
+  %i1 = tail call float @llvm.fmuladd.f32(float %neg, float 0.000000e+00, float 0.000000e+00)
+  %mul4 = fmul float undef, %i1
+  %neg7 = fneg float %mul
+  %i2 = tail call float @llvm.fmuladd.f32(float %neg7, float 0.000000e+00, float 0.000000e+00)
+  %mul8 = fmul float undef, %i2
+  %i3 = tail call float @llvm.fmuladd.f32(float %add, float 0.000000e+00, float 0.000000e+00)
+  %mul11 = fmul float %i3, 2.000000e+00
+  %div = fdiv float %mul2, 0.000000e+00
+  store float %div, ptr undef, align 4
+  %div12 = fdiv float %mul4, 0.000000e+00
+  %arrayidx13 = getelementptr inbounds float, ptr undef, i64 1
+  store float %div12, ptr %arrayidx13, align 4
+  %div14 = fdiv float %mul8, 0.000000e+00
+  %arrayidx15 = getelementptr inbounds float, ptr undef, i64 2
+  store float %div14, ptr %arrayidx15, align 4
+  %div16 = fdiv float %mul11, 0.000000e+00
+  %arrayidx17 = getelementptr inbounds float, ptr undef, i64 3
+  store float %div16, ptr %arrayidx17, align 4
+  ret void
+}
+
+declare float @llvm.fmuladd.f32(float, float, float)