[SLP][REVEC] Make shufflevector can be vectorized with ReorderIndices and ReuseShuffleIndices. (#114965)

Author: HanKuanChen

llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp

@@ -15645,9 +15645,6 @@ Value *BoUpSLP::vectorizeTree(TreeEntry *E, bool PostponedPHIs) {
     case Instruction::ShuffleVector: {
       Value *V;
       if (SLPReVec && !E->isAltShuffle()) {
-        assert(E->ReuseShuffleIndices.empty() &&
-               "Not support ReuseShuffleIndices yet.");
-        assert(E->ReorderIndices.empty() && "Not support ReorderIndices yet.");
         setInsertPointAfterBundle(E);
         Value *Src = vectorizeOperand(E, 0, PostponedPHIs);
         if (E->VectorizedValue) {
@@ -15665,6 +15662,9 @@ Value *BoUpSLP::vectorizeTree(TreeEntry *E, bool PostponedPHIs) {
                   [&SVSrc](int Mask) { return SVSrc->getShuffleMask()[Mask]; });
         V = Builder.CreateShuffleVector(SVSrc->getOperand(0), NewMask);
         propagateIRFlags(V, E->Scalars, VL0);
+        if (auto *I = dyn_cast<Instruction>(V))
+          V = propagateMetadata(I, E->Scalars);
+        V = FinalShuffle(V, E);
       } else {
         assert(E->isAltShuffle() &&
                ((Instruction::isBinaryOp(E->getOpcode()) &&
@@ -15795,11 +15795,11 @@ Value *BoUpSLP::vectorizeTree(TreeEntry *E, bool PostponedPHIs) {
           transformScalarShuffleIndiciesToVector(VecTy->getNumElements(), Mask);
         }
         V = Builder.CreateShuffleVector(V0, V1, Mask);
-      }
-      if (auto *I = dyn_cast<Instruction>(V)) {
-        V = propagateMetadata(I, E->Scalars);
-        GatherShuffleExtractSeq.insert(I);
-        CSEBlocks.insert(I->getParent());
+        if (auto *I = dyn_cast<Instruction>(V)) {
+          V = propagateMetadata(I, E->Scalars);
+          GatherShuffleExtractSeq.insert(I);
+          CSEBlocks.insert(I->getParent());
+        }
       }
 
       E->VectorizedValue = V;

llvm/test/Transforms/SLPVectorizer/revec-shufflevector.ll

@@ -82,3 +82,26 @@ entry:
   store <4 x i32> %4, ptr %8, align 4
   ret void
 }
+
+define void @test4(ptr %in, ptr %out) {
+; CHECK-LABEL: @test4(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    [[TMP0:%.*]] = load <8 x i32>, ptr [[IN:%.*]], align 4
+; CHECK-NEXT:    [[TMP1:%.*]] = shufflevector <8 x i32> [[TMP0]], <8 x i32> poison, <16 x i32> <i32 0, i32 1, i32 2, i32 3, i32 4, i32 5, i32 6, i32 7, i32 0, i32 1, i32 2, i32 3, i32 4, i32 5, i32 6, i32 7>
+; CHECK-NEXT:    store <16 x i32> [[TMP1]], ptr [[OUT:%.*]], align 4
+; CHECK-NEXT:    ret void
+;
+entry:
+  %0 = load <8 x i32>, ptr %in, align 4
+  %1 = shufflevector <8 x i32> %0, <8 x i32> poison, <4 x i32> <i32 0, i32 1, i32 2, i32 3>
+  %2 = shufflevector <8 x i32> %0, <8 x i32> poison, <4 x i32> <i32 4, i32 5, i32 6, i32 7>
+  %3 = getelementptr inbounds i32, ptr %out, i64 0
+  %4 = getelementptr inbounds i32, ptr %out, i64 4
+  %5 = getelementptr inbounds i32, ptr %out, i64 8
+  %6 = getelementptr inbounds i32, ptr %out, i64 12
+  store <4 x i32> %1, ptr %3, align 4
+  store <4 x i32> %2, ptr %4, align 4
+  store <4 x i32> %1, ptr %5, align 4
+  store <4 x i32> %2, ptr %6, align 4
+  ret void
+}