[SLP]Fix PR57447: Assertion `!getTreeEntry(V) && "Scalar already in tree!"' failed.

The pointer operands for the ScatterVectorize node may contain
non-instruction values and they are not checked for "already being
vectorized". Need to check that such pointers are already vectorized and
gather them instead of trying to build vectorize node to avoid compiler
crash.

Differential Revision: https://reviews.llvm.org/D132949

(cherry picked from commit ec06df9)

Author: alexey-bataev

llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp

@@ -4696,10 +4696,12 @@ void BoUpSLP::buildTree_rec(ArrayRef<Value *> VL, unsigned Depth,
   };
   SmallVector<unsigned> SortedIndices;
   BasicBlock *BB = nullptr;
+  bool IsScatterVectorizeUserTE =
+      UserTreeIdx.UserTE &&
+      UserTreeIdx.UserTE->State == TreeEntry::ScatterVectorize;
   bool AreAllSameInsts =
       (S.getOpcode() && allSameBlock(VL)) ||
-      (S.OpValue->getType()->isPointerTy() && UserTreeIdx.UserTE &&
-       UserTreeIdx.UserTE->State == TreeEntry::ScatterVectorize &&
+      (S.OpValue->getType()->isPointerTy() && IsScatterVectorizeUserTE &&
        VL.size() > 2 &&
        all_of(VL,
               [&BB](Value *V) {
@@ -4760,10 +4762,9 @@ void BoUpSLP::buildTree_rec(ArrayRef<Value *> VL, unsigned Depth,
 
   // Check that none of the instructions in the bundle are already in the tree.
   for (Value *V : VL) {
-    auto *I = dyn_cast<Instruction>(V);
-    if (!I)
+    if (!IsScatterVectorizeUserTE && !isa<Instruction>(V))
       continue;
-    if (getTreeEntry(I)) {
+    if (getTreeEntry(V)) {
       LLVM_DEBUG(dbgs() << "SLP: The instruction (" << *V
                         << ") is already in tree.\n");
       if (TryToFindDuplicates(S))
@@ -5213,19 +5214,16 @@ void BoUpSLP::buildTree_rec(ArrayRef<Value *> VL, unsigned Depth,
         }
       }
 
-      bool IsScatterUser =
-          UserTreeIdx.UserTE &&
-          UserTreeIdx.UserTE->State == TreeEntry::ScatterVectorize;
       // We don't combine GEPs with non-constant indexes.
       Type *Ty1 = VL0->getOperand(1)->getType();
       for (Value *V : VL) {
         auto *I = dyn_cast<GetElementPtrInst>(V);
         if (!I)
           continue;
         auto *Op = I->getOperand(1);
-        if ((!IsScatterUser && !isa<ConstantInt>(Op)) ||
+        if ((!IsScatterVectorizeUserTE && !isa<ConstantInt>(Op)) ||
             (Op->getType() != Ty1 &&
-             ((IsScatterUser && !isa<ConstantInt>(Op)) ||
+             ((IsScatterVectorizeUserTE && !isa<ConstantInt>(Op)) ||
               Op->getType()->getScalarSizeInBits() >
                   DL->getIndexSizeInBits(
                       V->getType()->getPointerAddressSpace())))) {

llvm/test/Transforms/SLPVectorizer/X86/scatter-vectorize-reused-pointer.ll

@@ -0,0 +1,57 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
+; RUN: opt -S -slp-vectorizer < %s -mtriple=x86_64-unknown-linux-gnu -mcpu=skylake -slp-threshold=-12 | FileCheck %s
+
+define void @test(i1 %c, ptr %arg) {
+; CHECK-LABEL: @test(
+; CHECK-NEXT:    br i1 [[C:%.*]], label [[IF:%.*]], label [[ELSE:%.*]]
+; CHECK:       if:
+; CHECK-NEXT:    [[TMP1:%.*]] = insertelement <4 x ptr> poison, ptr [[ARG:%.*]], i32 0
+; CHECK-NEXT:    [[SHUFFLE:%.*]] = shufflevector <4 x ptr> [[TMP1]], <4 x ptr> poison, <4 x i32> zeroinitializer
+; CHECK-NEXT:    [[TMP2:%.*]] = getelementptr i8, <4 x ptr> [[SHUFFLE]], <4 x i64> <i64 32, i64 24, i64 8, i64 0>
+; CHECK-NEXT:    [[TMP3:%.*]] = call <4 x i64> @llvm.masked.gather.v4i64.v4p0(<4 x ptr> [[TMP2]], i32 8, <4 x i1> <i1 true, i1 true, i1 true, i1 true>, <4 x i64> undef)
+; CHECK-NEXT:    br label [[JOIN:%.*]]
+; CHECK:       else:
+; CHECK-NEXT:    [[ARG_1:%.*]] = getelementptr inbounds i8, ptr [[ARG]], i64 8
+; CHECK-NEXT:    [[TMP4:%.*]] = insertelement <2 x ptr> poison, ptr [[ARG]], i32 0
+; CHECK-NEXT:    [[TMP5:%.*]] = insertelement <2 x ptr> [[TMP4]], ptr [[ARG]], i32 1
+; CHECK-NEXT:    [[TMP6:%.*]] = getelementptr i8, <2 x ptr> [[TMP5]], <2 x i64> <i64 32, i64 24>
+; CHECK-NEXT:    [[TMP7:%.*]] = insertelement <4 x ptr> poison, ptr [[ARG]], i32 3
+; CHECK-NEXT:    [[TMP8:%.*]] = shufflevector <2 x ptr> [[TMP6]], <2 x ptr> poison, <4 x i32> <i32 0, i32 1, i32 undef, i32 undef>
+; CHECK-NEXT:    [[TMP9:%.*]] = shufflevector <4 x ptr> [[TMP7]], <4 x ptr> [[TMP8]], <4 x i32> <i32 4, i32 5, i32 2, i32 3>
+; CHECK-NEXT:    [[TMP10:%.*]] = insertelement <4 x ptr> [[TMP9]], ptr [[ARG_1]], i32 2
+; CHECK-NEXT:    [[TMP11:%.*]] = call <4 x i64> @llvm.masked.gather.v4i64.v4p0(<4 x ptr> [[TMP10]], i32 8, <4 x i1> <i1 true, i1 true, i1 true, i1 true>, <4 x i64> undef)
+; CHECK-NEXT:    br label [[JOIN]]
+; CHECK:       join:
+; CHECK-NEXT:    [[TMP12:%.*]] = phi <4 x i64> [ [[TMP3]], [[IF]] ], [ [[TMP11]], [[ELSE]] ]
+; CHECK-NEXT:    ret void
+;
+  br i1 %c, label %if, label %else
+
+if:
+  %i2.0 = load i64, ptr %arg, align 8
+  %arg2.1 = getelementptr inbounds i8, ptr %arg, i64 8
+  %i2.1 = load i64, ptr %arg2.1, align 8
+  %arg2.2 = getelementptr inbounds i8, ptr %arg, i64 24
+  %i2.2 = load i64, ptr %arg2.2, align 8
+  %arg2.3 = getelementptr inbounds i8, ptr %arg, i64 32
+  %i2.3 = load i64, ptr %arg2.3, align 8
+  br label %join
+
+else:
+  %i.0 = load i64, ptr %arg, align 8
+  %arg.1 = getelementptr inbounds i8, ptr %arg, i64 8
+  %i.1 = load i64, ptr %arg.1, align 8
+  %arg.2 = getelementptr inbounds i8, ptr %arg, i64 24
+  %i.2 = load i64, ptr %arg.2, align 8
+  %arg.3 = getelementptr inbounds i8, ptr %arg, i64 32
+  %i.3 = load i64, ptr %arg.3, align 8
+  br label %join
+
+join:
+  %phi.3 = phi i64 [ %i2.3, %if ], [ %i.3, %else ]
+  %phi.2 = phi i64 [ %i2.2, %if ], [ %i.2, %else ]
+  %phi.1 = phi i64 [ %i2.1, %if ], [ %i.1, %else ]
+  %phi.0 = phi i64 [ %i2.0, %if ], [ %i.0, %else ]
+  ret void
+}
+