From 753eba64213ef20195644994df53d564f30eb65f Mon Sep 17 00:00:00 2001
From: Peter Waller <peter.waller@arm.com>
Date: Wed, 3 Nov 2021 13:39:38 +0000
Subject: [PATCH] Revert "[AArch64][SVE][InstCombine] Combine contiguous
 gather/scatter to load/store"

This reverts commit 1febf42f03f664ec84aedf0ece3b29f92b10dce9, which has
a use-of-uninitialized-memory bug.

See: https://reviews.llvm.org/D112076
---
 .../Target/AArch64/AArch64TargetTransformInfo.cpp  | 75 ------------------
 .../AArch64/sve-intrinsic-gatherscatter.ll         | 88 ----------------------
 2 files changed, 163 deletions(-)
 delete mode 100644 llvm/test/Transforms/InstCombine/AArch64/sve-intrinsic-gatherscatter.ll

diff --git a/llvm/lib/Target/AArch64/AArch64TargetTransformInfo.cpp b/llvm/lib/Target/AArch64/AArch64TargetTransformInfo.cpp
index 2e63d39..52429ef 100644
--- a/llvm/lib/Target/AArch64/AArch64TargetTransformInfo.cpp
+++ b/llvm/lib/Target/AArch64/AArch64TargetTransformInfo.cpp
@@ -864,77 +864,6 @@ static Optional<Instruction *> instCombineSVEZip(InstCombiner &IC,
   return None;
 }
 
-static Optional<Instruction *> instCombineLD1GatherIndex(InstCombiner &IC,
-                                                         IntrinsicInst &II) {
-  Value *Mask = II.getOperand(0);
-  Value *BasePtr = II.getOperand(1);
-  Value *Index = II.getOperand(2);
-  Type *Ty = II.getType();
-  Type *BasePtrTy = BasePtr->getType();
-  Value *PassThru = ConstantAggregateZero::get(Ty);
-
-  // Contiguous gather => masked load.
-  // (sve.ld1.gather.index Mask BasePtr (sve.index IndexBase 1))
-  // => (masked.load (gep BasePtr IndexBase) Align Mask zeroinitializer)
-  Value *IndexBase;
-  if (match(Index, m_Intrinsic<Intrinsic::aarch64_sve_index>(
-                       m_Value(IndexBase), m_SpecificInt(1)))) {
-    IRBuilder<> Builder(II.getContext());
-    Builder.SetInsertPoint(&II);
-
-    Align Alignment =
-        BasePtr->getPointerAlignment(II.getModule()->getDataLayout());
-
-    Type *VecPtrTy = PointerType::getUnqual(Ty);
-    Value *Ptr = Builder.CreateGEP(BasePtrTy->getPointerElementType(), BasePtr,
-                                   IndexBase);
-    Ptr = Builder.CreateBitCast(Ptr, VecPtrTy);
-    CallInst *MaskedLoad =
-        Builder.CreateMaskedLoad(Ty, Ptr, Alignment, Mask, PassThru);
-    MaskedLoad->takeName(&II);
-    return IC.replaceInstUsesWith(II, MaskedLoad);
-  }
-
-  return None;
-}
-
-static Optional<Instruction *> instCombineST1ScatterIndex(InstCombiner &IC,
-                                                          IntrinsicInst &II) {
-  Value *Val = II.getOperand(0);
-  Value *Mask = II.getOperand(1);
-  Value *BasePtr = II.getOperand(2);
-  Value *Index = II.getOperand(3);
-  Type *Ty = Val->getType();
-  Type *BasePtrTy = BasePtr->getType();
-
-  // Contiguous scatter => masked store.
-  // (sve.ld1.scatter.index Value Mask BasePtr (sve.index IndexBase 1))
-  // => (masked.store Value (gep BasePtr IndexBase) Align Mask)
-  Value *IndexBase;
-  if (match(Index, m_Intrinsic<Intrinsic::aarch64_sve_index>(
-                       m_Value(IndexBase), m_SpecificInt(1)))) {
-    IRBuilder<> Builder(II.getContext());
-    Builder.SetInsertPoint(&II);
-
-    Align Alignment =
-        BasePtr->getPointerAlignment(II.getModule()->getDataLayout());
-
-    Value *Ptr = Builder.CreateGEP(BasePtrTy->getPointerElementType(), BasePtr,
-                                   IndexBase);
-    Type *VecPtrTy = PointerType::getUnqual(Ty);
-    Ptr = Builder.CreateBitCast(Ptr, VecPtrTy);
-
-    CallInst *MaskedStore =
-        Builder.CreateMaskedStore(Val, Ptr, Alignment, Mask);
-    MaskedStore->takeName(&II);
-    II.eraseFromParent();
-
-    return IC.replaceInstUsesWith(II, MaskedStore);
-  }
-
-  return None;
-}
-
 Optional<Instruction *>
 AArch64TTIImpl::instCombineIntrinsic(InstCombiner &IC,
                                      IntrinsicInst &II) const {
@@ -986,10 +915,6 @@ AArch64TTIImpl::instCombineIntrinsic(InstCombiner &IC,
   case Intrinsic::aarch64_sve_zip1:
   case Intrinsic::aarch64_sve_zip2:
     return instCombineSVEZip(IC, II);
-  case Intrinsic::aarch64_sve_ld1_gather_index:
-    return instCombineLD1GatherIndex(IC, II);
-  case Intrinsic::aarch64_sve_st1_scatter_index:
-    return instCombineST1ScatterIndex(IC, II);
   }
 
   return None;
diff --git a/llvm/test/Transforms/InstCombine/AArch64/sve-intrinsic-gatherscatter.ll b/llvm/test/Transforms/InstCombine/AArch64/sve-intrinsic-gatherscatter.ll
deleted file mode 100644
index 2f665d5..0000000
--- a/llvm/test/Transforms/InstCombine/AArch64/sve-intrinsic-gatherscatter.ll
+++ /dev/null
@@ -1,88 +0,0 @@
-; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
-; RUN: opt -S -instcombine -dce < %s | FileCheck %s
-
-target triple = "aarch64-unknown-linux-gnu"
-
-;;
-;; Gathers.
-;;
-
-define <vscale x 2 x double> @test_ld1_gather_index_nxv2f64_stride1(<vscale x 2 x i1> %pred, double* %x, i64 %base) #0 {
-; CHECK-LABEL: @test_ld1_gather_index_nxv2f64_stride1(
-; CHECK-NEXT:    [[TMP1:%.*]] = getelementptr double, double* [[X:%.*]], i64 [[BASE:%.*]]
-; CHECK-NEXT:    [[TMP2:%.*]] = bitcast double* [[TMP1]] to <vscale x 2 x double>*
-; CHECK-NEXT:    [[LD:%.*]] = call <vscale x 2 x double> @llvm.masked.load.nxv2f64.p0nxv2f64(<vscale x 2 x double>* [[TMP2]], i32 1, <vscale x 2 x i1> [[PRED:%.*]], <vscale x 2 x double> zeroinitializer)
-; CHECK-NEXT:    ret <vscale x 2 x double> [[LD]]
-;
-  %idx = tail call <vscale x 2 x i64> @llvm.aarch64.sve.index.nxv2i64(i64 %base, i64 1)
-  %ld = tail call <vscale x 2 x double> @llvm.aarch64.sve.ld1.gather.index.nxv2f64(<vscale x 2 x i1> %pred, double* %x, <vscale x 2 x i64> %idx)
-  ret <vscale x 2 x double> %ld
-}
-
-define <vscale x 2 x double> @test_ld1_gather_index_nxv2f64_stride2_negtest(<vscale x 2 x i1> %pred, double* %x, i64 %base) #0 {
-; CHECK-LABEL: @test_ld1_gather_index_nxv2f64_stride2_negtest(
-; CHECK-NEXT:    [[IDX:%.*]] = tail call <vscale x 2 x i64> @llvm.aarch64.sve.index.nxv2i64(i64 [[BASE:%.*]], i64 2)
-; CHECK-NEXT:    [[LD:%.*]] = tail call <vscale x 2 x double> @llvm.aarch64.sve.ld1.gather.index.nxv2f64(<vscale x 2 x i1> [[PRED:%.*]], double* [[X:%.*]], <vscale x 2 x i64> [[IDX]])
-; CHECK-NEXT:    ret <vscale x 2 x double> [[LD]]
-;
-  %idx = tail call <vscale x 2 x i64> @llvm.aarch64.sve.index.nxv2i64(i64 %base, i64 2)
-  %ld = tail call <vscale x 2 x double> @llvm.aarch64.sve.ld1.gather.index.nxv2f64(<vscale x 2 x i1> %pred, double* %x, <vscale x 2 x i64> %idx)
-  ret <vscale x 2 x double> %ld
-}
-
-define <vscale x 2 x double> @test_ld1_gather_index_nxv2f64_stride1_align8(<vscale x 2 x i1> %pred, double* align 8 %x, i64 %base) #0 {
-; CHECK-LABEL: @test_ld1_gather_index_nxv2f64_stride1_align8(
-; CHECK-NEXT:    [[TMP1:%.*]] = getelementptr double, double* [[X:%.*]], i64 [[BASE:%.*]]
-; CHECK-NEXT:    [[TMP2:%.*]] = bitcast double* [[TMP1]] to <vscale x 2 x double>*
-; CHECK-NEXT:    [[LD:%.*]] = call <vscale x 2 x double> @llvm.masked.load.nxv2f64.p0nxv2f64(<vscale x 2 x double>* [[TMP2]], i32 8, <vscale x 2 x i1> [[PRED:%.*]], <vscale x 2 x double> zeroinitializer)
-; CHECK-NEXT:    ret <vscale x 2 x double> [[LD]]
-;
-  %idx = tail call <vscale x 2 x i64> @llvm.aarch64.sve.index.nxv2i64(i64 %base, i64 1)
-  %ld = tail call <vscale x 2 x double> @llvm.aarch64.sve.ld1.gather.index.nxv2f64(<vscale x 2 x i1> %pred, double* %x, <vscale x 2 x i64> %idx)
-  ret <vscale x 2 x double> %ld
-}
-
-;;
-;; Scatters.
-;;
-
-define void @test_st1_scatter_index_nxv2f64_stride1(<vscale x 2 x i1> %pred, double* %x, i64 %base, <vscale x 2 x double> %val) #0 {
-; CHECK-LABEL: @test_st1_scatter_index_nxv2f64_stride1(
-; CHECK-NEXT:    [[TMP1:%.*]] = getelementptr double, double* [[X:%.*]], i64 [[BASE:%.*]]
-; CHECK-NEXT:    [[TMP2:%.*]] = bitcast double* [[TMP1]] to <vscale x 2 x double>*
-; CHECK-NEXT:    call void @llvm.masked.store.nxv2f64.p0nxv2f64(<vscale x 2 x double> [[VAL:%.*]], <vscale x 2 x double>* [[TMP2]], i32 1, <vscale x 2 x i1> [[PRED:%.*]])
-; CHECK-NEXT:    ret void
-;
-  %idx = tail call <vscale x 2 x i64> @llvm.aarch64.sve.index.nxv2i64(i64 %base, i64 1)
-  tail call void @llvm.aarch64.sve.st1.scatter.index.nxv2f64(<vscale x 2 x double> %val, <vscale x 2 x i1> %pred, double* %x, <vscale x 2 x i64> %idx)
-  ret void
-}
-
-define void @test_st1_scatter_index_nxv2f64_stride2_negtest(<vscale x 2 x i1> %pred, double* %x, i64 %base, <vscale x 2 x double> %val) #0 {
-; CHECK-LABEL: @test_st1_scatter_index_nxv2f64_stride2_negtest(
-; CHECK-NEXT:    [[IDX:%.*]] = tail call <vscale x 2 x i64> @llvm.aarch64.sve.index.nxv2i64(i64 [[BASE:%.*]], i64 2)
-; CHECK-NEXT:    tail call void @llvm.aarch64.sve.st1.scatter.index.nxv2f64(<vscale x 2 x double> [[VAL:%.*]], <vscale x 2 x i1> [[PRED:%.*]], double* [[X:%.*]], <vscale x 2 x i64> [[IDX]])
-; CHECK-NEXT:    ret void
-;
-  %idx = tail call <vscale x 2 x i64> @llvm.aarch64.sve.index.nxv2i64(i64 %base, i64 2)
-  tail call void @llvm.aarch64.sve.st1.scatter.index.nxv2f64(<vscale x 2 x double> %val, <vscale x 2 x i1> %pred, double* %x, <vscale x 2 x i64> %idx)
-  ret void
-}
-
-define void @test_st1_scatter_index_nxv2f64_stride1_align8(<vscale x 2 x i1> %pred, double* align 8 %x, i64 %base, <vscale x 2 x double> %val) #0 {
-; CHECK-LABEL: @test_st1_scatter_index_nxv2f64_stride1_align8(
-; CHECK-NEXT:    [[TMP1:%.*]] = getelementptr double, double* [[X:%.*]], i64 [[BASE:%.*]]
-; CHECK-NEXT:    [[TMP2:%.*]] = bitcast double* [[TMP1]] to <vscale x 2 x double>*
-; CHECK-NEXT:    call void @llvm.masked.store.nxv2f64.p0nxv2f64(<vscale x 2 x double> [[VAL:%.*]], <vscale x 2 x double>* [[TMP2]], i32 8, <vscale x 2 x i1> [[PRED:%.*]])
-; CHECK-NEXT:    ret void
-;
-  %idx = tail call <vscale x 2 x i64> @llvm.aarch64.sve.index.nxv2i64(i64 %base, i64 1)
-  tail call void @llvm.aarch64.sve.st1.scatter.index.nxv2f64(<vscale x 2 x double> %val, <vscale x 2 x i1> %pred, double* %x, <vscale x 2 x i64> %idx)
-  ret void
-}
-
-declare <vscale x 2 x i64> @llvm.aarch64.sve.index.nxv2i64(i64, i64)
-declare <vscale x 2 x double> @llvm.aarch64.sve.ld1.gather.index.nxv2f64(<vscale x 2 x i1>, double*, <vscale x 2 x i64>)
-declare void @llvm.aarch64.sve.st1.scatter.index.nxv2f64(<vscale x 2 x double>, <vscale x 2 x i1>, double*, <vscale x 2 x i64>)
-
-attributes #0 = { "target-features"="+sve" }
-- 
2.7.4