Commit 0616e996 authored by Huihui Zhang's avatar Huihui Zhang
Browse files

[InstSimplify][SVE] Fix SimplifyGEPInst for scalable vector. 

Summary:
Skip folds that rely on DataLayout::getTypeAllocSize(). For scalable
vector, only minimal type alloc size is known at compile-time.

Reviewers: sdesmalen, efriedma, spatel, apazos

Reviewed By: efriedma

Subscribers: tschuett, hiraditya, rkruppe, psnobl, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D75892
parent b0bdb186

llvm/lib/Analysis/InstructionSimplify.cpp

+5 −2
Original line number Diff line number Diff line
@@ -4081,13 +4081,16 @@ static Value *SimplifyGEPInst(Type *SrcTy, ArrayRef<Value *> Ops, 
  if (isa<UndefValue>(Ops[0]))

    return UndefValue::get(GEPTy);



  bool IsScalableVec =

      SrcTy->isVectorTy() ? SrcTy->getVectorIsScalable() : false;



  if (Ops.size() == 2) {

    // getelementptr P, 0 -> P.

    if (match(Ops[1], m_Zero()) && Ops[0]->getType() == GEPTy)

      return Ops[0];



    Type *Ty = SrcTy;

    if (Ty->isSized()) {

    if (!IsScalableVec && Ty->isSized()) {

      Value *P;

      uint64_t C;

      uint64_t TyAllocSize = Q.DL.getTypeAllocSize(Ty);
@@ -4135,7 +4138,7 @@ static Value *SimplifyGEPInst(Type *SrcTy, ArrayRef<Value *> Ops, 
    }

  }



  if (Q.DL.getTypeAllocSize(LastType) == 1 &&

  if (!IsScalableVec && Q.DL.getTypeAllocSize(LastType) == 1 &&

      all_of(Ops.slice(1).drop_back(1),

             [](Value *Idx) { return match(Idx, m_Zero()); })) {

    unsigned IdxWidth =

llvm/test/Transforms/InstSimplify/vscale.ll

+39 −0
Original line number Diff line number Diff line
@@ -94,3 +94,42 @@ define i32 @insert_extract_element_same_vec_idx_2(<vscale x 4 x i32> %a) { 
  ret i32 %r

}



;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

;; Memory Access and Addressing Operations

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;



; getelementptr



define <vscale x 4 x i32*> @getelementptr_constant_foldable_1() {

; CHECK-LABEL: @getelementptr_constant_foldable_1(

; CHECK-NEXT:    ret <vscale x 4 x i32*> zeroinitializer

;

  %ptr = getelementptr i32, <vscale x 4 x i32*> zeroinitializer, <vscale x 4 x i64> undef

  ret <vscale x 4 x i32*> %ptr

}



define <vscale x 4 x <vscale x 4 x i32>*> @getelementptr_constant_foldable_2() {

; CHECK-LABEL: @getelementptr_constant_foldable_2(

; CHECK-NEXT:    ret <vscale x 4 x <vscale x 4 x i32>*> zeroinitializer

;

  %ptr = getelementptr <vscale x 4 x i32>, <vscale x 4 x i32>* null, <vscale x 4 x i64> undef

  ret <vscale x 4 x <vscale x 4 x i32>*> %ptr

}



; fold getelementptr P, 0 -> P.

define <vscale x 4 x i32>* @getelementptr_constant_foldable_3() {

; CHECK-LABEL: @getelementptr_constant_foldable_3(

; CHECK-NEXT:    ret <vscale x 4 x i32>* null

;

  %ptr = getelementptr <vscale x 4 x i32>, <vscale x 4 x i32>* null, i64 0

  ret <vscale x 4 x i32>* %ptr

}



define <vscale x 4 x i32>* @getelementptr_not_constant_foldable(i64 %x) {

; CHECK-LABEL: @getelementptr_not_constant_foldable(

; CHECK-NEXT:    [[PTR:%.*]] = getelementptr <vscale x 4 x i32>, <vscale x 4 x i32>* null, i64 [[X:%.*]]

; CHECK-NEXT:    ret <vscale x 4 x i32>* [[PTR]]

;

  %ptr = getelementptr <vscale x 4 x i32>, <vscale x 4 x i32>* null, i64 %x

  ret <vscale x 4 x i32>* %ptr

}