Commit fdbb1c2f authored by Tom Stellard's avatar Tom Stellard
Browse files

Merging r243462: 

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r243462 | Matthew.Arsenault | 2015-07-28 14:47:00 -0400 (Tue, 28 Jul 2015) | 5 lines

AMDGPU: Don't try to use LDS/vector for private if pointer value stored

If the pointer is the store's value operand, this would produce
a broken module. Make sure the use is actually for the pointer operand.

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llvm-svn: 253228
parent 443da758

llvm/lib/Target/AMDGPU/AMDGPUPromoteAlloca.cpp

+14 −4
Original line number Diff line number Diff line
@@ -134,13 +134,17 @@ static Value* GEPToVectorIndex(GetElementPtrInst *GEP) { 
//

// TODO: Check isTriviallyVectorizable for calls and handle other

// instructions.

static bool canVectorizeInst(Instruction *Inst) {

static bool canVectorizeInst(Instruction *Inst, User *User) {

  switch (Inst->getOpcode()) {

  case Instruction::Load:

  case Instruction::Store:

  case Instruction::BitCast:

  case Instruction::AddrSpaceCast:

    return true;

  case Instruction::Store: {

    // Must be the stored pointer operand, not a stored value.

    StoreInst *SI = cast<StoreInst>(Inst);

    return SI->getPointerOperand() == User;

  }

  default:

    return false;

  }
@@ -166,7 +170,7 @@ static bool tryPromoteAllocaToVector(AllocaInst *Alloca) { 
  for (User *AllocaUser : Alloca->users()) {

    GetElementPtrInst *GEP = dyn_cast<GetElementPtrInst>(AllocaUser);

    if (!GEP) {

      if (!canVectorizeInst(cast<Instruction>(AllocaUser)))

      if (!canVectorizeInst(cast<Instruction>(AllocaUser), Alloca))

        return false;



      WorkList.push_back(AllocaUser);
@@ -184,7 +188,7 @@ static bool tryPromoteAllocaToVector(AllocaInst *Alloca) { 


    GEPVectorIdx[GEP] = Index;

    for (User *GEPUser : AllocaUser->users()) {

      if (!canVectorizeInst(cast<Instruction>(GEPUser)))

      if (!canVectorizeInst(cast<Instruction>(GEPUser), AllocaUser))

        return false;



      WorkList.push_back(GEPUser);
@@ -255,6 +259,12 @@ static bool collectUsesWithPtrTypes(Value *Val, std::vector<Value*> &WorkList) { 
    if (UseInst && UseInst->getOpcode() == Instruction::PtrToInt)

      return false;



    if (StoreInst *SI = dyn_cast_or_null<StoreInst>(UseInst)) {

      // Reject if the stored value is not the pointer operand.

      if (SI->getPointerOperand() != Val)

        return false;

    }



    if (!User->getType()->isPointerTy())

      continue;

llvm/test/CodeGen/AMDGPU/promote-alloca-stored-pointer-value.ll

0 → 100644
+52 −0
Original line number Diff line number Diff line 
; RUN: llc -march=amdgcn < %s | FileCheck -check-prefix=GCN %s



; Pointer value is stored in a candidate for LDS usage.



; GCN-LABEL: {{^}}stored_lds_pointer_value:

; GCN: buffer_store_dword v

define void @stored_lds_pointer_value(float* addrspace(1)* %ptr) #0 {

  %tmp = alloca float

  store float 0.0, float *%tmp

  store float* %tmp, float* addrspace(1)* %ptr

  ret void

}



; GCN-LABEL: {{^}}stored_lds_pointer_value_gep:

; GCN-DAG: s_mov_b32 s{{[0-9]+}}, SCRATCH_RSRC_DWORD0

; GCN-DAG: s_mov_b32 s{{[0-9]+}}, SCRATCH_RSRC_DWORD1

; GCN: buffer_store_dword v

; GCN: buffer_store_dword v

define void @stored_lds_pointer_value_gep(float* addrspace(1)* %ptr, i32 %idx) #0 {

bb:

  %tmp = alloca float, i32 16

  store float 0.0, float* %tmp

  %tmp2 = getelementptr inbounds float, float* %tmp, i32 %idx

  store float* %tmp2, float* addrspace(1)* %ptr

  ret void

}



; Pointer value is stored in a candidate for vector usage

; GCN-LABEL: {{^}}stored_vector_pointer_value:

; GCN-DAG: s_mov_b32 s{{[0-9]+}}, SCRATCH_RSRC_DWORD0

; GCN-DAG: s_mov_b32 s{{[0-9]+}}, SCRATCH_RSRC_DWORD1

; GCN: buffer_store_dword

; GCN: buffer_store_dword

; GCN: buffer_store_dword

; GCN: buffer_store_dword

define void @stored_vector_pointer_value(i32* addrspace(1)* %out, i32 %index) {

entry:

  %tmp0 = alloca [4 x i32]

  %x = getelementptr [4 x i32], [4 x i32]* %tmp0, i32 0, i32 0

  %y = getelementptr [4 x i32], [4 x i32]* %tmp0, i32 0, i32 1

  %z = getelementptr [4 x i32], [4 x i32]* %tmp0, i32 0, i32 2

  %w = getelementptr [4 x i32], [4 x i32]* %tmp0, i32 0, i32 3

  store i32 0, i32* %x

  store i32 1, i32* %y

  store i32 2, i32* %z

  store i32 3, i32* %w

  %tmp1 = getelementptr [4 x i32], [4 x i32]* %tmp0, i32 0, i32 %index

  store i32* %tmp1, i32* addrspace(1)* %out

  ret void

}



attributes #0 = { nounwind }