[llvm] r326910 - [AMDGPU] Increased vector length for global/constant loads.
Farhana Aleen via llvm-commits
llvm-commits at lists.llvm.org
Wed Mar 7 09:09:18 PST 2018
Author: faaleen
Date: Wed Mar 7 09:09:18 2018
New Revision: 326910
URL: http://llvm.org/viewvc/llvm-project?rev=326910&view=rev
Log:
[AMDGPU] Increased vector length for global/constant loads.
Summary: GCN ISA supports instructions that can read 16 consecutive dwords from memory through the scalar data cache;
loadstoreVectorizer should take advantage of the wider vector length and pack 16/8 elements of dwords/quadwords.
Author: FarhanaAleen
Reviewed By: rampitec
Subscribers: llvm-commits, AMDGPU
Differential Revision: https://reviews.llvm.org/D44179
Added:
llvm/trunk/test/CodeGen/AMDGPU/load-constant-f32.ll
Modified:
llvm/trunk/lib/Target/AMDGPU/AMDGPUTargetTransformInfo.cpp
llvm/trunk/lib/Target/AMDGPU/AMDGPUTargetTransformInfo.h
llvm/trunk/lib/Target/AMDGPU/SIISelLowering.cpp
llvm/trunk/lib/Transforms/Vectorize/LoadStoreVectorizer.cpp
llvm/trunk/test/CodeGen/AMDGPU/load-constant-f64.ll
llvm/trunk/test/CodeGen/AMDGPU/waitcnt-looptest.ll
Modified: llvm/trunk/lib/Target/AMDGPU/AMDGPUTargetTransformInfo.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/AMDGPU/AMDGPUTargetTransformInfo.cpp?rev=326910&r1=326909&r2=326910&view=diff
==============================================================================
--- llvm/trunk/lib/Target/AMDGPU/AMDGPUTargetTransformInfo.cpp (original)
+++ llvm/trunk/lib/Target/AMDGPU/AMDGPUTargetTransformInfo.cpp Wed Mar 7 09:09:18 2018
@@ -234,12 +234,38 @@ unsigned AMDGPUTTIImpl::getMinVectorRegi
return 32;
}
+unsigned AMDGPUTTIImpl::getLoadVectorFactor(unsigned VF, unsigned LoadSize,
+ unsigned ChainSizeInBytes,
+ VectorType *VecTy) const {
+ unsigned VecRegBitWidth = VF * LoadSize;
+ if (VecRegBitWidth > 128 && VecTy->getScalarSizeInBits() < 32)
+ // TODO: Support element-size less than 32bit?
+ return 128 / LoadSize;
+
+ return VF;
+}
+
+unsigned AMDGPUTTIImpl::getStoreVectorFactor(unsigned VF, unsigned StoreSize,
+ unsigned ChainSizeInBytes,
+ VectorType *VecTy) const {
+ unsigned VecRegBitWidth = VF * StoreSize;
+ if (VecRegBitWidth > 128)
+ return 128 / StoreSize;
+
+ return VF;
+}
+
unsigned AMDGPUTTIImpl::getLoadStoreVecRegBitWidth(unsigned AddrSpace) const {
AMDGPUAS AS = ST->getAMDGPUAS();
if (AddrSpace == AS.GLOBAL_ADDRESS ||
AddrSpace == AS.CONSTANT_ADDRESS ||
- AddrSpace == AS.CONSTANT_ADDRESS_32BIT ||
- AddrSpace == AS.FLAT_ADDRESS)
+ AddrSpace == AS.CONSTANT_ADDRESS_32BIT) {
+ if (ST->getGeneration() <= AMDGPUSubtarget::NORTHERN_ISLANDS)
+ return 128;
+ return 512;
+ }
+
+ if (AddrSpace == AS.FLAT_ADDRESS)
return 128;
if (AddrSpace == AS.LOCAL_ADDRESS ||
AddrSpace == AS.REGION_ADDRESS)
@@ -250,8 +276,8 @@ unsigned AMDGPUTTIImpl::getLoadStoreVecR
if (ST->getGeneration() <= AMDGPUSubtarget::NORTHERN_ISLANDS &&
(AddrSpace == AS.PARAM_D_ADDRESS ||
AddrSpace == AS.PARAM_I_ADDRESS ||
- (AddrSpace >= AS.CONSTANT_BUFFER_0 &&
- AddrSpace <= AS.CONSTANT_BUFFER_15)))
+ (AddrSpace >= AS.CONSTANT_BUFFER_0 &&
+ AddrSpace <= AS.CONSTANT_BUFFER_15)))
return 128;
llvm_unreachable("unhandled address space");
}
Modified: llvm/trunk/lib/Target/AMDGPU/AMDGPUTargetTransformInfo.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/AMDGPU/AMDGPUTargetTransformInfo.h?rev=326910&r1=326909&r2=326910&view=diff
==============================================================================
--- llvm/trunk/lib/Target/AMDGPU/AMDGPUTargetTransformInfo.h (original)
+++ llvm/trunk/lib/Target/AMDGPU/AMDGPUTargetTransformInfo.h Wed Mar 7 09:09:18 2018
@@ -118,6 +118,12 @@ public:
unsigned getNumberOfRegisters(bool Vector) const;
unsigned getRegisterBitWidth(bool Vector) const;
unsigned getMinVectorRegisterBitWidth() const;
+ unsigned getLoadVectorFactor(unsigned VF, unsigned LoadSize,
+ unsigned ChainSizeInBytes,
+ VectorType *VecTy) const;
+ unsigned getStoreVectorFactor(unsigned VF, unsigned StoreSize,
+ unsigned ChainSizeInBytes,
+ VectorType *VecTy) const;
unsigned getLoadStoreVecRegBitWidth(unsigned AddrSpace) const;
bool isLegalToVectorizeMemChain(unsigned ChainSizeInBytes,
Modified: llvm/trunk/lib/Target/AMDGPU/SIISelLowering.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/AMDGPU/SIISelLowering.cpp?rev=326910&r1=326909&r2=326910&view=diff
==============================================================================
--- llvm/trunk/lib/Target/AMDGPU/SIISelLowering.cpp (original)
+++ llvm/trunk/lib/Target/AMDGPU/SIISelLowering.cpp Wed Mar 7 09:09:18 2018
@@ -3454,6 +3454,10 @@ bool SITargetLowering::isFMAFasterThanFM
return false;
}
+static bool isDwordAligned(unsigned Alignment) {
+ return Alignment % 4 == 0;
+}
+
//===----------------------------------------------------------------------===//
// Custom DAG Lowering Operations
//===----------------------------------------------------------------------===//
@@ -5353,9 +5357,10 @@ SDValue SITargetLowering::LowerLOAD(SDVa
assert(Op.getValueType().getVectorElementType() == MVT::i32 &&
"Custom lowering for non-i32 vectors hasn't been implemented.");
+ unsigned Alignment = Load->getAlignment();
unsigned AS = Load->getAddressSpace();
if (!allowsMemoryAccess(*DAG.getContext(), DAG.getDataLayout(), MemVT,
- AS, Load->getAlignment())) {
+ AS, Alignment)) {
SDValue Ops[2];
std::tie(Ops[0], Ops[1]) = expandUnalignedLoad(Load, DAG);
return DAG.getMergeValues(Ops, DL);
@@ -5383,7 +5388,8 @@ SDValue SITargetLowering::LowerLOAD(SDVa
AS == AMDGPUASI.CONSTANT_ADDRESS_32BIT ||
AS == AMDGPUASI.GLOBAL_ADDRESS) {
if (Subtarget->getScalarizeGlobalBehavior() && !Op->isDivergent() &&
- !Load->isVolatile() && isMemOpHasNoClobberedMemOperand(Load))
+ !Load->isVolatile() && isMemOpHasNoClobberedMemOperand(Load) &&
+ isDwordAligned(Alignment))
return SDValue();
// Non-uniform loads will be selected to MUBUF instructions, so they
// have the same legalization requirements as global and private
Modified: llvm/trunk/lib/Transforms/Vectorize/LoadStoreVectorizer.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Vectorize/LoadStoreVectorizer.cpp?rev=326910&r1=326909&r2=326910&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Vectorize/LoadStoreVectorizer.cpp (original)
+++ llvm/trunk/lib/Transforms/Vectorize/LoadStoreVectorizer.cpp Wed Mar 7 09:09:18 2018
@@ -666,8 +666,12 @@ Vectorizer::collectInstructions(BasicBlo
unsigned AS = Ptr->getType()->getPointerAddressSpace();
unsigned VecRegSize = TTI.getLoadStoreVecRegBitWidth(AS);
+ unsigned VF = VecRegSize / TySize;
+ VectorType *VecTy = dyn_cast<VectorType>(Ty);
+
// No point in looking at these if they're too big to vectorize.
- if (TySize > VecRegSize / 2)
+ if (TySize > VecRegSize / 2 ||
+ (VecTy && TTI.getLoadVectorFactor(VF, TySize, TySize / 8, VecTy) == 0))
continue;
// Make sure all the users of a vector are constant-index extracts.
@@ -709,8 +713,12 @@ Vectorizer::collectInstructions(BasicBlo
unsigned AS = Ptr->getType()->getPointerAddressSpace();
unsigned VecRegSize = TTI.getLoadStoreVecRegBitWidth(AS);
+ unsigned VF = VecRegSize / TySize;
+ VectorType *VecTy = dyn_cast<VectorType>(Ty);
+
// No point in looking at these if they're too big to vectorize.
- if (TySize > VecRegSize / 2)
+ if (TySize > VecRegSize / 2 ||
+ (VecTy && TTI.getStoreVectorFactor(VF, TySize, TySize / 8, VecTy) == 0))
continue;
if (isa<VectorType>(Ty) && !llvm::all_of(SI->users(), [](const User *U) {
Added: llvm/trunk/test/CodeGen/AMDGPU/load-constant-f32.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/AMDGPU/load-constant-f32.ll?rev=326910&view=auto
==============================================================================
--- llvm/trunk/test/CodeGen/AMDGPU/load-constant-f32.ll (added)
+++ llvm/trunk/test/CodeGen/AMDGPU/load-constant-f32.ll Wed Mar 7 09:09:18 2018
@@ -0,0 +1,37 @@
+; RUN: llc -march=amdgcn -verify-machineinstrs < %s | FileCheck -check-prefix=GCN -check-prefix=FUNC %s
+; RUN: llc -march=r600 -mcpu=redwood < %s | FileCheck -check-prefix=EG -check-prefix=FUNC %s
+
+; Tests whether a load chain of 8 constants gets vectorized into a wider load.
+; FUNC-LABEL: {{^}}constant_load_v8f32:
+; GCN: s_load_dwordx8
+; EG: VTX_READ_128
+; EG: VTX_READ_128
+define amdgpu_kernel void @constant_load_v8f32(float addrspace(4)* noalias nocapture readonly %weights, float addrspace(1)* noalias nocapture %out_ptr) {
+entry:
+ %out_ptr.promoted = load float, float addrspace(1)* %out_ptr, align 4
+ %tmp = load float, float addrspace(4)* %weights, align 4
+ %add = fadd float %tmp, %out_ptr.promoted
+ %arrayidx.1 = getelementptr inbounds float, float addrspace(4)* %weights, i64 1
+ %tmp1 = load float, float addrspace(4)* %arrayidx.1, align 4
+ %add.1 = fadd float %tmp1, %add
+ %arrayidx.2 = getelementptr inbounds float, float addrspace(4)* %weights, i64 2
+ %tmp2 = load float, float addrspace(4)* %arrayidx.2, align 4
+ %add.2 = fadd float %tmp2, %add.1
+ %arrayidx.3 = getelementptr inbounds float, float addrspace(4)* %weights, i64 3
+ %tmp3 = load float, float addrspace(4)* %arrayidx.3, align 4
+ %add.3 = fadd float %tmp3, %add.2
+ %arrayidx.4 = getelementptr inbounds float, float addrspace(4)* %weights, i64 4
+ %tmp4 = load float, float addrspace(4)* %arrayidx.4, align 4
+ %add.4 = fadd float %tmp4, %add.3
+ %arrayidx.5 = getelementptr inbounds float, float addrspace(4)* %weights, i64 5
+ %tmp5 = load float, float addrspace(4)* %arrayidx.5, align 4
+ %add.5 = fadd float %tmp5, %add.4
+ %arrayidx.6 = getelementptr inbounds float, float addrspace(4)* %weights, i64 6
+ %tmp6 = load float, float addrspace(4)* %arrayidx.6, align 4
+ %add.6 = fadd float %tmp6, %add.5
+ %arrayidx.7 = getelementptr inbounds float, float addrspace(4)* %weights, i64 7
+ %tmp7 = load float, float addrspace(4)* %arrayidx.7, align 4
+ %add.7 = fadd float %tmp7, %add.6
+ store float %add.7, float addrspace(1)* %out_ptr, align 4
+ ret void
+}
\ No newline at end of file
Modified: llvm/trunk/test/CodeGen/AMDGPU/load-constant-f64.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/AMDGPU/load-constant-f64.ll?rev=326910&r1=326909&r2=326910&view=diff
==============================================================================
--- llvm/trunk/test/CodeGen/AMDGPU/load-constant-f64.ll (original)
+++ llvm/trunk/test/CodeGen/AMDGPU/load-constant-f64.ll Wed Mar 7 09:09:18 2018
@@ -13,3 +13,36 @@ define amdgpu_kernel void @constant_load
}
attributes #0 = { nounwind }
+
+; Tests whether a load-chain of 8 constants of 64bit each gets vectorized into a wider load.
+; FUNC-LABEL: {{^}}constant_load_2v4f64:
+; GCN: s_load_dwordx16
+define amdgpu_kernel void @constant_load_2v4f64(double addrspace(4)* noalias nocapture readonly %weights, double addrspace(1)* noalias nocapture %out_ptr) {
+entry:
+ %out_ptr.promoted = load double, double addrspace(1)* %out_ptr, align 4
+ %tmp = load double, double addrspace(4)* %weights, align 4
+ %add = fadd double %tmp, %out_ptr.promoted
+ %arrayidx.1 = getelementptr inbounds double, double addrspace(4)* %weights, i64 1
+ %tmp1 = load double, double addrspace(4)* %arrayidx.1, align 4
+ %add.1 = fadd double %tmp1, %add
+ %arrayidx.2 = getelementptr inbounds double, double addrspace(4)* %weights, i64 2
+ %tmp2 = load double, double addrspace(4)* %arrayidx.2, align 4
+ %add.2 = fadd double %tmp2, %add.1
+ %arrayidx.3 = getelementptr inbounds double, double addrspace(4)* %weights, i64 3
+ %tmp3 = load double, double addrspace(4)* %arrayidx.3, align 4
+ %add.3 = fadd double %tmp3, %add.2
+ %arrayidx.4 = getelementptr inbounds double, double addrspace(4)* %weights, i64 4
+ %tmp4 = load double, double addrspace(4)* %arrayidx.4, align 4
+ %add.4 = fadd double %tmp4, %add.3
+ %arrayidx.5 = getelementptr inbounds double, double addrspace(4)* %weights, i64 5
+ %tmp5 = load double, double addrspace(4)* %arrayidx.5, align 4
+ %add.5 = fadd double %tmp5, %add.4
+ %arrayidx.6 = getelementptr inbounds double, double addrspace(4)* %weights, i64 6
+ %tmp6 = load double, double addrspace(4)* %arrayidx.6, align 4
+ %add.6 = fadd double %tmp6, %add.5
+ %arrayidx.7 = getelementptr inbounds double, double addrspace(4)* %weights, i64 7
+ %tmp7 = load double, double addrspace(4)* %arrayidx.7, align 4
+ %add.7 = fadd double %tmp7, %add.6
+ store double %add.7, double addrspace(1)* %out_ptr, align 4
+ ret void
+}
Modified: llvm/trunk/test/CodeGen/AMDGPU/waitcnt-looptest.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/AMDGPU/waitcnt-looptest.ll?rev=326910&r1=326909&r2=326910&view=diff
==============================================================================
--- llvm/trunk/test/CodeGen/AMDGPU/waitcnt-looptest.ll (original)
+++ llvm/trunk/test/CodeGen/AMDGPU/waitcnt-looptest.ll Wed Mar 7 09:09:18 2018
@@ -1,4 +1,4 @@
-; RUN: llc < %s -mtriple=amdgcn--amdhsa -mcpu=fiji -mattr=-flat-for-global | FileCheck --check-prefix=GCN %s
+; RUN: llc < %s -mtriple=amdgcn--amdhsa -mcpu=fiji -mattr=-flat-for-global -amdgpu-load-store-vectorizer=0 | FileCheck --check-prefix=GCN %s
; Check that the waitcnt insertion algorithm correctly propagates wait counts
; from before a loop to the loop header.
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