[SPIRV] Handle ptrcast between array and vector types#166418
Merged
[SPIRV] Handle ptrcast between array and vector types#166418
Conversation
This commit adds support for legalizing pointer casts between array and vector types within the SPIRV backend. This is necessary to handle cases where a vector is loaded from or stored to an array, which can occur with HLSL matrix types. The following changes are included: - Added to load a vector from an array. - Added to store a vector to an array. - Added the test case to verify the functionality.
Member
|
@llvm/pr-subscribers-backend-spir-v Author: Steven Perron (s-perron) ChangesThis commit adds support for legalizing pointer casts between array and vector types within the SPIRV backend. This is necessary to handle cases where a vector is loaded from or stored to an array, which can occur with HLSL matrix types. The following changes are included:
Full diff: https://github.com/llvm/llvm-project/pull/166418.diff 2 Files Affected:
diff --git a/llvm/lib/Target/SPIRV/SPIRVLegalizePointerCast.cpp b/llvm/lib/Target/SPIRV/SPIRVLegalizePointerCast.cpp
index 65dffc7908b78..87c0c8c5a7437 100644
--- a/llvm/lib/Target/SPIRV/SPIRVLegalizePointerCast.cpp
+++ b/llvm/lib/Target/SPIRV/SPIRVLegalizePointerCast.cpp
@@ -116,6 +116,85 @@ class SPIRVLegalizePointerCast : public FunctionPass {
return LI;
}
+ // Loads elements from an array and constructs a vector.
+ Value *loadVectorFromArray(IRBuilder<> &B, FixedVectorType *TargetType,
+ ArrayType *SourceType, Value *Source) {
+ // Ensure the element types of the array and vector are the same.
+ assert(TargetType->getElementType() == SourceType->getElementType() &&
+ "Element types of array and vector must be the same.");
+
+ // Load each element of the array.
+ SmallVector<Value *, 4> LoadedElements;
+ for (unsigned i = 0; i < TargetType->getNumElements(); ++i) {
+ // Create a GEP to access the i-th element of the array.
+ SmallVector<Type *, 2> Types = {Source->getType(), Source->getType()};
+ SmallVector<Value *, 4> Args;
+ Args.push_back(B.getInt1(true));
+ Args.push_back(Source);
+ Args.push_back(B.getInt32(0));
+ Args.push_back(ConstantInt::get(B.getInt32Ty(), i));
+ auto *ElementPtr = B.CreateIntrinsic(Intrinsic::spv_gep, {Types}, {Args});
+ GR->buildAssignPtr(B, TargetType->getElementType(), ElementPtr);
+
+ // Load the value from the element pointer.
+ Value *Load = B.CreateLoad(TargetType->getElementType(), ElementPtr);
+ buildAssignType(B, TargetType->getElementType(), Load);
+ LoadedElements.push_back(Load);
+ }
+
+ // Build the vector from the loaded elements.
+ Value *NewVector = UndefValue::get(TargetType);
+ buildAssignType(B, TargetType, NewVector);
+
+ for (unsigned i = 0; i < TargetType->getNumElements(); ++i) {
+ Value *Index = B.getInt32(i);
+ SmallVector<Type *, 4> Types = {TargetType, TargetType,
+ TargetType->getElementType(),
+ Index->getType()};
+ SmallVector<Value *> Args = {NewVector, LoadedElements[i], Index};
+ NewVector = B.CreateIntrinsic(Intrinsic::spv_insertelt, {Types}, {Args});
+ buildAssignType(B, TargetType, NewVector);
+ }
+ return NewVector;
+ }
+
+ // Stores elements from a vector into an array.
+ void storeArrayFromVector(IRBuilder<> &B, Value *SrcVector,
+ Value *DstArrayPtr, ArrayType *ArrTy,
+ Align Alignment) {
+ auto *VecTy = cast<FixedVectorType>(SrcVector->getType());
+
+ // Ensure the element types of the array and vector are the same.
+ assert(VecTy->getElementType() == ArrTy->getElementType() &&
+ "Element types of array and vector must be the same.");
+
+ for (unsigned i = 0; i < VecTy->getNumElements(); ++i) {
+ // Create a GEP to access the i-th element of the array.
+ SmallVector<Type *, 2> Types = {DstArrayPtr->getType(),
+ DstArrayPtr->getType()};
+ SmallVector<Value *, 4> Args;
+ Args.push_back(B.getInt1(true));
+ Args.push_back(DstArrayPtr);
+ Args.push_back(B.getInt32(0));
+ Args.push_back(ConstantInt::get(B.getInt32Ty(), i));
+ auto *ElementPtr = B.CreateIntrinsic(Intrinsic::spv_gep, {Types}, {Args});
+ GR->buildAssignPtr(B, ArrTy->getElementType(), ElementPtr);
+
+ // Extract the element from the vector and store it.
+ Value *Index = B.getInt32(i);
+ SmallVector<Type *, 3> EltTypes = {VecTy->getElementType(), VecTy,
+ Index->getType()};
+ SmallVector<Value *, 2> EltArgs = {SrcVector, Index};
+ Value *Element =
+ B.CreateIntrinsic(Intrinsic::spv_extractelt, {EltTypes}, {EltArgs});
+ buildAssignType(B, VecTy->getElementType(), Element);
+
+ Types = {Element->getType(), ElementPtr->getType()};
+ Args = {Element, ElementPtr, B.getInt16(2), B.getInt8(Alignment.value())};
+ B.CreateIntrinsic(Intrinsic::spv_store, {Types}, {Args});
+ }
+ }
+
// Replaces the load instruction to get rid of the ptrcast used as source
// operand.
void transformLoad(IRBuilder<> &B, LoadInst *LI, Value *CastedOperand,
@@ -154,6 +233,8 @@ class SPIRVLegalizePointerCast : public FunctionPass {
// - float v = s.m;
else if (SST && SST->getTypeAtIndex(0u) == ToTy)
Output = loadFirstValueFromAggregate(B, ToTy, OriginalOperand, LI);
+ else if (SAT && DVT && SAT->getElementType() == DVT->getElementType())
+ Output = loadVectorFromArray(B, DVT, SAT, OriginalOperand);
else
llvm_unreachable("Unimplemented implicit down-cast from load.");
@@ -288,6 +369,7 @@ class SPIRVLegalizePointerCast : public FunctionPass {
auto *S_VT = dyn_cast<FixedVectorType>(FromTy);
auto *D_ST = dyn_cast<StructType>(ToTy);
auto *D_VT = dyn_cast<FixedVectorType>(ToTy);
+ auto *D_AT = dyn_cast<ArrayType>(ToTy);
B.SetInsertPoint(BadStore);
if (D_ST && isTypeFirstElementAggregate(FromTy, D_ST))
@@ -296,6 +378,8 @@ class SPIRVLegalizePointerCast : public FunctionPass {
storeVectorFromVector(B, Src, Dst, Alignment);
else if (D_VT && !S_VT && FromTy == D_VT->getElementType())
storeToFirstValueAggregate(B, Src, Dst, D_VT, Alignment);
+ else if (D_AT && S_VT && S_VT->getElementType() == D_AT->getElementType())
+ storeArrayFromVector(B, Src, Dst, D_AT, Alignment);
else
llvm_unreachable("Unsupported ptrcast use in store. Please fix.");
diff --git a/llvm/test/CodeGen/SPIRV/pointers/load-store-vec-from-array.ll b/llvm/test/CodeGen/SPIRV/pointers/load-store-vec-from-array.ll
new file mode 100644
index 0000000000000..2a6d799c5bff6
--- /dev/null
+++ b/llvm/test/CodeGen/SPIRV/pointers/load-store-vec-from-array.ll
@@ -0,0 +1,54 @@
+; RUN: llc -O0 -verify-machineinstrs -mtriple=spirv-unknown-vulkan %s -o - | FileCheck %s
+; RUN: %if spirv-tools %{ llc -O0 -verify-machineinstrs -mtriple=spirv-unknown-vulkan %s -o - -filetype=obj | spirv-val %}
+
+; CHECK-DAG: [[FLOAT:%[0-9]+]] = OpTypeFloat 32
+; CHECK-DAG: [[VEC4FLOAT:%[0-9]+]] = OpTypeVector [[FLOAT]] 4
+; CHECK-DAG: [[UINT_TYPE:%[0-9]+]] = OpTypeInt 32 0
+; CHECK-DAG: [[UINT4:%[0-9]+]] = OpConstant [[UINT_TYPE]] 4
+; CHECK-DAG: [[ARRAY4FLOAT:%[0-9]+]] = OpTypeArray [[FLOAT]] [[UINT4]]
+; CHECK-DAG: [[PTR_ARRAY4FLOAT:%[0-9]+]] = OpTypePointer Private [[ARRAY4FLOAT]]
+; CHECK-DAG: [[G_IN:%[0-9]+]] = OpVariable [[PTR_ARRAY4FLOAT]] Private
+; CHECK-DAG: [[G_OUT:%[0-9]+]] = OpVariable [[PTR_ARRAY4FLOAT]] Private
+; CHECK-DAG: [[UINT0:%[0-9]+]] = OpConstant [[UINT_TYPE]] 0
+; CHECK-DAG: [[UINT1:%[0-9]+]] = OpConstant [[UINT_TYPE]] 1
+; CHECK-DAG: [[UINT2:%[0-9]+]] = OpConstant [[UINT_TYPE]] 2
+; CHECK-DAG: [[UINT3:%[0-9]+]] = OpConstant [[UINT_TYPE]] 3
+; CHECK-DAG: [[PTR_FLOAT:%[0-9]+]] = OpTypePointer Private [[FLOAT]]
+; CHECK-DAG: [[UNDEF_VEC:%[0-9]+]] = OpUndef [[VEC4FLOAT]]
+
+@G_in = internal addrspace(10) global [4 x float] zeroinitializer
+@G_out = internal addrspace(10) global [4 x float] zeroinitializer
+
+define spir_func void @main() {
+entry:
+; CHECK: [[GEP0:%[0-9]+]] = OpInBoundsAccessChain [[PTR_FLOAT]] [[G_IN]] [[UINT0]]
+; CHECK-NEXT: [[LOAD0:%[0-9]+]] = OpLoad [[FLOAT]] [[GEP0]]
+; CHECK-NEXT: [[GEP1:%[0-9]+]] = OpInBoundsAccessChain [[PTR_FLOAT]] [[G_IN]] [[UINT1]]
+; CHECK-NEXT: [[LOAD1:%[0-9]+]] = OpLoad [[FLOAT]] [[GEP1]]
+; CHECK-NEXT: [[GEP2:%[0-9]+]] = OpInBoundsAccessChain [[PTR_FLOAT]] [[G_IN]] [[UINT2]]
+; CHECK-NEXT: [[LOAD2:%[0-9]+]] = OpLoad [[FLOAT]] [[GEP2]]
+; CHECK-NEXT: [[GEP3:%[0-9]+]] = OpInBoundsAccessChain [[PTR_FLOAT]] [[G_IN]] [[UINT3]]
+; CHECK-NEXT: [[LOAD3:%[0-9]+]] = OpLoad [[FLOAT]] [[GEP3]]
+; CHECK-NEXT: [[VEC_INSERT0:%[0-9]+]] = OpCompositeInsert [[VEC4FLOAT]] [[LOAD0]] [[UNDEF_VEC]] 0
+; CHECK-NEXT: [[VEC_INSERT1:%[0-9]+]] = OpCompositeInsert [[VEC4FLOAT]] [[LOAD1]] [[VEC_INSERT0]] 1
+; CHECK-NEXT: [[VEC_INSERT2:%[0-9]+]] = OpCompositeInsert [[VEC4FLOAT]] [[LOAD2]] [[VEC_INSERT1]] 2
+; CHECK-NEXT: [[VEC:%[0-9]+]] = OpCompositeInsert [[VEC4FLOAT]] [[LOAD3]] [[VEC_INSERT2]] 3
+ %0 = load <4 x float>, ptr addrspace(10) @G_in, align 64
+
+; CHECK-NEXT: [[GEP_OUT0:%[0-9]+]] = OpInBoundsAccessChain [[PTR_FLOAT]] [[G_OUT]] [[UINT0]]
+; CHECK-NEXT: [[VEC_EXTRACT0:%[0-9]+]] = OpCompositeExtract [[FLOAT]] [[VEC]] 0
+; CHECK-NEXT: OpStore [[GEP_OUT0]] [[VEC_EXTRACT0]]
+; CHECK-NEXT: [[GEP_OUT1:%[0-9]+]] = OpInBoundsAccessChain [[PTR_FLOAT]] [[G_OUT]] [[UINT1]]
+; CHECK-NEXT: [[VEC_EXTRACT1:%[0-9]+]] = OpCompositeExtract [[FLOAT]] [[VEC]] 1
+; CHECK-NEXT: OpStore [[GEP_OUT1]] [[VEC_EXTRACT1]]
+; CHECK-NEXT: [[GEP_OUT2:%[0-9]+]] = OpInBoundsAccessChain [[PTR_FLOAT]] [[G_OUT]] [[UINT2]]
+; CHECK-NEXT: [[VEC_EXTRACT2:%[0-9]+]] = OpCompositeExtract [[FLOAT]] [[VEC]] 2
+; CHECK-NEXT: OpStore [[GEP_OUT2]] [[VEC_EXTRACT2]]
+; CHECK-NEXT: [[GEP_OUT3:%[0-9]+]] = OpInBoundsAccessChain [[PTR_FLOAT]] [[G_OUT]] [[UINT3]]
+; CHECK-NEXT: [[VEC_EXTRACT3:%[0-9]+]] = OpCompositeExtract [[FLOAT]] [[VEC]] 3
+; CHECK-NEXT: OpStore [[GEP_OUT3]] [[VEC_EXTRACT3]]
+ store <4 x float> %0, ptr addrspace(10) @G_out, align 64
+
+; CHECK-NEXT: OpReturn
+ ret void
+}
|
|
✅ With the latest revision this PR passed the undef deprecator. |
Keenuts
reviewed
Nov 6, 2025
Contributor
Keenuts
left a comment
Keenuts
left a comment
There was a problem hiding this comment.
a question but otherwise looks good
luciechoi
approved these changes
Nov 11, 2025
Keenuts
approved these changes
Nov 12, 2025
git-crd
pushed a commit
to git-crd/crd-llvm-project
that referenced
this pull request
Nov 13, 2025
This commit adds support for legalizing pointer casts between array and vector types within the SPIRV backend. This is necessary to handle cases where a vector is loaded from or stored to an array, which can occur with HLSL matrix types. The following changes are included: - Added to load a vector from an array. - Added to store a vector to an array. - Added the test case to verify the functionality.
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
4 participants
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
This commit adds support for legalizing pointer casts between array and vector types within the SPIRV backend.
This is necessary to handle cases where a vector is loaded from or stored to an array, which can occur with HLSL matrix types.
The following changes are included: