[SM6.10] LinAlg Validation: MatrixStoreToMemory by V-FEXrt · Pull Request #8834 · microsoft/DirectXShaderCompiler

Ashley Coleman (V-FEXrt) · 2026-08-26T17:41:28Z

Fixes #8498

Implements LinAlg MatrixStoreToMemory validation rules

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Fixes #8498 Implements LinAlg MatrixStoreToMemory validation rules

Copilot

Pull request overview

Implements Shader Model 6.10 validation for LinAlgMatrixStoreToMemory.

Changes:

Validates matrix scope, groupshared type/capacity, offset, and stride.
Adds validation rules, diagnostics, and type utilities.
Adds validation coverage and updates CodeGen fixtures.

Reviewed changes

Copilot reviewed 8 out of 8 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
`utils/hct/hctdb.py`	Defines new validation diagnostics.
`tools/clang/test/LitDXILValidation/LinAlgMatrix/linalgmatrix-matrixstoretomemory.ll`	Tests store validation rules.
`tools/clang/test/CodeGenDXIL/hlsl/linalg/builtins/matrixstoretomemory/vector-array.hlsl`	Updates vector-array fixture.
`tools/clang/test/CodeGenDXIL/hlsl/linalg/builtins/matrixstoretomemory/nominal.hlsl`	Updates nominal fixture.
`lib/DxilValidation/DxilValidationUtils.h`	Declares native-type comparison helper.
`lib/DxilValidation/DxilValidationUtils.cpp`	Implements component/native-type matching.
`lib/DxilValidation/DxilValidation.cpp`	Implements store-to-memory validation.
`docs/DXIL.rst`	Documents new validation rules.

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@@ -1225,6 +1226,66 @@ static void ValidateLinAlgMatrixStoreToDescriptor(CallInst *CI,
 static void ValidateLinAlgMatrixStoreToMemory(CallInst *CI,
                                              ValidationContext &ValCtx) {
  ValidateLinAlgOpParameters(CI, ValCtx);


Chris B (llvm-beanz) · 2026-09-01T19:44:04Z

+  GEPOperator *GSGEP = cast<GEPOperator>(Op.get_memory());
+  GlobalVariable *GSMem = cast<GlobalVariable>(GSGEP->getPointerOperand());


I think this comment is technically correct in that we don't disallow such a formation, but I'm not actually sure it is possible to generate such code from the frontend.

Joshua Batista (bob80905) · 2026-08-26T18:01:00Z

+  GlobalVariable *GSMem = cast<GlobalVariable>(GSGEP->getPointerOperand());
+  Type *GSMemInnerTy = GSMem->getType();
+  unsigned GSScalarCount = 1;
+  if (PointerType *GSMemPtrTy = dyn_cast<PointerType>(GSMemInnerTy))


Consider making this an unconditional cast ? Or assert if this fails?

Ashley Coleman (V-FEXrt) · 2026-08-26T22:54:53Z

This was ported over from #8824 going to copy comments over

Ashley Coleman (V-FEXrt) · 2026-08-26T22:55:55Z

+        CI, ValidationRule::InstrLinAlgMatrixScopeMismatch2,
+        {"Input", MatrixScopeToString(Mat->Scope), "Wave", "ThreadGroup"});
+
+  GEPOperator *GSGEP = cast<GEPOperator>(Op.get_memory());


Chris B (@llvm-beanz) I'm pretty sure there is a better way to pull the inner most type out from the memory operator here but I just wanted to get something written down to unblock progress.

Does this seem right or should I do something else here. also can we even assume its always a GEP? Copilot seems to say no but I'm not sure what else it would be

You can simplify it a bit using getSequentialElementType(). Something like:

while(SequentialType* ST = dyn_cast<SequentialType>(GSMemInnerTy)) GSMemInnerTy = ST->getSequentialElementType();

That will walk the types up because getSequentialElementType works for pointers, arrays, and vectors.

Ashley Coleman (V-FEXrt) · 2026-08-26T22:56:20Z

+  unsigned GSScalarCount = 1;
+  if (PointerType *GSMemPtrTy = dyn_cast<PointerType>(GSMemInnerTy))
+    GSMemInnerTy = GSMemPtrTy->getPointerElementType();
+  if (ArrayType *GSMemArrTy = dyn_cast<ArrayType>(GSMemInnerTy)) {


From Alex: Should we check if nested arrarys are permitted?

this will be resolved by the loop version Chris provided above

Ashley Coleman (V-FEXrt) · 2026-08-26T22:56:52Z

  return OS.str();
 }

+bool IsComponentTypeSameNativeType(DXIL::ComponentType CT, llvm::Type *Ty) {


Chris B (@llvm-beanz) I think this is necessary since we don't really have a mapping for ComponentType to llvm::Type but figured I'd specifically highlight it since imo it's not trivially correct

seems reasonable to me

Damyan Pepper (damyanp)

LGTM, but I suspect you will want to get an answer to https://github.com/microsoft/DirectXShaderCompiler/pull/8834/changes#r3867347681 (or address it in a follow-up.)

Chris B (llvm-beanz)

Left a few comments. Take or leave the feedback. The only one that probably matters a bit is that maybe looping to get the sequential element type is a good changes since it does handle more cases and is simpler.

Chris B (llvm-beanz) · 2026-09-01T19:41:39Z

+        CI, ValidationRule::InstrLinAlgMatrixScopeMismatch2,
+        {"Input", MatrixScopeToString(Mat->Scope), "Wave", "ThreadGroup"});
+
+  GEPOperator *GSGEP = cast<GEPOperator>(Op.get_memory());


You can simplify it a bit using getSequentialElementType(). Something like:

while(SequentialType* ST = dyn_cast<SequentialType>(GSMemInnerTy)) GSMemInnerTy = ST->getSequentialElementType();

That will walk the types up because getSequentialElementType works for pointers, arrays, and vectors.

Chris B (llvm-beanz) · 2026-09-01T19:42:37Z

  return OS.str();
 }

+bool IsComponentTypeSameNativeType(DXIL::ComponentType CT, llvm::Type *Ty) {


seems reasonable to me

Chris B (llvm-beanz) · 2026-09-01T19:44:04Z

+  GEPOperator *GSGEP = cast<GEPOperator>(Op.get_memory());
+  GlobalVariable *GSMem = cast<GlobalVariable>(GSGEP->getPointerOperand());


I think this comment is technically correct in that we don't disallow such a formation, but I'm not actually sure it is possible to generate such code from the frontend.

Ashley Coleman (V-FEXrt) · 2026-09-01T21:29:48Z

Perfect! That's exactly the kind of feedback I was looking for:)

I'm going to go ahead and merge the PR so I can make progress on the stack but I'll fix this as a follow up once everything goes in. (This change applies to a few of the stacked PRs)

[SM6.10] LinAlg Validation: MatrixStoreToMemory

c86ad69

Fixes #8498 Implements LinAlg MatrixStoreToMemory validation rules

Copilot AI balanced review requested due to automatic review settings August 26, 2026 17:41

github-project-automation Bot added this to HLSL Roadmap Aug 26, 2026

github-project-automation Bot moved this to New in HLSL Roadmap Aug 26, 2026

Copilot started reviewing on behalf of Ashley Coleman (V-FEXrt) August 26, 2026 17:42 View session

Copilot AI reviewed Aug 26, 2026

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Joshua Batista (bob80905) reviewed Aug 26, 2026

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Joshua Batista (bob80905) approved these changes Aug 26, 2026

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Ashley Coleman (V-FEXrt) commented Aug 26, 2026

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Damyan Pepper (damyanp) reviewed Aug 27, 2026

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Damyan Pepper (damyanp) mentioned this pull request Aug 27, 2026

[SM6.10] LinAlg Validation: MatrixAccumulateToMemory #8835

Merged

Chris B (llvm-beanz) approved these changes Sep 1, 2026

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Ashley Coleman (V-FEXrt) merged commit fe09c22 into main Sep 1, 2026
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Ashley Coleman (V-FEXrt) deleted the linalg-vali-matrixstoretomemory branch September 1, 2026 21:35

github-project-automation Bot moved this from New to Done in HLSL Roadmap Sep 1, 2026

		GEPOperator *GSGEP = cast<GEPOperator>(Op.get_memory());
		GlobalVariable *GSMem = cast<GlobalVariable>(GSGEP->getPointerOperand());

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Ashley Coleman (V-FEXrt) commented Aug 26, 2026

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Ashley Coleman (V-FEXrt) commented Aug 26, 2026

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Ashley Coleman (V-FEXrt) commented Sep 1, 2026

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