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Merged
banach-space merged 3 commits into from
Dec 18, 2025
Merged

[CIR] Introduce syntax for scalable vectors #172683

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69cff0c
[CIR] Introduce syntax for scalable vectors
banach-space Dec 17, 2025
59e3270
Remove unnecessary braces
banach-space Dec 17, 2025
44b6e72
Add a test for the parser
banach-space Dec 17, 2025
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13 changes: 9 additions & 4 deletions clang/include/clang/CIR/Dialect/IR/CIRTypes.td
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Original file line number Diff line number Diff line change
Expand Up @@ -430,6 +430,7 @@ def CIR_VectorType : CIR_Type<"Vector", "vector", [

```mlir
vector-type ::= !cir.vector<size x element-type>
size ::= (decimal-literal | `[` decimal-literal `]`)
element-type ::= float-type | integer-type | pointer-type
```

Expand All @@ -442,6 +443,13 @@ def CIR_VectorType : CIR_Type<"Vector", "vector", [
!cir.vector<4 x !cir.int<u, 8>>
!cir.vector<2 x !cir.float>
```

Scalable vectors are indicated by enclosing size in square brackets.

Example:
```mlir
!cir.vector<[4] x !cir.int<u, 8>>
```
}];

let parameters = (ins
Expand All @@ -450,10 +458,6 @@ def CIR_VectorType : CIR_Type<"Vector", "vector", [
OptionalParameter<"bool">:$is_scalable
);

let assemblyFormat = [{
`<` $size `x` $element_type `>`
}];

let builders = [
TypeBuilderWithInferredContext<(ins
"mlir::Type":$element_type, "uint64_t":$size, CArg<"bool",
Expand All @@ -471,6 +475,7 @@ def CIR_VectorType : CIR_Type<"Vector", "vector", [

let genVerifyDecl = 1;
let skipDefaultBuilders = 1;
let hasCustomAssemblyFormat = 1;
}

//===----------------------------------------------------------------------===//
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69 changes: 69 additions & 0 deletions clang/lib/CIR/Dialect/IR/CIRTypes.cpp
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Expand Up @@ -828,6 +828,75 @@ mlir::LogicalResult cir::VectorType::verify(
return success();
}

mlir::Type cir::VectorType::parse(::mlir::AsmParser &odsParser) {

llvm::SMLoc odsLoc = odsParser.getCurrentLocation();
mlir::Builder odsBuilder(odsParser.getContext());
mlir::FailureOr<::mlir::Type> elementType;
mlir::FailureOr<uint64_t> size;
bool isScalabe = false;

// Parse literal '<'
if (odsParser.parseLess())
return {};

// Parse literal '[', if present, and set the scalability flag accordingly
if (odsParser.parseOptionalLSquare().succeeded())
isScalabe = true;

// Parse variable 'size'
size = mlir::FieldParser<uint64_t>::parse(odsParser);
if (mlir::failed(size)) {
odsParser.emitError(odsParser.getCurrentLocation(),
"failed to parse CIR_VectorType parameter 'size' which "
"is to be a `uint64_t`");
return {};
}

// Parse literal ']', which is expected when dealing with scalable
// dim sizes
if (isScalabe && odsParser.parseRSquare().failed()) {
odsParser.emitError(odsParser.getCurrentLocation(),
"missing closing `]` for scalable dim size");
return {};
}

// Parse literal 'x'
if (odsParser.parseKeyword("x"))
return {};

// Parse variable 'elementType'
elementType = mlir::FieldParser<::mlir::Type>::parse(odsParser);
if (mlir::failed(elementType)) {
odsParser.emitError(odsParser.getCurrentLocation(),
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@AmrDeveloper AmrDeveloper Dec 17, 2025

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Should we add an invalid vector cir test to make sure errors are emitted correctly

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@banach-space banach-space Dec 17, 2025

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This might be different in CIR, but in MLIR we don't really test the parser and tests in invalid.mlir (and similar) are reserved for verification errors.

I am happy to add a test if you think that that would be helpful, but we’d probably want to add a dedicated file for parser errors - perhaps one already exists? I didn’t find any.

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@AmrDeveloper AmrDeveloper Dec 17, 2025

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Usually, for the handwritten parser or verifier, we have a invalid-<>.cir file to test it, for example, clang/test/CIR/IR/invalid-vector.cir, I think we can add a small test for scalable vector type syntax. What do you think? @andykaylor

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@AmrDeveloper AmrDeveloper Dec 17, 2025

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BTW, Only this error need to be covered "missing closing ] for scalable dim size", the other already covered in this test :D

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@banach-space banach-space Dec 17, 2025

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Added a test in this commit.

IMO, it's not great :/ (suggestions for improvement are welcome) .Testing !cir.vector<[1 x !s32i> (instead of !cir.vector<[1 x] !s32i>) would be better, but the former is captured by Parser::parseDialectSymbolBody with:

/llvm-project/clang/test/CIR/IR/invalid-vector.cir:17:30: error: unbalanced '[' character in pretty dialect name
  %3 = cir.alloca !cir.vector<[1 x !s32i>, !cir.ptr<!cir.vector<[1] x !s32i>>
                             ^

That error is hit before getting into cir::VectorType::parse.

Btw, I don't want to come across as nit-picking or pushing back, but I see quite a few CIR parser errors that are not tested, e.g.

llvm-project/clang/lib/CIR/Dialect/IR/CIRTypes.cpp

Line 154 in fa511cd

parser.emitError(loc, "invalid self-reference within record");

Perhaps it would be better to skip testing in this case as well? WDYT?

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@AmrDeveloper AmrDeveloper Dec 17, 2025

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Thanks for adding it. I am fine with both options, but I think it will be better to keep this test case 🤔

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@andykaylor andykaylor Dec 17, 2025

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Btw, I don't want to come across as nit-picking or pushing back, but I see quite a few CIR parser errors that are not tested, e.g.

I'm sure we've been inconsistent about this. I generally only look for tests for verifier errors and have been satisfied with round-trip tests for printing/parsing. My view is that the tests for the verifier check that we are correctly catching incorrectly constructed IR, which can occur anywhere during IR generation or processing, whereas the printing and parsing are paired so they test each other for correctness.

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@banach-space banach-space Dec 18, 2025

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Lets me keep the test for now, we can always remove it later.

"failed to parse CIR_VectorType parameter "
"'elementType' which is to be a `mlir::Type`");
return {};
}

// Parse literal '>'
if (odsParser.parseGreater())
return {};
return odsParser.getChecked<VectorType>(odsLoc, odsParser.getContext(),
mlir::Type((*elementType)),
uint64_t((*size)), isScalabe);
}

void cir::VectorType::print(mlir::AsmPrinter &odsPrinter) const {
mlir::Builder odsBuilder(getContext());
odsPrinter << "<";
if (this->getIsScalable())
odsPrinter << "[";

odsPrinter.printStrippedAttrOrType(getSize());
if (this->getIsScalable())
odsPrinter << "]";
odsPrinter << ' ' << "x";
odsPrinter << ' ';
odsPrinter.printStrippedAttrOrType(getElementType());
odsPrinter << ">";
}

//===----------------------------------------------------------------------===//
// TargetAddressSpace definitions
//===----------------------------------------------------------------------===//
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10 changes: 10 additions & 0 deletions clang/test/CIR/IR/invalid-vector.cir
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Expand Up @@ -11,6 +11,16 @@ cir.global external @vec_b = #cir.zero : !cir.vector<4 x !cir.array<!s32i x 10>>

// -----

cir.func @invalid_scalable_vec_syntax() {
// expected-error@+2 {{missing closing `]` for scalable dim size}}
// expected-error @below {{expected ']'}}
%3 = cir.alloca !cir.vector<[1 x] !s32i>, !cir.ptr<!cir.vector<[1] x !s32i>>
cir.return

}

// -----

!s32i = !cir.int<s, 32>
!s64i = !cir.int<s, 64>

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2 changes: 2 additions & 0 deletions clang/test/CIR/IR/vector.cir
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Expand Up @@ -23,13 +23,15 @@ cir.func @vec_int_test() {
%0 = cir.alloca !cir.vector<4 x !s32i>, !cir.ptr<!cir.vector<4 x !s32i>>, ["a"]
%1 = cir.alloca !cir.vector<3 x !s32i>, !cir.ptr<!cir.vector<3 x !s32i>>, ["b"]
%2 = cir.alloca !cir.vector<2 x !s32i>, !cir.ptr<!cir.vector<2 x !s32i>>, ["c"]
%3 = cir.alloca !cir.vector<[1] x !s32i>, !cir.ptr<!cir.vector<[1] x !s32i>>, ["d"]
cir.return
}

// CHECK: cir.func{{.*}} @vec_int_test() {
// CHECK: %0 = cir.alloca !cir.vector<4 x !s32i>, !cir.ptr<!cir.vector<4 x !s32i>>, ["a"]
// CHECK: %1 = cir.alloca !cir.vector<3 x !s32i>, !cir.ptr<!cir.vector<3 x !s32i>>, ["b"]
// CHECK: %2 = cir.alloca !cir.vector<2 x !s32i>, !cir.ptr<!cir.vector<2 x !s32i>>, ["c"]
// CHECK: %3 = cir.alloca !cir.vector<[1] x !s32i>, !cir.ptr<!cir.vector<[1] x !s32i>>, ["d"]
// CHECK: cir.return
// CHECK: }

Expand Down