[Mlir-commits] [mlir] [MLIR][XeGPU] Add sg_map attribute to support Work Item level semantics (PR #108864)
llvmlistbot at llvm.org
llvmlistbot at llvm.org
Mon Sep 16 10:44:18 PDT 2024
llvmbot wrote:
<!--LLVM PR SUMMARY COMMENT-->
@llvm/pr-subscribers-mlir
Author: Petr Kurapov (kurapov-peter)
<details>
<summary>Changes</summary>
The PR adds an attribute (sg_map) describing the distribution of computation among work items for xegpu operations to be used in lowering passes. The map is attached to the tensor descriptor, so the constructor and the type are updated. Tests check the custom parser & printer. The attribute is optional now, so no other changes required.
The complete description of the attribute can be found [here](https://github.com/intel/mlir-extensions/blob/main/docs/rfcs/XeGPU.md#xegpu-attributes-to-support-work-item-level-semantics).
---
Full diff: https://github.com/llvm/llvm-project/pull/108864.diff
4 Files Affected:
- (modified) mlir/include/mlir/Dialect/XeGPU/IR/XeGPUAttrs.td (+32)
- (modified) mlir/include/mlir/Dialect/XeGPU/IR/XeGPUTypes.td (+13-3)
- (modified) mlir/lib/Dialect/XeGPU/IR/XeGPUDialect.cpp (+99-12)
- (modified) mlir/test/Dialect/XeGPU/XeGPUOps.mlir (+15)
``````````diff
diff --git a/mlir/include/mlir/Dialect/XeGPU/IR/XeGPUAttrs.td b/mlir/include/mlir/Dialect/XeGPU/IR/XeGPUAttrs.td
index f3ca09a6a68ea8..576c79f66aaed9 100644
--- a/mlir/include/mlir/Dialect/XeGPU/IR/XeGPUAttrs.td
+++ b/mlir/include/mlir/Dialect/XeGPU/IR/XeGPUAttrs.td
@@ -116,4 +116,36 @@ def XeGPU_FenceScopeAttr:
let assemblyFormat = "$value";
}
+def XeGPU_SGMapAttr : XeGPUAttr<"SGMap", "sg_map"> {
+ let summary = [{
+ Describes the mapping between work item (WI) and the 2D tensor specified by the tensor descriptor.
+ }];
+ let description = [{
+ To distribute the XeGPU operation to work items, the tensor_desc must be specified with the sg_map
+ attribute at the tensor description creation time.
+ Within the `sg_map`, `wi_layout` specifies the layout of work items,
+ describing the mapping of work items to the tensor.
+ wi_layout[0] x wi_layout[1] must be equal to the total number of work items within a subgroup.
+ `wi_data` specifies the minimum number of data elements assigned to each work item for a single distribution.
+
+ E.g., #xegpu.sg_map<wi_layout = [1, 16], wi_data = [1, 1]>
+ In this example, the subgroup has 16 work items in wi_layout=[1, 16],
+ each accessing 1 element as specified by wi_data=[1, 1].
+
+ `wi_data[0] * wi_data[1]` can be greater than 1, meaning that each work item operates on multiple elements,
+ which is eventually lowered to "SIMT-flavor" vector, like SPIR-V vector or llvm vector.
+ The multiple elements indicated by `wi_data` can only be from one dimension and must be contiguous in the memory along either dimension.
+ }];
+ let parameters = (ins
+ ArrayRefParameter<"uint32_t">:$wi_layout,
+ ArrayRefParameter<"uint32_t">:$wi_data);
+
+ let builders = [
+ AttrBuilder<(ins)>
+ ];
+
+ let hasCustomAssemblyFormat = 1;
+ let genVerifyDecl = 1;
+}
+
#endif // MLIR_DIALECT_XEGPU_IR_XEGPUATTRS_TD
\ No newline at end of file
diff --git a/mlir/include/mlir/Dialect/XeGPU/IR/XeGPUTypes.td b/mlir/include/mlir/Dialect/XeGPU/IR/XeGPUTypes.td
index 9f101a71697b56..c0d7a08a6cb3a2 100644
--- a/mlir/include/mlir/Dialect/XeGPU/IR/XeGPUTypes.td
+++ b/mlir/include/mlir/Dialect/XeGPU/IR/XeGPUTypes.td
@@ -63,7 +63,7 @@ def XeGPU_TensorDesc: XeGPUTypeDef<"TensorDesc", "tensor_desc",
element-type ::= float-type | integer-type | index-type
dim-list := (static-dim-list `x`)?
static-dim-list ::= decimal-literal `x` decimal-literal
- attr-list = (, memory_scope = value)? (, arr_len = value)? (, boundary_check = value)? (, scattered = value)?
+ attr-list = (, memory_scope = value)? (, arr_len = value)? (, boundary_check = value)? (, scattered = value)? (, sg_map `<` wi_layout = value, wi_data = value `>`)?
```
Examples:
@@ -77,12 +77,16 @@ def XeGPU_TensorDesc: XeGPUTypeDef<"TensorDesc", "tensor_desc",
// A TensorDesc with 8x16 f32 elements for a memory region in shared memory space.
xegpu.tensor_desc<8x16xf32, #xegpu.tdesc_attr<memory_scope = slm>>
+
+ // A TensorDesc with a sg_map
+ xegpu.tensor_desc<8x16xf32, #xegpu.sg_map<wi_layout = [1, 16], wi_data = [1, 1]>>
```
}];
let parameters = (ins ArrayRefParameter<"int64_t">: $shape,
"mlir::Type": $elementType,
- OptionalParameter<"mlir::Attribute">: $encoding);
+ OptionalParameter<"mlir::Attribute">: $encoding,
+ OptionalParameter<"mlir::Attribute">: $sg_map);
let builders = [
TypeBuilderWithInferredContext<(ins
@@ -91,7 +95,9 @@ def XeGPU_TensorDesc: XeGPUTypeDef<"TensorDesc", "tensor_desc",
CArg<"bool", "false">: $scattered,
CArg<"int", "1">: $array_length,
CArg<"xegpu::MemoryScope", "xegpu::MemoryScope::Global">:$memory_scope,
- CArg<"bool", "true">: $boundary_check
+ CArg<"bool", "true">: $boundary_check,
+ CArg<"llvm::ArrayRef<uint32_t>", "{}">: $wi_layout,
+ CArg<"llvm::ArrayRef<uint32_t>", "{}">: $wi_data
)>
];
@@ -114,6 +120,10 @@ def XeGPU_TensorDesc: XeGPUTypeDef<"TensorDesc", "tensor_desc",
return llvm::dyn_cast_if_present<TensorDescAttr>(getEncoding());
}
+ SGMapAttr getSGMapAttr() const {
+ return llvm::dyn_cast_if_present<SGMapAttr>(getSgMap());
+ }
+
xegpu::MemoryScope getMemoryScope() const {
auto attr = getEncodingAsTensorDescAttr();
if (attr && attr.getMemoryScope())
diff --git a/mlir/lib/Dialect/XeGPU/IR/XeGPUDialect.cpp b/mlir/lib/Dialect/XeGPU/IR/XeGPUDialect.cpp
index 24719fe748fe4f..cbc140c465e1ec 100644
--- a/mlir/lib/Dialect/XeGPU/IR/XeGPUDialect.cpp
+++ b/mlir/lib/Dialect/XeGPU/IR/XeGPUDialect.cpp
@@ -44,6 +44,77 @@ TensorDescAttr TensorDescAttr::get(mlir::MLIRContext *context,
return Base::get(context, scopeAttr, lengthAttr, boundaryAttr, scatteredAttr);
}
+//===----------------------------------------------------------------------===//
+// XeGPU_SGMapAttr
+//===----------------------------------------------------------------------===//
+namespace {
+template <typename T, unsigned N>
+LogicalResult parseIntArrayField(::mlir::AsmParser &parser,
+ llvm::SmallVector<T, N> &result,
+ llvm::StringRef fieldName) {
+ if (failed(parser.parseKeyword(fieldName))) {
+ parser.emitError(parser.getCurrentLocation(),
+ "unexpected field name. Expected " + fieldName + ".");
+ return failure();
+ }
+
+ if (failed(parser.parseEqual())) {
+ parser.emitError(parser.getCurrentLocation(), "expected '=' sign.");
+ return failure();
+ }
+
+ auto elemParser = [&]() -> llvm::ParseResult {
+ uint32_t elem = 0;
+ auto res = parser.parseInteger(elem);
+ result.push_back(elem);
+ return res;
+ };
+
+ return parser.parseCommaSeparatedList(AsmParser::Delimiter::Square,
+ elemParser, fieldName);
+}
+} // namespace
+
+mlir::Attribute SGMapAttr::parse(::mlir::AsmParser &parser,
+ ::mlir::Type attrType) {
+ if (failed(parser.parseLess()))
+ return {};
+
+ llvm::SmallVector<uint32_t, 2> wi_layout, wi_data;
+ if (failed(parseIntArrayField(parser, wi_layout, "wi_layout")))
+ return {};
+
+ if (failed(parser.parseComma()))
+ return {};
+
+ if (failed(parseIntArrayField(parser, wi_data, "wi_data")))
+ return {};
+
+ return SGMapAttr::getChecked(
+ [&]() { return parser.emitError(parser.getNameLoc()); },
+ parser.getContext(), wi_layout, wi_data);
+}
+
+void SGMapAttr::print(::mlir::AsmPrinter &printer) const {
+ printer << "<";
+ printer.printKeywordOrString("wi_layout");
+ printer << " = [" << getWiLayout() << "], ";
+ printer.printKeywordOrString("wi_data");
+ printer << " = [" << getWiData() << "]";
+ printer << ">";
+}
+
+LogicalResult
+SGMapAttr::verify(llvm::function_ref<mlir::InFlightDiagnostic()> emitError,
+ llvm::ArrayRef<uint32_t> wi_layout,
+ llvm::ArrayRef<uint32_t> wi_data) {
+ if (wi_layout.size() != 2)
+ return emitError() << "expected wi_layout of size 2";
+ if (wi_data.size() != 2)
+ return emitError() << "expected wi_data of size 2";
+ return success();
+}
+
//===----------------------------------------------------------------------===//
// XeGPU_TensorDescType
//===----------------------------------------------------------------------===//
@@ -51,6 +122,7 @@ mlir::Type TensorDescType::parse(::mlir::AsmParser &parser) {
llvm::SmallVector<int64_t> shape;
mlir::Type elementType;
mlir::FailureOr<mlir::Attribute> encoding;
+ mlir::FailureOr<mlir::Attribute> sg_map;
// Parse literal '<'
if (parser.parseLess())
@@ -69,14 +141,22 @@ mlir::Type TensorDescType::parse(::mlir::AsmParser &parser) {
}
// parse optional attributes
- if (mlir::succeeded(parser.parseOptionalComma())) {
- encoding = mlir::FieldParser<mlir::Attribute>::parse(parser);
- if (mlir::failed(encoding)) {
- parser.emitError(
- parser.getCurrentLocation(),
- "Failed to parse the attribute field for TensorDescType.\n");
- return {};
+ while (mlir::succeeded(parser.parseOptionalComma())) {
+ mlir::Attribute attr;
+ ParseResult res = parser.parseAttribute(attr);
+ if (mlir::succeeded(res)) {
+ if (mlir::isa<SGMapAttr>(attr)) {
+ sg_map = attr;
+ continue;
+ }
+ if (mlir::isa<TensorDescAttr>(attr)) {
+ encoding = attr;
+ continue;
+ }
}
+ parser.emitError(parser.getCurrentLocation(),
+ "Failed to parse the attribute.\n");
+ return {};
}
// Parse literal '>'
@@ -84,7 +164,8 @@ mlir::Type TensorDescType::parse(::mlir::AsmParser &parser) {
return {};
return TensorDescType::get(parser.getContext(), shape, elementType,
- encoding.value_or(mlir::Attribute()));
+ encoding.value_or(mlir::Attribute()),
+ sg_map.value_or(mlir::Attribute()));
}
void TensorDescType::print(::mlir::AsmPrinter &printer) const {
@@ -104,17 +185,23 @@ void TensorDescType::print(::mlir::AsmPrinter &printer) const {
if (auto encoding = getEncoding())
printer << ", " << encoding;
+ if (auto sg_map = getSgMap())
+ printer << ", " << sg_map;
+
printer << ">";
}
TensorDescType TensorDescType::get(llvm::ArrayRef<int64_t> shape,
mlir::Type elementType, bool scattered,
int array_length, MemoryScope memory_scope,
- bool boundary_check) {
+ bool boundary_check,
+ llvm::ArrayRef<uint32_t> wi_layout,
+ llvm::ArrayRef<uint32_t> wi_data) {
auto context = elementType.getContext();
- auto attr = TensorDescAttr::get(context, memory_scope, array_length,
- boundary_check, scattered);
- return Base::get(context, shape, elementType, attr);
+ auto tensorDescAttr = TensorDescAttr::get(context, memory_scope, array_length,
+ boundary_check, scattered);
+ auto sgMapAttr = SGMapAttr::get(context, wi_layout, wi_data);
+ return Base::get(context, shape, elementType, tensorDescAttr, sgMapAttr);
}
} // namespace xegpu
diff --git a/mlir/test/Dialect/XeGPU/XeGPUOps.mlir b/mlir/test/Dialect/XeGPU/XeGPUOps.mlir
index 35d44cf56a239b..eb242f8aa88e64 100644
--- a/mlir/test/Dialect/XeGPU/XeGPUOps.mlir
+++ b/mlir/test/Dialect/XeGPU/XeGPUOps.mlir
@@ -13,6 +13,14 @@ gpu.func @test_create_nd_tdesc_vc_1(%src: memref<24x32xf32>) {
gpu.return
}
+// CHECK: gpu.func @test_create_nd_tdesc_with_sg_map(%[[arg0:.*]]: memref<24x32xf32>) {
+gpu.func @test_create_nd_tdesc_with_sg_map(%src: memref<24x32xf32>) {
+ // CHECK: %[[REG:.*]] = xegpu.create_nd_tdesc %arg0[0, 0] : memref<24x32xf32> -> !xegpu.tensor_desc<8x16xf32, #xegpu.sg_map<wi_layout = [1, 16], wi_data = [1, 1]>>
+ %1 = xegpu.create_nd_tdesc %src[0, 0] : memref<24x32xf32> ->
+ !xegpu.tensor_desc<8x16xf32, #xegpu.sg_map<wi_layout = [1, 16], wi_data = [1, 1]>>
+ gpu.return
+}
+
// CHECK: gpu.func @test_create_nd_tdesc_vc_2(%[[arg0:.*]]: ui64, %[[arg1:.*]]: index, %[[arg2:.*]]: index, %[[arg3:.*]]: index, %[[arg4:.*]]: index) {
gpu.func @test_create_nd_tdesc_vc_2(%src: ui64, %w : index, %h : index, %x : index, %y : index) {
//CHECK: %[[C:.*]] = arith.constant 1 : index
@@ -36,6 +44,13 @@ gpu.func @test_create_nd_tdesc_vc_4(%src: memref<2x24x32xf32>) {
gpu.return
}
+// CHECK: gpu.func @test_create_nd_tdesc_vc_5(%[[arg0:.*]]: memref<24x32xf32>) {
+gpu.func @test_create_nd_tdesc_vc_5(%src: memref<24x32xf32>) {
+ // CHECK: %[[REG:.*]] = xegpu.create_nd_tdesc %[[arg0]][0, 0] : memref<24x32xf32> -> !xegpu.tensor_desc<24x16xf32, #xegpu.tdesc_attr<array_length = 2 : i64>, #xegpu.sg_map<wi_layout = [1, 16], wi_data = [1, 1]>
+ %1 = xegpu.create_nd_tdesc %src[0, 0] : memref<24x32xf32> -> !xegpu.tensor_desc<24x16xf32, #xegpu.tdesc_attr<array_length = 2>, #xegpu.sg_map<wi_layout = [1, 16], wi_data = [1, 1]>>
+ gpu.return
+}
+
// CHECK: gpu.func @test_prefetch_nd_vc(%[[arg0:.*]]: memref<24x32xf16>) {
gpu.func @test_prefetch_nd_vc(%src: memref<24x32xf16>) {
// CHECK: %[[R0:.*]] = xegpu.create_nd_tdesc %[[arg0]][0, 0] : memref<24x32xf16> -> !xegpu.tensor_desc<8x16xf16>
``````````
</details>
https://github.com/llvm/llvm-project/pull/108864
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