1 | //===- TensorToSPIRV.cpp - Tensor to SPIR-V Patterns ----------------------===// |
2 | // |
3 | // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
4 | // See https://llvm.org/LICENSE.txt for license information. |
5 | // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
6 | // |
7 | //===----------------------------------------------------------------------===// |
8 | // |
9 | // This file implements patterns to convert Tensor dialect to SPIR-V dialect. |
10 | // |
11 | //===----------------------------------------------------------------------===// |
12 | |
13 | #include "mlir/Conversion/TensorToSPIRV/TensorToSPIRV.h" |
14 | #include "../SPIRVCommon/Pattern.h" |
15 | #include "mlir/Dialect/SPIRV/IR/SPIRVDialect.h" |
16 | #include "mlir/Dialect/SPIRV/IR/SPIRVOps.h" |
17 | #include "mlir/Dialect/SPIRV/Transforms/SPIRVConversion.h" |
18 | #include "mlir/Dialect/SPIRV/Utils/LayoutUtils.h" |
19 | #include "mlir/Dialect/Tensor/IR/Tensor.h" |
20 | #include "mlir/IR/AffineMap.h" |
21 | #include "llvm/Support/Debug.h" |
22 | |
23 | #define DEBUG_TYPE "tensor-to-spirv-pattern" |
24 | |
25 | using namespace mlir; |
26 | |
27 | //===----------------------------------------------------------------------===// |
28 | // Operation conversion |
29 | //===----------------------------------------------------------------------===// |
30 | |
31 | namespace { |
32 | |
33 | /// Converts tensor.extract into loading using access chains from SPIR-V local |
34 | /// variables. |
35 | class final |
36 | : public OpConversionPattern<tensor::ExtractOp> { |
37 | public: |
38 | (const TypeConverter &typeConverter, MLIRContext *context, |
39 | int64_t threshold, PatternBenefit benefit = 1) |
40 | : OpConversionPattern(typeConverter, context, benefit), |
41 | byteCountThreshold(threshold) {} |
42 | |
43 | LogicalResult |
44 | matchAndRewrite(tensor::ExtractOp , OpAdaptor adaptor, |
45 | ConversionPatternRewriter &rewriter) const override { |
46 | auto tensorType = cast<RankedTensorType>(extractOp.getTensor().getType()); |
47 | |
48 | if (!isa<spirv::ScalarType>(tensorType.getElementType())) |
49 | return rewriter.notifyMatchFailure(extractOp, "unsupported type" ); |
50 | if (!tensorType.hasStaticShape()) |
51 | return rewriter.notifyMatchFailure(extractOp, "non-static tensor" ); |
52 | |
53 | if (tensorType.getNumElements() * tensorType.getElementTypeBitWidth() > |
54 | byteCountThreshold * 8) |
55 | return rewriter.notifyMatchFailure(extractOp, |
56 | "exceeding byte count threshold" ); |
57 | |
58 | Location loc = extractOp.getLoc(); |
59 | |
60 | int64_t rank = tensorType.getRank(); |
61 | SmallVector<int64_t, 4> strides(rank, 1); |
62 | for (int i = rank - 2; i >= 0; --i) { |
63 | strides[i] = strides[i + 1] * tensorType.getDimSize(i + 1); |
64 | } |
65 | |
66 | Type varType = spirv::PointerType::get(adaptor.getTensor().getType(), |
67 | spirv::StorageClass::Function); |
68 | |
69 | spirv::VariableOp varOp; |
70 | if (adaptor.getTensor().getDefiningOp<spirv::ConstantOp>()) { |
71 | // We could use the initializer directly; but certain driver compilers |
72 | // have bugs dealing with that. So for now, use spirv.Store for |
73 | // initialization. |
74 | varOp = rewriter.create<spirv::VariableOp>(loc, varType, |
75 | spirv::StorageClass::Function, |
76 | /*initializer=*/nullptr); |
77 | rewriter.create<spirv::StoreOp>(loc, varOp, adaptor.getTensor()); |
78 | } else { |
79 | // Need to store the value to the local variable. It's questionable |
80 | // whether we want to support such case though. |
81 | return failure(); |
82 | } |
83 | |
84 | auto &typeConverter = *getTypeConverter<SPIRVTypeConverter>(); |
85 | auto indexType = typeConverter.getIndexType(); |
86 | |
87 | Value index = spirv::linearizeIndex(indices: adaptor.getIndices(), strides, |
88 | /*offset=*/0, integerType: indexType, loc, builder&: rewriter); |
89 | auto acOp = rewriter.create<spirv::AccessChainOp>(loc, varOp, index); |
90 | |
91 | rewriter.replaceOpWithNewOp<spirv::LoadOp>(extractOp, acOp); |
92 | |
93 | return success(); |
94 | } |
95 | |
96 | private: |
97 | int64_t ; |
98 | }; |
99 | |
100 | } // namespace |
101 | |
102 | //===----------------------------------------------------------------------===// |
103 | // Pattern population |
104 | //===----------------------------------------------------------------------===// |
105 | |
106 | void mlir::populateTensorToSPIRVPatterns( |
107 | const SPIRVTypeConverter &typeConverter, int64_t byteCountThreshold, |
108 | RewritePatternSet &patterns) { |
109 | patterns.add<TensorExtractPattern>(arg: typeConverter, args: patterns.getContext(), |
110 | args&: byteCountThreshold); |
111 | } |
112 | |