xref: /llvm-project/mlir/lib/Dialect/Vector/Transforms/LowerVectorInterleave.cpp (revision db791b278a414fb6df1acc1799adcf11d8fb9169)
1 //===- LowerVectorInterleave.cpp - Lower 'vector.interleave' operation ----===//
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 target-independent rewrites and utilities to lower the
10 // 'vector.interleave' operation.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #include "mlir/Dialect/Vector/IR/VectorOps.h"
15 #include "mlir/Dialect/Vector/Transforms/LoweringPatterns.h"
16 #include "mlir/Dialect/Vector/Utils/VectorUtils.h"
17 #include "mlir/IR/BuiltinTypes.h"
18 #include "mlir/IR/PatternMatch.h"
19 
20 #define DEBUG_TYPE "vector-interleave-lowering"
21 
22 using namespace mlir;
23 using namespace mlir::vector;
24 
25 namespace {
26 
27 /// A one-shot unrolling of vector.interleave to the `targetRank`.
28 ///
29 /// Example:
30 ///
31 /// ```mlir
32 /// vector.interleave %a, %b : vector<1x2x3x4xi64> -> vector<1x2x3x8xi64>
33 /// ```
34 /// Would be unrolled to:
35 /// ```mlir
36 /// %result = arith.constant dense<0> : vector<1x2x3x8xi64>
37 /// %0 = vector.extract %a[0, 0, 0]                 ─┐
38 ///        : vector<4xi64> from vector<1x2x3x4xi64>  |
39 /// %1 = vector.extract %b[0, 0, 0]                  |
40 ///        : vector<4xi64> from vector<1x2x3x4xi64>  | - Repeated 6x for
41 /// %2 = vector.interleave %0, %1 :                  |   all leading positions
42 ///        : vector<4xi64> -> vector<8xi64>          |
43 /// %3 = vector.insert %2, %result [0, 0, 0]         |
44 ///        : vector<8xi64> into vector<1x2x3x8xi64>  ┘
45 /// ```
46 ///
47 /// Note: If any leading dimension before the `targetRank` is scalable the
48 /// unrolling will stop before the scalable dimension.
49 class UnrollInterleaveOp final : public OpRewritePattern<vector::InterleaveOp> {
50 public:
UnrollInterleaveOp(int64_t targetRank,MLIRContext * context,PatternBenefit benefit=1)51   UnrollInterleaveOp(int64_t targetRank, MLIRContext *context,
52                      PatternBenefit benefit = 1)
53       : OpRewritePattern(context, benefit), targetRank(targetRank){};
54 
matchAndRewrite(vector::InterleaveOp op,PatternRewriter & rewriter) const55   LogicalResult matchAndRewrite(vector::InterleaveOp op,
56                                 PatternRewriter &rewriter) const override {
57     VectorType resultType = op.getResultVectorType();
58     auto unrollIterator = vector::createUnrollIterator(resultType, targetRank);
59     if (!unrollIterator)
60       return failure();
61 
62     auto loc = op.getLoc();
63     Value result = rewriter.create<arith::ConstantOp>(
64         loc, resultType, rewriter.getZeroAttr(resultType));
65     for (auto position : *unrollIterator) {
66       Value extractLhs = rewriter.create<ExtractOp>(loc, op.getLhs(), position);
67       Value extractRhs = rewriter.create<ExtractOp>(loc, op.getRhs(), position);
68       Value interleave =
69           rewriter.create<InterleaveOp>(loc, extractLhs, extractRhs);
70       result = rewriter.create<InsertOp>(loc, interleave, result, position);
71     }
72 
73     rewriter.replaceOp(op, result);
74     return success();
75   }
76 
77 private:
78   int64_t targetRank = 1;
79 };
80 
81 /// A one-shot unrolling of vector.deinterleave to the `targetRank`.
82 ///
83 /// Example:
84 ///
85 /// ```mlir
86 /// %0, %1 = vector.deinterleave %a : vector<1x2x3x8xi64> -> vector<1x2x3x4xi64>
87 /// ```
88 /// Would be unrolled to:
89 /// ```mlir
90 /// %result = arith.constant dense<0> : vector<1x2x3x4xi64>
91 /// %0 = vector.extract %a[0, 0, 0]                  ─┐
92 ///        : vector<8xi64> from vector<1x2x3x8xi64>   |
93 /// %1, %2 = vector.deinterleave %0                   |
94 ///        : vector<8xi64> -> vector<4xi64>           | -- Initial deinterleave
95 /// %3 = vector.insert %1, %result [0, 0, 0]          |    operation unrolled.
96 ///        : vector<4xi64> into vector<1x2x3x4xi64>   |
97 /// %4 = vector.insert %2, %result [0, 0, 0]          |
98 ///        : vector<4xi64> into vector<1x2x3x4xi64>   ┘
99 /// %5 = vector.extract %a[0, 0, 1]                  ─┐
100 ///        : vector<8xi64> from vector<1x2x3x8xi64>   |
101 /// %6, %7 = vector.deinterleave %5                   |
102 ///        : vector<8xi64> -> vector<4xi64>           | -- Recursive pattern for
103 /// %8 = vector.insert %6, %3 [0, 0, 1]               |    subsequent unrolled
104 ///        : vector<4xi64> into vector<1x2x3x4xi64>   |    deinterleave
105 /// %9 = vector.insert %7, %4 [0, 0, 1]               |    operations. Repeated
106 ///        : vector<4xi64> into vector<1x2x3x4xi64>   ┘    5x in this case.
107 /// ```
108 ///
109 /// Note: If any leading dimension before the `targetRank` is scalable the
110 /// unrolling will stop before the scalable dimension.
111 class UnrollDeinterleaveOp final
112     : public OpRewritePattern<vector::DeinterleaveOp> {
113 public:
UnrollDeinterleaveOp(int64_t targetRank,MLIRContext * context,PatternBenefit benefit=1)114   UnrollDeinterleaveOp(int64_t targetRank, MLIRContext *context,
115                        PatternBenefit benefit = 1)
116       : OpRewritePattern(context, benefit), targetRank(targetRank) {};
117 
matchAndRewrite(vector::DeinterleaveOp op,PatternRewriter & rewriter) const118   LogicalResult matchAndRewrite(vector::DeinterleaveOp op,
119                                 PatternRewriter &rewriter) const override {
120     VectorType resultType = op.getResultVectorType();
121     auto unrollIterator = vector::createUnrollIterator(resultType, targetRank);
122     if (!unrollIterator)
123       return failure();
124 
125     auto loc = op.getLoc();
126     Value emptyResult = rewriter.create<arith::ConstantOp>(
127         loc, resultType, rewriter.getZeroAttr(resultType));
128     Value evenResult = emptyResult;
129     Value oddResult = emptyResult;
130 
131     for (auto position : *unrollIterator) {
132       auto extractSrc =
133           rewriter.create<vector::ExtractOp>(loc, op.getSource(), position);
134       auto deinterleave =
135           rewriter.create<vector::DeinterleaveOp>(loc, extractSrc);
136       evenResult = rewriter.create<vector::InsertOp>(
137           loc, deinterleave.getRes1(), evenResult, position);
138       oddResult = rewriter.create<vector::InsertOp>(loc, deinterleave.getRes2(),
139                                                     oddResult, position);
140     }
141     rewriter.replaceOp(op, ValueRange{evenResult, oddResult});
142     return success();
143   }
144 
145 private:
146   int64_t targetRank = 1;
147 };
148 /// Rewrite vector.interleave op into an equivalent vector.shuffle op, when
149 /// applicable: `sourceType` must be 1D and non-scalable.
150 ///
151 /// Example:
152 ///
153 /// ```mlir
154 /// vector.interleave %a, %b : vector<7xi16> -> vector<14xi16>
155 /// ```
156 ///
157 /// Is rewritten into:
158 ///
159 /// ```mlir
160 /// vector.shuffle %arg0, %arg1 [0, 7, 1, 8, 2, 9, 3, 10, 4, 11, 5, 12, 6, 13]
161 ///   : vector<7xi16>, vector<7xi16>
162 /// ```
163 struct InterleaveToShuffle final : OpRewritePattern<vector::InterleaveOp> {
164   using OpRewritePattern::OpRewritePattern;
165 
matchAndRewrite__anon4ebd91ac0111::InterleaveToShuffle166   LogicalResult matchAndRewrite(vector::InterleaveOp op,
167                                 PatternRewriter &rewriter) const override {
168     VectorType sourceType = op.getSourceVectorType();
169     if (sourceType.getRank() != 1 || sourceType.isScalable()) {
170       return failure();
171     }
172     int64_t n = sourceType.getNumElements();
173     auto seq = llvm::seq<int64_t>(2 * n);
174     auto zip = llvm::to_vector(llvm::map_range(
175         seq, [n](int64_t i) { return (i % 2 ? n : 0) + i / 2; }));
176     rewriter.replaceOpWithNewOp<ShuffleOp>(op, op.getLhs(), op.getRhs(), zip);
177     return success();
178   }
179 };
180 
181 } // namespace
182 
populateVectorInterleaveLoweringPatterns(RewritePatternSet & patterns,int64_t targetRank,PatternBenefit benefit)183 void mlir::vector::populateVectorInterleaveLoweringPatterns(
184     RewritePatternSet &patterns, int64_t targetRank, PatternBenefit benefit) {
185   patterns.add<UnrollInterleaveOp, UnrollDeinterleaveOp>(
186       targetRank, patterns.getContext(), benefit);
187 }
188 
populateVectorInterleaveToShufflePatterns(RewritePatternSet & patterns,PatternBenefit benefit)189 void mlir::vector::populateVectorInterleaveToShufflePatterns(
190     RewritePatternSet &patterns, PatternBenefit benefit) {
191   patterns.add<InterleaveToShuffle>(patterns.getContext(), benefit);
192 }
193