1//===- GlobalIdRewriter.cpp - Implementation of GlobalId rewriting -------===//
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 in-dialect rewriting of the global_id op for archs
10// where global_id.x = threadId.x + blockId.x * blockDim.x
11//
12//===----------------------------------------------------------------------===//
13
14#include "mlir/Dialect/GPU/IR/GPUDialect.h"
15#include "mlir/Dialect/GPU/Transforms/Passes.h"
16#include "mlir/Dialect/Index/IR/IndexOps.h"
17#include "mlir/IR/Builders.h"
18#include "mlir/IR/PatternMatch.h"
19#include "mlir/Pass/Pass.h"
20
21using namespace mlir;
22
23namespace {
24struct GpuGlobalIdRewriter : public OpRewritePattern<gpu::GlobalIdOp> {
25 using OpRewritePattern<gpu::GlobalIdOp>::OpRewritePattern;
26
27 LogicalResult matchAndRewrite(gpu::GlobalIdOp op,
28 PatternRewriter &rewriter) const override {
29 Location loc = op.getLoc();
30 auto dim = op.getDimension();
31 auto blockId = rewriter.create<gpu::BlockIdOp>(loc, dim);
32 auto blockDim = rewriter.create<gpu::BlockDimOp>(loc, dim);
33 // Compute blockId.x * blockDim.x
34 auto tmp = rewriter.create<index::MulOp>(op.getLoc(), blockId, blockDim);
35 auto threadId = rewriter.create<gpu::ThreadIdOp>(loc, dim);
36 // Compute threadId.x + blockId.x * blockDim.x
37 rewriter.replaceOpWithNewOp<index::AddOp>(op, threadId, tmp);
38 return success();
39 }
40};
41} // namespace
42
43void mlir::populateGpuGlobalIdPatterns(RewritePatternSet &patterns) {
44 patterns.add<GpuGlobalIdRewriter>(arg: patterns.getContext());
45}
46

source code of mlir/lib/Dialect/GPU/Transforms/GlobalIdRewriter.cpp