1 //===- ConvertGPULaunchFuncToVulkanLaunchFunc.cpp - MLIR conversion pass --===//
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 a pass to convert gpu launch function into a vulkan
10 // launch function. Creates a SPIR-V binary shader from the `spirv::ModuleOp`
11 // using `spirv::serialize` function, attaches binary data and entry point name
12 // as an attributes to vulkan launch call op.
13 //
14 //===----------------------------------------------------------------------===//
15 
16 #include "../PassDetail.h"
17 #include "mlir/Conversion/GPUToVulkan/ConvertGPUToVulkanPass.h"
18 #include "mlir/Dialect/GPU/GPUDialect.h"
19 #include "mlir/Dialect/SPIRV/SPIRVOps.h"
20 #include "mlir/Dialect/SPIRV/Serialization.h"
21 #include "mlir/Dialect/StandardOps/IR/Ops.h"
22 #include "mlir/IR/Attributes.h"
23 #include "mlir/IR/Builders.h"
24 #include "mlir/IR/Function.h"
25 #include "mlir/IR/Module.h"
26 #include "mlir/IR/StandardTypes.h"
27 
28 using namespace mlir;
29 
30 static constexpr const char *kSPIRVBlobAttrName = "spirv_blob";
31 static constexpr const char *kSPIRVEntryPointAttrName = "spirv_entry_point";
32 static constexpr const char *kVulkanLaunch = "vulkanLaunch";
33 
34 namespace {
35 
36 /// A pass to convert gpu launch op to vulkan launch call op, by creating a
37 /// SPIR-V binary shader from `spirv::ModuleOp` using `spirv::serialize`
38 /// function and attaching binary data and entry point name as an attributes to
39 /// created vulkan launch call op.
40 class ConvertGpuLaunchFuncToVulkanLaunchFunc
41     : public ConvertGpuLaunchFuncToVulkanLaunchFuncBase<
42           ConvertGpuLaunchFuncToVulkanLaunchFunc> {
43 public:
44   void runOnOperation() override;
45 
46 private:
47   /// Creates a SPIR-V binary shader from the given `module` using
48   /// `spirv::serialize` function.
49   LogicalResult createBinaryShader(ModuleOp module,
50                                    std::vector<char> &binaryShader);
51 
52   /// Converts the given `launchOp` to vulkan launch call.
53   void convertGpuLaunchFunc(gpu::LaunchFuncOp launchOp);
54 
55   /// Checks where the given type is supported by Vulkan runtime.
56   bool isSupportedType(Type type) {
57     // TODO(denis0x0D): Handle other types.
58     if (auto memRefType = type.dyn_cast_or_null<MemRefType>())
59       return memRefType.hasRank() &&
60              (memRefType.getRank() >= 1 && memRefType.getRank() <= 3);
61     return false;
62   }
63 
64   /// Declares the vulkan launch function. Returns an error if the any type of
65   /// operand is unsupported by Vulkan runtime.
66   LogicalResult declareVulkanLaunchFunc(Location loc,
67                                         gpu::LaunchFuncOp launchOp);
68 
69 private:
70   /// The number of vulkan launch configuration operands, placed at the leading
71   /// positions of the operand list.
72   static constexpr unsigned kVulkanLaunchNumConfigOperands = 3;
73 };
74 
75 } // anonymous namespace
76 
77 void ConvertGpuLaunchFuncToVulkanLaunchFunc::runOnOperation() {
78   bool done = false;
79   getOperation().walk([this, &done](gpu::LaunchFuncOp op) {
80     if (done) {
81       op.emitError("should only contain one 'gpu::LaunchFuncOp' op");
82       return signalPassFailure();
83     }
84     done = true;
85     convertGpuLaunchFunc(op);
86   });
87 
88   // Erase `gpu::GPUModuleOp` and `spirv::Module` operations.
89   for (auto gpuModule :
90        llvm::make_early_inc_range(getOperation().getOps<gpu::GPUModuleOp>()))
91     gpuModule.erase();
92 
93   for (auto spirvModule :
94        llvm::make_early_inc_range(getOperation().getOps<spirv::ModuleOp>()))
95     spirvModule.erase();
96 }
97 
98 LogicalResult ConvertGpuLaunchFuncToVulkanLaunchFunc::declareVulkanLaunchFunc(
99     Location loc, gpu::LaunchFuncOp launchOp) {
100   OpBuilder builder(getOperation().getBody()->getTerminator());
101 
102   // Workgroup size is written into the kernel. So to properly modelling
103   // vulkan launch, we have to skip local workgroup size configuration here.
104   SmallVector<Type, 8> gpuLaunchTypes(launchOp.getOperandTypes());
105   // The first kVulkanLaunchNumConfigOperands of the gpu.launch_func op are the
106   // same as the config operands for the vulkan launch call op.
107   SmallVector<Type, 8> vulkanLaunchTypes(gpuLaunchTypes.begin(),
108                                          gpuLaunchTypes.begin() +
109                                              kVulkanLaunchNumConfigOperands);
110   vulkanLaunchTypes.append(gpuLaunchTypes.begin() +
111                                gpu::LaunchOp::kNumConfigOperands,
112                            gpuLaunchTypes.end());
113 
114   // Check that all operands have supported types except those for the
115   // launch configuration.
116   for (auto type :
117        llvm::drop_begin(vulkanLaunchTypes, kVulkanLaunchNumConfigOperands)) {
118     if (!isSupportedType(type))
119       return launchOp.emitError() << type << " is unsupported to run on Vulkan";
120   }
121 
122   // Declare vulkan launch function.
123   builder.create<FuncOp>(
124       loc, kVulkanLaunch,
125       FunctionType::get(vulkanLaunchTypes, ArrayRef<Type>{}, loc->getContext()),
126       ArrayRef<NamedAttribute>{});
127 
128   return success();
129 }
130 
131 LogicalResult ConvertGpuLaunchFuncToVulkanLaunchFunc::createBinaryShader(
132     ModuleOp module, std::vector<char> &binaryShader) {
133   bool done = false;
134   SmallVector<uint32_t, 0> binary;
135   for (auto spirvModule : module.getOps<spirv::ModuleOp>()) {
136     if (done)
137       return spirvModule.emitError("should only contain one 'spv.module' op");
138     done = true;
139 
140     if (failed(spirv::serialize(spirvModule, binary)))
141       return failure();
142   }
143   binaryShader.resize(binary.size() * sizeof(uint32_t));
144   std::memcpy(binaryShader.data(), reinterpret_cast<char *>(binary.data()),
145               binaryShader.size());
146   return success();
147 }
148 
149 void ConvertGpuLaunchFuncToVulkanLaunchFunc::convertGpuLaunchFunc(
150     gpu::LaunchFuncOp launchOp) {
151   ModuleOp module = getOperation();
152   OpBuilder builder(launchOp);
153   Location loc = launchOp.getLoc();
154 
155   // Serialize `spirv::Module` into binary form.
156   std::vector<char> binary;
157   if (failed(createBinaryShader(module, binary)))
158     return signalPassFailure();
159 
160   // Declare vulkan launch function.
161   if (failed(declareVulkanLaunchFunc(loc, launchOp)))
162     return signalPassFailure();
163 
164   SmallVector<Value, 8> gpuLaunchOperands(launchOp.getOperands());
165   SmallVector<Value, 8> vulkanLaunchOperands(
166       gpuLaunchOperands.begin(),
167       gpuLaunchOperands.begin() + kVulkanLaunchNumConfigOperands);
168   vulkanLaunchOperands.append(gpuLaunchOperands.begin() +
169                                   gpu::LaunchOp::kNumConfigOperands,
170                               gpuLaunchOperands.end());
171 
172   // Create vulkan launch call op.
173   auto vulkanLaunchCallOp = builder.create<CallOp>(
174       loc, ArrayRef<Type>{}, builder.getSymbolRefAttr(kVulkanLaunch),
175       vulkanLaunchOperands);
176 
177   // Set SPIR-V binary shader data as an attribute.
178   vulkanLaunchCallOp.setAttr(
179       kSPIRVBlobAttrName,
180       StringAttr::get({binary.data(), binary.size()}, loc->getContext()));
181 
182   // Set entry point name as an attribute.
183   vulkanLaunchCallOp.setAttr(
184       kSPIRVEntryPointAttrName,
185       StringAttr::get(launchOp.kernel(), loc->getContext()));
186 
187   launchOp.erase();
188 }
189 
190 std::unique_ptr<mlir::OperationPass<mlir::ModuleOp>>
191 mlir::createConvertGpuLaunchFuncToVulkanLaunchFuncPass() {
192   return std::make_unique<ConvertGpuLaunchFuncToVulkanLaunchFunc>();
193 }
194