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[flang][cuda] Convert cuf.shared_memory operation to LLVM ops #131396

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1 change: 1 addition & 0 deletions flang/include/flang/Optimizer/Builder/CUFCommon.h
Original file line number Diff line number Diff line change
Expand Up @@ -14,6 +14,7 @@
#include "mlir/IR/BuiltinOps.h"

static constexpr llvm::StringRef cudaDeviceModuleName = "cuda_device_mod";
static constexpr llvm::StringRef cudaSharedMemSuffix = "__shared_mem";

namespace fir {
class FirOpBuilder;
Expand Down
70 changes: 69 additions & 1 deletion flang/lib/Optimizer/Transforms/CUFGPUToLLVMConversion.cpp
Original file line number Diff line number Diff line change
Expand Up @@ -7,12 +7,15 @@
//===----------------------------------------------------------------------===//

#include "flang/Optimizer/Transforms/CUFGPUToLLVMConversion.h"
#include "flang/Optimizer/Builder/CUFCommon.h"
#include "flang/Optimizer/CodeGen/TypeConverter.h"
#include "flang/Optimizer/Dialect/CUF/CUFOps.h"
#include "flang/Optimizer/Support/DataLayout.h"
#include "flang/Runtime/CUDA/common.h"
#include "flang/Support/Fortran.h"
#include "mlir/Conversion/LLVMCommon/Pattern.h"
#include "mlir/Dialect/GPU/IR/GPUDialect.h"
#include "mlir/Dialect/LLVMIR/NVVMDialect.h"
#include "mlir/Pass/Pass.h"
#include "mlir/Transforms/DialectConversion.h"
#include "mlir/Transforms/GreedyPatternRewriteDriver.h"
Expand Down Expand Up @@ -175,6 +178,69 @@ struct GPULaunchKernelConversion
}
};

static std::string getFuncName(cuf::SharedMemoryOp op) {
if (auto gpuFuncOp = op->getParentOfType<mlir::gpu::GPUFuncOp>())
return gpuFuncOp.getName().str();
if (auto funcOp = op->getParentOfType<mlir::func::FuncOp>())
return funcOp.getName().str();
if (auto llvmFuncOp = op->getParentOfType<mlir::LLVM::LLVMFuncOp>())
return llvmFuncOp.getSymName().str();
return "";
}

static mlir::Value createAddressOfOp(mlir::ConversionPatternRewriter &rewriter,
mlir::Location loc,
gpu::GPUModuleOp gpuMod,
std::string &sharedGlobalName) {
auto llvmPtrTy = mlir::LLVM::LLVMPointerType::get(
rewriter.getContext(), mlir::NVVM::NVVMMemorySpace::kSharedMemorySpace);
if (auto g = gpuMod.lookupSymbol<fir::GlobalOp>(sharedGlobalName))
return rewriter.create<mlir::LLVM::AddressOfOp>(loc, llvmPtrTy,
g.getSymName());
if (auto g = gpuMod.lookupSymbol<mlir::LLVM::GlobalOp>(sharedGlobalName))
return rewriter.create<mlir::LLVM::AddressOfOp>(loc, llvmPtrTy,
g.getSymName());
return {};
}

struct CUFSharedMemoryOpConversion
: public mlir::ConvertOpToLLVMPattern<cuf::SharedMemoryOp> {
explicit CUFSharedMemoryOpConversion(
const fir::LLVMTypeConverter &typeConverter, mlir::PatternBenefit benefit)
: mlir::ConvertOpToLLVMPattern<cuf::SharedMemoryOp>(typeConverter,
benefit) {}
using OpAdaptor = typename cuf::SharedMemoryOp::Adaptor;

mlir::LogicalResult
matchAndRewrite(cuf::SharedMemoryOp op, OpAdaptor adaptor,
mlir::ConversionPatternRewriter &rewriter) const override {
mlir::Location loc = op->getLoc();
if (!op.getOffset())
mlir::emitError(loc,
"cuf.shared_memory must have an offset for code gen");

auto gpuMod = op->getParentOfType<gpu::GPUModuleOp>();
std::string sharedGlobalName =
(getFuncName(op) + llvm::Twine(cudaSharedMemSuffix)).str();
mlir::Value sharedGlobalAddr =
createAddressOfOp(rewriter, loc, gpuMod, sharedGlobalName);

if (!sharedGlobalAddr)
mlir::emitError(loc, "Could not find the shared global operation\n");

auto castPtr = rewriter.create<mlir::LLVM::AddrSpaceCastOp>(
loc, mlir::LLVM::LLVMPointerType::get(rewriter.getContext()),
sharedGlobalAddr);
mlir::Type baseType = castPtr->getResultTypes().front();
llvm::SmallVector<mlir::LLVM::GEPArg> gepArgs = {
static_cast<int32_t>(*op.getOffset())};
mlir::Value shmemPtr = rewriter.create<mlir::LLVM::GEPOp>(
loc, baseType, rewriter.getI8Type(), castPtr, gepArgs);
rewriter.replaceOp(op, {shmemPtr});
return mlir::success();
}
};

class CUFGPUToLLVMConversion
: public fir::impl::CUFGPUToLLVMConversionBase<CUFGPUToLLVMConversion> {
public:
Expand All @@ -194,6 +260,7 @@ class CUFGPUToLLVMConversion
/*forceUnifiedTBAATree=*/false, *dl);
cuf::populateCUFGPUToLLVMConversionPatterns(typeConverter, patterns);
target.addIllegalOp<mlir::gpu::LaunchFuncOp>();
target.addIllegalOp<cuf::SharedMemoryOp>();
target.addLegalDialect<mlir::LLVM::LLVMDialect>();
if (mlir::failed(mlir::applyPartialConversion(getOperation(), target,
std::move(patterns)))) {
Expand All @@ -208,5 +275,6 @@ class CUFGPUToLLVMConversion
void cuf::populateCUFGPUToLLVMConversionPatterns(
const fir::LLVMTypeConverter &converter, mlir::RewritePatternSet &patterns,
mlir::PatternBenefit benefit) {
patterns.add<GPULaunchKernelConversion>(converter, benefit);
patterns.add<CUFSharedMemoryOpConversion, GPULaunchKernelConversion>(
converter, benefit);
}
20 changes: 20 additions & 0 deletions flang/test/Fir/CUDA/cuda-shared-to-llvm.mlir
Original file line number Diff line number Diff line change
@@ -0,0 +1,20 @@
// RUN: fir-opt --split-input-file --cuf-gpu-convert-to-llvm %s | FileCheck %s

module attributes {dlti.dl_spec = #dlti.dl_spec<#dlti.dl_entry<!llvm.ptr, dense<64> : vector<4xi64>>, #dlti.dl_entry<!llvm.ptr<271>, dense<32> : vector<4xi64>>, #dlti.dl_entry<!llvm.ptr<270>, dense<32> : vector<4xi64>>, #dlti.dl_entry<f128, dense<128> : vector<2xi64>>, #dlti.dl_entry<f64, dense<64> : vector<2xi64>>, #dlti.dl_entry<f80, dense<128> : vector<2xi64>>, #dlti.dl_entry<f16, dense<16> : vector<2xi64>>, #dlti.dl_entry<i32, dense<32> : vector<2xi64>>, #dlti.dl_entry<i16, dense<16> : vector<2xi64>>, #dlti.dl_entry<i128, dense<128> : vector<2xi64>>, #dlti.dl_entry<i8, dense<8> : vector<2xi64>>, #dlti.dl_entry<!llvm.ptr<272>, dense<64> : vector<4xi64>>, #dlti.dl_entry<i64, dense<64> : vector<2xi64>>, #dlti.dl_entry<i1, dense<8> : vector<2xi64>>, #dlti.dl_entry<"dlti.endianness", "little">, #dlti.dl_entry<"dlti.stack_alignment", 128 : i64>>, fir.defaultkind = "a1c4d8i4l4r4", fir.kindmap = "", gpu.container_module, llvm.data_layout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-i128:128-f80:128-n8:16:32:64-S128", llvm.ident = "flang version 20.0.0 (https://github.com/llvm/llvm-project.git cae351f3453a0a26ec8eb2ddaf773c24a29d929e)", llvm.target_triple = "x86_64-unknown-linux-gnu"} {
gpu.module @cuda_device_mod {
llvm.func @_QPshared_static() {
%0 = cuf.shared_memory i32 {bindc_name = "a", offset = 0 : i32, uniq_name = "_QFshared_staticEa"} -> !fir.ref<i32>
%1 = cuf.shared_memory i32 {bindc_name = "b", offset = 4 : i32, uniq_name = "_QFshared_staticEb"} -> !fir.ref<i32>
llvm.return
}
llvm.mlir.global common @_QPshared_static__shared_mem(dense<0> : vector<28xi8>) {addr_space = 3 : i32, alignment = 8 : i64} : !llvm.array<28 x i8>
}
}

// CHECK-LABEL: llvm.func @_QPshared_static()
// CHECK: %[[ADDR0:.*]] = llvm.mlir.addressof @_QPshared_static__shared_mem : !llvm.ptr<3>
// CHECK: %[[ADDRCAST0:.*]] = llvm.addrspacecast %[[ADDR0]] : !llvm.ptr<3> to !llvm.ptr
// CHECK: %[[A:.*]] = llvm.getelementptr %[[ADDRCAST0]][0] : (!llvm.ptr) -> !llvm.ptr, i8
// CHECK: %[[ADDR1:.*]] = llvm.mlir.addressof @_QPshared_static__shared_mem : !llvm.ptr<3>
// CHECK: %[[ADDRCAST1:.*]] = llvm.addrspacecast %[[ADDR1]] : !llvm.ptr<3> to !llvm.ptr
// CHECK: %[[B:.*]] = llvm.getelementptr %[[ADDRCAST1]][4] : (!llvm.ptr) -> !llvm.ptr, i8