[flang-commits] [flang] 5e1f87e - [flang][cuda] Correctly allocate memory for descriptor load (#120164)

via flang-commits flang-commits at lists.llvm.org
Mon Dec 16 19:12:09 PST 2024


Author: Valentin Clement (バレンタイン クレメン)
Date: 2024-12-16T19:12:05-08:00
New Revision: 5e1f87e849d1f94f3e8baf190be20219edf44584

URL: https://github.com/llvm/llvm-project/commit/5e1f87e849d1f94f3e8baf190be20219edf44584
DIFF: https://github.com/llvm/llvm-project/commit/5e1f87e849d1f94f3e8baf190be20219edf44584.diff

LOG: [flang][cuda] Correctly allocate memory for descriptor load (#120164)

CodeGen will allocate memory for a new descriptor on descriptor loads.
CUDA Fortran local descriptor are allocated in managed memory by the
runtime. The newly allocated storage for cuda descriptor must also be
allocated through the runtime.

Added: 
    flang/test/Fir/CUDA/cuda-code-gen.mlir

Modified: 
    flang/lib/Optimizer/CodeGen/CodeGen.cpp

Removed: 
    


################################################################################
diff  --git a/flang/lib/Optimizer/CodeGen/CodeGen.cpp b/flang/lib/Optimizer/CodeGen/CodeGen.cpp
index 5345d64c330f06..082f2b15512b8b 100644
--- a/flang/lib/Optimizer/CodeGen/CodeGen.cpp
+++ b/flang/lib/Optimizer/CodeGen/CodeGen.cpp
@@ -23,6 +23,7 @@
 #include "flang/Optimizer/Support/InternalNames.h"
 #include "flang/Optimizer/Support/TypeCode.h"
 #include "flang/Optimizer/Support/Utils.h"
+#include "flang/Runtime/CUDA/descriptor.h"
 #include "flang/Runtime/allocator-registry-consts.h"
 #include "flang/Runtime/descriptor-consts.h"
 #include "flang/Semantics/runtime-type-info.h"
@@ -2970,6 +2971,93 @@ struct GlobalOpConversion : public fir::FIROpConversion<fir::GlobalOp> {
   }
 };
 
+static mlir::Value genSourceFile(mlir::Location loc, mlir::ModuleOp mod,
+                                 mlir::ConversionPatternRewriter &rewriter) {
+  auto ptrTy = mlir::LLVM::LLVMPointerType::get(rewriter.getContext());
+  if (auto flc = mlir::dyn_cast<mlir::FileLineColLoc>(loc)) {
+    auto fn = flc.getFilename().str() + '\0';
+    std::string globalName = fir::factory::uniqueCGIdent("cl", fn);
+
+    if (auto g = mod.lookupSymbol<fir::GlobalOp>(globalName)) {
+      return rewriter.create<mlir::LLVM::AddressOfOp>(loc, ptrTy, g.getName());
+    } else if (auto g = mod.lookupSymbol<mlir::LLVM::GlobalOp>(globalName)) {
+      return rewriter.create<mlir::LLVM::AddressOfOp>(loc, ptrTy, g.getName());
+    }
+
+    auto crtInsPt = rewriter.saveInsertionPoint();
+    rewriter.setInsertionPoint(mod.getBody(), mod.getBody()->end());
+    auto arrayTy = mlir::LLVM::LLVMArrayType::get(
+        mlir::IntegerType::get(rewriter.getContext(), 8), fn.size());
+    mlir::LLVM::GlobalOp globalOp = rewriter.create<mlir::LLVM::GlobalOp>(
+        loc, arrayTy, /*constant=*/true, mlir::LLVM::Linkage::Linkonce,
+        globalName, mlir::Attribute());
+
+    mlir::Region &region = globalOp.getInitializerRegion();
+    mlir::Block *block = rewriter.createBlock(&region);
+    rewriter.setInsertionPoint(block, block->begin());
+    mlir::Value constValue = rewriter.create<mlir::LLVM::ConstantOp>(
+        loc, arrayTy, rewriter.getStringAttr(fn));
+    rewriter.create<mlir::LLVM::ReturnOp>(loc, constValue);
+    rewriter.restoreInsertionPoint(crtInsPt);
+    return rewriter.create<mlir::LLVM::AddressOfOp>(loc, ptrTy,
+                                                    globalOp.getName());
+  }
+  return rewriter.create<mlir::LLVM::ZeroOp>(loc, ptrTy);
+}
+
+static mlir::Value genSourceLine(mlir::Location loc,
+                                 mlir::ConversionPatternRewriter &rewriter) {
+  if (auto flc = mlir::dyn_cast<mlir::FileLineColLoc>(loc))
+    return rewriter.create<mlir::LLVM::ConstantOp>(loc, rewriter.getI32Type(),
+                                                   flc.getLine());
+  return rewriter.create<mlir::LLVM::ConstantOp>(loc, rewriter.getI32Type(), 0);
+}
+
+static mlir::Value
+genCUFAllocDescriptor(mlir::Location loc,
+                      mlir::ConversionPatternRewriter &rewriter,
+                      mlir::ModuleOp mod, fir::BaseBoxType boxTy,
+                      const fir::LLVMTypeConverter &typeConverter) {
+  std::optional<mlir::DataLayout> dl =
+      fir::support::getOrSetDataLayout(mod, /*allowDefaultLayout=*/true);
+  if (!dl)
+    mlir::emitError(mod.getLoc(),
+                    "module operation must carry a data layout attribute "
+                    "to generate llvm IR from FIR");
+
+  mlir::Value sourceFile = genSourceFile(loc, mod, rewriter);
+  mlir::Value sourceLine = genSourceLine(loc, rewriter);
+
+  mlir::MLIRContext *ctx = mod.getContext();
+
+  mlir::LLVM::LLVMPointerType llvmPointerType =
+      mlir::LLVM::LLVMPointerType::get(ctx);
+  mlir::Type llvmInt32Type = mlir::IntegerType::get(ctx, 32);
+  mlir::Type llvmIntPtrType =
+      mlir::IntegerType::get(ctx, typeConverter.getPointerBitwidth(0));
+  auto fctTy = mlir::LLVM::LLVMFunctionType::get(
+      llvmPointerType, {llvmIntPtrType, llvmPointerType, llvmInt32Type});
+
+  auto llvmFunc = mod.lookupSymbol<mlir::LLVM::LLVMFuncOp>(
+      RTNAME_STRING(CUFAllocDesciptor));
+  auto funcFunc =
+      mod.lookupSymbol<mlir::func::FuncOp>(RTNAME_STRING(CUFAllocDesciptor));
+  if (!llvmFunc && !funcFunc)
+    mlir::OpBuilder::atBlockEnd(mod.getBody())
+        .create<mlir::LLVM::LLVMFuncOp>(loc, RTNAME_STRING(CUFAllocDesciptor),
+                                        fctTy);
+
+  mlir::Type structTy = typeConverter.convertBoxTypeAsStruct(boxTy);
+  std::size_t boxSize = dl->getTypeSizeInBits(structTy) / 8;
+  mlir::Value sizeInBytes =
+      genConstantIndex(loc, llvmIntPtrType, rewriter, boxSize);
+  llvm::SmallVector args = {sizeInBytes, sourceFile, sourceLine};
+  return rewriter
+      .create<mlir::LLVM::CallOp>(loc, fctTy, RTNAME_STRING(CUFAllocDesciptor),
+                                  args)
+      .getResult();
+}
+
 /// `fir.load` --> `llvm.load`
 struct LoadOpConversion : public fir::FIROpConversion<fir::LoadOp> {
   using FIROpConversion::FIROpConversion;
@@ -2986,9 +3074,23 @@ struct LoadOpConversion : public fir::FIROpConversion<fir::LoadOp> {
       // loading a fir.ref<fir.box> is implemented as taking a snapshot of the
       // descriptor value into a new descriptor temp.
       auto inputBoxStorage = adaptor.getOperands()[0];
+      mlir::Value newBoxStorage;
       mlir::Location loc = load.getLoc();
-      auto newBoxStorage =
-          genAllocaAndAddrCastWithType(loc, llvmLoadTy, defaultAlign, rewriter);
+      if (auto callOp = mlir::dyn_cast_or_null<mlir::LLVM::CallOp>(
+              inputBoxStorage.getDefiningOp())) {
+        if (callOp.getCallee() &&
+            (*callOp.getCallee())
+                .starts_with(RTNAME_STRING(CUFAllocDesciptor))) {
+          // CUDA Fortran local descriptor are allocated in managed memory. So
+          // new storage must be allocated the same way.
+          auto mod = load->getParentOfType<mlir::ModuleOp>();
+          newBoxStorage =
+              genCUFAllocDescriptor(loc, rewriter, mod, boxTy, lowerTy());
+        }
+      }
+      if (!newBoxStorage)
+        newBoxStorage = genAllocaAndAddrCastWithType(loc, llvmLoadTy,
+                                                     defaultAlign, rewriter);
 
       TypePair boxTypePair{boxTy, llvmLoadTy};
       mlir::Value boxSize =

diff  --git a/flang/test/Fir/CUDA/cuda-code-gen.mlir b/flang/test/Fir/CUDA/cuda-code-gen.mlir
new file mode 100644
index 00000000000000..55e473ef2549e3
--- /dev/null
+++ b/flang/test/Fir/CUDA/cuda-code-gen.mlir
@@ -0,0 +1,29 @@
+// RUN: fir-opt --split-input-file --fir-to-llvm-ir="target=x86_64-unknown-linux-gnu" %s | FileCheck %s
+
+module attributes {dlti.dl_spec = #dlti.dl_spec<#dlti.dl_entry<f80, dense<128> : vector<2xi64>>, #dlti.dl_entry<i128, dense<128> : vector<2xi64>>, #dlti.dl_entry<i64, dense<64> : vector<2xi64>>, #dlti.dl_entry<!llvm.ptr<272>, 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<f16, dense<16> : vector<2xi64>>, #dlti.dl_entry<i32, dense<32> : vector<2xi64>>, #dlti.dl_entry<i16, dense<16> : vector<2xi64>>, #dlti.dl_entry<i8, dense<8> : vector<2xi64>>, #dlti.dl_entry<i1, dense<8> : vector<2xi64>>, #dlti.dl_entry<!llvm.ptr, dense<64> : vector<4xi64>>, #dlti.dl_entry<"dlti.endianness", "little">, #dlti.dl_entry<"dlti.stack_alignment", 128 : i64>>} {
+
+  func.func @_QQmain() attributes {fir.bindc_name = "cufkernel_global"} {
+    %c0 = arith.constant 0 : index
+    %0 = fir.address_of(@_QQclX3C737464696E3E00) : !fir.ref<!fir.char<1,8>>
+    %c4_i32 = arith.constant 4 : i32
+    %c48 = arith.constant 48 : index
+    %1 = fir.convert %c48 : (index) -> i64
+    %2 = fir.convert %0 : (!fir.ref<!fir.char<1,8>>) -> !fir.ref<i8>
+    %3 = fir.call @_FortranACUFAllocDesciptor(%1, %2, %c4_i32) : (i64, !fir.ref<i8>, i32) -> !fir.ref<!fir.box<none>>
+    %4 = fir.convert %3 : (!fir.ref<!fir.box<none>>) -> !fir.ref<!fir.box<!fir.heap<!fir.array<?xi32>>>>
+    %5 = fir.zero_bits !fir.heap<!fir.array<?xi32>>
+    %6 = fircg.ext_embox %5(%c0) {allocator_idx = 2 : i32} : (!fir.heap<!fir.array<?xi32>>, index) -> !fir.box<!fir.heap<!fir.array<?xi32>>>
+    fir.store %6 to %4 : !fir.ref<!fir.box<!fir.heap<!fir.array<?xi32>>>>
+    %8 = fir.load %3 : !fir.ref<!fir.box<none>>
+    return
+  }
+
+  // CHECK-LABEL: llvm.func @_QQmain()
+  // CHECK-COUNT-2: llvm.call @_FortranACUFAllocDesciptor 
+
+  fir.global linkonce @_QQclX3C737464696E3E00 constant : !fir.char<1,8> {
+    %0 = fir.string_lit "<stdin>\00"(8) : !fir.char<1,8>
+    fir.has_value %0 : !fir.char<1,8>
+  }
+  func.func private @_FortranACUFAllocDesciptor(i64, !fir.ref<i8>, i32) -> !fir.ref<!fir.box<none>> attributes {fir.runtime}
+}


        


More information about the flang-commits mailing list