diff --git a/clang/lib/CIR/Lowering/DirectToLLVM/LowerToLLVM.cpp b/clang/lib/CIR/Lowering/DirectToLLVM/LowerToLLVM.cpp index 3cd7de0a56bc3..dfe07e821d767 100644 --- a/clang/lib/CIR/Lowering/DirectToLLVM/LowerToLLVM.cpp +++ b/clang/lib/CIR/Lowering/DirectToLLVM/LowerToLLVM.cpp @@ -919,13 +919,45 @@ rewriteCallOrInvoke(mlir::Operation *op, mlir::ValueRange callOperands, memoryEffects, noUnwind, willReturn); mlir::LLVM::LLVMFunctionType llvmFnTy; + + // Temporary to handle the case where we need to prepend an operand if the + // callee is an alias. + SmallVector adjustedCallOperands; + if (calleeAttr) { // direct call - mlir::FunctionOpInterface fn = - mlir::SymbolTable::lookupNearestSymbolFrom( - op, calleeAttr); - assert(fn && "Did not find function for call"); - llvmFnTy = cast( - converter->convertType(fn.getFunctionType())); + mlir::Operation *callee = + mlir::SymbolTable::lookupNearestSymbolFrom(op, calleeAttr); + if (auto fn = mlir::dyn_cast(callee)) { + llvmFnTy = converter->convertType( + fn.getFunctionType()); + assert(llvmFnTy && "Failed to convert function type"); + } else if (auto alias = mlir::cast(callee)) { + // If the callee was an alias. In that case, + // we need to prepend the address of the alias to the operands. The + // way aliases work in the LLVM dialect is a little counter-intuitive. + // The AliasOp itself is a pseudo-function that returns the address of + // the global value being aliased, but when we generate the call we + // need to insert an operation that gets the address of the AliasOp. + // This all gets sorted out when the LLVM dialect is lowered to LLVM IR. + auto symAttr = mlir::cast(calleeAttr); + auto addrOfAlias = + mlir::LLVM::AddressOfOp::create( + rewriter, op->getLoc(), + mlir::LLVM::LLVMPointerType::get(rewriter.getContext()), symAttr) + .getResult(); + adjustedCallOperands.push_back(addrOfAlias); + + // Now add the regular operands and assign this to the range value. + llvm::append_range(adjustedCallOperands, callOperands); + callOperands = adjustedCallOperands; + + // Clear the callee attribute because we're calling an alias. + calleeAttr = {}; + llvmFnTy = mlir::cast(alias.getType()); + } else { + // Was this an ifunc? + return op->emitError("Unexpected callee type!"); + } } else { // indirect call assert(!op->getOperands().empty() && "operands list must no be empty for the indirect call"); @@ -1166,6 +1198,30 @@ void CIRToLLVMFuncOpLowering::lowerFuncAttributes( } } +mlir::LogicalResult CIRToLLVMFuncOpLowering::matchAndRewriteAlias( + cir::FuncOp op, llvm::StringRef aliasee, mlir::Type ty, OpAdaptor adaptor, + mlir::ConversionPatternRewriter &rewriter) const { + SmallVector attributes; + lowerFuncAttributes(op, /*filterArgAndResAttrs=*/false, attributes); + + mlir::Location loc = op.getLoc(); + auto aliasOp = rewriter.replaceOpWithNewOp( + op, ty, convertLinkage(op.getLinkage()), op.getName(), op.getDsoLocal(), + /*threadLocal=*/false, attributes); + + // Create the alias body + mlir::OpBuilder builder(op.getContext()); + mlir::Block *block = builder.createBlock(&aliasOp.getInitializerRegion()); + builder.setInsertionPointToStart(block); + // The type of AddressOfOp is always a pointer. + assert(!cir::MissingFeatures::addressSpace()); + mlir::Type ptrTy = mlir::LLVM::LLVMPointerType::get(ty.getContext()); + auto addrOp = mlir::LLVM::AddressOfOp::create(builder, loc, ptrTy, aliasee); + mlir::LLVM::ReturnOp::create(builder, loc, addrOp); + + return mlir::success(); +} + mlir::LogicalResult CIRToLLVMFuncOpLowering::matchAndRewrite( cir::FuncOp op, OpAdaptor adaptor, mlir::ConversionPatternRewriter &rewriter) const { @@ -1190,6 +1246,11 @@ mlir::LogicalResult CIRToLLVMFuncOpLowering::matchAndRewrite( resultType ? resultType : mlir::LLVM::LLVMVoidType::get(getContext()), signatureConversion.getConvertedTypes(), /*isVarArg=*/fnType.isVarArg()); + + // If this is an alias, it needs to be lowered to llvm::AliasOp. + if (std::optional aliasee = op.getAliasee()) + return matchAndRewriteAlias(op, *aliasee, llvmFnTy, adaptor, rewriter); + // LLVMFuncOp expects a single FileLine Location instead of a fused // location. mlir::Location loc = op.getLoc(); diff --git a/clang/lib/CIR/Lowering/DirectToLLVM/LowerToLLVM.h b/clang/lib/CIR/Lowering/DirectToLLVM/LowerToLLVM.h index 2911ced66e58e..46c8ebc3cf7e2 100644 --- a/clang/lib/CIR/Lowering/DirectToLLVM/LowerToLLVM.h +++ b/clang/lib/CIR/Lowering/DirectToLLVM/LowerToLLVM.h @@ -257,6 +257,11 @@ class CIRToLLVMFuncOpLowering : public mlir::OpConversionPattern { cir::FuncOp func, bool filterArgAndResAttrs, mlir::SmallVectorImpl &result) const; + mlir::LogicalResult + matchAndRewriteAlias(cir::FuncOp op, llvm::StringRef aliasee, mlir::Type ty, + OpAdaptor adaptor, + mlir::ConversionPatternRewriter &rewriter) const; + public: using mlir::OpConversionPattern::OpConversionPattern; diff --git a/clang/test/CIR/CodeGen/ctor-alias.cpp b/clang/test/CIR/CodeGen/ctor-alias.cpp index a20e206c6d714..c4bf455e3a09b 100644 --- a/clang/test/CIR/CodeGen/ctor-alias.cpp +++ b/clang/test/CIR/CodeGen/ctor-alias.cpp @@ -11,6 +11,8 @@ struct B { B::B() { } +// LLVM: @_ZN1BC1Ev = alias void (ptr), ptr @_ZN1BC2Ev + // OGCG: @_ZN1BC1Ev = unnamed_addr alias void (ptr), ptr @_ZN1BC2Ev // CHECK: cir.func{{.*}} @_ZN1BC2Ev(%arg0: !cir.ptr @@ -25,15 +27,30 @@ B::B() { // LLVM: store ptr %[[THIS_ARG]], ptr %[[THIS_ADDR]] // LLVM: %[[THIS:.*]] = load ptr, ptr %[[THIS_ADDR]] -// This should be an alias, like the similar OGCG alias above, but that's not -// implemented yet. -// LLVM: declare dso_local void @_ZN1BC1Ev(ptr) - // OGCG: define{{.*}} @_ZN1BC2Ev(ptr{{.*}} %[[THIS_ARG:.*]]) // OGCG: %[[THIS_ADDR:.*]] = alloca ptr // OGCG: store ptr %[[THIS_ARG]], ptr %[[THIS_ADDR]] // OGCG: %[[THIS:.*]] = load ptr, ptr %[[THIS_ADDR]] +void bar() { + B b; +} + +// CHECK: cir.func{{.*}} @_Z3barv() +// CHECK: %[[B:.*]] = cir.alloca !rec_B, !cir.ptr, ["b", init] +// CHECK: cir.call @_ZN1BC1Ev(%[[B]]) : (!cir.ptr) -> () +// CHECK: cir.return + +// LLVM: define{{.*}} void @_Z3barv() +// LLVM: %[[B:.*]] = alloca %struct.B, i64 1, align 1 +// LLVM: call void @_ZN1BC1Ev(ptr %[[B]]) +// LLVM: ret void + +// OGCG: define{{.*}} void @_Z3barv() +// OGCG: %[[B:.*]] = alloca %struct.B, align 1 +// OGCG: call void @_ZN1BC1Ev(ptr{{.*}} %[[B]]) +// OGCG: ret void + // The constructor in this cases is handled by RAUW rather than aliasing. struct Struk { Struk() {} diff --git a/clang/test/CIR/CodeGen/dtor-alias.cpp b/clang/test/CIR/CodeGen/dtor-alias.cpp index e37ddabb5b4fd..f4d54dfd7da26 100644 --- a/clang/test/CIR/CodeGen/dtor-alias.cpp +++ b/clang/test/CIR/CodeGen/dtor-alias.cpp @@ -11,6 +11,8 @@ struct B { B::~B() { } +// LLVM: @_ZN1BD1Ev = alias void (ptr), ptr @_ZN1BD2Ev + // OGCG: @_ZN1BD1Ev = unnamed_addr alias void (ptr), ptr @_ZN1BD2Ev // CHECK: cir.func{{.*}} @_ZN1BD2Ev(%arg0: !cir.ptr @@ -25,10 +27,6 @@ B::~B() { // LLVM: store ptr %[[THIS_ARG]], ptr %[[THIS_ADDR]] // LLVM: %[[THIS:.*]] = load ptr, ptr %[[THIS_ADDR]] -// This should be an alias, like the similar OGCG alias above, but that's not -// implemented yet. -// LLVM: declare dso_local void @_ZN1BD1Ev(ptr) - // OGCG: define{{.*}} @_ZN1BD2Ev(ptr{{.*}} %[[THIS_ARG:.*]]) // OGCG: %[[THIS_ADDR:.*]] = alloca ptr // OGCG: store ptr %[[THIS_ARG]], ptr %[[THIS_ADDR]]