================ @@ -0,0 +1,274 @@ +//===--- CIRGenExprAgg.cpp - Emit CIR Code from Aggregate Expressions -----===// +// +// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. +// See https://llvm.org/LICENSE.txt for license information. +// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception +// +//===----------------------------------------------------------------------===// +// +// This contains code to emit Aggregate Expr nodes as CIR code. +// +//===----------------------------------------------------------------------===// + +#include "CIRGenBuilder.h" +#include "CIRGenFunction.h" +#include "CIRGenValue.h" +#include "clang/CIR/Dialect/IR/CIRAttrs.h" + +#include "clang/AST/Expr.h" +#include "clang/AST/StmtVisitor.h" +#include <cstdint> + +using namespace clang; +using namespace clang::CIRGen; + +namespace { +class AggExprEmitter : public StmtVisitor<AggExprEmitter> { + + CIRGenFunction &cgf; + AggValueSlot dest; + + AggValueSlot ensureSlot(mlir::Location loc, QualType t) { + if (!dest.isIgnored()) + return dest; + llvm_unreachable("Slot for ignored address NTI"); + } + +public: + AggExprEmitter(CIRGenFunction &cgf, AggValueSlot dest) + : cgf(cgf), dest(dest) {} + + void emitArrayInit(Address destPtr, cir::ArrayType arrayTy, QualType arrayQTy, + Expr *exprToVisit, ArrayRef<Expr *> args, + Expr *arrayFiller); + + void emitInitializationToLValue(Expr *e, LValue lv); + + void emitNullInitializationToLValue(mlir::Location loc, LValue lv); + + void Visit(Expr *e) { StmtVisitor<AggExprEmitter>::Visit(e); } + + void VisitInitListExpr(InitListExpr *e); + + void visitCXXParenListOrInitListExpr(Expr *e, ArrayRef<Expr *> args, + FieldDecl *initializedFieldInUnion, + Expr *arrayFiller); +}; + +} // namespace + +static bool isTrivialFiller(Expr *e) { + if (!e) + return true; + + if (isa<ImplicitValueInitExpr>(e)) + return true; + + if (auto *ile = dyn_cast<InitListExpr>(e)) { + if (ile->getNumInits()) + return false; + return isTrivialFiller(ile->getArrayFiller()); + } + + if (const auto *cons = dyn_cast_or_null<CXXConstructExpr>(e)) + return cons->getConstructor()->isDefaultConstructor() && + cons->getConstructor()->isTrivial(); + + return false; +} + +void AggExprEmitter::emitArrayInit(Address destPtr, cir::ArrayType arrayTy, + QualType arrayQTy, Expr *e, + ArrayRef<Expr *> args, Expr *arrayFiller) { + CIRGenBuilderTy &builder = cgf.getBuilder(); + const mlir::Location loc = cgf.getLoc(e->getSourceRange()); + + const uint64_t numInitElements = args.size(); + + const QualType elementType = + cgf.getContext().getAsArrayType(arrayQTy)->getElementType(); + + if (elementType.isDestructedType()) { + llvm_unreachable("dtorKind NYI"); + } + + const QualType elementPtrType = cgf.getContext().getPointerType(elementType); + + const mlir::Type cirElementType = cgf.convertType(elementType); + const cir::PointerType cirElementPtrType = + builder.getPointerTo(cirElementType); + + auto begin = builder.create<cir::CastOp>(loc, cirElementPtrType, + cir::CastKind::array_to_ptrdecay, + destPtr.getPointer()); + + const CharUnits elementSize = + cgf.getContext().getTypeSizeInChars(elementType); + const CharUnits elementAlign = + destPtr.getAlignment().alignmentOfArrayElement(elementSize); + + // The 'current element to initialize'. The invariants on this + // variable are complicated. Essentially, after each iteration of + // the loop, it points to the last initialized element, except + // that it points to the beginning of the array before any + // elements have been initialized. + mlir::Value element = begin; + + // Don't build the 'one' before the cycle to avoid + // emmiting the redundant `cir.const 1` instrs. + mlir::Value one; + + // Emit the explicit initializers. + for (uint64_t i = 0; i != numInitElements; ++i) { + // Advance to the next element. + if (i > 0) { + one = builder.getConstantInt(loc, cgf.PtrDiffTy, i); + element = + builder.create<cir::PtrStrideOp>(loc, cirElementPtrType, begin, one); + } + + const Address address = Address(element, cirElementType, elementAlign); + const LValue elementLV = LValue::makeAddr(address, elementType); + emitInitializationToLValue(args[i], elementLV); + } + + const uint64_t numArrayElements = arrayTy.getSize(); + + // Check whether there's a non-trivial array-fill expression. + const bool hasTrivialFiller = isTrivialFiller(arrayFiller); + + // Any remaining elements need to be zero-initialized, possibly + // using the filler expression. We can skip this if the we're + // emitting to zeroed memory. + if (numInitElements != numArrayElements && + !(dest.isZeroed() && hasTrivialFiller && + cgf.getTypes().isZeroInitializable(elementType))) { + // Advance to the start of the rest of the array. + if (numInitElements) { + one = builder.getConstantInt(loc, cgf.PtrDiffTy, 1); + element = builder.create<cir::PtrStrideOp>(loc, cirElementPtrType, + element, one); + } + + // Allocate the temporary variable + // to store the pointer to first unitialized element + auto tmpAddr = cgf.createTempAlloca( + cirElementPtrType, cgf.getPointerAlign(), loc, "arrayinit.temp", false); + LValue tmpLV = LValue::makeAddr(tmpAddr, elementPtrType); + cgf.emitStoreThroughLValue(RValue::get(element), tmpLV); + + // TODO(CIR): Replace this part later with cir::DoWhileOp + for (unsigned i = numInitElements; i != numArrayElements; ++i) { + cir::LoadOp currentElement = + builder.createLoad(loc, tmpAddr.getPointer()); + + // Emit the actual filler expression. + const LValue elementLV = LValue::makeAddr( + Address(currentElement, cirElementType, elementAlign), elementType); + + if (arrayFiller) + emitInitializationToLValue(arrayFiller, elementLV); + else + emitNullInitializationToLValue(loc, elementLV); + + // Advance pointer and store them to temporary variable + one = builder.getConstantInt(loc, cgf.PtrDiffTy, 1); + auto nextElement = builder.create<cir::PtrStrideOp>( ---------------- andykaylor wrote:
As above, I'd prefer `createPtrStride()` and that will mean you shouldn't use `auto`. https://github.com/llvm/llvm-project/pull/132974 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
