mirror of
https://github.com/carbon-language/carbon-lang.git
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Jon Ross-Perkins
1c748c0f14
Continuing along with #3070. Note this is just a file rename, with BUILD edits; every file previously in semantics/ should show as moved (except maybe BUILDs, which split).
114 lines
4.0 KiB
C++
114 lines
4.0 KiB
C++
// Part of the Carbon Language project, under the Apache License v2.0 with LLVM
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// Exceptions. See /LICENSE for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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#include "toolchain/lower/function_context.h"
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#include "toolchain/sem_ir/file.h"
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namespace Carbon::Lower {
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FunctionContext::FunctionContext(FileContext& file_context,
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llvm::Function* function)
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: file_context_(&file_context),
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function_(function),
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builder_(file_context.llvm_context()) {}
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auto FunctionContext::GetBlock(SemIR::NodeBlockId block_id)
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-> llvm::BasicBlock* {
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llvm::BasicBlock*& entry = blocks_[block_id];
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if (!entry) {
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entry = llvm::BasicBlock::Create(llvm_context(), "", function_);
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}
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return entry;
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}
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auto FunctionContext::TryToReuseBlock(SemIR::NodeBlockId block_id,
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llvm::BasicBlock* block) -> bool {
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if (!blocks_.insert({block_id, block}).second) {
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return false;
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}
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if (block == synthetic_block_) {
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synthetic_block_ = nullptr;
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}
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return true;
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}
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auto FunctionContext::GetBlockArg(SemIR::NodeBlockId block_id,
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SemIR::TypeId type_id) -> llvm::PHINode* {
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llvm::BasicBlock* block = GetBlock(block_id);
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// Find the existing phi, if any.
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auto phis = block->phis();
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if (!phis.empty()) {
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CARBON_CHECK(std::next(phis.begin()) == phis.end())
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<< "Expected at most one phi, found "
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<< std::distance(phis.begin(), phis.end());
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return &*phis.begin();
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}
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// The number of predecessor slots to reserve.
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static constexpr unsigned NumReservedPredecessors = 2;
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auto* phi = llvm::PHINode::Create(GetType(type_id), NumReservedPredecessors);
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phi->insertInto(block, block->begin());
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return phi;
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}
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auto FunctionContext::CreateSyntheticBlock() -> llvm::BasicBlock* {
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synthetic_block_ = llvm::BasicBlock::Create(llvm_context(), "", function_);
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return synthetic_block_;
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}
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auto FunctionContext::FinishInitialization(SemIR::TypeId type_id,
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SemIR::NodeId dest_id,
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SemIR::NodeId source_id) -> void {
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switch (SemIR::GetInitializingRepresentation(semantics_ir(), type_id).kind) {
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case SemIR::InitializingRepresentation::None:
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case SemIR::InitializingRepresentation::InPlace:
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break;
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case SemIR::InitializingRepresentation::ByCopy:
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CopyValue(type_id, source_id, dest_id);
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break;
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}
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}
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auto FunctionContext::CopyValue(SemIR::TypeId type_id, SemIR::NodeId source_id,
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SemIR::NodeId dest_id) -> void {
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switch (auto rep = SemIR::GetValueRepresentation(semantics_ir(), type_id);
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rep.kind) {
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case SemIR::ValueRepresentation::None:
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break;
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case SemIR::ValueRepresentation::Copy:
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builder().CreateStore(GetLocalLoaded(source_id), GetLocal(dest_id));
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break;
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case SemIR::ValueRepresentation::Pointer: {
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const auto& layout = llvm_module().getDataLayout();
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auto* type = GetType(type_id);
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// TODO: Compute known alignment of the source and destination, which may
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// be greater than the alignment computed by LLVM.
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auto align = layout.getABITypeAlign(type);
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// TODO: Attach !tbaa.struct metadata indicating which portions of the
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// type we actually need to copy and which are padding.
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builder().CreateMemCpy(GetLocal(dest_id), align, GetLocal(source_id),
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align, layout.getTypeAllocSize(type));
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break;
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}
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case SemIR::ValueRepresentation::Custom:
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CARBON_FATAL() << "TODO: Add support for CopyValue with custom value rep";
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}
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}
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auto FunctionContext::GetLocalLoaded(SemIR::NodeId node_id) -> llvm::Value* {
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auto* value = GetLocal(node_id);
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if (llvm::isa<llvm::AllocaInst, llvm::GetElementPtrInst>(value)) {
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auto* load_type = GetType(semantics_ir().GetNode(node_id).type_id());
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return builder().CreateLoad(load_type, value);
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} else {
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// No load is needed.
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return value;
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}
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}
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} // namespace Carbon::Lower
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