Mercurial > hg > CbC > CbC_llvm
diff tools/llvm-mca/CodeRegionGenerator.cpp @ 147:c2174574ed3a
LLVM 10
author | Shinji KONO <kono@ie.u-ryukyu.ac.jp> |
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date | Wed, 14 Aug 2019 16:55:33 +0900 |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/tools/llvm-mca/CodeRegionGenerator.cpp Wed Aug 14 16:55:33 2019 +0900 @@ -0,0 +1,140 @@ +//===----------------------- CodeRegionGenerator.cpp ------------*- C++ -*-===// +// +// 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 +// +//===----------------------------------------------------------------------===// +/// \file +/// +/// This file defines classes responsible for generating llvm-mca +/// CodeRegions from various types of input. llvm-mca only analyzes CodeRegions, +/// so the classes here provide the input-to-CodeRegions translation. +// +//===----------------------------------------------------------------------===// + +#include "CodeRegionGenerator.h" +#include "llvm/ADT/ArrayRef.h" +#include "llvm/ADT/StringRef.h" +#include "llvm/MC/MCParser/MCTargetAsmParser.h" +#include "llvm/MC/MCStreamer.h" +#include "llvm/MC/MCTargetOptions.h" +#include "llvm/Support/Error.h" +#include "llvm/Support/SMLoc.h" +#include <memory> + +namespace llvm { +namespace mca { + +// This virtual dtor serves as the anchor for the CodeRegionGenerator class. +CodeRegionGenerator::~CodeRegionGenerator() {} + +// A comment consumer that parses strings. The only valid tokens are strings. +class MCACommentConsumer : public AsmCommentConsumer { +public: + CodeRegions &Regions; + + MCACommentConsumer(CodeRegions &R) : Regions(R) {} + void HandleComment(SMLoc Loc, StringRef CommentText) override; +}; + +// This class provides the callbacks that occur when parsing input assembly. +class MCStreamerWrapper final : public MCStreamer { + CodeRegions &Regions; + +public: + MCStreamerWrapper(MCContext &Context, mca::CodeRegions &R) + : MCStreamer(Context), Regions(R) {} + + // We only want to intercept the emission of new instructions. + virtual void EmitInstruction(const MCInst &Inst, + const MCSubtargetInfo &/* unused */) override { + Regions.addInstruction(Inst); + } + + bool EmitSymbolAttribute(MCSymbol *Symbol, MCSymbolAttr Attribute) override { + return true; + } + + void EmitCommonSymbol(MCSymbol *Symbol, uint64_t Size, + unsigned ByteAlignment) override {} + void EmitZerofill(MCSection *Section, MCSymbol *Symbol = nullptr, + uint64_t Size = 0, unsigned ByteAlignment = 0, + SMLoc Loc = SMLoc()) override {} + void EmitGPRel32Value(const MCExpr *Value) override {} + void BeginCOFFSymbolDef(const MCSymbol *Symbol) override {} + void EmitCOFFSymbolStorageClass(int StorageClass) override {} + void EmitCOFFSymbolType(int Type) override {} + void EndCOFFSymbolDef() override {} + + ArrayRef<MCInst> GetInstructionSequence(unsigned Index) const { + return Regions.getInstructionSequence(Index); + } +}; + +void MCACommentConsumer::HandleComment(SMLoc Loc, StringRef CommentText) { + // Skip empty comments. + StringRef Comment(CommentText); + if (Comment.empty()) + return; + + // Skip spaces and tabs. + unsigned Position = Comment.find_first_not_of(" \t"); + if (Position >= Comment.size()) + // We reached the end of the comment. Bail out. + return; + + Comment = Comment.drop_front(Position); + if (Comment.consume_front("LLVM-MCA-END")) { + // Skip spaces and tabs. + Position = Comment.find_first_not_of(" \t"); + if (Position < Comment.size()) + Comment = Comment.drop_front(Position); + Regions.endRegion(Comment, Loc); + return; + } + + // Try to parse the LLVM-MCA-BEGIN comment. + if (!Comment.consume_front("LLVM-MCA-BEGIN")) + return; + + // Skip spaces and tabs. + Position = Comment.find_first_not_of(" \t"); + if (Position < Comment.size()) + Comment = Comment.drop_front(Position); + // Use the rest of the string as a descriptor for this code snippet. + Regions.beginRegion(Comment, Loc); +} + +Expected<const CodeRegions &> AsmCodeRegionGenerator::parseCodeRegions() { + MCTargetOptions Opts; + Opts.PreserveAsmComments = false; + MCStreamerWrapper Str(Ctx, Regions); + + // Create a MCAsmParser and setup the lexer to recognize llvm-mca ASM + // comments. + std::unique_ptr<MCAsmParser> Parser( + createMCAsmParser(Regions.getSourceMgr(), Ctx, Str, MAI)); + MCAsmLexer &Lexer = Parser->getLexer(); + MCACommentConsumer CC(Regions); + Lexer.setCommentConsumer(&CC); + // Enable support for MASM literal numbers (example: 05h, 101b). + Lexer.setLexMasmIntegers(true); + + std::unique_ptr<MCTargetAsmParser> TAP( + TheTarget.createMCAsmParser(STI, *Parser, MCII, Opts)); + if (!TAP) + return make_error<StringError>( + "This target does not support assembly parsing.", + inconvertibleErrorCode()); + Parser->setTargetParser(*TAP); + Parser->Run(false); + + // Set the assembler dialect from the input. llvm-mca will use this as the + // default dialect when printing reports. + AssemblerDialect = Parser->getAssemblerDialect(); + return Regions; +} + +} // namespace mca +} // namespace llvm