llvm/llvm/lib/Support/RISCVISAUtils.cpp

//===-- RISCVISAUtils.cpp - RISC-V ISA Utilities --------------------------===//
//
// 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
//
//===----------------------------------------------------------------------===//
//
// Utilities shared by TableGen and RISCVISAInfo.
//
//===----------------------------------------------------------------------===//

#include "llvm/Support/RISCVISAUtils.h"
#include "llvm/ADT/StringExtras.h"
#include <cassert>

usingnamespacellvm;

// We rank extensions in the following order:
// -Single letter extensions in canonical order.
// -Unknown single letter extensions in alphabetical order.
// -Multi-letter extensions starting with 'z' sorted by canonical order of
//  the second letter then sorted alphabetically.
// -Multi-letter extensions starting with 's' in alphabetical order.
// -(TODO) Multi-letter extensions starting with 'zxm' in alphabetical order.
// -X extensions in alphabetical order.
// -Unknown multi-letter extensions in alphabetical order.
// These flags are used to indicate the category. The first 6 bits store the
// single letter extension rank for single letter and multi-letter extensions
// starting with 'z'.
enum RankFlags { … };

// Get the rank for single-letter extension, lower value meaning higher
// priority.
static unsigned singleLetterExtensionRank(char Ext) { … }

// Get the rank for multi-letter extension, lower value meaning higher
// priority/order in canonical order.
static unsigned getExtensionRank(const std::string &ExtName) { … }

// Compare function for extension.
// Only compare the extension name, ignore version comparison.
bool llvm::RISCVISAUtils::compareExtension(const std::string &LHS,
                                           const std::string &RHS) { … }