bolt/deps/llvm-18.1.8/llvm/lib/Target/LoongArch/LoongArchSubtarget.cpp
2025-02-14 19:21:04 +01:00

91 lines
3.3 KiB
C++

//===-- LoongArchSubtarget.cpp - LoongArch Subtarget Information -*- 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
//
//===----------------------------------------------------------------------===//
//
// This file implements the LoongArch specific subclass of TargetSubtargetInfo.
//
//===----------------------------------------------------------------------===//
#include "LoongArchSubtarget.h"
#include "LoongArchFrameLowering.h"
#include "MCTargetDesc/LoongArchBaseInfo.h"
using namespace llvm;
#define DEBUG_TYPE "loongarch-subtarget"
#define GET_SUBTARGETINFO_TARGET_DESC
#define GET_SUBTARGETINFO_CTOR
#include "LoongArchGenSubtargetInfo.inc"
void LoongArchSubtarget::anchor() {}
LoongArchSubtarget &LoongArchSubtarget::initializeSubtargetDependencies(
const Triple &TT, StringRef CPU, StringRef TuneCPU, StringRef FS,
StringRef ABIName) {
bool Is64Bit = TT.isArch64Bit();
if (CPU.empty() || CPU == "generic")
CPU = Is64Bit ? "generic-la64" : "generic-la32";
if (TuneCPU.empty())
TuneCPU = CPU;
ParseSubtargetFeatures(CPU, TuneCPU, FS);
initializeProperties(TuneCPU);
if (Is64Bit) {
GRLenVT = MVT::i64;
GRLen = 64;
}
if (HasLA32 == HasLA64)
report_fatal_error("Please use one feature of 32bit and 64bit.");
if (Is64Bit && HasLA32)
report_fatal_error("Feature 32bit should be used for loongarch32 target.");
if (!Is64Bit && HasLA64)
report_fatal_error("Feature 64bit should be used for loongarch64 target.");
TargetABI = LoongArchABI::computeTargetABI(TT, ABIName);
return *this;
}
void LoongArchSubtarget::initializeProperties(StringRef TuneCPU) {
// Initialize CPU specific properties. We should add a tablegen feature for
// this in the future so we can specify it together with the subtarget
// features.
// TODO: Check TuneCPU and override defaults (that are for LA464) once we
// support optimizing for more uarchs.
// Default to the alignment settings empirically confirmed to perform best
// on LA464, with 4-wide instruction fetch and decode stages. These settings
// can also be overridden in initializeProperties.
//
// We default to such higher-than-minimum alignments because we assume that:
//
// * these settings should benefit most existing uarchs/users,
// * future general-purpose LoongArch cores are likely to have issue widths
// equal to or wider than 4,
// * instruction sequences best for LA464 should not pessimize other future
// uarchs, and
// * narrower cores would not suffer much (aside from slightly increased
// ICache footprint maybe), compared to the gains everywhere else.
PrefFunctionAlignment = Align(32);
PrefLoopAlignment = Align(16);
MaxBytesForAlignment = 16;
}
LoongArchSubtarget::LoongArchSubtarget(const Triple &TT, StringRef CPU,
StringRef TuneCPU, StringRef FS,
StringRef ABIName,
const TargetMachine &TM)
: LoongArchGenSubtargetInfo(TT, CPU, TuneCPU, FS),
FrameLowering(
initializeSubtargetDependencies(TT, CPU, TuneCPU, FS, ABIName)),
InstrInfo(*this), RegInfo(getHwMode()), TLInfo(TM, *this) {}