1
0
mirror of https://github.com/RPCS3/llvm-mirror.git synced 2024-11-23 03:02:36 +01:00
llvm-mirror/lib/Target/Lanai/LanaiSubtarget.cpp
Craig Topper 10839866a1 [X86][MC][Target] Initial backend support a tune CPU to support -mtune
This patch implements initial backend support for a -mtune CPU controlled by a "tune-cpu" function attribute. If the attribute is not present X86 will use the resolved CPU from target-cpu attribute or command line.

This patch adds MC layer support a tune CPU. Each CPU now has two sets of features stored in their GenSubtargetInfo.inc tables . These features lists are passed separately to the Processor and ProcessorModel classes in tablegen. The tune list defaults to an empty list to avoid changes to non-X86. This annoyingly increases the size of static tables on all target as we now store 24 more bytes per CPU. I haven't quantified the overall impact, but I can if we're concerned.

One new test is added to X86 to show a few tuning features with mismatched tune-cpu and target-cpu/target-feature attributes to demonstrate independent control. Another new test is added to demonstrate that the scheduler model follows the tune CPU.

I have not added a -mtune to llc/opt or MC layer command line yet. With no attributes we'll just use the -mcpu for both. MC layer tools will always follow the normal CPU for tuning.

Differential Revision: https://reviews.llvm.org/D85165
2020-08-14 15:31:50 -07:00

47 lines
1.7 KiB
C++

//===- LanaiSubtarget.cpp - Lanai 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 Lanai specific subclass of TargetSubtarget.
//
//===----------------------------------------------------------------------===//
#include "LanaiSubtarget.h"
#include "Lanai.h"
#define DEBUG_TYPE "lanai-subtarget"
#define GET_SUBTARGETINFO_TARGET_DESC
#define GET_SUBTARGETINFO_CTOR
#include "LanaiGenSubtargetInfo.inc"
using namespace llvm;
void LanaiSubtarget::initSubtargetFeatures(StringRef CPU, StringRef FS) {
std::string CPUName = std::string(CPU);
if (CPUName.empty())
CPUName = "generic";
ParseSubtargetFeatures(CPUName, /*TuneCPU*/ CPUName, FS);
}
LanaiSubtarget &LanaiSubtarget::initializeSubtargetDependencies(StringRef CPU,
StringRef FS) {
initSubtargetFeatures(CPU, FS);
return *this;
}
LanaiSubtarget::LanaiSubtarget(const Triple &TargetTriple, StringRef Cpu,
StringRef FeatureString, const TargetMachine &TM,
const TargetOptions & /*Options*/,
CodeModel::Model /*CodeModel*/,
CodeGenOpt::Level /*OptLevel*/)
: LanaiGenSubtargetInfo(TargetTriple, Cpu, /*TuneCPU*/ Cpu, FeatureString),
FrameLowering(initializeSubtargetDependencies(Cpu, FeatureString)),
InstrInfo(), TLInfo(TM, *this), TSInfo() {}