llvm-project/llvm/lib/CodeGen/TargetOptionsImpl.cpp

60 lines
2.2 KiB
C++

//===-- TargetOptionsImpl.cpp - Options that apply to all targets ----------==//
//
// 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 methods in the TargetOptions.
//
//===----------------------------------------------------------------------===//
#include "llvm/CodeGen/MachineFrameInfo.h"
#include "llvm/CodeGen/MachineFunction.h"
#include "llvm/CodeGen/TargetFrameLowering.h"
#include "llvm/CodeGen/TargetSubtargetInfo.h"
#include "llvm/IR/Function.h"
#include "llvm/IR/Module.h"
#include "llvm/Target/TargetOptions.h"
using namespace llvm;
/// DisableFramePointerElim - This returns true if frame pointer elimination
/// optimization should be disabled for the given machine function.
bool TargetOptions::DisableFramePointerElim(const MachineFunction &MF) const {
// Check to see if the target want to forcably keep frame pointer.
if (MF.getSubtarget().getFrameLowering()->keepFramePointer(MF))
return true;
const Function &F = MF.getFunction();
// TODO: Remove support for old `fp elim` function attributes after fully
// migrate to use "frame-pointer"
if (!F.hasFnAttribute("frame-pointer")) {
// Check to see if we should eliminate all frame pointers.
if (F.getFnAttribute("no-frame-pointer-elim").getValueAsString() == "true")
return true;
// Check to see if we should eliminate non-leaf frame pointers.
if (F.hasFnAttribute("no-frame-pointer-elim-non-leaf"))
return MF.getFrameInfo().hasCalls();
return false;
}
StringRef FP = F.getFnAttribute("frame-pointer").getValueAsString();
if (FP == "all")
return true;
if (FP == "non-leaf")
return MF.getFrameInfo().hasCalls();
if (FP == "none")
return false;
llvm_unreachable("unknown frame pointer flag");
}
/// HonorSignDependentRoundingFPMath - Return true if the codegen must assume
/// that the rounding mode of the FPU can change from its default.
bool TargetOptions::HonorSignDependentRoundingFPMath() const {
return !UnsafeFPMath && HonorSignDependentRoundingFPMathOption;
}