llvm/lib/CodeGen/TargetOptionsImpl.cpp

   1 //===-- TargetOptionsImpl.cpp - Options that apply to all targets ----------==//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8 //
   9 // This file implements the methods in the TargetOptions.
  10 //
  11 //===----------------------------------------------------------------------===//
  12
  13 #include "llvm/CodeGen/MachineFrameInfo.h"
  14 #include "llvm/CodeGen/MachineFunction.h"
  15 #include "llvm/CodeGen/TargetFrameLowering.h"
  16 #include "llvm/CodeGen/TargetSubtargetInfo.h"
  17 #include "llvm/IR/Function.h"
  18 #include "llvm/IR/Module.h"
  19 #include "llvm/Target/TargetOptions.h"
  20 using namespace llvm;
  21
  22 /// DisableFramePointerElim - This returns true if frame pointer elimination
  23 /// optimization should be disabled for the given machine function.
  24 bool TargetOptions::DisableFramePointerElim(const MachineFunction &MF) const {
  25   // Check to see if the target want to forcably keep frame pointer.
  26   if (MF.getSubtarget().getFrameLowering()->keepFramePointer(MF))
  27     return true;
  28
  29   const Function &F = MF.getFunction();
  30
  31   if (!F.hasFnAttribute("frame-pointer"))
  32     return false;
  33   StringRef FP = F.getFnAttribute("frame-pointer").getValueAsString();
  34   if (FP == "all")
  35     return true;
  36   if (FP == "non-leaf")
  37     return MF.getFrameInfo().hasCalls();
  38   if (FP == "none")
  39     return false;
  40   llvm_unreachable("unknown frame pointer flag");
  41 }
  42
  43 /// HonorSignDependentRoundingFPMath - Return true if the codegen must assume
  44 /// that the rounding mode of the FPU can change from its default.
  45 bool TargetOptions::HonorSignDependentRoundingFPMath() const {
  46   return !UnsafeFPMath && HonorSignDependentRoundingFPMathOption;
  47 }
  48
  49 /// NOTE: There are targets that still do not support the debug entry values
  50 /// production and that is being controlled with the SupportsDebugEntryValues.
  51 /// In addition, SCE debugger does not have the feature implemented, so prefer
  52 /// not to emit the debug entry values in that case.
  53 /// The EnableDebugEntryValues can be used for the testing purposes.
  54 bool TargetOptions::ShouldEmitDebugEntryValues() const {
  55   return (SupportsDebugEntryValues && DebuggerTuning != DebuggerKind::SCE) ||
  56          EnableDebugEntryValues;
  57 }