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/Target/TargetOptions.h"
  19 using namespace llvm;
  20
  21 /// DisableFramePointerElim - This returns true if frame pointer elimination
  22 /// optimization should be disabled for the given machine function.
  23 bool TargetOptions::DisableFramePointerElim(const MachineFunction &MF) const {
  24   // Check to see if the target want to forcably keep frame pointer.
  25   if (MF.getSubtarget().getFrameLowering()->keepFramePointer(MF))
  26     return true;
  27
  28   const Function &F = MF.getFunction();
  29
  30   if (!F.hasFnAttribute("frame-pointer"))
  31     return false;
  32   StringRef FP = F.getFnAttribute("frame-pointer").getValueAsString();
  33   if (FP == "all")
  34     return true;
  35   if (FP == "non-leaf")
  36     return MF.getFrameInfo().hasCalls();
  37   if (FP == "none")
  38     return false;
  39   llvm_unreachable("unknown frame pointer flag");
  40 }
  41
  42 /// HonorSignDependentRoundingFPMath - Return true if the codegen must assume
  43 /// that the rounding mode of the FPU can change from its default.
  44 bool TargetOptions::HonorSignDependentRoundingFPMath() const {
  45   return !UnsafeFPMath && HonorSignDependentRoundingFPMathOption;
  46 }
  47
  48 /// NOTE: There are targets that still do not support the debug entry values
  49 /// production and that is being controlled with the SupportsDebugEntryValues.
  50 /// In addition, SCE debugger does not have the feature implemented, so prefer
  51 /// not to emit the debug entry values in that case.
  52 /// The EnableDebugEntryValues can be used for the testing purposes.
  53 bool TargetOptions::ShouldEmitDebugEntryValues() const {
  54   return (SupportsDebugEntryValues && DebuggerTuning != DebuggerKind::SCE) ||
  55          EnableDebugEntryValues;
  56 }