1 //===-- TargetOptionsImpl.cpp - Options that apply to all targets ----------==// 2 // 3 // The LLVM Compiler Infrastructure 4 // 5 // This file is distributed under the University of Illinois Open Source 6 // License. See LICENSE.TXT for details. 7 // 8 //===----------------------------------------------------------------------===// 9 // 10 // This file implements the methods in the TargetOptions. 11 // 12 //===----------------------------------------------------------------------===// 13 14 #include "llvm/CodeGen/MachineFrameInfo.h" 15 #include "llvm/CodeGen/MachineFunction.h" 16 #include "llvm/CodeGen/TargetFrameLowering.h" 17 #include "llvm/CodeGen/TargetSubtargetInfo.h" 18 #include "llvm/IR/Function.h" 19 #include "llvm/IR/Module.h" 20 #include "llvm/Target/TargetOptions.h" 21 using namespace llvm; 22 23 /// DisableFramePointerElim - This returns true if frame pointer elimination 24 /// optimization should be disabled for the given machine function. DisableFramePointerElim(const MachineFunction & MF) const25bool TargetOptions::DisableFramePointerElim(const MachineFunction &MF) const { 26 // Check to see if the target want to forcably keep frame pointer. 27 if (MF.getSubtarget().getFrameLowering()->keepFramePointer(MF)) 28 return true; 29 30 const Function &F = MF.getFunction(); 31 32 // TODO: Remove support for old `fp elim` function attributes after fully 33 // migrate to use "frame-pointer" 34 if (!F.hasFnAttribute("frame-pointer")) { 35 // Check to see if we should eliminate all frame pointers. 36 if (F.getFnAttribute("no-frame-pointer-elim").getValueAsString() == "true") 37 return true; 38 39 // Check to see if we should eliminate non-leaf frame pointers. 40 if (F.hasFnAttribute("no-frame-pointer-elim-non-leaf")) 41 return MF.getFrameInfo().hasCalls(); 42 43 return false; 44 } 45 46 StringRef FP = F.getFnAttribute("frame-pointer").getValueAsString(); 47 if (FP == "all") 48 return true; 49 if (FP == "non-leaf") 50 return MF.getFrameInfo().hasCalls(); 51 if (FP == "none") 52 return false; 53 llvm_unreachable("unknown frame pointer flag"); 54 } 55 56 /// HonorSignDependentRoundingFPMath - Return true if the codegen must assume 57 /// that the rounding mode of the FPU can change from its default. HonorSignDependentRoundingFPMath() const58bool TargetOptions::HonorSignDependentRoundingFPMath() const { 59 return !UnsafeFPMath && HonorSignDependentRoundingFPMathOption; 60 } 61