1 //===-- llvm/Target/TargetOptions.h - Target Options ------------*- C++ -*-===// 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 defines command line option flags that are shared across various 11 // targets. 12 // 13 //===----------------------------------------------------------------------===// 14 15 #ifndef LLVM_TARGET_TARGETOPTIONS_H 16 #define LLVM_TARGET_TARGETOPTIONS_H 17 18 #include <string> 19 20 namespace llvm { 21 class MachineFunction; 22 class StringRef; 23 24 // Possible float ABI settings. Used with FloatABIType in TargetOptions.h. 25 namespace FloatABI { 26 enum ABIType { 27 Default, // Target-specific (either soft or hard depending on triple,etc). 28 Soft, // Soft float. 29 Hard // Hard float. 30 }; 31 } 32 33 namespace FPOpFusion { 34 enum FPOpFusionMode { 35 Fast, // Enable fusion of FP ops wherever it's profitable. 36 Standard, // Only allow fusion of 'blessed' ops (currently just fmuladd). 37 Strict // Never fuse FP-ops. 38 }; 39 } 40 41 class TargetOptions { 42 public: 43 TargetOptions() 44 : PrintMachineCode(false), NoFramePointerElim(false), 45 LessPreciseFPMADOption(false), 46 UnsafeFPMath(false), NoInfsFPMath(false), 47 NoNaNsFPMath(false), HonorSignDependentRoundingFPMathOption(false), 48 UseSoftFloat(false), NoZerosInBSS(false), 49 JITEmitDebugInfo(false), JITEmitDebugInfoToDisk(false), 50 GuaranteedTailCallOpt(false), DisableTailCalls(false), 51 StackAlignmentOverride(0), 52 EnableFastISel(false), PositionIndependentExecutable(false), 53 EnableSegmentedStacks(false), UseInitArray(false), TrapFuncName(""), 54 FloatABIType(FloatABI::Default), AllowFPOpFusion(FPOpFusion::Standard) 55 {} 56 57 /// PrintMachineCode - This flag is enabled when the -print-machineinstrs 58 /// option is specified on the command line, and should enable debugging 59 /// output from the code generator. 60 unsigned PrintMachineCode : 1; 61 62 /// NoFramePointerElim - This flag is enabled when the -disable-fp-elim is 63 /// specified on the command line. If the target supports the frame pointer 64 /// elimination optimization, this option should disable it. 65 unsigned NoFramePointerElim : 1; 66 67 /// DisableFramePointerElim - This returns true if frame pointer elimination 68 /// optimization should be disabled for the given machine function. 69 bool DisableFramePointerElim(const MachineFunction &MF) const; 70 71 /// LessPreciseFPMAD - This flag is enabled when the 72 /// -enable-fp-mad is specified on the command line. When this flag is off 73 /// (the default), the code generator is not allowed to generate mad 74 /// (multiply add) if the result is "less precise" than doing those 75 /// operations individually. 76 unsigned LessPreciseFPMADOption : 1; 77 bool LessPreciseFPMAD() const; 78 79 /// UnsafeFPMath - This flag is enabled when the 80 /// -enable-unsafe-fp-math flag is specified on the command line. When 81 /// this flag is off (the default), the code generator is not allowed to 82 /// produce results that are "less precise" than IEEE allows. This includes 83 /// use of X86 instructions like FSIN and FCOS instead of libcalls. 84 /// UnsafeFPMath implies LessPreciseFPMAD. 85 unsigned UnsafeFPMath : 1; 86 87 /// NoInfsFPMath - This flag is enabled when the 88 /// -enable-no-infs-fp-math flag is specified on the command line. When 89 /// this flag is off (the default), the code generator is not allowed to 90 /// assume the FP arithmetic arguments and results are never +-Infs. 91 unsigned NoInfsFPMath : 1; 92 93 /// NoNaNsFPMath - This flag is enabled when the 94 /// -enable-no-nans-fp-math flag is specified on the command line. When 95 /// this flag is off (the default), the code generator is not allowed to 96 /// assume the FP arithmetic arguments and results are never NaNs. 97 unsigned NoNaNsFPMath : 1; 98 99 /// HonorSignDependentRoundingFPMath - This returns true when the 100 /// -enable-sign-dependent-rounding-fp-math is specified. If this returns 101 /// false (the default), the code generator is allowed to assume that the 102 /// rounding behavior is the default (round-to-zero for all floating point 103 /// to integer conversions, and round-to-nearest for all other arithmetic 104 /// truncations). If this is enabled (set to true), the code generator must 105 /// assume that the rounding mode may dynamically change. 106 unsigned HonorSignDependentRoundingFPMathOption : 1; 107 bool HonorSignDependentRoundingFPMath() const; 108 109 /// UseSoftFloat - This flag is enabled when the -soft-float flag is 110 /// specified on the command line. When this flag is on, the code generator 111 /// will generate libcalls to the software floating point library instead of 112 /// target FP instructions. 113 unsigned UseSoftFloat : 1; 114 115 /// NoZerosInBSS - By default some codegens place zero-initialized data to 116 /// .bss section. This flag disables such behaviour (necessary, e.g. for 117 /// crt*.o compiling). 118 unsigned NoZerosInBSS : 1; 119 120 /// JITEmitDebugInfo - This flag indicates that the JIT should try to emit 121 /// debug information and notify a debugger about it. 122 unsigned JITEmitDebugInfo : 1; 123 124 /// JITEmitDebugInfoToDisk - This flag indicates that the JIT should write 125 /// the object files generated by the JITEmitDebugInfo flag to disk. This 126 /// flag is hidden and is only for debugging the debug info. 127 unsigned JITEmitDebugInfoToDisk : 1; 128 129 /// GuaranteedTailCallOpt - This flag is enabled when -tailcallopt is 130 /// specified on the commandline. When the flag is on, participating targets 131 /// will perform tail call optimization on all calls which use the fastcc 132 /// calling convention and which satisfy certain target-independent 133 /// criteria (being at the end of a function, having the same return type 134 /// as their parent function, etc.), using an alternate ABI if necessary. 135 unsigned GuaranteedTailCallOpt : 1; 136 137 /// DisableTailCalls - This flag controls whether we will use tail calls. 138 /// Disabling them may be useful to maintain a correct call stack. 139 unsigned DisableTailCalls : 1; 140 141 /// StackAlignmentOverride - Override default stack alignment for target. 142 unsigned StackAlignmentOverride; 143 144 /// EnableFastISel - This flag enables fast-path instruction selection 145 /// which trades away generated code quality in favor of reducing 146 /// compile time. 147 unsigned EnableFastISel : 1; 148 149 /// PositionIndependentExecutable - This flag indicates whether the code 150 /// will eventually be linked into a single executable, despite the PIC 151 /// relocation model being in use. It's value is undefined (and irrelevant) 152 /// if the relocation model is anything other than PIC. 153 unsigned PositionIndependentExecutable : 1; 154 155 unsigned EnableSegmentedStacks : 1; 156 157 /// UseInitArray - Use .init_array instead of .ctors for static 158 /// constructors. 159 unsigned UseInitArray : 1; 160 161 /// getTrapFunctionName - If this returns a non-empty string, this means 162 /// isel should lower Intrinsic::trap to a call to the specified function 163 /// name instead of an ISD::TRAP node. 164 std::string TrapFuncName; 165 StringRef getTrapFunctionName() const; 166 167 /// FloatABIType - This setting is set by -float-abi=xxx option is specfied 168 /// on the command line. This setting may either be Default, Soft, or Hard. 169 /// Default selects the target's default behavior. Soft selects the ABI for 170 /// UseSoftFloat, but does not indicate that FP hardware may not be used. 171 /// Such a combination is unfortunately popular (e.g. arm-apple-darwin). 172 /// Hard presumes that the normal FP ABI is used. 173 FloatABI::ABIType FloatABIType; 174 175 /// AllowFPOpFusion - This flag is set by the -fuse-fp-ops=xxx option. 176 /// This controls the creation of fused FP ops that store intermediate 177 /// results in higher precision than IEEE allows (E.g. FMAs). 178 /// 179 /// Fast mode - allows formation of fused FP ops whenever they're 180 /// profitable. 181 /// Standard mode - allow fusion only for 'blessed' FP ops. At present the 182 /// only blessed op is the fmuladd intrinsic. In the future more blessed ops 183 /// may be added. 184 /// Strict mode - allow fusion only if/when it can be proven that the excess 185 /// precision won't effect the result. 186 /// 187 /// Note: This option only controls formation of fused ops by the 188 /// optimizers. Fused operations that are explicitly specified (e.g. FMA 189 /// via the llvm.fma.* intrinsic) will always be honored, regardless of 190 /// the value of this option. 191 FPOpFusion::FPOpFusionMode AllowFPOpFusion; 192 }; 193 194 // Comparison operators: 195 196 197 inline bool operator==(const TargetOptions &LHS, 198 const TargetOptions &RHS) { 199 #define ARE_EQUAL(X) LHS.X == RHS.X 200 return 201 ARE_EQUAL(UnsafeFPMath) && 202 ARE_EQUAL(NoInfsFPMath) && 203 ARE_EQUAL(NoNaNsFPMath) && 204 ARE_EQUAL(HonorSignDependentRoundingFPMathOption) && 205 ARE_EQUAL(UseSoftFloat) && 206 ARE_EQUAL(NoZerosInBSS) && 207 ARE_EQUAL(JITEmitDebugInfo) && 208 ARE_EQUAL(JITEmitDebugInfoToDisk) && 209 ARE_EQUAL(GuaranteedTailCallOpt) && 210 ARE_EQUAL(DisableTailCalls) && 211 ARE_EQUAL(StackAlignmentOverride) && 212 ARE_EQUAL(EnableFastISel) && 213 ARE_EQUAL(PositionIndependentExecutable) && 214 ARE_EQUAL(EnableSegmentedStacks) && 215 ARE_EQUAL(UseInitArray) && 216 ARE_EQUAL(TrapFuncName) && 217 ARE_EQUAL(FloatABIType) && 218 ARE_EQUAL(AllowFPOpFusion); 219 #undef ARE_EQUAL 220 } 221 222 inline bool operator!=(const TargetOptions &LHS, 223 const TargetOptions &RHS) { 224 return !(LHS == RHS); 225 } 226 227 } // End llvm namespace 228 229 #endif 230
