1 //===-- llvm/Target/TargetOptions.h - Target Options ------------*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file defines command line option flags that are shared across various
13 //===----------------------------------------------------------------------===//
15 #ifndef LLVM_TARGET_TARGETOPTIONS_H
16 #define LLVM_TARGET_TARGETOPTIONS_H
21 class MachineFunction;
24 // Possible float ABI settings. Used with FloatABIType in TargetOptions.h.
27 Default, // Target-specific (either soft or hard depending on triple,etc).
33 namespace FPOpFusion {
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.
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)
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;
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;
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;
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;
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;
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;
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;
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;
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;
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;
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;
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;
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;
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;
141 /// StackAlignmentOverride - Override default stack alignment for target.
142 unsigned StackAlignmentOverride;
144 /// EnableFastISel - This flag enables fast-path instruction selection
145 /// which trades away generated code quality in favor of reducing
147 unsigned EnableFastISel : 1;
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;
155 unsigned EnableSegmentedStacks : 1;
157 /// UseInitArray - Use .init_array instead of .ctors for static
159 unsigned UseInitArray : 1;
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;
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;
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).
179 /// Fast mode - allows formation of fused FP ops whenever they're
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
184 /// Strict mode - allow fusion only if/when it can be proven that the excess
185 /// precision won't effect the result.
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;
194 // Comparison operators:
197 inline bool operator==(const TargetOptions &LHS,
198 const TargetOptions &RHS) {
199 #define ARE_EQUAL(X) LHS.X == RHS.X
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);
222 inline bool operator!=(const TargetOptions &LHS,
223 const TargetOptions &RHS) {
224 return !(LHS == RHS);
227 } // End llvm namespace