TargetOptions.h revision c8578948c9b35080dedd6527abf4f48fc4de43d3 
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
18namespace llvm {
19  class MachineFunction;
20
21  // Possible float ABI settings. Used with FloatABIType in TargetOptions.h.
22  namespace FloatABI {
23    enum ABIType {
24      Default, // Target-specific (either soft of hard depending on triple, etc).
25      Soft, // Soft float.
26      Hard  // Hard float.
27    };
28  }
29
30  /// PrintMachineCode - This flag is enabled when the -print-machineinstrs
31  /// option is specified on the command line, and should enable debugging
32  /// output from the code generator.
33  extern bool PrintMachineCode;
34
35  /// NoFramePointerElim - This flag is enabled when the -disable-fp-elim is
36  /// specified on the command line.  If the target supports the frame pointer
37  /// elimination optimization, this option should disable it.
38  extern bool NoFramePointerElim;
39
40  /// NoFramePointerElimNonLeaf - This flag is enabled when the
41  /// -disable-non-leaf-fp-elim is specified on the command line. If the target
42  /// supports the frame pointer elimination optimization, this option should
43  /// disable it for non-leaf functions.
44  extern bool NoFramePointerElimNonLeaf;
45
46  /// DisableFramePointerElim - This returns true if frame pointer elimination
47  /// optimization should be disabled for the given machine function.
48  extern bool DisableFramePointerElim(const MachineFunction &MF);
49
50  /// LessPreciseFPMAD - This flag is enabled when the
51  /// -enable-fp-mad is specified on the command line.  When this flag is off
52  /// (the default), the code generator is not allowed to generate mad
53  /// (multiply add) if the result is "less precise" than doing those operations
54  /// individually.
55  extern bool LessPreciseFPMADOption;
56  extern bool LessPreciseFPMAD();
57
58  /// NoExcessFPPrecision - This flag is enabled when the
59  /// -disable-excess-fp-precision flag is specified on the command line.  When
60  /// this flag is off (the default), the code generator is allowed to produce
61  /// results that are "more precise" than IEEE allows.  This includes use of
62  /// FMA-like operations and use of the X86 FP registers without rounding all
63  /// over the place.
64  extern bool NoExcessFPPrecision;
65
66  /// UnsafeFPMath - This flag is enabled when the
67  /// -enable-unsafe-fp-math flag is specified on the command line.  When
68  /// this flag is off (the default), the code generator is not allowed to
69  /// produce results that are "less precise" than IEEE allows.  This includes
70  /// use of X86 instructions like FSIN and FCOS instead of libcalls.
71  /// UnsafeFPMath implies LessPreciseFPMAD.
72  extern bool UnsafeFPMath;
73
74  /// NoInfsFPMath - This flag is enabled when the
75  /// -enable-no-infs-fp-math flag is specified on the command line. When
76  /// this flag is off (the default), the code generator is not allowed to
77  /// assume the FP arithmetic arguments and results are never +-Infs.
78  extern bool NoInfsFPMath;
79
80  /// NoNaNsFPMath - This flag is enabled when the
81  /// -enable-no-nans-fp-math flag is specified on the command line. When
82  /// this flag is off (the default), the code generator is not allowed to
83  /// assume the FP arithmetic arguments and results are never NaNs.
84  extern bool NoNaNsFPMath;
85
86  /// HonorSignDependentRoundingFPMath - This returns true when the
87  /// -enable-sign-dependent-rounding-fp-math is specified.  If this returns
88  /// false (the default), the code generator is allowed to assume that the
89  /// rounding behavior is the default (round-to-zero for all floating point to
90  /// integer conversions, and round-to-nearest for all other arithmetic
91  /// truncations).  If this is enabled (set to true), the code generator must
92  /// assume that the rounding mode may dynamically change.
93  extern bool HonorSignDependentRoundingFPMathOption;
94  extern bool HonorSignDependentRoundingFPMath();
95
96  /// UseSoftFloat - This flag is enabled when the -soft-float flag is specified
97  /// on the command line.  When this flag is on, the code generator will
98  /// generate libcalls to the software floating point library instead of
99  /// target FP instructions.
100  extern bool UseSoftFloat;
101
102  /// FloatABIType - This setting is set by -float-abi=xxx option is specfied
103  /// on the command line. This setting may either be Default, Soft, or Hard.
104  /// Default selects the target's default behavior. Soft selects the ABI for
105  /// UseSoftFloat, but does not inidcate that FP hardware may not be used.
106  /// Such a combination is unfortunately popular (e.g. arm-apple-darwin).
107  /// Hard presumes that the normal FP ABI is used.
108  extern FloatABI::ABIType FloatABIType;
109
110  /// NoZerosInBSS - By default some codegens place zero-initialized data to
111  /// .bss section. This flag disables such behaviour (necessary, e.g. for
112  /// crt*.o compiling).
113  extern bool NoZerosInBSS;
114
115  /// JITExceptionHandling - This flag indicates that the JIT should emit
116  /// exception handling information.
117  extern bool JITExceptionHandling;
118
119  /// JITEmitDebugInfo - This flag indicates that the JIT should try to emit
120  /// debug information and notify a debugger about it.
121  extern bool JITEmitDebugInfo;
122
123  /// JITEmitDebugInfoToDisk - This flag indicates that the JIT should write
124  /// the object files generated by the JITEmitDebugInfo flag to disk.  This
125  /// flag is hidden and is only for debugging the debug info.
126  extern bool JITEmitDebugInfoToDisk;
127
128  /// UnwindTablesMandatory - This flag indicates that unwind tables should
129  /// be emitted for all functions.
130  extern bool UnwindTablesMandatory;
131
132  /// GuaranteedTailCallOpt - This flag is enabled when -tailcallopt is
133  /// specified on the commandline. When the flag is on, participating targets
134  /// will perform tail call optimization on all calls which use the fastcc
135  /// calling convention and which satisfy certain target-independent
136  /// criteria (being at the end of a function, having the same return type
137  /// as their parent function, etc.), using an alternate ABI if necessary.
138  extern bool GuaranteedTailCallOpt;
139
140  /// StackAlignment - Override default stack alignment for target.
141  extern unsigned StackAlignment;
142
143  /// RealignStack - This flag indicates whether the stack should be
144  /// automatically realigned, if needed.
145  extern bool RealignStack;
146
147  /// DisableJumpTables - This flag indicates jump tables should not be
148  /// generated.
149  extern bool DisableJumpTables;
150
151  /// EnableFastISel - This flag enables fast-path instruction selection
152  /// which trades away generated code quality in favor of reducing
153  /// compile time.
154  extern bool EnableFastISel;
155
156  /// StrongPHIElim - This flag enables more aggressive PHI elimination
157  /// wth earlier copy coalescing.
158  extern bool StrongPHIElim;
159
160  /// getTrapFunctionName - If this returns a non-empty string, this means isel
161  /// should lower Intrinsic::trap to a call to the specified function name
162  /// instead of an ISD::TRAP node.
163  extern StringRef getTrapFunctionName();
164
165} // End llvm namespace
166
167#endif
168