TargetOptions.h revision 84a61269370138b68ae2bcd6711a9ae8004fd77a 
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  class StringRef;
21
22  // Possible float ABI settings. Used with FloatABIType in TargetOptions.h.
23  namespace FloatABI {
24    enum ABIType {
25      Default, // Target-specific (either soft of hard depending on triple, etc).
26      Soft, // Soft float.
27      Hard  // Hard float.
28    };
29  }
30
31  /// PrintMachineCode - This flag is enabled when the -print-machineinstrs
32  /// option is specified on the command line, and should enable debugging
33  /// output from the code generator.
34  extern bool PrintMachineCode;
35
36  /// NoFramePointerElim - This flag is enabled when the -disable-fp-elim is
37  /// specified on the command line.  If the target supports the frame pointer
38  /// elimination optimization, this option should disable it.
39  extern bool NoFramePointerElim;
40
41  /// NoFramePointerElimNonLeaf - This flag is enabled when the
42  /// -disable-non-leaf-fp-elim is specified on the command line. If the target
43  /// supports the frame pointer elimination optimization, this option should
44  /// disable it for non-leaf functions.
45  extern bool NoFramePointerElimNonLeaf;
46
47  /// DisableFramePointerElim - This returns true if frame pointer elimination
48  /// optimization should be disabled for the given machine function.
49  extern bool DisableFramePointerElim(const MachineFunction &MF);
50
51  /// LessPreciseFPMAD - This flag is enabled when the
52  /// -enable-fp-mad is specified on the command line.  When this flag is off
53  /// (the default), the code generator is not allowed to generate mad
54  /// (multiply add) if the result is "less precise" than doing those operations
55  /// individually.
56  extern bool LessPreciseFPMADOption;
57  extern bool LessPreciseFPMAD();
58
59  /// NoExcessFPPrecision - This flag is enabled when the
60  /// -disable-excess-fp-precision flag is specified on the command line.  When
61  /// this flag is off (the default), the code generator is allowed to produce
62  /// results that are "more precise" than IEEE allows.  This includes use of
63  /// FMA-like operations and use of the X86 FP registers without rounding all
64  /// over the place.
65  extern bool NoExcessFPPrecision;
66
67  /// UnsafeFPMath - This flag is enabled when the
68  /// -enable-unsafe-fp-math flag is specified on the command line.  When
69  /// this flag is off (the default), the code generator is not allowed to
70  /// produce results that are "less precise" than IEEE allows.  This includes
71  /// use of X86 instructions like FSIN and FCOS instead of libcalls.
72  /// UnsafeFPMath implies LessPreciseFPMAD.
73  extern bool UnsafeFPMath;
74
75  /// NoInfsFPMath - This flag is enabled when the
76  /// -enable-no-infs-fp-math flag is specified on the command line. When
77  /// this flag is off (the default), the code generator is not allowed to
78  /// assume the FP arithmetic arguments and results are never +-Infs.
79  extern bool NoInfsFPMath;
80
81  /// NoNaNsFPMath - This flag is enabled when the
82  /// -enable-no-nans-fp-math flag is specified on the command line. When
83  /// this flag is off (the default), the code generator is not allowed to
84  /// assume the FP arithmetic arguments and results are never NaNs.
85  extern bool NoNaNsFPMath;
86
87  /// HonorSignDependentRoundingFPMath - This returns true when the
88  /// -enable-sign-dependent-rounding-fp-math is specified.  If this returns
89  /// false (the default), the code generator is allowed to assume that the
90  /// rounding behavior is the default (round-to-zero for all floating point to
91  /// integer conversions, and round-to-nearest for all other arithmetic
92  /// truncations).  If this is enabled (set to true), the code generator must
93  /// assume that the rounding mode may dynamically change.
94  extern bool HonorSignDependentRoundingFPMathOption;
95  extern bool HonorSignDependentRoundingFPMath();
96
97  /// UseSoftFloat - This flag is enabled when the -soft-float flag is specified
98  /// on the command line.  When this flag is on, the code generator will
99  /// generate libcalls to the software floating point library instead of
100  /// target FP instructions.
101  extern bool UseSoftFloat;
102
103  /// FloatABIType - This setting is set by -float-abi=xxx option is specfied
104  /// on the command line. This setting may either be Default, Soft, or Hard.
105  /// Default selects the target's default behavior. Soft selects the ABI for
106  /// UseSoftFloat, but does not inidcate that FP hardware may not be used.
107  /// Such a combination is unfortunately popular (e.g. arm-apple-darwin).
108  /// Hard presumes that the normal FP ABI is used.
109  extern FloatABI::ABIType FloatABIType;
110
111  /// NoZerosInBSS - By default some codegens place zero-initialized data to
112  /// .bss section. This flag disables such behaviour (necessary, e.g. for
113  /// crt*.o compiling).
114  extern bool NoZerosInBSS;
115
116  /// JITExceptionHandling - This flag indicates that the JIT should emit
117  /// exception handling information.
118  extern bool JITExceptionHandling;
119
120  /// JITEmitDebugInfo - This flag indicates that the JIT should try to emit
121  /// debug information and notify a debugger about it.
122  extern bool JITEmitDebugInfo;
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  extern bool JITEmitDebugInfoToDisk;
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  extern bool GuaranteedTailCallOpt;
136
137  /// StackAlignmentOverride - Override default stack alignment for target.
138  extern unsigned StackAlignmentOverride;
139
140  /// RealignStack - This flag indicates whether the stack should be
141  /// automatically realigned, if needed.
142  extern bool RealignStack;
143
144  /// DisableJumpTables - This flag indicates jump tables should not be
145  /// generated.
146  extern bool DisableJumpTables;
147
148  /// EnableFastISel - This flag enables fast-path instruction selection
149  /// which trades away generated code quality in favor of reducing
150  /// compile time.
151  extern bool EnableFastISel;
152
153  /// StrongPHIElim - This flag enables more aggressive PHI elimination
154  /// wth earlier copy coalescing.
155  extern bool StrongPHIElim;
156
157  /// getTrapFunctionName - If this returns a non-empty string, this means isel
158  /// should lower Intrinsic::trap to a call to the specified function name
159  /// instead of an ISD::TRAP node.
160  extern StringRef getTrapFunctionName();
161
162  extern bool EnableSegmentedStacks;
163
164} // End llvm namespace
165
166#endif
167