1 //=====---- X86Subtarget.h - Define Subtarget for the X86 -----*- C++ -*--====//
3 // The LLVM Compiler Infrastructure
5 // This file was developed by Nate Begeman and is distributed under the
6 // University of Illinois Open Source License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file declares the X86 specific subclass of TargetSubtarget.
12 //===----------------------------------------------------------------------===//
14 #ifndef X86SUBTARGET_H
15 #define X86SUBTARGET_H
17 #include "llvm/GlobalValue.h"
18 #include "llvm/Target/TargetSubtarget.h"
25 class X86Subtarget : public TargetSubtarget {
27 enum AsmWriterFlavorTy {
33 NoMMXSSE, MMX, SSE1, SSE2, SSE3
37 NoThreeDNow, ThreeDNow, ThreeDNowA
40 /// AsmFlavor - Which x86 asm dialect to use.
41 AsmWriterFlavorTy AsmFlavor;
43 /// X86SSELevel - MMX, SSE1, SSE2, SSE3, or none supported.
44 X86SSEEnum X86SSELevel;
46 /// X863DNowLevel - 3DNow or 3DNow Athlon, or none supported.
47 X863DNowEnum X863DNowLevel;
49 /// HasX86_64 - True if the processor supports X86-64 instructions.
52 /// stackAlignment - The minimum alignment known to hold of the stack frame on
53 /// entry to the function and which must be maintained by every function.
54 unsigned stackAlignment;
56 /// Min. memset / memcpy size that is turned into rep/movs, rep/stos ops.
57 unsigned MinRepStrSizeThreshold;
60 /// Is64Bit - True if the processor supports 64-bit instructions and module
61 /// pointer size is 64 bit.
66 isELF, isCygwin, isDarwin, isWindows
69 /// This constructor initializes the data members to match that
70 /// of the specified module.
72 X86Subtarget(const Module &M, const std::string &FS, bool is64Bit);
74 /// getStackAlignment - Returns the minimum alignment known to hold of the
75 /// stack frame on entry to the function and which must be maintained by every
76 /// function for this subtarget.
77 unsigned getStackAlignment() const { return stackAlignment; }
79 /// getMinRepStrSizeThreshold - Returns the minimum memset / memcpy size
80 /// required to turn the operation into a X86 rep/movs or rep/stos
81 /// instruction. This is only used if the src / dst alignment is not DWORD
83 unsigned getMinRepStrSizeThreshold() const { return MinRepStrSizeThreshold; }
85 /// ParseSubtargetFeatures - Parses features string setting specified
86 /// subtarget options. Definition of function is auto generated by tblgen.
87 void ParseSubtargetFeatures(const std::string &FS, const std::string &CPU);
89 /// AutoDetectSubtargetFeatures - Auto-detect CPU features using CPUID
91 void AutoDetectSubtargetFeatures();
93 bool is64Bit() const { return Is64Bit; }
95 bool hasMMX() const { return X86SSELevel >= MMX; }
96 bool hasSSE1() const { return X86SSELevel >= SSE1; }
97 bool hasSSE2() const { return X86SSELevel >= SSE2; }
98 bool hasSSE3() const { return X86SSELevel >= SSE3; }
99 bool has3DNow() const { return X863DNowLevel >= ThreeDNow; }
100 bool has3DNowA() const { return X863DNowLevel >= ThreeDNowA; }
102 bool isFlavorAtt() const { return AsmFlavor == att; }
103 bool isFlavorIntel() const { return AsmFlavor == intel; }
105 bool isTargetDarwin() const { return TargetType == isDarwin; }
106 bool isTargetELF() const { return TargetType == isELF; }
107 bool isTargetWindows() const { return TargetType == isWindows; }
108 bool isTargetCygwin() const { return TargetType == isCygwin; }
110 /// True if accessing the GV requires an extra load. For Windows, dllimported
111 /// symbols are indirect, loading the value at address GV rather then the
112 /// value of GV itself. This means that the GlobalAddress must be in the base
113 /// or index register of the address, not the GV offset field.
114 bool GVRequiresExtraLoad(const GlobalValue* GV, bool isDirectCall) const
116 if (isTargetDarwin()) {
117 return (!isDirectCall &&
118 (GV->hasWeakLinkage() || GV->hasLinkOnceLinkage() ||
119 (GV->isExternal() && !GV->hasNotBeenReadFromBytecode())));
120 } else if (isTargetCygwin() || isTargetWindows()) {
121 return (GV->hasDLLImportLinkage());
129 /// GetCpuIDAndInfo - Execute the specified cpuid and return the 4 values in
130 /// the specified arguments. If we can't run cpuid on the host, return true.
131 bool GetCpuIDAndInfo(unsigned value, unsigned *rEAX, unsigned *rEBX,
132 unsigned *rECX, unsigned *rEDX);
135 } // End llvm namespace