LLVM API Documentation

X86Subtarget.h

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00001 //=====---- X86Subtarget.h - Define Subtarget for the X86 -----*- C++ -*--====//
00002 //
00003 //                     The LLVM Compiler Infrastructure
00004 //
00005 // This file was developed by Nate Begeman and is distributed under the
00006 // University of Illinois Open Source License. See LICENSE.TXT for details.
00007 //
00008 //===----------------------------------------------------------------------===//
00009 //
00010 // This file declares the X86 specific subclass of TargetSubtarget.
00011 //
00012 //===----------------------------------------------------------------------===//
00013 
00014 #ifndef X86SUBTARGET_H
00015 #define X86SUBTARGET_H
00016 
00017 #include "llvm/Target/TargetSubtarget.h"
00018 
00019 #include <string>
00020 
00021 namespace llvm {
00022 class Module;
00023 
00024 class X86Subtarget : public TargetSubtarget {
00025 protected:
00026   enum X86SSEEnum {
00027     NoMMXSSE, MMX, SSE1, SSE2, SSE3
00028   };
00029 
00030   enum X863DNowEnum {
00031     NoThreeDNow, ThreeDNow, ThreeDNowA
00032   };
00033 
00034   /// X86SSELevel - MMX, SSE1, SSE2, SSE3, or none supported.
00035   X86SSEEnum X86SSELevel;
00036 
00037   /// X863DNowLevel - 3DNow or 3DNow Athlon, or none supported.
00038   X863DNowEnum X863DNowLevel;
00039 
00040   /// Is64Bit - True if the processor supports Em64T.
00041   bool Is64Bit;
00042 
00043   /// stackAlignment - The minimum alignment known to hold of the stack frame on
00044   /// entry to the function and which must be maintained by every function.
00045   unsigned stackAlignment;
00046 
00047   /// Min. memset / memcpy size that is turned into rep/movs, rep/stos ops.
00048   unsigned MinRepStrSizeThreshold;
00049 
00050 public:
00051   enum {
00052     isELF, isCygwin, isDarwin, isWindows
00053   } TargetType;
00054     
00055   /// This constructor initializes the data members to match that
00056   /// of the specified module.
00057   ///
00058   X86Subtarget(const Module &M, const std::string &FS);
00059 
00060   /// getStackAlignment - Returns the minimum alignment known to hold of the
00061   /// stack frame on entry to the function and which must be maintained by every
00062   /// function for this subtarget.
00063   unsigned getStackAlignment() const { return stackAlignment; }
00064 
00065   /// getMinRepStrSizeThreshold - Returns the minimum memset / memcpy size
00066   /// required to turn the operation into a X86 rep/movs or rep/stos
00067   /// instruction. This is only used if the src / dst alignment is not DWORD
00068   /// aligned.
00069   unsigned getMinRepStrSizeThreshold() const { return MinRepStrSizeThreshold; }
00070  
00071   /// ParseSubtargetFeatures - Parses features string setting specified 
00072   /// subtarget options.  Definition of function is auto generated by tblgen.
00073   void ParseSubtargetFeatures(const std::string &FS, const std::string &CPU);
00074 
00075   bool is64Bit() const { return Is64Bit; }
00076 
00077   bool hasMMX() const { return X86SSELevel >= MMX; }
00078   bool hasSSE1() const { return X86SSELevel >= SSE1; }
00079   bool hasSSE2() const { return X86SSELevel >= SSE2; }
00080   bool hasSSE3() const { return X86SSELevel >= SSE3; }
00081   bool has3DNow() const { return X863DNowLevel >= ThreeDNow; }
00082   bool has3DNowA() const { return X863DNowLevel >= ThreeDNowA; }
00083 
00084   bool isTargetDarwin() const { return TargetType == isDarwin; }
00085 };
00086 } // End llvm namespace
00087 
00088 #endif