lib/Target/ARM/ARMSubtarget.cpp

   1 //===-- ARMSubtarget.cpp - ARM Subtarget Information ------------*- 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 implements the ARM specific subclass of TargetSubtarget.
  11 //
  12 //===----------------------------------------------------------------------===//
  13
  14 #include "ARMSubtarget.h"
  15 #include "ARMGenSubtarget.inc"
  16 #include "llvm/Module.h"
  17 using namespace llvm;
  18
  19 ARMSubtarget::ARMSubtarget(const Module &M, const std::string &FS, bool thumb)
  20   : ARMArchVersion(V4T)
  21   , HasVFP2(false)
  22   , IsThumb(thumb)
  23   , UseThumbBacktraces(false)
  24   , IsR9Reserved(false)
  25   , stackAlignment(4)
  26   , TargetType(isELF) // Default to ELF unless otherwise specified.
  27   , TargetABI(ARM_ABI_APCS) {
  28
  29   // Determine default and user specified characteristics
  30   std::string CPU = "generic";
  31
  32   // Parse features string.
  33   ParseSubtargetFeatures(FS, CPU);
  34
  35   // Set the boolean corresponding to the current target triple, or the default
  36   // if one cannot be determined, to true.
  37   const std::string& TT = M.getTargetTriple();
  38   unsigned Len = TT.length();
  39   unsigned Idx = 0;
  40   if (Len >= 5 && TT.substr(0, 4) == "armv")
  41     Idx = 4;
  42   else if (Len >= 6 && TT.substr(0, 6) == "thumb") {
  43     IsThumb = true;
  44     if (Len >= 7 && TT[5] == 'v')
  45       Idx = 6;
  46   }
  47   if (Idx) {
  48     unsigned SubVer = TT[Idx];
  49     if (SubVer > '4' && SubVer <= '9') {
  50       if (SubVer >= '6')
  51         ARMArchVersion = V6;
  52       else if (SubVer == '5') {
  53         ARMArchVersion = V5T;
  54         if (Len >= Idx+3 && TT[Idx+1] == 't' && TT[Idx+2] == 'e')
  55           ARMArchVersion = V5TE;
  56       }
  57     }
  58   }
  59
  60   if (Len >= 10) {
  61     if (TT.find("-darwin") != std::string::npos)
  62       // arm-darwin
  63       TargetType = isDarwin;
  64   } else if (TT.empty()) {
  65 #if defined(__APPLE__)
  66     TargetType = isDarwin;
  67 #endif
  68   }
  69
  70   if (TT.find("eabi") != std::string::npos)
  71     TargetABI = ARM_ABI_AAPCS;
  72
  73   if (isAAPCS_ABI())
  74     stackAlignment = 8;
  75
  76   if (isTargetDarwin()) {
  77     UseThumbBacktraces = true;
  78     IsR9Reserved = true;
  79   }
  80 }