lib/Target/PowerPC/PPCMachOWriterInfo.cpp

   1 //===-- PPCMachOWriterInfo.cpp - Mach-O Writer Info for the PowerPC -------===//
   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 Mach-O writer information for the PowerPC backend.
  11 //
  12 //===----------------------------------------------------------------------===//
  13
  14 #include "PPCMachOWriterInfo.h"
  15 #include "PPCRelocations.h"
  16 #include "PPCTargetMachine.h"
  17 #include "llvm/CodeGen/MachORelocation.h"
  18 #include "llvm/Support/OutputBuffer.h"
  19 using namespace llvm;
  20
  21 PPCMachOWriterInfo::PPCMachOWriterInfo(const PPCTargetMachine &TM)
  22   : TargetMachOWriterInfo(TM.getTargetData()->getPointerSizeInBits() == 64 ?
  23                           HDR_CPU_TYPE_POWERPC64 :
  24                           HDR_CPU_TYPE_POWERPC,
  25                           HDR_CPU_SUBTYPE_POWERPC_ALL) {}
  26 PPCMachOWriterInfo::~PPCMachOWriterInfo() {}
  27
  28 /// GetTargetRelocation - For the MachineRelocation MR, convert it to one or
  29 /// more PowerPC MachORelocation(s), add the new relocations to the
  30 /// MachOSection, and rewrite the instruction at the section offset if required
  31 /// by that relocation type.
  32 unsigned PPCMachOWriterInfo::GetTargetRelocation(MachineRelocation &MR,
  33                                                  unsigned FromIdx,
  34                                                  unsigned ToAddr,
  35                                                  unsigned ToIdx,
  36                                                  OutputBuffer &RelocOut,
  37                                                  OutputBuffer &SecOut,
  38                                                  bool Scattered,
  39                                                  bool isExtern) const {
  40   unsigned NumRelocs = 0;
  41   uint64_t Addr = 0;
  42
  43   // Get the address of whatever it is we're relocating, if possible.
  44   if (!isExtern)
  45     Addr = (uintptr_t)MR.getResultPointer() + ToAddr;
  46
  47   switch ((PPC::RelocationType)MR.getRelocationType()) {
  48   default: assert(0 && "Unknown PPC relocation type!");
  49   case PPC::reloc_absolute_low_ix:
  50     assert(0 && "Unhandled PPC relocation type!");
  51     break;
  52   case PPC::reloc_vanilla:
  53     {
  54       // FIXME: need to handle 64 bit vanilla relocs
  55       MachORelocation VANILLA(MR.getMachineCodeOffset(), ToIdx,
  56                               false, 2, isExtern,
  57                               PPC_RELOC_VANILLA,
  58                               Scattered, (intptr_t)MR.getResultPointer());
  59       ++NumRelocs;
  60
  61       if (Scattered) {
  62         RelocOut.outword(VANILLA.getPackedFields());
  63         RelocOut.outword(VANILLA.getAddress());
  64       } else {
  65         RelocOut.outword(VANILLA.getAddress());
  66         RelocOut.outword(VANILLA.getPackedFields());
  67       }
  68
  69       intptr_t SymbolOffset;
  70
  71       if (Scattered)
  72         SymbolOffset = Addr + MR.getConstantVal();
  73       else
  74         SymbolOffset = Addr;
  75
  76       printf("vanilla fixup: sec_%x[%x] = %x\n", FromIdx,
  77              unsigned(MR.getMachineCodeOffset()),
  78              unsigned(SymbolOffset));
  79       SecOut.fixword(SymbolOffset, MR.getMachineCodeOffset());
  80     }
  81     break;
  82   case PPC::reloc_pcrel_bx:
  83     {
  84       // FIXME: Presumably someday we will need to branch to other, non-extern
  85       // functions too.  Need to figure out some way to distinguish between
  86       // target is BB and target is function.
  87       if (isExtern) {
  88         MachORelocation BR24(MR.getMachineCodeOffset(), ToIdx, true, 2,
  89                              isExtern, PPC_RELOC_BR24, Scattered,
  90                              (intptr_t)MR.getMachineCodeOffset());
  91         RelocOut.outword(BR24.getAddress());
  92         RelocOut.outword(BR24.getPackedFields());
  93         ++NumRelocs;
  94       }
  95
  96       Addr -= MR.getMachineCodeOffset();
  97       Addr >>= 2;
  98       Addr &= 0xFFFFFF;
  99       Addr <<= 2;
 100       Addr |= (SecOut[MR.getMachineCodeOffset()] << 24);
 101       Addr |= (SecOut[MR.getMachineCodeOffset()+3] & 0x3);
 102       SecOut.fixword(Addr, MR.getMachineCodeOffset());
 103       break;
 104     }
 105   case PPC::reloc_pcrel_bcx:
 106     {
 107       Addr -= MR.getMachineCodeOffset();
 108       Addr &= 0xFFFC;
 109
 110       SecOut.fixhalf(Addr, MR.getMachineCodeOffset() + 2);
 111       break;
 112     }
 113   case PPC::reloc_absolute_high:
 114     {
 115       MachORelocation HA16(MR.getMachineCodeOffset(), ToIdx, false, 2,
 116                            isExtern, PPC_RELOC_HA16);
 117       MachORelocation PAIR(Addr & 0xFFFF, 0xFFFFFF, false, 2, isExtern,
 118                            PPC_RELOC_PAIR);
 119       NumRelocs = 2;
 120
 121       RelocOut.outword(HA16.getRawAddress());
 122       RelocOut.outword(HA16.getPackedFields());
 123       RelocOut.outword(PAIR.getRawAddress());
 124       RelocOut.outword(PAIR.getPackedFields());
 125
 126       Addr += 0x8000;
 127
 128       SecOut.fixhalf(Addr >> 16, MR.getMachineCodeOffset() + 2);
 129       break;
 130     }
 131   case PPC::reloc_absolute_low:
 132     {
 133       MachORelocation LO16(MR.getMachineCodeOffset(), ToIdx, false, 2,
 134                            isExtern, PPC_RELOC_LO16);
 135       MachORelocation PAIR(Addr >> 16, 0xFFFFFF, false, 2, isExtern,
 136                            PPC_RELOC_PAIR);
 137       NumRelocs = 2;
 138
 139       RelocOut.outword(LO16.getRawAddress());
 140       RelocOut.outword(LO16.getPackedFields());
 141       RelocOut.outword(PAIR.getRawAddress());
 142       RelocOut.outword(PAIR.getPackedFields());
 143
 144       SecOut.fixhalf(Addr, MR.getMachineCodeOffset() + 2);
 145       break;
 146     }
 147   }
 148
 149   return NumRelocs;
 150 }