llvm/lib/Target/PowerPC/PPCGenRegisterBankInfo.def

   1 //===- PPCGenRegisterBankInfo.def -------------------------------*- C++ -*-==//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8 /// \file
   9 /// This file defines all the static objects used by PPCRegisterBankInfo.
  10 /// \todo This should be generated by TableGen, because the logic here can be
  11 ///  derived from register bank definition. Not yet implemented.
  12 //===----------------------------------------------------------------------===//
  13
  14 namespace llvm {
  15 const RegisterBankInfo::PartialMapping PPCGenRegisterBankInfo::PartMappings[]{
  16     /* StartIdx, Length, RegBank */
  17     // 0: GPR 32-bit value.
  18     {0, 32, PPC::GPRRegBank},
  19     // 1: GPR 64-bit value.
  20     {0, 64, PPC::GPRRegBank},
  21     // 2: FPR 32-bit value
  22     {0, 32, PPC::FPRRegBank},
  23     // 3: FPR 64-bit value
  24     {0, 64, PPC::FPRRegBank},
  25     // 4: 128-bit vector (VSX, Altivec)
  26     {0, 128, PPC::VECRegBank},
  27     // 5: CR 4-bit value
  28     {0, 4, PPC::CRRegBank},
  29 };
  30
  31 // ValueMappings.
  32 // Pointers to the entries in this array are returned by getValueMapping() and
  33 // getCopyMapping().
  34 //
  35 // The array has the following structure:
  36 // - At index 0 is the invalid entry.
  37 // - After that, the mappings for the register types from PartialMappingIdx
  38 //   follow. Each mapping consists of 3 entries, which is needed to cover
  39 //   3-operands instructions.
  40 // - Last, mappings for cross-register bank moves follow. Since COPY has only
  41 //   2 operands, a mapping consists of 2 entries.
  42 const RegisterBankInfo::ValueMapping PPCGenRegisterBankInfo::ValMappings[]{
  43     /* BreakDown, NumBreakDowns */
  44     // 0: invalid
  45     {nullptr, 0},
  46     // 1: GPR 32-bit value.
  47     {&PPCGenRegisterBankInfo::PartMappings[PMI_GPR32 - PMI_Min], 1},
  48     {&PPCGenRegisterBankInfo::PartMappings[PMI_GPR32 - PMI_Min], 1},
  49     {&PPCGenRegisterBankInfo::PartMappings[PMI_GPR32 - PMI_Min], 1},
  50     // 4: GPR 64-bit value.
  51     {&PPCGenRegisterBankInfo::PartMappings[PMI_GPR64 - PMI_Min], 1},
  52     {&PPCGenRegisterBankInfo::PartMappings[PMI_GPR64 - PMI_Min], 1},
  53     {&PPCGenRegisterBankInfo::PartMappings[PMI_GPR64 - PMI_Min], 1},
  54     // 7: FPR 32-bit value.
  55     {&PPCGenRegisterBankInfo::PartMappings[PMI_FPR32 - PMI_Min], 1},
  56     {&PPCGenRegisterBankInfo::PartMappings[PMI_FPR32 - PMI_Min], 1},
  57     {&PPCGenRegisterBankInfo::PartMappings[PMI_FPR32 - PMI_Min], 1},
  58     // 10: FPR 64-bit value.
  59     {&PPCGenRegisterBankInfo::PartMappings[PMI_FPR64 - PMI_Min], 1},
  60     {&PPCGenRegisterBankInfo::PartMappings[PMI_FPR64 - PMI_Min], 1},
  61     {&PPCGenRegisterBankInfo::PartMappings[PMI_FPR64 - PMI_Min], 1},
  62     // 13: 128-bit vector.
  63     {&PPCGenRegisterBankInfo::PartMappings[PMI_VEC128 - PMI_Min], 1},
  64     {&PPCGenRegisterBankInfo::PartMappings[PMI_VEC128 - PMI_Min], 1},
  65     {&PPCGenRegisterBankInfo::PartMappings[PMI_VEC128 - PMI_Min], 1},
  66     // 16: CR 4-bit value.
  67     {&PPCGenRegisterBankInfo::PartMappings[PMI_CR - PMI_Min], 1},
  68 };
  69
  70 // TODO Too simple!
  71 const RegisterBankInfo::ValueMapping *
  72 PPCGenRegisterBankInfo::getValueMapping(PartialMappingIdx RBIdx) {
  73   assert(RBIdx != PartialMappingIdx::PMI_None && "No mapping needed for that");
  74
  75   unsigned ValMappingIdx = RBIdx - PMI_Min;
  76
  77   return &ValMappings[1 + 3 * ValMappingIdx];
  78 }
  79
  80 const PPCGenRegisterBankInfo::PartialMappingIdx
  81   PPCGenRegisterBankInfo::BankIDToCopyMapIdx[]{
  82     PMI_None,
  83     PMI_FPR64,  // FPR
  84     PMI_GPR64,  // GPR
  85     PMI_VEC128, // VEC
  86 };
  87
  88 // TODO Too simple!
  89 const RegisterBankInfo::ValueMapping *
  90 PPCGenRegisterBankInfo::getCopyMapping(unsigned DstBankID, unsigned SrcBankID,
  91                                        unsigned Size) {
  92   assert(DstBankID < PPC::NumRegisterBanks && "Invalid bank ID");
  93   assert(SrcBankID < PPC::NumRegisterBanks && "Invalid bank ID");
  94   PartialMappingIdx DstRBIdx = BankIDToCopyMapIdx[DstBankID];
  95   PartialMappingIdx SrcRBIdx = BankIDToCopyMapIdx[SrcBankID];
  96   assert(DstRBIdx != PMI_None && "No such mapping");
  97   assert(SrcRBIdx != PMI_None && "No such mapping");
  98
  99   if (DstRBIdx == SrcRBIdx)
 100     return getValueMapping(DstRBIdx);
 101
 102   assert(Size <= 128 && "Can currently handle types up to 128 bits (vectors)!");
 103   // TODO: This function needs to be updated to handle all cases for
 104   //       GPRs, FPRs and vectors. It currently only handles bitcasting to
 105   //       the same type and has only mainly been tested for bitcasting
 106   //       between different vector types.
 107   unsigned ValMappingIdx = DstRBIdx - PMI_Min;
 108
 109   return &ValMappings[1 + 3 * ValMappingIdx];
 110 }
 111
 112 } // namespace llvm