lib/Target/SystemZ/SystemZInstrBuilder.h

   1 //===- SystemZInstrBuilder.h - Functions to aid building  insts -*- 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 exposes functions that may be used with BuildMI from the
  11 // MachineInstrBuilder.h file to handle SystemZ'isms in a clean way.
  12 //
  13 // The BuildMem function may be used with the BuildMI function to add entire
  14 // memory references in a single, typed, function call.
  15 //
  16 // For reference, the order of operands for memory references is:
  17 // (Operand), Base, Displacement, Index.
  18 //
  19 //===----------------------------------------------------------------------===//
  20
  21 #ifndef SYSTEMZINSTRBUILDER_H
  22 #define SYSTEMZINSTRBUILDER_H
  23
  24 #include "llvm/CodeGen/MachineFrameInfo.h"
  25 #include "llvm/CodeGen/MachineInstrBuilder.h"
  26 #include "llvm/CodeGen/PseudoSourceValue.h"
  27
  28 namespace llvm {
  29
  30 /// SystemZAddressMode - This struct holds a generalized full x86 address mode.
  31 /// The base register can be a frame index, which will eventually be replaced
  32 /// with R15 or R11 and Disp being offsetted accordingly.
  33 struct SystemZAddressMode {
  34   enum {
  35     RegBase,
  36     FrameIndexBase
  37   } BaseType;
  38
  39   union {
  40     unsigned Reg;
  41     int FrameIndex;
  42   } Base;
  43
  44   unsigned IndexReg;
  45   int32_t Disp;
  46   GlobalValue *GV;
  47
  48   SystemZAddressMode() : BaseType(RegBase), IndexReg(0), Disp(0) {
  49     Base.Reg = 0;
  50   }
  51 };
  52
  53 /// addDirectMem - This function is used to add a direct memory reference to the
  54 /// current instruction -- that is, a dereference of an address in a register,
  55 /// with no index or displacement.
  56 ///
  57 static inline const MachineInstrBuilder &
  58 addDirectMem(const MachineInstrBuilder &MIB, unsigned Reg) {
  59   // Because memory references are always represented with 3
  60   // values, this adds: Reg, [0, NoReg] to the instruction.
  61   return MIB.addReg(Reg).addImm(0).addReg(0);
  62 }
  63
  64 static inline const MachineInstrBuilder &
  65 addOffset(const MachineInstrBuilder &MIB, int Offset) {
  66   return MIB.addImm(Offset).addReg(0);
  67 }
  68
  69 /// addRegOffset - This function is used to add a memory reference of the form
  70 /// [Reg + Offset], i.e., one with no or index, but with a
  71 /// displacement. An example is: 10(%r15).
  72 ///
  73 static inline const MachineInstrBuilder &
  74 addRegOffset(const MachineInstrBuilder &MIB,
  75              unsigned Reg, bool isKill, int Offset) {
  76   return addOffset(MIB.addReg(Reg, getKillRegState(isKill)), Offset);
  77 }
  78
  79 /// addRegReg - This function is used to add a memory reference of the form:
  80 /// [Reg + Reg].
  81 static inline const MachineInstrBuilder &
  82 addRegReg(const MachineInstrBuilder &MIB,
  83             unsigned Reg1, bool isKill1, unsigned Reg2, bool isKill2) {
  84   return MIB.addReg(Reg1, getKillRegState(isKill1)).addImm(0)
  85     .addReg(Reg2, getKillRegState(isKill2));
  86 }
  87
  88 static inline const MachineInstrBuilder &
  89 addFullAddress(const MachineInstrBuilder &MIB, const SystemZAddressMode &AM) {
  90   if (AM.BaseType == SystemZAddressMode::RegBase)
  91     MIB.addReg(AM.Base.Reg);
  92   else if (AM.BaseType == SystemZAddressMode::FrameIndexBase)
  93     MIB.addFrameIndex(AM.Base.FrameIndex);
  94   else
  95     assert(0);
  96
  97   return MIB.addImm(AM.Disp).addReg(AM.IndexReg);
  98 }
  99
 100 /// addFrameReference - This function is used to add a reference to the base of
 101 /// an abstract object on the stack frame of the current function.  This
 102 /// reference has base register as the FrameIndex offset until it is resolved.
 103 /// This allows a constant offset to be specified as well...
 104 ///
 105 static inline const MachineInstrBuilder &
 106 addFrameReference(const MachineInstrBuilder &MIB, int FI, int Offset = 0) {
 107   MachineInstr *MI = MIB;
 108   MachineFunction &MF = *MI->getParent()->getParent();
 109   MachineFrameInfo &MFI = *MF.getFrameInfo();
 110   const TargetInstrDesc &TID = MI->getDesc();
 111   unsigned Flags = 0;
 112   if (TID.mayLoad())
 113     Flags |= MachineMemOperand::MOLoad;
 114   if (TID.mayStore())
 115     Flags |= MachineMemOperand::MOStore;
 116   MachineMemOperand MMO(PseudoSourceValue::getFixedStack(FI),
 117                         Flags,
 118                         MFI.getObjectOffset(FI) + Offset,
 119                         MFI.getObjectSize(FI),
 120                         MFI.getObjectAlignment(FI));
 121   return addOffset(MIB.addFrameIndex(FI), Offset)
 122             .addMemOperand(MMO);
 123 }
 124
 125 } // End llvm namespace
 126
 127 #endif