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