
/*---------------------------------------------------------------*/
/*---                                                         ---*/
/*--- This file (x86h_defs.c) is                              ---*/
/*--- Copyright (c) 2004 OpenWorks LLP.  All rights reserved. ---*/
/*---                                                         ---*/
/*---------------------------------------------------------------*/

#include "libvex_basictypes.h"
#include "libvex.h"

#include "vex_util.h"
#include "host_regs.h"
#include "x86host_defs.h"


/* --------- Registers. --------- */

void ppHRegX86 ( HReg reg ) 
{
   Int r;
   static Char* ireg32_names[8] 
     = { "%eax", "%ecx", "%edx", "%ebx", "%esp", "%ebp", "%esi", "%edi" };
   /* Be generic for all virtual regs. */
   if (hregIsVirtual(reg)) {
      ppHReg(reg);
      return;
   }
   /* But specific for real regs. */
   switch (hregClass(reg)) {
      case HRcInt:
         r = hregNumber(reg);
         vassert(r >= 0 && r < 8);
         vex_printf("%s", ireg32_names[r]);
         return;
      case HRcFloat:
         r = hregNumber(reg);
         vassert(r >= 0 && r < 6);
         vex_printf("%%fake%d", r);
         return;
      case HRcVector:
         vpanic("ppHRegX86: real vector reg");
     default:
         vpanic("ppHRegX86");
   }
}

HReg hregX86_EAX ( void ) { return mkHReg(0, HRcInt, False); }
HReg hregX86_EBX ( void ) { return mkHReg(3, HRcInt, False); }
HReg hregX86_ECX ( void ) { return mkHReg(1, HRcInt, False); }
HReg hregX86_EDX ( void ) { return mkHReg(2, HRcInt, False); }
HReg hregX86_ESP ( void ) { return mkHReg(4, HRcInt, False); }
HReg hregX86_EBP ( void ) { return mkHReg(5, HRcInt, False); }
HReg hregX86_ESI ( void ) { return mkHReg(6, HRcInt, False); }
HReg hregX86_EDI ( void ) { return mkHReg(7, HRcInt, False); }

void getAllocableRegs_X86 ( Int* nregs, HReg** arr )
{
   *nregs = 6;
   *arr = LibVEX_Alloc(*nregs * sizeof(HReg));
   (*arr)[0] = hregX86_EAX();
   (*arr)[1] = hregX86_EBX();
   (*arr)[2] = hregX86_ECX();
   (*arr)[3] = hregX86_EDX();
   (*arr)[4] = hregX86_ESI();
   (*arr)[5] = hregX86_EDI();
}


/* --------- Condition codes, Intel encoding. --------- */

Char* showX86CondCode ( X86CondCode cond )
{
   switch (cond) {
      case Xcc_O:      return "o";
      case Xcc_NO:     return "no";
      case Xcc_B:      return "b";
      case Xcc_NB:     return "nb";
      case Xcc_Z:      return "z";
      case Xcc_NZ:     return "nz";
      case Xcc_BE:     return "be";
      case Xcc_NBE:    return "nbe";
      case Xcc_S:      return "s";
      case Xcc_NS:     return "ns";
      case Xcc_P:      return "p";
      case Xcc_NP:     return "np";
      case Xcc_L:      return "l";
      case Xcc_NL:     return "nl";
      case Xcc_LE:     return "le";
      case Xcc_NLE:    return "nle";
      case Xcc_ALWAYS: return "ALWAYS";
      default: vpanic("ppX86CondCode");
   }
}


/* --------- X86AMode: memory address expressions. --------- */

X86AMode* X86AMode_IR ( UInt imm32, HReg reg ) {
   X86AMode* am = LibVEX_Alloc(sizeof(X86AMode));
   am->tag = Xam_IR;
   am->Xam.IR.imm = imm32;
   am->Xam.IR.reg = reg;
   return am;
}
X86AMode* X86AMode_IRRS ( UInt imm32, HReg base, HReg index, Int shift ) {
   X86AMode* am = LibVEX_Alloc(sizeof(X86AMode));
   am->tag = Xam_IRRS;
   am->Xam.IRRS.imm = imm32;
   am->Xam.IRRS.base = base;
   am->Xam.IRRS.index = index;
   am->Xam.IRRS.shift = shift;
   vassert(shift >= 0 && shift <= 3);
   return am;
}

void ppX86AMode ( X86AMode* am ) {
   switch (am->tag) {
      case Xam_IR: 
         if (am->Xam.IR.imm == 0)
            vex_printf("(");
         else
            vex_printf("0x%x(", am->Xam.IR.imm);
         ppHRegX86(am->Xam.IR.reg);
         vex_printf(")");
         return;
      case Xam_IRRS:
         vex_printf("0x%x(", am->Xam.IRRS.imm);
         ppHRegX86(am->Xam.IRRS.base);
         vex_printf(",");
         ppHRegX86(am->Xam.IRRS.index);
         vex_printf(",%d)", 1 << am->Xam.IRRS.shift);
         return;
      default:
         vpanic("ppX86AMode");
   }
}

static void addRegUsage_X86AMode ( HRegUsage* u, X86AMode* am ) {
   switch (am->tag) {
      case Xam_IR: 
         addHRegUse(u, HRmRead, am->Xam.IR.reg);
         return;
      case Xam_IRRS:
         addHRegUse(u, HRmRead, am->Xam.IRRS.base);
         addHRegUse(u, HRmRead, am->Xam.IRRS.index);
         return;
      default:
         vpanic("addRegUsage_X86AMode");
   }
}

static void mapRegs_X86AMode ( HRegRemap* m, X86AMode* am ) {
   switch (am->tag) {
      case Xam_IR: 
         am->Xam.IR.reg = lookupHRegRemap(m, am->Xam.IR.reg);
         return;
      case Xam_IRRS:
         am->Xam.IRRS.base = lookupHRegRemap(m, am->Xam.IRRS.base);
         am->Xam.IRRS.index = lookupHRegRemap(m, am->Xam.IRRS.index);
         return;
      default:
         vpanic("mapRegs_X86AMode");
   }
}

/* --------- Operand, which can be reg, immediate or memory. --------- */

X86RMI* X86RMI_Imm ( UInt imm32 ) {
   X86RMI* op         = LibVEX_Alloc(sizeof(X86RMI));
   op->tag            = Xrmi_Imm;
   op->Xrmi.Imm.imm32 = imm32;
   return op;
}
X86RMI* X86RMI_Reg ( HReg reg ) {
   X86RMI* op       = LibVEX_Alloc(sizeof(X86RMI));
   op->tag          = Xrmi_Reg;
   op->Xrmi.Reg.reg = reg;
   return op;
}
X86RMI* X86RMI_Mem ( X86AMode* am ) {
   X86RMI* op      = LibVEX_Alloc(sizeof(X86RMI));
   op->tag         = Xrmi_Mem;
   op->Xrmi.Mem.am = am;
   return op;
}

void ppX86RMI ( X86RMI* op ) {
   switch (op->tag) {
      case Xrmi_Imm: 
         vex_printf("$0x%x", op->Xrmi.Imm.imm32);
         return;
      case Xrmi_Reg: 
         ppHRegX86(op->Xrmi.Reg.reg);
         return;
      case Xrmi_Mem: 
         ppX86AMode(op->Xrmi.Mem.am);
         return;
     default: 
         vpanic("ppX86RMI");
   }
}

/* An X86RMI can only be used in a "read" context (what would it mean
   to write or modify a literal?) and so we enumerate its registers
   accordingly. */
static void addRegUsage_X86RMI ( HRegUsage* u, X86RMI* op ) {
   switch (op->tag) {
      case Xrmi_Imm: 
         return;
      case Xrmi_Reg: 
         addHRegUse(u, HRmRead, op->Xrmi.Reg.reg);
         return;
      case Xrmi_Mem: 
         addRegUsage_X86AMode(u, op->Xrmi.Mem.am);
         return;
      default: 
         vpanic("addRegUsage_X86RMI");
   }
}

static void mapRegs_X86RMI ( HRegRemap* m, X86RMI* op ) {
   switch (op->tag) {
      case Xrmi_Imm: 
         return;
      case Xrmi_Reg: 
         op->Xrmi.Reg.reg = lookupHRegRemap(m, op->Xrmi.Reg.reg);
         return;
      case Xrmi_Mem: 
         mapRegs_X86AMode(m, op->Xrmi.Mem.am);
         return;
      default: 
         vpanic("mapRegs_X86RMI");
   }
}


/* --------- Operand, which can be reg or immediate only. --------- */

X86RI* X86RI_Imm ( UInt imm32 ) {
   X86RI* op         = LibVEX_Alloc(sizeof(X86RI));
   op->tag           = Xri_Imm;
   op->Xri.Imm.imm32 = imm32;
   return op;
}
X86RI* X86RI_Reg ( HReg reg ) {
   X86RI* op       = LibVEX_Alloc(sizeof(X86RI));
   op->tag         = Xri_Reg;
   op->Xri.Reg.reg = reg;
   return op;
}

void ppX86RI ( X86RI* op ) {
   switch (op->tag) {
      case Xri_Imm: 
         vex_printf("$0x%x", op->Xri.Imm.imm32);
         return;
      case Xri_Reg: 
         ppHRegX86(op->Xri.Reg.reg);
         return;
     default: 
         vpanic("ppX86RI");
   }
}

/* An X86RI can only be used in a "read" context (what would it mean
   to write or modify a literal?) and so we enumerate its registers
   accordingly. */
static void addRegUsage_X86RI ( HRegUsage* u, X86RI* op ) {
   switch (op->tag) {
      case Xri_Imm: 
         return;
      case Xri_Reg: 
         addHRegUse(u, HRmRead, op->Xri.Reg.reg);
         return;
      default: 
         vpanic("addRegUsage_X86RI");
   }
}

static void mapRegs_X86RI ( HRegRemap* m, X86RI* op ) {
   switch (op->tag) {
      case Xri_Imm: 
         return;
      case Xri_Reg: 
         op->Xri.Reg.reg = lookupHRegRemap(m, op->Xri.Reg.reg);
         return;
      default: 
         vpanic("mapRegs_X86RI");
   }
}


/* --------- Operand, which can be reg or memory only. --------- */

X86RM* X86RM_Reg ( HReg reg ) {
   X86RM* op       = LibVEX_Alloc(sizeof(X86RM));
   op->tag         = Xrm_Reg;
   op->Xrm.Reg.reg = reg;
   return op;
}
X86RM* X86RM_Mem ( X86AMode* am ) {
   X86RM* op      = LibVEX_Alloc(sizeof(X86RM));
   op->tag        = Xrm_Mem;
   op->Xrm.Mem.am = am;
   return op;
}

void ppX86RM ( X86RM* op ) {
   switch (op->tag) {
      case Xrm_Mem: 
         ppX86AMode(op->Xrm.Mem.am);
         return;
      case Xrm_Reg: 
         ppHRegX86(op->Xrm.Reg.reg);
         return;
     default: 
         vpanic("ppX86RM");
   }
}

/* Because an X86RM can be both a source or destination operand, we
   have to supply a mode -- pertaining to the operand as a whole --
   indicating how it's being used. */
static void addRegUsage_X86RM ( HRegUsage* u, X86RM* op, HRegMode mode ) {
   switch (op->tag) {
      case Xrm_Mem: 
         /* Memory is read, written or modified.  So we just want to
            know the regs read by the amode. */
         addRegUsage_X86AMode(u, op->Xrm.Mem.am);
         return;
      case Xrm_Reg: 
         /* reg is read, written or modified.  Add it in the
            appropriate way. */
         addHRegUse(u, mode, op->Xrm.Reg.reg);
         return;
     default: 
         vpanic("addRegUsage_X86RM");
   }
}

static void mapRegs_X86RM ( HRegRemap* m, X86RM* op )
{
   switch (op->tag) {
      case Xrm_Mem: 
         mapRegs_X86AMode(m, op->Xrm.Mem.am);
         return;
      case Xrm_Reg: 
         op->Xrm.Reg.reg = lookupHRegRemap(m, op->Xrm.Reg.reg);
         return;
     default: 
         vpanic("mapRegs_X86RM");
   }
}


/* --------- Instructions. --------- */

Char* showX86ScalarSz ( X86ScalarSz sz ) {
   switch (sz) {
      case Xss_16: return "w";
      case Xss_32: return "l";
      default: vpanic("ppX86ScalarSz");
   }
}

Char* showX86UnaryOp ( X86UnaryOp op ) {
   switch (op) {
      case Xun_Not: return "not";
      case Xun_Neg: return "neg";
      default: vpanic("ppX86UnaryOp");
   }
}

Char* showX86AluOp ( X86AluOp op ) {
   switch (op) {
      case Xalu_MOV:  return "mov";
      case Xalu_CMP:  return "cmp";
      case Xalu_TEST: return "test";
      case Xalu_ADD:  return "add";
      case Xalu_SUB:  return "sub";
      case Xalu_ADC:  return "adc";
      case Xalu_SBB:  return "sbb";
      case Xalu_AND:  return "and";
      case Xalu_OR:   return "or";
      case Xalu_XOR:  return "xor";
      case Xalu_MUL:  return "mul";
      default: vpanic("ppX86AluOp");
   }
}

Char* showX86ShiftOp ( X86ShiftOp op ) {
   switch (op) {
      case Xsh_SHL: return "shl";
      case Xsh_SHR: return "shr";
      case Xsh_SAR: return "sar";
      case Xsh_ROL: return "rol";
      case Xsh_ROR: return "ror";
      default: vpanic("ppX86ShiftOp");
   }
}

X86Instr* X86Instr_Alu32R ( X86AluOp op, X86RMI* src, HReg dst ) {
   X86Instr* i       = LibVEX_Alloc(sizeof(X86Instr));
   i->tag            = Xin_Alu32R;
   i->Xin.Alu32R.op  = op;
   i->Xin.Alu32R.src = src;
   i->Xin.Alu32R.dst = dst;
   return i;
}
X86Instr* X86Instr_Alu32M ( X86AluOp op, X86RI* src, X86AMode* dst ) {
   X86Instr* i       = LibVEX_Alloc(sizeof(X86Instr));
   i->tag            = Xin_Alu32M;
   i->Xin.Alu32M.op  = op;
   i->Xin.Alu32M.src = src;
   i->Xin.Alu32M.dst = dst;
   return i;
}
X86Instr* X86Instr_Unary32  ( X86UnaryOp op, X86RM* dst ) {
   X86Instr* i        = LibVEX_Alloc(sizeof(X86Instr));
   i->tag             = Xin_Unary32;
   i->Xin.Unary32.op  = op;
   i->Xin.Unary32.dst = dst;
   return i;
}
X86Instr* X86Instr_MulL ( Bool syned, X86ScalarSz ssz , X86RM* src ) {
   X86Instr* i        = LibVEX_Alloc(sizeof(X86Instr));
   i->tag             = Xin_MulL;
   i->Xin.MulL.syned  = syned;
   i->Xin.MulL.ssz    = ssz;
   i->Xin.MulL.src    = src;
   return i;
}
X86Instr* X86Instr_Div ( Bool syned, X86ScalarSz ssz, X86RM* src ) {
   X86Instr* i        = LibVEX_Alloc(sizeof(X86Instr));
   i->tag             = Xin_Div;
   i->Xin.Div.syned   = syned;
   i->Xin.Div.ssz     = ssz;
   i->Xin.Div.src     = src;
   return i;
}
X86Instr* X86Instr_Sh32 ( X86ShiftOp op, UInt src, X86RM* dst ) {
   X86Instr* i     = LibVEX_Alloc(sizeof(X86Instr));
   i->tag          = Xin_Sh32;
   i->Xin.Sh32.op  = op;
   i->Xin.Sh32.src = src;
   i->Xin.Sh32.dst = dst;
   return i;
}
X86Instr* X86Instr_Sh3232  ( X86ShiftOp op, UInt amt, HReg rHi, HReg rLo ) {
   X86Instr* i       = LibVEX_Alloc(sizeof(X86Instr));
   i->tag            = Xin_Sh3232;
   i->Xin.Sh3232.op  = op;
   i->Xin.Sh3232.amt = amt;
   i->Xin.Sh3232.rHi = rHi;
   i->Xin.Sh3232.rLo = rLo;
   vassert(op == Xsh_SHL || op == Xsh_SHR);
   return i;
}
X86Instr* X86Instr_Push( X86RMI* src ) {
   X86Instr* i     = LibVEX_Alloc(sizeof(X86Instr));
   i->tag          = Xin_Push;
   i->Xin.Push.src = src;
   return i;
}
X86Instr* X86Instr_Call ( HReg target ) {
   X86Instr* i        = LibVEX_Alloc(sizeof(X86Instr));
   i->tag             = Xin_Call;
   i->Xin.Call.target = target;
   return i;
}
X86Instr* X86Instr_Goto ( X86CondCode cond, X86RI* dst ) {
   X86Instr* i      = LibVEX_Alloc(sizeof(X86Instr));
   i->tag           = Xin_Goto;
   i->Xin.Goto.cond = cond;
   i->Xin.Goto.dst  = dst;
   return i;
}
X86Instr* X86Instr_CMov32  ( X86CondCode cond, X86RM* src, HReg dst ) {
   X86Instr* i        = LibVEX_Alloc(sizeof(X86Instr));
   i->tag             = Xin_CMov32;
   i->Xin.CMov32.cond = cond;
   i->Xin.CMov32.src  = src;
   i->Xin.CMov32.dst  = dst;
   vassert(cond != Xcc_ALWAYS);
   return i;
}
X86Instr* X86Instr_LoadEX ( UChar szSmall, Bool syned,
                            X86AMode* src, HReg dst ) {
   X86Instr* i           = LibVEX_Alloc(sizeof(X86Instr));
   i->tag                = Xin_LoadEX;
   i->Xin.LoadEX.szSmall = szSmall;
   i->Xin.LoadEX.syned   = syned;
   i->Xin.LoadEX.src     = src;
   i->Xin.LoadEX.dst     = dst;
   vassert(szSmall == 1 || szSmall == 2);
   return i;
}
X86Instr* X86Instr_Store  ( UChar sz, HReg src, X86AMode* dst ) {
   X86Instr* i      = LibVEX_Alloc(sizeof(X86Instr));
   i->tag           = Xin_Store;
   i->Xin.Store.sz  = sz;
   i->Xin.Store.src = src;
   i->Xin.Store.dst = dst;
   vassert(sz == 1 || sz == 2);
   return i;
}


void ppX86Instr ( X86Instr* i ) {
   switch (i->tag) {
      case Xin_Alu32R:
         vex_printf("%sl ", showX86AluOp(i->Xin.Alu32R.op));
         ppX86RMI(i->Xin.Alu32R.src);
         vex_printf(",");
         ppHRegX86(i->Xin.Alu32R.dst);
         return;
      case Xin_Alu32M:
         vex_printf("%sl ", showX86AluOp(i->Xin.Alu32M.op));
         ppX86RI(i->Xin.Alu32M.src);
         vex_printf(",");
         ppX86AMode(i->Xin.Alu32M.dst);
         return;
      case Xin_Unary32:
         vex_printf("%sl ", showX86UnaryOp(i->Xin.Unary32.op));
         ppX86RM(i->Xin.Unary32.dst);
         return;
      case Xin_MulL:
         vex_printf("%cmul%s ",
                    i->Xin.MulL.syned ? 's' : 'u',
                    showX86ScalarSz(i->Xin.MulL.ssz));
         ppX86RM(i->Xin.MulL.src);
         return;
      case Xin_Div:
         vex_printf("%cdiv%s ",
                    i->Xin.Div.syned ? 's' : 'u',
                    showX86ScalarSz(i->Xin.Div.ssz));
         ppX86RM(i->Xin.Div.src);
         return;
      case Xin_Sh32:
         vex_printf("%sl ", showX86ShiftOp(i->Xin.Sh32.op));
         if (i->Xin.Sh32.src == 0)
           vex_printf(" %%cl,"); 
         else 
            vex_printf(" $%d,", i->Xin.Sh32.src);
         ppX86RM(i->Xin.Sh32.dst);
         return;
      case Xin_Sh3232:
         vex_printf("%sdl ", showX86ShiftOp(i->Xin.Sh3232.op));
         if (i->Xin.Sh3232.amt == 0)
           vex_printf(" %%cl,"); 
         else 
            vex_printf(" $%d,", i->Xin.Sh3232.amt);
         ppHRegX86(i->Xin.Sh3232.rLo);
         vex_printf(",");
         ppHRegX86(i->Xin.Sh3232.rHi);
         return;
      case Xin_Push:
         vex_printf("pushl ");
         ppX86RMI(i->Xin.Push.src);
         return;
      case Xin_Call:
         vex_printf("call *");
         ppHRegX86(i->Xin.Call.target);
         break;
      case Xin_Goto:
         if (i->Xin.Goto.cond == Xcc_ALWAYS) {
            vex_printf("movl ");
            ppX86RI(i->Xin.Goto.dst);
            vex_printf(",%%eax ; ret");
         } else {
            vex_printf("if (%%eflags.%s) { movl ", 
                       showX86CondCode(i->Xin.Goto.cond));
            ppX86RI(i->Xin.Goto.dst);
            vex_printf(",%%eax ; ret }");
         }
         return;
      case Xin_CMov32:
         vex_printf("cmovl%s ", showX86CondCode(i->Xin.CMov32.cond));
         ppX86RM(i->Xin.CMov32.src);
         vex_printf(",");
         ppHRegX86(i->Xin.CMov32.dst);
         return;
      case Xin_LoadEX:
         vex_printf("mov%c%cl ",
                    i->Xin.LoadEX.syned ? 's' : 'z',
                    i->Xin.LoadEX.szSmall==1 ? 'b' : 'w');
         ppX86AMode(i->Xin.LoadEX.src);
         vex_printf(",");
         ppHRegX86(i->Xin.LoadEX.dst);
         return;
      case Xin_Store:
         vex_printf("mov%c ", i->Xin.Store.sz==1 ? 'b' : 'w');
         ppHRegX86(i->Xin.Store.src);
         vex_printf(",");
         ppX86AMode(i->Xin.Store.dst);
         return;
      default:
         vpanic("ppX86Instr");
   }
}

/* --------- Helpers for register allocation. --------- */

void getRegUsage_X86Instr (HRegUsage* u, X86Instr* i)
{
   initHRegUsage(u);
   switch (i->tag) {
      case Xin_Alu32R:
         addRegUsage_X86RMI(u, i->Xin.Alu32R.src);
         if (i->Xin.Alu32R.op == Xalu_MOV) {
            addHRegUse(u, HRmWrite,  i->Xin.Alu32R.dst);
            return;
         }
         if (i->Xin.Alu32R.op == Xalu_CMP 
             || i->Xin.Alu32R.op == Xalu_TEST) {
            addHRegUse(u, HRmRead,  i->Xin.Alu32R.dst);
            return;
         }
         addHRegUse(u, HRmModify, i->Xin.Alu32R.dst);
         return;
      case Xin_Alu32M:
         addRegUsage_X86RI(u, i->Xin.Alu32M.src);
         addRegUsage_X86AMode(u, i->Xin.Alu32M.dst);
         return;
      case Xin_Unary32:
         addRegUsage_X86RM(u, i->Xin.Unary32.dst, HRmModify);
         return;
      case Xin_MulL:
         addRegUsage_X86RM(u, i->Xin.MulL.src, HRmRead);
         addHRegUse(u, HRmModify, hregX86_EAX());
         addHRegUse(u, HRmWrite, hregX86_EDX());
         return;
      case Xin_Div:
         addRegUsage_X86RM(u, i->Xin.Div.src, HRmRead);
         addHRegUse(u, HRmModify, hregX86_EAX());
         addHRegUse(u, HRmModify, hregX86_EDX());
         return;
      case Xin_Sh32:
         addRegUsage_X86RM(u, i->Xin.Sh32.dst, HRmModify);
         if (i->Xin.Sh32.src == 0)
            addHRegUse(u, HRmRead, hregX86_ECX());
         return;
      case Xin_Sh3232:
         addHRegUse(u, HRmRead, i->Xin.Sh3232.rLo);
         addHRegUse(u, HRmModify, i->Xin.Sh3232.rHi);
         if (i->Xin.Sh3232.amt == 0)
            addHRegUse(u, HRmRead, hregX86_ECX());
         return;
      case Xin_Push:
         addRegUsage_X86RMI(u, i->Xin.Push.src);
         addHRegUse(u, HRmModify, hregX86_ESP());
         return;
      case Xin_Call:
         addHRegUse(u, HRmRead, i->Xin.Call.target);
         /* claim it trashes all the callee-saved regs */
         /* except I have no idea what they are */
         addHRegUse(u, HRmWrite, hregX86_EAX());
         addHRegUse(u, HRmWrite, hregX86_ECX());
         addHRegUse(u, HRmWrite, hregX86_EDX());
         return;
      case Xin_Goto:
         addRegUsage_X86RI(u, i->Xin.Goto.dst);
         addHRegUse(u, HRmWrite, hregX86_EAX());
         return;
      case Xin_CMov32:
         addRegUsage_X86RM(u, i->Xin.CMov32.src, HRmRead);
         addHRegUse(u, HRmModify, i->Xin.CMov32.dst);
         return;
      case Xin_LoadEX:
         addRegUsage_X86AMode(u, i->Xin.LoadEX.src);
         addHRegUse(u, HRmWrite, i->Xin.LoadEX.dst);
         return;
      case Xin_Store:
         addHRegUse(u, HRmRead, i->Xin.Store.src);
         addRegUsage_X86AMode(u, i->Xin.Store.dst);
         return;
      default:
         ppX86Instr(i);
         vpanic("getRegUsage_X86Instr");
   }
}

/* local helper */
static void mapReg(HRegRemap* m, HReg* r)
{
   *r = lookupHRegRemap(m, *r);
}

void mapRegs_X86Instr (HRegRemap* m, X86Instr* i)
{
   switch (i->tag) {
      case Xin_Alu32R:
         mapRegs_X86RMI(m, i->Xin.Alu32R.src);
         mapReg(m, &i->Xin.Alu32R.dst);
         return;
      case Xin_Alu32M:
         mapRegs_X86RI(m, i->Xin.Alu32M.src);
         mapRegs_X86AMode(m, i->Xin.Alu32M.dst);
         return;
      case Xin_Unary32:
         mapRegs_X86RM(m, i->Xin.Unary32.dst);
         return;
      case Xin_MulL:
         mapRegs_X86RM(m, i->Xin.MulL.src);
         return;
      case Xin_Div:
         mapRegs_X86RM(m, i->Xin.Div.src);
         return;
      case Xin_Sh32:
         mapRegs_X86RM(m, i->Xin.Sh32.dst);
         return;
      case Xin_Sh3232:
         mapReg(m, &i->Xin.Sh3232.rLo);
         mapReg(m, &i->Xin.Sh3232.rHi);
         return;
      case Xin_Push:
         mapRegs_X86RMI(m, i->Xin.Push.src);
         return;
      case Xin_Call:
         mapReg(m, &i->Xin.Call.target);
         return;
      case Xin_Goto:
         mapRegs_X86RI(m, i->Xin.Goto.dst);
         return;
      case Xin_CMov32:
         mapRegs_X86RM(m, i->Xin.CMov32.src);
         mapReg(m, &i->Xin.CMov32.dst);
         return;
      case Xin_LoadEX:
         mapRegs_X86AMode(m, i->Xin.LoadEX.src);
         mapReg(m, &i->Xin.LoadEX.dst);
         return;
      case Xin_Store:
         mapReg(m, &i->Xin.Store.src);
         mapRegs_X86AMode(m, i->Xin.Store.dst);
         return;
      default:
         ppX86Instr(i);
         vpanic("mapRegs_X86Instr");
   }
}

Bool isMove_X86Instr ( X86Instr* i, HReg* src, HReg* dst )
{
   if (i->tag != Xin_Alu32R)
      return False;
   if (i->Xin.Alu32R.op != Xalu_MOV)
      return False;
   if (i->Xin.Alu32R.src->tag != Xrmi_Reg)
      return False;
   *src = i->Xin.Alu32R.src->Xrmi.Reg.reg;
   *dst = i->Xin.Alu32R.dst;
   return True;
}

X86Instr* genSpill_X86 ( HReg rreg, Int offset )
{
   vassert(!hregIsVirtual(rreg));
   switch (hregClass(rreg)) {
      case HRcInt:
        return
        X86Instr_Alu32M ( Xalu_MOV, X86RI_Reg(rreg), 
                          X86AMode_IR(offset + 0x1000, 
                                      hregX86_EBP()));
      default: 
         ppHRegClass(hregClass(rreg));
         vpanic("genSpill_X86: unimplemented regclass");
   }
}

X86Instr* genReload_X86 ( HReg rreg, Int offset )
{
   vassert(!hregIsVirtual(rreg));
   switch (hregClass(rreg)) {
      case HRcInt:
        return
        X86Instr_Alu32R ( Xalu_MOV, 
                          X86RMI_Mem(X86AMode_IR(offset + 0x1000, 
                                                 hregX86_EBP())),
                          rreg );
      default: 
         ppHRegClass(hregClass(rreg));
         vpanic("genReload_X86: unimplemented regclass");
   }
}


/* --------- The x86 assembler (bleh.) --------- */

static UInt iregNo ( HReg r )
{
   UInt n;
   vassert(hregClass(r) == HRcInt);
   vassert(!hregIsVirtual(r));
   n = hregNumber(r);
   vassert(n <= 7);
   return n;
}

static UChar mkModRegRM ( UChar mod, UChar reg, UChar regmem )
{
   return ((mod & 3) << 6) | ((reg & 7) << 3) | (regmem & 7);
}

static UChar mkSIB ( Int shift, Int regindex, Int regbase )
{
   return ((shift & 3) << 6) | ((regindex & 7) << 3) | (regbase & 7);
}

static UChar* emit32 ( UChar* p, UInt w32 )
{
   *p++ = (w32)       & 0x000000FF;
   *p++ = (w32 >>  8) & 0x000000FF;
   *p++ = (w32 >> 16) & 0x000000FF;
   *p++ = (w32 >> 24) & 0x000000FF;
   return p;
}

/* Does a sign-extend of the lowest 8 bits give 
   the original number? */
static Bool fits8bits ( UInt w32 )
{
   Int i32 = (Int)w32;
   return i32 == ((i32 << 24) >> 24);
}


/* Forming mod-reg-rm bytes and scale-index-base bytes.

     greg,  0(ereg)    |  ereg != ESP && ereg != EBP
                       =  00 greg ereg

     greg,  d8(ereg)   |  ereg != ESP
                       =  01 greg ereg, d8

     greg,  d32(ereg)  |  ereg != ESP
                       =  10 greg ereg, d32

     -----------------------------------------------

     greg,  d8(base,index,scale)  
               |  index != ESP
               =  01 greg 100, scale index base, d8

     greg,  d32(base,index,scale)
               |  index != ESP
               =  10 greg 100, scale index base, d32
*/
static UChar* doAMode_M ( UChar* p, HReg greg, X86AMode* am ) 
{
   if (am->tag == Xam_IR) {
      if (am->Xam.IR.imm == 0 
          && am->Xam.IR.reg != hregX86_ESP()
          && am->Xam.IR.reg != hregX86_EBP() ) {
         *p++ = mkModRegRM(0, iregNo(greg), iregNo(am->Xam.IR.reg));
         return p;
      }
      if (fits8bits(am->Xam.IR.imm)
          && am->Xam.IR.reg != hregX86_ESP()) {
         *p++ = mkModRegRM(1, iregNo(greg), iregNo(am->Xam.IR.reg));
         *p++ = am->Xam.IR.imm & 0xFF;
         return p;
      }
      if (am->Xam.IR.reg != hregX86_ESP()) {
         *p++ = mkModRegRM(2, iregNo(greg), iregNo(am->Xam.IR.reg));
         p = emit32(p, am->Xam.IR.imm);
         return p;
      }
      ppX86AMode(am);
      vpanic("doAMode_M: can't emit amode IR");
      /*NOTREACHED*/
   }
   if (am->tag == Xam_IRRS) {
      if (fits8bits(am->Xam.IRRS.imm)
          && am->Xam.IRRS.index != hregX86_ESP()) {
         *p++ = mkModRegRM(1, iregNo(greg), 4);
         *p++ = mkSIB(am->Xam.IRRS.shift, am->Xam.IRRS.index, 
                                          am->Xam.IRRS.base);
         *p++ = am->Xam.IRRS.imm & 0xFF;
         return p;
      }
      if (am->Xam.IRRS.index != hregX86_ESP()) {
         *p++ = mkModRegRM(2, iregNo(greg), 4);
         *p++ = mkSIB(am->Xam.IRRS.shift, am->Xam.IRRS.index,
                                          am->Xam.IRRS.base);
         p = emit32(p, am->Xam.IRRS.imm);
         return p;
      }
      ppX86AMode(am);
      vpanic("doAMode_M: can't emit amode IRRS");
      /*NOTREACHED*/
   }
   vpanic("doAMode_M: unknown amode");
   /*NOTREACHED*/
}


/* Emit a mod-reg-rm byte when the rm bit denotes a reg. */
static UChar* doAMode_R ( UChar* p, HReg greg, HReg ereg ) 
{
   *p++ = mkModRegRM(3, iregNo(greg), iregNo(ereg));
   return p;
}


/* Emit an instruction into buf and return the number of bytes used.
   Note that buf is not the insn's final place, and therefore it is
   imperative to emit position-independent code. */

Int emit_X86Instr ( UChar* buf, Int nbuf, X86Instr* i )
{
  UInt opc, opc_rr, subopc_imm, opc_imma;

   UChar* p = &buf[0];
   vassert(nbuf >= 32);

   /* Wrap an integer as a int register, for use assembling
      GrpN insns, in which the greg field is used as a sub-opcode
      and does not really contain a register. */
#  define fake(_n) mkHReg((_n), HRcInt, False)

   switch (i->tag) {

   case Xin_Alu32R:
      /* Deal specially with MOV */
      if (i->Xin.Alu32R.op == Xalu_MOV) {
         switch (i->Xin.Alu32R.src->tag) {
            case Xrmi_Imm:
               *p++ = 0xB8 + iregNo(i->Xin.Alu32R.dst);
               p = emit32(p, i->Xin.Alu32R.src->Xrmi.Imm.imm32);
               goto done;
            case Xrmi_Reg:
              *p++ = 0x89;
              p = doAMode_R(p, i->Xin.Alu32R.src->Xrmi.Reg.reg,
                            i->Xin.Alu32R.dst);
              goto done;
            case Xrmi_Mem:
               *p++ = 0x8B;
               p = doAMode_M(p, i->Xin.Alu32R.dst, 
                                i->Xin.Alu32R.src->Xrmi.Mem.am);
               goto done;
            default:
               goto bad;
         }
      }
      /* ADD/SUB/ADC/SBB/AND/OR/XOR/TEST/CMP */
      opc = opc_rr = subopc_imm = opc_imma = 0;
      switch (i->Xin.Alu32R.op) {
         case Xalu_ADD: opc = 0x03; opc_rr = 0x01; 
                        subopc_imm = 0; opc_imma = 0x05; break;
         case Xalu_SUB: opc = 0x2B; opc_rr = 0x29; 
                        subopc_imm = 5; opc_imma = 0x2D; break;
         default: goto bad;
      }
      switch (i->Xin.Alu32R.src->tag) {
         case Xrmi_Imm:
            if (i->Xin.Alu32R.dst == hregX86_EAX()
                && !fits8bits(i->Xin.Alu32R.src->Xrmi.Imm.imm32)) {
               *p++ = opc_imma;
               p = emit32(p, i->Xin.Alu32R.src->Xrmi.Imm.imm32);
            } else
               if (fits8bits(i->Xin.Alu32R.src->Xrmi.Imm.imm32)) {
               *p++ = 0x83; 
               p    = doAMode_R(p, fake(subopc_imm), i->Xin.Alu32R.dst);
               *p++ = 0xFF & i->Xin.Alu32R.src->Xrmi.Imm.imm32;
            } else {
               *p++ = 0x81; 
               p    = doAMode_R(p, fake(subopc_imm), i->Xin.Alu32R.dst);
               p    = emit32(p, i->Xin.Alu32R.src->Xrmi.Imm.imm32);
            }
            goto done;
         case Xrmi_Reg:
            *p++ = opc_rr;
            p = doAMode_R(p, i->Xin.Alu32R.src->Xrmi.Reg.reg,
                             i->Xin.Alu32R.dst);
            goto done;
         case Xrmi_Mem:
            *p++ = opc;
            p = doAMode_M(p, i->Xin.Alu32R.dst,
                             i->Xin.Alu32R.src->Xrmi.Mem.am);
            goto done;
         default: 
            goto bad;
      }
      break;

   case Xin_Alu32M:
      /* Deal specially with MOV */
      if (i->Xin.Alu32M.op == Xalu_MOV) {
         switch (i->Xin.Alu32M.src->tag) {
            case Xri_Reg:
               *p++ = 0x89;
               p = doAMode_M(p, i->Xin.Alu32M.src->Xri.Reg.reg,
                                i->Xin.Alu32M.dst);
               goto done;
            case Xri_Imm:
               *p++ = 0xC7;
               p = doAMode_M(p, fake(0), i->Xin.Alu32M.dst);
               p = emit32(p, i->Xin.Alu32M.src->Xri.Imm.imm32);
               goto done;
            default: 
               goto bad;
         }
      }
      /* ADD/SUB/ADC/SBB/AND/OR/XOR/TEST/CMP */
      opc = subopc_imm = opc_imma = 0;
      switch (i->Xin.Alu32M.op) {
         case Xalu_ADD: opc = 0x01; subopc_imm = 0; break;
         default: goto bad;
      }
      switch (i->Xin.Alu32M.src->tag) {
         case Xri_Reg:
            *p++ = opc;
            p = doAMode_M(p, i->Xin.Alu32M.src->Xri.Reg.reg,
                             i->Xin.Alu32M.dst);
            goto done;
         case Xri_Imm:
            if (fits8bits(i->Xin.Alu32M.src->Xri.Imm.imm32)) {
               *p++ = 0x83;
               p    = doAMode_M(p, fake(subopc_imm), i->Xin.Alu32M.dst);
               *p++ = 0xFF & i->Xin.Alu32M.src->Xri.Imm.imm32;
               goto done;
            } else {
               *p++ = 0x81;
               p    = doAMode_M(p, fake(subopc_imm), i->Xin.Alu32M.dst);
               p    = emit32(p, i->Xin.Alu32M.src->Xri.Imm.imm32);
               goto done;
            }
         default: 
            goto bad;
      }
      break;

   default: 
      goto bad;
   }

  bad:
   ppX86Instr(i);
   vpanic("emit_X86Instr");
   /*NOTREACHED*/
   
  done:
   vassert(p - &buf[0] <= 32);
   return p - &buf[0];

#   undef fake
}


/* Self-contained test; can be called directly from
   main. */
void test_asm86 ( void )
{
  UChar buf[32];
  Int i, n;
  HReg edi = hregX86_EDI();
  HReg esi = hregX86_ESI();
  HReg ecx = hregX86_ECX();
  HReg ebp = hregX86_EBP();
  HReg eax = hregX86_EAX();
  HReg esp = hregX86_ESP();

#define T(_iii)                                        \
  do { X86Instr* iii = _iii;                        \
       vex_printf("\n   ");                        \
       ppX86Instr(iii);                                \
       vex_printf("\n   ");                        \
       n = emit_X86Instr( buf, 32, iii );        \
       for (i = 0; i < n; i++) {                \
           if (buf[i] < 0x10)                   \
              vex_printf("0%x ", (Int)buf[i]);  \
           else                                 \
              vex_printf("%x ", (Int)buf[i]);        \
       }                                        \
       vex_printf("\n");                        \
  } while (0)

#if 0
T( X86Instr_Alu32R(Xalu_MOV, X86RMI_Reg(esi), edi) );
T( X86Instr_Alu32R(Xalu_MOV, X86RMI_Imm(0x12345678), edi) );
T( X86Instr_Alu32R(Xalu_MOV, X86RMI_Mem(X86AMode_IR(0,esi)), edi) );
T( X86Instr_Alu32R(Xalu_MOV, X86RMI_Mem(X86AMode_IR(0,ebp)), edi) );
T( X86Instr_Alu32R(Xalu_MOV, X86RMI_Mem(X86AMode_IR(1,esi)), edi) );
T( X86Instr_Alu32R(Xalu_MOV, X86RMI_Mem(X86AMode_IR(1,ebp)), edi) );
T( X86Instr_Alu32R(Xalu_MOV, X86RMI_Mem(X86AMode_IR(127,esi)), edi) );
T( X86Instr_Alu32R(Xalu_MOV, X86RMI_Mem(X86AMode_IR(256,esi)), edi) );
T( X86Instr_Alu32R(Xalu_MOV, X86RMI_Mem(X86AMode_IRRS(1,esi,ecx,0)), edi) );
T( X86Instr_Alu32R(Xalu_MOV, X86RMI_Mem(X86AMode_IRRS(1,esi,ecx,3)), edi) );
T( X86Instr_Alu32R(Xalu_MOV, X86RMI_Mem(X86AMode_IRRS(127,esi,ecx,3)), edi) );
T( X86Instr_Alu32R(Xalu_MOV, X86RMI_Mem(X86AMode_IRRS(256,esi,ecx,3)), edi) );
#endif

#if 0
T( X86Instr_Alu32M(Xalu_MOV, X86RI_Imm(9), X86AMode_IR(0,esi)) );
T( X86Instr_Alu32M(Xalu_MOV, X86RI_Reg(edi), X86AMode_IR(0,esi)) );
T( X86Instr_Alu32M(Xalu_MOV, X86RI_Imm(999), X86AMode_IRRS(256,esi,ecx,3)) );
T( X86Instr_Alu32M(Xalu_MOV, X86RI_Reg(ebp), X86AMode_IRRS(256,esi,ecx,3)) );
#endif

#if 0
T( X86Instr_Alu32R(Xalu_ADD, X86RMI_Imm(0x42), eax) );
T( X86Instr_Alu32R(Xalu_ADD, X86RMI_Imm(0x41424344), eax) );
T( X86Instr_Alu32R(Xalu_ADD, X86RMI_Imm(0x42), esp) );
T( X86Instr_Alu32R(Xalu_ADD, X86RMI_Imm(0x41424344), esp) );
T( X86Instr_Alu32R(Xalu_ADD, X86RMI_Reg(esi), edi) );
T( X86Instr_Alu32R(Xalu_ADD, X86RMI_Mem(X86AMode_IR(1,esi)), edi) );
#endif

#if 0
T( X86Instr_Alu32R(Xalu_SUB, X86RMI_Imm(0x42), eax) );
T( X86Instr_Alu32R(Xalu_SUB, X86RMI_Imm(0x41424344), eax) );
T( X86Instr_Alu32R(Xalu_SUB, X86RMI_Imm(0x42), esp) );
T( X86Instr_Alu32R(Xalu_SUB, X86RMI_Imm(0x41424344), esp) );
T( X86Instr_Alu32R(Xalu_SUB, X86RMI_Reg(esi), edi) );
T( X86Instr_Alu32R(Xalu_SUB, X86RMI_Mem(X86AMode_IR(1,esi)), edi) );
#endif

#if 0
T( X86Instr_Alu32M(Xalu_ADD, X86RI_Imm(0x42), X86AMode_IR(0x99,esi)) );
T( X86Instr_Alu32M(Xalu_ADD, X86RI_Imm(0x4243), X86AMode_IR(0x99,esi)) );
T( X86Instr_Alu32M(Xalu_ADD, X86RI_Reg(ecx), X86AMode_IR(0x99,ebp)) );
T( X86Instr_Alu32M(Xalu_ADD, X86RI_Reg(ecx), X86AMode_IR(0x80,ebp)) );
T( X86Instr_Alu32M(Xalu_ADD, X86RI_Reg(ecx), X86AMode_IR(0x7F,ebp)) );
#endif

#undef T
}


/*---------------------------------------------------------------*/
/*--- end                                         x86h_defs.c ---*/
/*---------------------------------------------------------------*/