xref: /external/valgrind/main/VEX/priv/guest_arm64_helpers.c

/*---------------------------------------------------------------*/
/*--- begin                             guest_arm64_helpers.c ---*/
/*---------------------------------------------------------------*/

/*
   This file is part of Valgrind, a dynamic binary instrumentation
   framework.

   Copyright (C) 2013-2013 OpenWorks
      info@open-works.net

   This program is free software; you can redistribute it and/or
   modify it under the terms of the GNU General Public License as
   published by the Free Software Foundation; either version 2 of the
   License, or (at your option) any later version.

   This program is distributed in the hope that it will be useful, but
   WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
   02110-1301, USA.

   The GNU General Public License is contained in the file COPYING.
*/

#include "libvex_basictypes.h"
#include "libvex_emnote.h"
#include "libvex_guest_arm64.h"
#include "libvex_ir.h"
#include "libvex.h"

#include "main_util.h"
#include "main_globals.h"
#include "guest_generic_bb_to_IR.h"
#include "guest_arm64_defs.h"


/* This file contains helper functions for arm guest code.  Calls to
   these functions are generated by the back end.  These calls are of
   course in the host machine code and this file will be compiled to
   host machine code, so that all makes sense.

   Only change the signatures of these helper functions very
   carefully.  If you change the signature here, you'll have to change
   the parameters passed to it in the IR calls constructed by
   guest_arm64_toIR.c.
*/


/* Set to 1 to get detailed profiling info about individual N, Z, C
   and V flag evaluation. */
#define PROFILE_NZCV_FLAGS 0

#if PROFILE_NZCV_FLAGS

static UInt tab_eval[ARM64G_CC_OP_NUMBER][16];
static UInt initted = 0;
static UInt tot_evals = 0;

static void initCounts ( void )
{
   UInt i, j;
   for (i = 0; i < ARM64G_CC_OP_NUMBER; i++) {
      for (j = 0; j < 16; j++) {
         tab_eval[i][j] = 0;
      }
   }
   initted = 1;
}

static void showCounts ( void )
{
   const HChar* nameCC[16]
      = { "EQ", "NE", "CS", "CC", "MI", "PL", "VS", "VC",
          "HI", "LS", "GE", "LT", "GT", "LE", "AL", "NV" };
   UInt i, j;
   ULong sum = 0;
   vex_printf("\nCC_OP          0         1         2         3    "
              "     4         5         6\n");
   vex_printf(  "--------------------------------------------------"
              "--------------------------\n");
   for (j = 0; j < 16; j++) {
      vex_printf("%2d %s  ", j, nameCC[j]);
      for (i = 0; i < ARM64G_CC_OP_NUMBER; i++) {
         vex_printf("%9d ", tab_eval[i][j]);
         sum += tab_eval[i][j];
      }
      vex_printf("\n");
   }
   vex_printf("(In total %llu calls)\n", sum);
}

#define NOTE_EVAL(_cc_op, _cond) \
   do { \
      if (!initted) initCounts(); \
      vassert( ((UInt)(_cc_op)) < ARM64G_CC_OP_NUMBER); \
      vassert( ((UInt)(_cond)) < 16); \
      tab_eval[(UInt)(_cc_op)][(UInt)(cond)]++;  \
      tot_evals++; \
      if (0 == (tot_evals & 0x7FFF)) \
        showCounts(); \
   } while (0)

#endif /* PROFILE_NZCV_FLAGS */


/* Calculate the N flag from the supplied thunk components, in the
   least significant bit of the word.  Returned bits 63:1 are zero. */
static
ULong arm64g_calculate_flag_n ( ULong cc_op, ULong cc_dep1,
                                ULong cc_dep2, ULong cc_dep3 )
{
   switch (cc_op) {
      case ARM64G_CC_OP_COPY: {
         /* (nzcv:28x0, unused, unused) */
         ULong nf   = (cc_dep1 >> ARM64G_CC_SHIFT_N) & 1;
         return nf;
      }
      case ARM64G_CC_OP_ADD32: {
         /* (argL, argR, unused) */
         UInt  argL = (UInt)cc_dep1;
         UInt  argR = (UInt)cc_dep2;
         UInt  res  = argL + argR;
         ULong nf   = (ULong)(res >> 31);
         return nf;
      }
      case ARM64G_CC_OP_ADD64: {
         /* (argL, argR, unused) */
         ULong argL = cc_dep1;
         ULong argR = cc_dep2;
         ULong res  = argL + argR;
         ULong nf   = (ULong)(res >> 63);
         return nf;
      }
      case ARM64G_CC_OP_SUB32: {
         /* (argL, argR, unused) */
         UInt  argL = (UInt)cc_dep1;
         UInt  argR = (UInt)cc_dep2;
         UInt  res  = argL - argR;
         ULong nf   = (ULong)(res >> 31);
         return nf;
      }
      case ARM64G_CC_OP_SUB64: {
         /* (argL, argR, unused) */
         ULong argL = cc_dep1;
         ULong argR = cc_dep2;
         ULong res  = argL - argR;
         ULong nf   = res >> 63;
         return nf;
      }
      case ARM64G_CC_OP_ADC32: {
         /* (argL, argR, oldC) */
         UInt  argL = cc_dep1;
         UInt  argR = cc_dep2;
         UInt  oldC = cc_dep3;
         vassert((oldC & ~1) == 0);
         UInt  res  = argL + argR + oldC;
         ULong nf   = res >> 31;
         return nf;
      }
      case ARM64G_CC_OP_ADC64: {
         /* (argL, argR, oldC) */
         ULong argL = cc_dep1;
         ULong argR = cc_dep2;
         ULong oldC = cc_dep3;
         vassert((oldC & ~1) == 0);
         ULong res  = argL + argR + oldC;
         ULong nf   = res >> 63;
         return nf;
      }
      case ARM64G_CC_OP_SBC32: {
         /* (argL, argR, oldC) */
         UInt  argL = cc_dep1;
         UInt  argR = cc_dep2;
         UInt  oldC = cc_dep3;
         vassert((oldC & ~1) == 0);
         UInt  res  = argL - argR - (oldC ^ 1);
         ULong nf   = res >> 31;
         return nf;
      }
      case ARM64G_CC_OP_SBC64: {
         /* (argL, argR, oldC) */
         ULong argL = cc_dep1;
         ULong argR = cc_dep2;
         ULong oldC = cc_dep3;
         vassert((oldC & ~1) == 0);
         ULong res  = argL - argR - (oldC ^ 1);
         ULong nf   = res >> 63;
         return nf;
      }
      case ARM64G_CC_OP_LOGIC32: {
         /* (res, unused, unused) */
         UInt  res = (UInt)cc_dep1;
         ULong nf  = res >> 31;
         return nf;
      }
      case ARM64G_CC_OP_LOGIC64: {
         /* (res, unused, unused) */
         ULong res = cc_dep1;
         ULong nf  = res >> 63;
         return nf;
      }
//ZZ       case ARMG_CC_OP_MUL: {
//ZZ          /* (res, unused, oldC:oldV) */
//ZZ          UInt res  = cc_dep1;
//ZZ          UInt nf   = res >> 31;
//ZZ          return nf;
//ZZ       }
//ZZ       case ARMG_CC_OP_MULL: {
//ZZ          /* (resLo32, resHi32, oldC:oldV) */
//ZZ          UInt resHi32 = cc_dep2;
//ZZ          UInt nf      = resHi32 >> 31;
//ZZ          return nf;
//ZZ       }
      default:
         /* shouldn't really make these calls from generated code */
         vex_printf("arm64g_calculate_flag_n"
                    "( op=%llu, dep1=0x%llx, dep2=0x%llx, dep3=0x%llx )\n",
                    cc_op, cc_dep1, cc_dep2, cc_dep3 );
         vpanic("arm64g_calculate_flag_n");
   }
}


/* Calculate the Z flag from the supplied thunk components, in the
   least significant bit of the word.  Returned bits 63:1 are zero. */
static
ULong arm64g_calculate_flag_z ( ULong cc_op, ULong cc_dep1,
                                ULong cc_dep2, ULong cc_dep3 )
{
   switch (cc_op) {
      case ARM64G_CC_OP_COPY: {
         /* (nzcv:28x0, unused, unused) */
         ULong zf   = (cc_dep1 >> ARM64G_CC_SHIFT_Z) & 1;
         return zf;
      }
      case ARM64G_CC_OP_ADD32: {
         /* (argL, argR, unused) */
         UInt  argL = (UInt)cc_dep1;
         UInt  argR = (UInt)cc_dep2;
         UInt  res  = argL + argR;
         ULong zf   = res == 0;
         return zf;
      }
      case ARM64G_CC_OP_ADD64: {
         /* (argL, argR, unused) */
         ULong argL = cc_dep1;
         ULong argR = cc_dep2;
         ULong res  = argL + argR;
         ULong zf   = res == 0;
         return zf;
      }
      case ARM64G_CC_OP_SUB32: {
         /* (argL, argR, unused) */
         UInt  argL = (UInt)cc_dep1;
         UInt  argR = (UInt)cc_dep2;
         UInt  res  = argL - argR;
         ULong zf   = res == 0;
         return zf;
      }
      case ARM64G_CC_OP_SUB64: {
         /* (argL, argR, unused) */
         ULong argL = cc_dep1;
         ULong argR = cc_dep2;
         ULong res  = argL - argR;
         ULong zf   = res == 0;
         return zf;
      }
      case ARM64G_CC_OP_ADC32: {
         /* (argL, argR, oldC) */
         UInt  argL = cc_dep1;
         UInt  argR = cc_dep2;
         UInt  oldC = cc_dep3;
         vassert((oldC & ~1) == 0);
         UInt  res  = argL + argR + oldC;
         ULong zf   = res == 0;
         return zf;
      }
      case ARM64G_CC_OP_ADC64: {
         /* (argL, argR, oldC) */
         ULong argL = cc_dep1;
         ULong argR = cc_dep2;
         ULong oldC = cc_dep3;
         vassert((oldC & ~1) == 0);
         ULong res  = argL + argR + oldC;
         ULong zf   = res == 0;
         return zf;
      }
      case ARM64G_CC_OP_SBC32: {
         /* (argL, argR, oldC) */
         UInt  argL = cc_dep1;
         UInt  argR = cc_dep2;
         UInt  oldC = cc_dep3;
         vassert((oldC & ~1) == 0);
         UInt  res  = argL - argR - (oldC ^ 1);
         ULong zf   = res == 0;
         return zf;
      }
      case ARM64G_CC_OP_SBC64: {
         /* (argL, argR, oldC) */
         ULong argL = cc_dep1;
         ULong argR = cc_dep2;
         ULong oldC = cc_dep3;
         vassert((oldC & ~1) == 0);
         ULong res  = argL - argR - (oldC ^ 1);
         ULong zf   = res == 0;
         return zf;
      }
      case ARM64G_CC_OP_LOGIC32: {
         /* (res, unused, unused) */
         UInt  res  = (UInt)cc_dep1;
         ULong zf   = res == 0;
         return zf;
      }
      case ARM64G_CC_OP_LOGIC64: {
         /* (res, unused, unused) */
         ULong res  = cc_dep1;
         ULong zf   = res == 0;
         return zf;
      }
//ZZ       case ARMG_CC_OP_MUL: {
//ZZ          /* (res, unused, oldC:oldV) */
//ZZ          UInt res  = cc_dep1;
//ZZ          UInt zf   = res == 0;
//ZZ          return zf;
//ZZ       }
//ZZ       case ARMG_CC_OP_MULL: {
//ZZ          /* (resLo32, resHi32, oldC:oldV) */
//ZZ          UInt resLo32 = cc_dep1;
//ZZ          UInt resHi32 = cc_dep2;
//ZZ          UInt zf      = (resHi32|resLo32) == 0;
//ZZ          return zf;
//ZZ       }
      default:
         /* shouldn't really make these calls from generated code */
         vex_printf("arm64g_calculate_flag_z"
                    "( op=%llu, dep1=0x%llx, dep2=0x%llx, dep3=0x%llx )\n",
                    cc_op, cc_dep1, cc_dep2, cc_dep3 );
         vpanic("arm64g_calculate_flag_z");
   }
}


/* CALLED FROM GENERATED CODE: CLEAN HELPER */
/* Calculate the C flag from the supplied thunk components, in the
   least significant bit of the word.  Returned bits 63:1 are zero. */
ULong arm64g_calculate_flag_c ( ULong cc_op, ULong cc_dep1,
                                ULong cc_dep2, ULong cc_dep3 )
{
   switch (cc_op) {
      case ARM64G_CC_OP_COPY: {
         /* (nzcv:28x0, unused, unused) */
         ULong cf = (cc_dep1 >> ARM64G_CC_SHIFT_C) & 1;
         return cf;
      }
      case ARM64G_CC_OP_ADD32: {
         /* (argL, argR, unused) */
         UInt  argL = (UInt)cc_dep1;
         UInt  argR = (UInt)cc_dep2;
         UInt  res  = argL + argR;
         ULong cf   = res < argL;
         return cf;
      }
      case ARM64G_CC_OP_ADD64: {
         /* (argL, argR, unused) */
         ULong argL = cc_dep1;
         ULong argR = cc_dep2;
         ULong res  = argL + argR;
         ULong cf   = res < argL;
         return cf;
      }
      case ARM64G_CC_OP_SUB32: {
         /* (argL, argR, unused) */
         UInt  argL = (UInt)cc_dep1;
         UInt  argR = (UInt)cc_dep2;
         ULong cf   = argL >= argR;
         return cf;
      }
      case ARM64G_CC_OP_SUB64: {
         /* (argL, argR, unused) */
         ULong argL = cc_dep1;
         ULong argR = cc_dep2;
         ULong cf   = argL >= argR;
         return cf;
      }
      case ARM64G_CC_OP_ADC32: {
         /* (argL, argR, oldC) */
         UInt  argL = cc_dep1;
         UInt  argR = cc_dep2;
         UInt  oldC = cc_dep3;
         vassert((oldC & ~1) == 0);
         UInt  res  = argL + argR + oldC;
         ULong cf   = oldC ? (res <= argL) : (res < argL);
         return cf;
      }
      case ARM64G_CC_OP_ADC64: {
         /* (argL, argR, oldC) */
         ULong argL = cc_dep1;
         ULong argR = cc_dep2;
         ULong oldC = cc_dep3;
         vassert((oldC & ~1) == 0);
         ULong res  = argL + argR + oldC;
         ULong cf   = oldC ? (res <= argL) : (res < argL);
         return cf;
      }
      case ARM64G_CC_OP_SBC32: {
         /* (argL, argR, oldC) */
         UInt  argL = cc_dep1;
         UInt  argR = cc_dep2;
         UInt  oldC = cc_dep3;
         vassert((oldC & ~1) == 0);
         ULong cf   = oldC ? (argL >= argR) : (argL > argR);
         return cf;
      }
      case ARM64G_CC_OP_SBC64: {
         /* (argL, argR, oldC) */
         ULong argL = cc_dep1;
         ULong argR = cc_dep2;
         ULong oldC = cc_dep3;
         vassert((oldC & ~1) == 0);
         ULong cf   = oldC ? (argL >= argR) : (argL > argR);
         return cf;
      }
      case ARM64G_CC_OP_LOGIC32:
      case ARM64G_CC_OP_LOGIC64: {
         /* (res, unused, unused) */
         return 0; // C after logic is zero on arm64
      }
//ZZ       case ARMG_CC_OP_MUL: {
//ZZ          /* (res, unused, oldC:oldV) */
//ZZ          UInt oldC = (cc_dep3 >> 1) & 1;
//ZZ          vassert((cc_dep3 & ~3) == 0);
//ZZ          UInt cf   = oldC;
//ZZ          return cf;
//ZZ       }
//ZZ       case ARMG_CC_OP_MULL: {
//ZZ          /* (resLo32, resHi32, oldC:oldV) */
//ZZ          UInt oldC    = (cc_dep3 >> 1) & 1;
//ZZ          vassert((cc_dep3 & ~3) == 0);
//ZZ          UInt cf      = oldC;
//ZZ          return cf;
//ZZ       }
      default:
         /* shouldn't really make these calls from generated code */
         vex_printf("arm64g_calculate_flag_c"
                    "( op=%llu, dep1=0x%llx, dep2=0x%llx, dep3=0x%llx )\n",
                    cc_op, cc_dep1, cc_dep2, cc_dep3 );
         vpanic("arm64g_calculate_flag_c");
   }
}


/* CALLED FROM GENERATED CODE: CLEAN HELPER */
/* Calculate the V flag from the supplied thunk components, in the
   least significant bit of the word.  Returned bits 63:1 are zero. */
static
ULong arm64g_calculate_flag_v ( ULong cc_op, ULong cc_dep1,
                                ULong cc_dep2, ULong cc_dep3 )
{
   switch (cc_op) {
      case ARM64G_CC_OP_COPY: {
         /* (nzcv:28x0, unused, unused) */
         ULong vf   = (cc_dep1 >> ARM64G_CC_SHIFT_V) & 1;
         return vf;
      }
      case ARM64G_CC_OP_ADD32: {
         /* (argL, argR, unused) */
         UInt  argL = (UInt)cc_dep1;
         UInt  argR = (UInt)cc_dep2;
         UInt  res  = argL + argR;
         ULong vf   = (ULong)(((res ^ argL) & (res ^ argR)) >> 31);
         return vf;
      }
      case ARM64G_CC_OP_ADD64: {
         /* (argL, argR, unused) */
         ULong argL = cc_dep1;
         ULong argR = cc_dep2;
         ULong res  = argL + argR;
         ULong vf   = ((res ^ argL) & (res ^ argR)) >> 63;
         return vf;
      }
      case ARM64G_CC_OP_SUB32: {
         /* (argL, argR, unused) */
         UInt  argL = (UInt)cc_dep1;
         UInt  argR = (UInt)cc_dep2;
         UInt  res  = argL - argR;
         ULong vf   = (ULong)(((argL ^ argR) & (argL ^ res)) >> 31);
         return vf;
      }
      case ARM64G_CC_OP_SUB64: {
         /* (argL, argR, unused) */
         ULong argL = cc_dep1;
         ULong argR = cc_dep2;
         ULong res  = argL - argR;
         ULong vf   = (((argL ^ argR) & (argL ^ res))) >> 63;
         return vf;
      }
      case ARM64G_CC_OP_ADC32: {
         /* (argL, argR, oldC) */
         UInt  argL = cc_dep1;
         UInt  argR = cc_dep2;
         UInt  oldC = cc_dep3;
         vassert((oldC & ~1) == 0);
         UInt  res  = argL + argR + oldC;
         ULong vf   = ((res ^ argL) & (res ^ argR)) >> 31;
         return vf;
      }
      case ARM64G_CC_OP_ADC64: {
         /* (argL, argR, oldC) */
         ULong argL = cc_dep1;
         ULong argR = cc_dep2;
         ULong oldC = cc_dep3;
         vassert((oldC & ~1) == 0);
         ULong res  = argL + argR + oldC;
         ULong vf   = ((res ^ argL) & (res ^ argR)) >> 63;
         return vf;
      }
      case ARM64G_CC_OP_SBC32: {
         /* (argL, argR, oldC) */
         UInt  argL = cc_dep1;
         UInt  argR = cc_dep2;
         UInt  oldC = cc_dep3;
         vassert((oldC & ~1) == 0);
         UInt  res  = argL - argR - (oldC ^ 1);
         ULong vf   = ((argL ^ argR) & (argL ^ res)) >> 31;
         return vf;
      }
      case ARM64G_CC_OP_SBC64: {
         /* (argL, argR, oldC) */
         ULong argL = cc_dep1;
         ULong argR = cc_dep2;
         ULong oldC = cc_dep3;
         vassert((oldC & ~1) == 0);
         ULong res  = argL - argR - (oldC ^ 1);
         ULong vf   = ((argL ^ argR) & (argL ^ res)) >> 63;
         return vf;
      }
      case ARM64G_CC_OP_LOGIC32:
      case ARM64G_CC_OP_LOGIC64: {
         /* (res, unused, unused) */
         return 0; // V after logic is zero on arm64
      }
//ZZ       case ARMG_CC_OP_MUL: {
//ZZ          /* (res, unused, oldC:oldV) */
//ZZ          UInt oldV = (cc_dep3 >> 0) & 1;
//ZZ          vassert((cc_dep3 & ~3) == 0);
//ZZ          UInt vf   = oldV;
//ZZ          return vf;
//ZZ       }
//ZZ       case ARMG_CC_OP_MULL: {
//ZZ          /* (resLo32, resHi32, oldC:oldV) */
//ZZ          UInt oldV    = (cc_dep3 >> 0) & 1;
//ZZ          vassert((cc_dep3 & ~3) == 0);
//ZZ          UInt vf      = oldV;
//ZZ          return vf;
//ZZ       }
      default:
         /* shouldn't really make these calls from generated code */
         vex_printf("arm64g_calculate_flag_v"
                    "( op=%llu, dep1=0x%llx, dep2=0x%llx, dep3=0x%llx )\n",
                    cc_op, cc_dep1, cc_dep2, cc_dep3 );
         vpanic("arm64g_calculate_flag_v");
   }
}


/* CALLED FROM GENERATED CODE: CLEAN HELPER */
/* Calculate NZCV from the supplied thunk components, in the positions
   they appear in the CPSR, viz bits 31:28 for N Z C V respectively.
   Returned bits 27:0 are zero. */
ULong arm64g_calculate_flags_nzcv ( ULong cc_op, ULong cc_dep1,
                                    ULong cc_dep2, ULong cc_dep3 )
{
   ULong f;
   ULong res = 0;
   f = 1 & arm64g_calculate_flag_n(cc_op, cc_dep1, cc_dep2, cc_dep3);
   res |= (f << ARM64G_CC_SHIFT_N);
   f = 1 & arm64g_calculate_flag_z(cc_op, cc_dep1, cc_dep2, cc_dep3);
   res |= (f << ARM64G_CC_SHIFT_Z);
   f = 1 & arm64g_calculate_flag_c(cc_op, cc_dep1, cc_dep2, cc_dep3);
   res |= (f << ARM64G_CC_SHIFT_C);
   f = 1 & arm64g_calculate_flag_v(cc_op, cc_dep1, cc_dep2, cc_dep3);
   res |= (f << ARM64G_CC_SHIFT_V);
   return res;
}

//ZZ
//ZZ /* CALLED FROM GENERATED CODE: CLEAN HELPER */
//ZZ /* Calculate the QC flag from the arguments, in the lowest bit
//ZZ    of the word (bit 0).  Urr, having this out of line is bizarre.
//ZZ    Push back inline. */
//ZZ UInt armg_calculate_flag_qc ( UInt resL1, UInt resL2,
//ZZ                               UInt resR1, UInt resR2 )
//ZZ {
//ZZ    if (resL1 != resR1 || resL2 != resR2)
//ZZ       return 1;
//ZZ    else
//ZZ       return 0;
//ZZ }

/* CALLED FROM GENERATED CODE: CLEAN HELPER */
/* Calculate the specified condition from the thunk components, in the
   lowest bit of the word (bit 0).  Returned bits 63:1 are zero. */
ULong arm64g_calculate_condition ( /* ARM64Condcode << 4 | cc_op */
                                   ULong cond_n_op ,
                                   ULong cc_dep1,
                                   ULong cc_dep2, ULong cc_dep3 )
{
   ULong cond  = cond_n_op >> 4;
   ULong cc_op = cond_n_op & 0xF;
   ULong inv   = cond & 1;
   ULong nf, zf, vf, cf;

#  if PROFILE_NZCV_FLAGS
   NOTE_EVAL(cc_op, cond);
#  endif

   //   vex_printf("XXXXXXXX %llx %llx %llx %llx\n",
   //              cond_n_op, cc_dep1, cc_dep2, cc_dep3);

   switch (cond) {
      case ARM64CondEQ:    // Z=1         => z
      case ARM64CondNE:    // Z=0
         zf = arm64g_calculate_flag_z(cc_op, cc_dep1, cc_dep2, cc_dep3);
         return inv ^ zf;

      case ARM64CondCS:    // C=1         => c
      case ARM64CondCC:    // C=0
         cf = arm64g_calculate_flag_c(cc_op, cc_dep1, cc_dep2, cc_dep3);
         return inv ^ cf;

      case ARM64CondMI:    // N=1         => n
      case ARM64CondPL:    // N=0
         nf = arm64g_calculate_flag_n(cc_op, cc_dep1, cc_dep2, cc_dep3);
         return inv ^ nf;

      case ARM64CondVS:    // V=1         => v
      case ARM64CondVC:    // V=0
         vf = arm64g_calculate_flag_v(cc_op, cc_dep1, cc_dep2, cc_dep3);
         return inv ^ vf;

      case ARM64CondHI:    // C=1 && Z=0   => c & ~z
      case ARM64CondLS:    // C=0 || Z=1
         cf = arm64g_calculate_flag_c(cc_op, cc_dep1, cc_dep2, cc_dep3);
         zf = arm64g_calculate_flag_z(cc_op, cc_dep1, cc_dep2, cc_dep3);
         return inv ^ (1 & (cf & ~zf));

      case ARM64CondGE:    // N=V          => ~(n^v)
      case ARM64CondLT:    // N!=V
         nf = arm64g_calculate_flag_n(cc_op, cc_dep1, cc_dep2, cc_dep3);
         vf = arm64g_calculate_flag_v(cc_op, cc_dep1, cc_dep2, cc_dep3);
         return inv ^ (1 & ~(nf ^ vf));

      case ARM64CondGT:    // Z=0 && N=V   => ~z & ~(n^v)  =>  ~(z | (n^v))
      case ARM64CondLE:    // Z=1 || N!=V
         nf = arm64g_calculate_flag_n(cc_op, cc_dep1, cc_dep2, cc_dep3);
         vf = arm64g_calculate_flag_v(cc_op, cc_dep1, cc_dep2, cc_dep3);
         zf = arm64g_calculate_flag_z(cc_op, cc_dep1, cc_dep2, cc_dep3);
         return inv ^ (1 & ~(zf | (nf ^ vf)));

      case ARM64CondAL:    // 1
      case ARM64CondNV:    // 1
         return 1;

      default:
         /* shouldn't really make these calls from generated code */
         vex_printf("arm64g_calculate_condition(ARM64)"
                    "( %llu, %llu, 0x%llx, 0x%llx, 0x%llx )\n",
                    cond, cc_op, cc_dep1, cc_dep2, cc_dep3 );
         vpanic("armg_calculate_condition(ARM64)");
   }
}


/*---------------------------------------------------------------*/
/*--- Flag-helpers translation-time function specialisers.    ---*/
/*--- These help iropt specialise calls the above run-time    ---*/
/*--- flags functions.                                        ---*/
/*---------------------------------------------------------------*/

/* Used by the optimiser to try specialisations.  Returns an
   equivalent expression, or NULL if none. */

static Bool isU64 ( IRExpr* e, ULong n )
{
   return
      toBool( e->tag == Iex_Const
              && e->Iex.Const.con->tag == Ico_U64
              && e->Iex.Const.con->Ico.U64 == n );
}

IRExpr* guest_arm64_spechelper ( const HChar* function_name,
                                 IRExpr** args,
                                 IRStmt** precedingStmts,
                                 Int      n_precedingStmts )
{
#  define unop(_op,_a1) IRExpr_Unop((_op),(_a1))
#  define binop(_op,_a1,_a2) IRExpr_Binop((_op),(_a1),(_a2))
#  define mkU64(_n) IRExpr_Const(IRConst_U64(_n))
#  define mkU8(_n)  IRExpr_Const(IRConst_U8(_n))

   Int i, arity = 0;
   for (i = 0; args[i]; i++)
      arity++;
//ZZ #  if 0
//ZZ    vex_printf("spec request:\n");
//ZZ    vex_printf("   %s  ", function_name);
//ZZ    for (i = 0; i < arity; i++) {
//ZZ       vex_printf("  ");
//ZZ       ppIRExpr(args[i]);
//ZZ    }
//ZZ    vex_printf("\n");
//ZZ #  endif

   /* --------- specialising "arm64g_calculate_condition" --------- */

   if (vex_streq(function_name, "arm64g_calculate_condition")) {

      /* specialise calls to the "arm64g_calculate_condition" function.
         Not sure whether this is strictly necessary, but: the
         replacement IR must produce only the values 0 or 1.  Bits
         63:1 are required to be zero. */
      IRExpr *cond_n_op, *cc_dep1, *cc_dep2, *cc_ndep;
      vassert(arity == 4);
      cond_n_op = args[0]; /* (ARM64Condcode << 4)  |  ARM64G_CC_OP_* */
      cc_dep1   = args[1];
      cc_dep2   = args[2];
      cc_ndep   = args[3];

      /*---------------- SUB64 ----------------*/

      /* 0, 1 */
      if (isU64(cond_n_op, (ARM64CondEQ << 4) | ARM64G_CC_OP_SUB64)) {
         /* EQ after SUB --> test argL == argR */
         return unop(Iop_1Uto64,
                     binop(Iop_CmpEQ64, cc_dep1, cc_dep2));
      }
      if (isU64(cond_n_op, (ARM64CondNE << 4) | ARM64G_CC_OP_SUB64)) {
         /* NE after SUB --> test argL != argR */
         return unop(Iop_1Uto64,
                     binop(Iop_CmpNE64, cc_dep1, cc_dep2));
      }

      /* 2, 3 */
      if (isU64(cond_n_op, (ARM64CondCS << 4) | ARM64G_CC_OP_SUB64)) {
         /* CS after SUB --> test argL >=u argR
                         --> test argR <=u argL */
         return unop(Iop_1Uto64,
                     binop(Iop_CmpLE64U, cc_dep2, cc_dep1));
      }
      if (isU64(cond_n_op, (ARM64CondCC << 4) | ARM64G_CC_OP_SUB64)) {
         /* CC after SUB --> test argL <u argR */
         return unop(Iop_1Uto64,
                     binop(Iop_CmpLT64U, cc_dep1, cc_dep2));
      }

      /* 8, 9 */
      if (isU64(cond_n_op, (ARM64CondLS << 4) | ARM64G_CC_OP_SUB64)) {
         /* LS after SUB --> test argL <=u argR */
         return unop(Iop_1Uto64,
                     binop(Iop_CmpLE64U, cc_dep1, cc_dep2));
      }
      if (isU64(cond_n_op, (ARM64CondHI << 4) | ARM64G_CC_OP_SUB64)) {
         /* HI after SUB --> test argL >u argR
                         --> test argR <u argL */
         return unop(Iop_1Uto64,
                     binop(Iop_CmpLT64U, cc_dep2, cc_dep1));
      }

      /* 10, 11 */
      if (isU64(cond_n_op, (ARM64CondLT << 4) | ARM64G_CC_OP_SUB64)) {
         /* LT after SUB --> test argL <s argR */
         return unop(Iop_1Uto64,
                     binop(Iop_CmpLT64S, cc_dep1, cc_dep2));
      }
      if (isU64(cond_n_op, (ARM64CondGE << 4) | ARM64G_CC_OP_SUB64)) {
         /* GE after SUB --> test argL >=s argR
                         --> test argR <=s argL */
         return unop(Iop_1Uto64,
                     binop(Iop_CmpLE64S, cc_dep2, cc_dep1));
      }

      /* 12, 13 */
      if (isU64(cond_n_op, (ARM64CondGT << 4) | ARM64G_CC_OP_SUB64)) {
         /* GT after SUB --> test argL >s argR
                         --> test argR <s argL */
         return unop(Iop_1Uto64,
                     binop(Iop_CmpLT64S, cc_dep2, cc_dep1));
      }
      if (isU64(cond_n_op, (ARM64CondLE << 4) | ARM64G_CC_OP_SUB64)) {
         /* LE after SUB --> test argL <=s argR */
         return unop(Iop_1Uto64,
                     binop(Iop_CmpLE64S, cc_dep1, cc_dep2));
      }

      /*---------------- SUB32 ----------------*/

      /* 0, 1 */
      if (isU64(cond_n_op, (ARM64CondEQ << 4) | ARM64G_CC_OP_SUB32)) {
         /* EQ after SUB --> test argL == argR */
         return unop(Iop_1Uto64,
                     binop(Iop_CmpEQ32, unop(Iop_64to32, cc_dep1),
                                        unop(Iop_64to32, cc_dep2)));
      }
      if (isU64(cond_n_op, (ARM64CondNE << 4) | ARM64G_CC_OP_SUB32)) {
         /* NE after SUB --> test argL != argR */
         return unop(Iop_1Uto64,
                     binop(Iop_CmpNE32, unop(Iop_64to32, cc_dep1),
                                        unop(Iop_64to32, cc_dep2)));
      }

      /* 2, 3 */
      if (isU64(cond_n_op, (ARM64CondCS << 4) | ARM64G_CC_OP_SUB32)) {
         /* CS after SUB --> test argL >=u argR
                         --> test argR <=u argL */
         return unop(Iop_1Uto64,
                     binop(Iop_CmpLE32U, unop(Iop_64to32, cc_dep2),
                                         unop(Iop_64to32, cc_dep1)));
      }
      if (isU64(cond_n_op, (ARM64CondCC << 4) | ARM64G_CC_OP_SUB32)) {
         /* CC after SUB --> test argL <u argR */
         return unop(Iop_1Uto64,
                     binop(Iop_CmpLT32U, unop(Iop_64to32, cc_dep1),
                                         unop(Iop_64to32, cc_dep2)));
      }

      /* 8, 9 */
      if (isU64(cond_n_op, (ARM64CondLS << 4) | ARM64G_CC_OP_SUB32)) {
         /* LS after SUB --> test argL <=u argR */
         return unop(Iop_1Uto64,
                     binop(Iop_CmpLE32U, unop(Iop_64to32, cc_dep1),
                                         unop(Iop_64to32, cc_dep2)));
      }
      if (isU64(cond_n_op, (ARM64CondHI << 4) | ARM64G_CC_OP_SUB32)) {
         /* HI after SUB --> test argL >u argR
                         --> test argR <u argL */
         return unop(Iop_1Uto64,
                     binop(Iop_CmpLT32U, unop(Iop_64to32, cc_dep2),
                                         unop(Iop_64to32, cc_dep1)));
      }

      /* 10, 11 */
      if (isU64(cond_n_op, (ARM64CondLT << 4) | ARM64G_CC_OP_SUB32)) {
         /* LT after SUB --> test argL <s argR */
         return unop(Iop_1Uto64,
                     binop(Iop_CmpLT32S, unop(Iop_64to32, cc_dep1),
                                         unop(Iop_64to32, cc_dep2)));
      }
      if (isU64(cond_n_op, (ARM64CondGE << 4) | ARM64G_CC_OP_SUB32)) {
         /* GE after SUB --> test argL >=s argR
                         --> test argR <=s argL */
         return unop(Iop_1Uto64,
                     binop(Iop_CmpLE32S, unop(Iop_64to32, cc_dep2),
                                         unop(Iop_64to32, cc_dep1)));
      }

      /* 12, 13 */
      if (isU64(cond_n_op, (ARM64CondGT << 4) | ARM64G_CC_OP_SUB32)) {
         /* GT after SUB --> test argL >s argR
                         --> test argR <s argL */
         return unop(Iop_1Uto64,
                     binop(Iop_CmpLT32S, unop(Iop_64to32, cc_dep2),
                                         unop(Iop_64to32, cc_dep1)));
      }
      if (isU64(cond_n_op, (ARM64CondLE << 4) | ARM64G_CC_OP_SUB32)) {
         /* LE after SUB --> test argL <=s argR */
         return unop(Iop_1Uto64,
                     binop(Iop_CmpLE32S, unop(Iop_64to32, cc_dep1),
                                         unop(Iop_64to32, cc_dep2)));
      }

      /*---------------- SBC64 ----------------*/

      if (isU64(cond_n_op, (ARM64CondCS << 4) | ARM64G_CC_OP_SBC64)) {
         /* This seems to happen a lot in softfloat code, eg __divdf3+140 */
         /* thunk is: (dep1=argL, dep2=argR, ndep=oldC) */
         /* HS after SBC (same as C after SBC below)
            --> oldC ? (argL >=u argR) : (argL >u argR)
            --> oldC ? (argR <=u argL) : (argR <u argL)
         */
         return
            IRExpr_ITE(
               binop(Iop_CmpNE64, cc_ndep, mkU64(0)),
               /* case oldC != 0 */
               unop(Iop_1Uto64, binop(Iop_CmpLE32U, cc_dep2, cc_dep1)),
               /* case oldC == 0 */
               unop(Iop_1Uto64, binop(Iop_CmpLT32U, cc_dep2, cc_dep1))
            );
      }

      /*---------------- SBC32 ----------------*/

      if (isU64(cond_n_op, (ARM64CondCS << 4) | ARM64G_CC_OP_SBC32)) {
         /* This seems to happen a lot in softfloat code, eg __divdf3+140 */
         /* thunk is: (dep1=argL, dep2=argR, ndep=oldC) */
         /* HS after SBC (same as C after SBC below)
            --> oldC ? (argL >=u argR) : (argL >u argR)
            --> oldC ? (argR <=u argL) : (argR <u argL)
         */
         return
            IRExpr_ITE(
               binop(Iop_CmpNE64, cc_ndep, mkU64(0)),
               /* case oldC != 0 */
               unop(Iop_1Uto64, binop(Iop_CmpLE32U, unop(Iop_64to32, cc_dep2),
                                                    unop(Iop_64to32, cc_dep1))),
               /* case oldC == 0 */
               unop(Iop_1Uto64, binop(Iop_CmpLT32U, unop(Iop_64to32, cc_dep2),
                                                    unop(Iop_64to32, cc_dep1)))
            );
      }

//ZZ       /*---------------- LOGIC ----------------*/
//ZZ
//ZZ       if (isU32(cond_n_op, (ARMCondEQ << 4) | ARMG_CC_OP_LOGIC)) {
//ZZ          /* EQ after LOGIC --> test res == 0 */
//ZZ          return unop(Iop_1Uto32,
//ZZ                      binop(Iop_CmpEQ32, cc_dep1, mkU32(0)));
//ZZ       }
//ZZ       if (isU32(cond_n_op, (ARMCondNE << 4) | ARMG_CC_OP_LOGIC)) {
//ZZ          /* NE after LOGIC --> test res != 0 */
//ZZ          return unop(Iop_1Uto32,
//ZZ                      binop(Iop_CmpNE32, cc_dep1, mkU32(0)));
//ZZ       }
//ZZ
//ZZ       if (isU32(cond_n_op, (ARMCondPL << 4) | ARMG_CC_OP_LOGIC)) {
//ZZ          /* PL after LOGIC --> test (res >> 31) == 0 */
//ZZ          return unop(Iop_1Uto32,
//ZZ                      binop(Iop_CmpEQ32,
//ZZ                            binop(Iop_Shr32, cc_dep1, mkU8(31)),
//ZZ                            mkU32(0)));
//ZZ       }
//ZZ       if (isU32(cond_n_op, (ARMCondMI << 4) | ARMG_CC_OP_LOGIC)) {
//ZZ          /* MI after LOGIC --> test (res >> 31) == 1 */
//ZZ          return unop(Iop_1Uto32,
//ZZ                      binop(Iop_CmpEQ32,
//ZZ                            binop(Iop_Shr32, cc_dep1, mkU8(31)),
//ZZ                            mkU32(1)));
//ZZ       }

      /*---------------- COPY ----------------*/

      if (isU64(cond_n_op, (ARM64CondEQ << 4) | ARM64G_CC_OP_COPY)) {
         /* EQ after COPY --> (cc_dep1 >> ARM64G_CC_SHIFT_Z) & 1 */
         return binop(Iop_And64,
                      binop(Iop_Shr64, cc_dep1,
                                       mkU8(ARM64G_CC_SHIFT_Z)),
                      mkU64(1));
      }
      if (isU64(cond_n_op, (ARM64CondNE << 4) | ARM64G_CC_OP_COPY)) {
         /* NE after COPY --> ((cc_dep1 >> ARM64G_CC_SHIFT_Z) ^ 1) & 1 */
         return binop(Iop_And64,
                      binop(Iop_Xor64,
                            binop(Iop_Shr64, cc_dep1,
                                             mkU8(ARM64G_CC_SHIFT_Z)),
                            mkU64(1)),
                      mkU64(1));
      }

//ZZ       /*----------------- AL -----------------*/
//ZZ
//ZZ       /* A critically important case for Thumb code.
//ZZ
//ZZ          What we're trying to spot is the case where cond_n_op is an
//ZZ          expression of the form Or32(..., 0xE0) since that means the
//ZZ          caller is asking for CondAL and we can simply return 1
//ZZ          without caring what the ... part is.  This is a potentially
//ZZ          dodgy kludge in that it assumes that the ... part has zeroes
//ZZ          in bits 7:4, so that the result of the Or32 is guaranteed to
//ZZ          be 0xE in bits 7:4.  Given that the places where this first
//ZZ          arg are constructed (in guest_arm_toIR.c) are very
//ZZ          constrained, we can get away with this.  To make this
//ZZ          guaranteed safe would require to have a new primop, Slice44
//ZZ          or some such, thusly
//ZZ
//ZZ          Slice44(arg1, arg2) = 0--(24)--0 arg1[7:4] arg2[3:0]
//ZZ
//ZZ          and we would then look for Slice44(0xE0, ...)
//ZZ          which would give the required safety property.
//ZZ
//ZZ          It would be infeasibly expensive to scan backwards through
//ZZ          the entire block looking for an assignment to the temp, so
//ZZ          just look at the previous 16 statements.  That should find it
//ZZ          if it is an interesting case, as a result of how the
//ZZ          boilerplate guff at the start of each Thumb insn translation
//ZZ          is made.
//ZZ       */
//ZZ       if (cond_n_op->tag == Iex_RdTmp) {
//ZZ          Int    j;
//ZZ          IRTemp look_for = cond_n_op->Iex.RdTmp.tmp;
//ZZ          Int    limit    = n_precedingStmts - 16;
//ZZ          if (limit < 0) limit = 0;
//ZZ          if (0) vex_printf("scanning %d .. %d\n", n_precedingStmts-1, limit);
//ZZ          for (j = n_precedingStmts - 1; j >= limit; j--) {
//ZZ             IRStmt* st = precedingStmts[j];
//ZZ             if (st->tag == Ist_WrTmp
//ZZ                 && st->Ist.WrTmp.tmp == look_for
//ZZ                 && st->Ist.WrTmp.data->tag == Iex_Binop
//ZZ                 && st->Ist.WrTmp.data->Iex.Binop.op == Iop_Or32
//ZZ                 && isU32(st->Ist.WrTmp.data->Iex.Binop.arg2, (ARMCondAL << 4)))
//ZZ                return mkU32(1);
//ZZ          }
//ZZ          /* Didn't find any useful binding to the first arg
//ZZ             in the previous 16 stmts. */
//ZZ       }
   }

//ZZ    /* --------- specialising "armg_calculate_flag_c" --------- */
//ZZ
//ZZ    else
//ZZ    if (vex_streq(function_name, "armg_calculate_flag_c")) {
//ZZ
//ZZ       /* specialise calls to the "armg_calculate_flag_c" function.
//ZZ          Note that the returned value must be either 0 or 1; nonzero
//ZZ          bits 31:1 are not allowed.  In turn, incoming oldV and oldC
//ZZ          values (from the thunk) are assumed to have bits 31:1
//ZZ          clear. */
//ZZ       IRExpr *cc_op, *cc_dep1, *cc_dep2, *cc_ndep;
//ZZ       vassert(arity == 4);
//ZZ       cc_op   = args[0]; /* ARMG_CC_OP_* */
//ZZ       cc_dep1 = args[1];
//ZZ       cc_dep2 = args[2];
//ZZ       cc_ndep = args[3];
//ZZ
//ZZ       if (isU32(cc_op, ARMG_CC_OP_LOGIC)) {
//ZZ          /* Thunk args are (result, shco, oldV) */
//ZZ          /* C after LOGIC --> shco */
//ZZ          return cc_dep2;
//ZZ       }
//ZZ
//ZZ       if (isU32(cc_op, ARMG_CC_OP_SUB)) {
//ZZ          /* Thunk args are (argL, argR, unused) */
//ZZ          /* C after SUB --> argL >=u argR
//ZZ                         --> argR <=u argL */
//ZZ          return unop(Iop_1Uto32,
//ZZ                      binop(Iop_CmpLE32U, cc_dep2, cc_dep1));
//ZZ       }
//ZZ
//ZZ       if (isU32(cc_op, ARMG_CC_OP_SBB)) {
//ZZ          /* This happens occasionally in softfloat code, eg __divdf3+140 */
//ZZ          /* thunk is: (dep1=argL, dep2=argR, ndep=oldC) */
//ZZ          /* C after SBB (same as HS after SBB above)
//ZZ             --> oldC ? (argL >=u argR) : (argL >u argR)
//ZZ             --> oldC ? (argR <=u argL) : (argR <u argL)
//ZZ          */
//ZZ          return
//ZZ             IRExpr_ITE(
//ZZ                binop(Iop_CmpNE32, cc_ndep, mkU32(0)),
//ZZ                /* case oldC != 0 */
//ZZ                unop(Iop_1Uto32, binop(Iop_CmpLE32U, cc_dep2, cc_dep1)),
//ZZ                /* case oldC == 0 */
//ZZ                unop(Iop_1Uto32, binop(Iop_CmpLT32U, cc_dep2, cc_dep1))
//ZZ             );
//ZZ       }
//ZZ
//ZZ    }
//ZZ
//ZZ    /* --------- specialising "armg_calculate_flag_v" --------- */
//ZZ
//ZZ    else
//ZZ    if (vex_streq(function_name, "armg_calculate_flag_v")) {
//ZZ
//ZZ       /* specialise calls to the "armg_calculate_flag_v" function.
//ZZ          Note that the returned value must be either 0 or 1; nonzero
//ZZ          bits 31:1 are not allowed.  In turn, incoming oldV and oldC
//ZZ          values (from the thunk) are assumed to have bits 31:1
//ZZ          clear. */
//ZZ       IRExpr *cc_op, *cc_dep1, *cc_dep2, *cc_ndep;
//ZZ       vassert(arity == 4);
//ZZ       cc_op   = args[0]; /* ARMG_CC_OP_* */
//ZZ       cc_dep1 = args[1];
//ZZ       cc_dep2 = args[2];
//ZZ       cc_ndep = args[3];
//ZZ
//ZZ       if (isU32(cc_op, ARMG_CC_OP_LOGIC)) {
//ZZ          /* Thunk args are (result, shco, oldV) */
//ZZ          /* V after LOGIC --> oldV */
//ZZ          return cc_ndep;
//ZZ       }
//ZZ
//ZZ       if (isU32(cc_op, ARMG_CC_OP_SUB)) {
//ZZ          /* Thunk args are (argL, argR, unused) */
//ZZ          /* V after SUB
//ZZ             --> let res = argL - argR
//ZZ                 in ((argL ^ argR) & (argL ^ res)) >> 31
//ZZ             --> ((argL ^ argR) & (argL ^ (argL - argR))) >> 31
//ZZ          */
//ZZ          IRExpr* argL = cc_dep1;
//ZZ          IRExpr* argR = cc_dep2;
//ZZ          return
//ZZ             binop(Iop_Shr32,
//ZZ                   binop(Iop_And32,
//ZZ                         binop(Iop_Xor32, argL, argR),
//ZZ                         binop(Iop_Xor32, argL, binop(Iop_Sub32, argL, argR))
//ZZ                   ),
//ZZ                   mkU8(31)
//ZZ             );
//ZZ       }
//ZZ
//ZZ       if (isU32(cc_op, ARMG_CC_OP_SBB)) {
//ZZ          /* This happens occasionally in softfloat code, eg __divdf3+140 */
//ZZ          /* thunk is: (dep1=argL, dep2=argR, ndep=oldC) */
//ZZ          /* V after SBB
//ZZ             --> let res = argL - argR - (oldC ^ 1)
//ZZ                 in  (argL ^ argR) & (argL ^ res) & 1
//ZZ          */
//ZZ          return
//ZZ             binop(
//ZZ                Iop_And32,
//ZZ                binop(
//ZZ                   Iop_And32,
//ZZ                   // argL ^ argR
//ZZ                   binop(Iop_Xor32, cc_dep1, cc_dep2),
//ZZ                   // argL ^ (argL - argR - (oldC ^ 1))
//ZZ                   binop(Iop_Xor32,
//ZZ                         cc_dep1,
//ZZ                         binop(Iop_Sub32,
//ZZ                               binop(Iop_Sub32, cc_dep1, cc_dep2),
//ZZ                               binop(Iop_Xor32, cc_ndep, mkU32(1)))
//ZZ                   )
//ZZ                ),
//ZZ                mkU32(1)
//ZZ             );
//ZZ       }
//ZZ
//ZZ    }

#  undef unop
#  undef binop
#  undef mkU64
#  undef mkU8

   return NULL;
}


/*----------------------------------------------*/
/*--- The exported fns ..                    ---*/
/*----------------------------------------------*/

//ZZ /* VISIBLE TO LIBVEX CLIENT */
//ZZ #if 0
//ZZ void LibVEX_GuestARM_put_flags ( UInt flags_native,
//ZZ                                  /*OUT*/VexGuestARMState* vex_state )
//ZZ {
//ZZ    vassert(0); // FIXME
//ZZ
//ZZ    /* Mask out everything except N Z V C. */
//ZZ    flags_native
//ZZ       &= (ARMG_CC_MASK_N | ARMG_CC_MASK_Z | ARMG_CC_MASK_V | ARMG_CC_MASK_C);
//ZZ
//ZZ    vex_state->guest_CC_OP   = ARMG_CC_OP_COPY;
//ZZ    vex_state->guest_CC_DEP1 = flags_native;
//ZZ    vex_state->guest_CC_DEP2 = 0;
//ZZ    vex_state->guest_CC_NDEP = 0;
//ZZ }
//ZZ #endif

/* VISIBLE TO LIBVEX CLIENT */
ULong LibVEX_GuestARM64_get_nzcv ( /*IN*/const VexGuestARM64State* vex_state )
{
   ULong nzcv = 0;
   // NZCV
   nzcv |= arm64g_calculate_flags_nzcv(
               vex_state->guest_CC_OP,
               vex_state->guest_CC_DEP1,
               vex_state->guest_CC_DEP2,
               vex_state->guest_CC_NDEP
            );
   vassert(0 == (nzcv & 0xFFFFFFFF0FFFFFFFULL));
//ZZ    // Q
//ZZ    if (vex_state->guest_QFLAG32 > 0)
//ZZ       cpsr |= (1 << 27);
//ZZ    // GE
//ZZ    if (vex_state->guest_GEFLAG0 > 0)
//ZZ       cpsr |= (1 << 16);
//ZZ    if (vex_state->guest_GEFLAG1 > 0)
//ZZ       cpsr |= (1 << 17);
//ZZ    if (vex_state->guest_GEFLAG2 > 0)
//ZZ       cpsr |= (1 << 18);
//ZZ    if (vex_state->guest_GEFLAG3 > 0)
//ZZ       cpsr |= (1 << 19);
//ZZ    // M
//ZZ    cpsr |= (1 << 4); // 0b10000 means user-mode
//ZZ    // J,T   J (bit 24) is zero by initialisation above
//ZZ    // T  we copy from R15T[0]
//ZZ    if (vex_state->guest_R15T & 1)
//ZZ       cpsr |= (1 << 5);
//ZZ    // ITSTATE we punt on for the time being.  Could compute it
//ZZ    // if needed though.
//ZZ    // E, endianness, 0 (littleendian) from initialisation above
//ZZ    // A,I,F disable some async exceptions.  Not sure about these.
//ZZ    // Leave as zero for the time being.
   return nzcv;
}

/* VISIBLE TO LIBVEX CLIENT */
void LibVEX_GuestARM64_initialise ( /*OUT*/VexGuestARM64State* vex_state )
{
   vex_bzero(vex_state, sizeof(*vex_state));
//ZZ    vex_state->host_EvC_FAILADDR = 0;
//ZZ    vex_state->host_EvC_COUNTER = 0;
//ZZ
//ZZ    vex_state->guest_R0  = 0;
//ZZ    vex_state->guest_R1  = 0;
//ZZ    vex_state->guest_R2  = 0;
//ZZ    vex_state->guest_R3  = 0;
//ZZ    vex_state->guest_R4  = 0;
//ZZ    vex_state->guest_R5  = 0;
//ZZ    vex_state->guest_R6  = 0;
//ZZ    vex_state->guest_R7  = 0;
//ZZ    vex_state->guest_R8  = 0;
//ZZ    vex_state->guest_R9  = 0;
//ZZ    vex_state->guest_R10 = 0;
//ZZ    vex_state->guest_R11 = 0;
//ZZ    vex_state->guest_R12 = 0;
//ZZ    vex_state->guest_R13 = 0;
//ZZ    vex_state->guest_R14 = 0;
//ZZ    vex_state->guest_R15T = 0;  /* NB: implies ARM mode */
//ZZ
   vex_state->guest_CC_OP   = ARM64G_CC_OP_COPY;
//ZZ    vex_state->guest_CC_DEP1 = 0;
//ZZ    vex_state->guest_CC_DEP2 = 0;
//ZZ    vex_state->guest_CC_NDEP = 0;
//ZZ    vex_state->guest_QFLAG32 = 0;
//ZZ    vex_state->guest_GEFLAG0 = 0;
//ZZ    vex_state->guest_GEFLAG1 = 0;
//ZZ    vex_state->guest_GEFLAG2 = 0;
//ZZ    vex_state->guest_GEFLAG3 = 0;
//ZZ
//ZZ    vex_state->guest_EMNOTE  = EmNote_NONE;
//ZZ    vex_state->guest_CMSTART = 0;
//ZZ    vex_state->guest_CMLEN   = 0;
//ZZ    vex_state->guest_NRADDR  = 0;
//ZZ    vex_state->guest_IP_AT_SYSCALL = 0;
//ZZ
//ZZ    vex_state->guest_D0  = 0;
//ZZ    vex_state->guest_D1  = 0;
//ZZ    vex_state->guest_D2  = 0;
//ZZ    vex_state->guest_D3  = 0;
//ZZ    vex_state->guest_D4  = 0;
//ZZ    vex_state->guest_D5  = 0;
//ZZ    vex_state->guest_D6  = 0;
//ZZ    vex_state->guest_D7  = 0;
//ZZ    vex_state->guest_D8  = 0;
//ZZ    vex_state->guest_D9  = 0;
//ZZ    vex_state->guest_D10 = 0;
//ZZ    vex_state->guest_D11 = 0;
//ZZ    vex_state->guest_D12 = 0;
//ZZ    vex_state->guest_D13 = 0;
//ZZ    vex_state->guest_D14 = 0;
//ZZ    vex_state->guest_D15 = 0;
//ZZ    vex_state->guest_D16 = 0;
//ZZ    vex_state->guest_D17 = 0;
//ZZ    vex_state->guest_D18 = 0;
//ZZ    vex_state->guest_D19 = 0;
//ZZ    vex_state->guest_D20 = 0;
//ZZ    vex_state->guest_D21 = 0;
//ZZ    vex_state->guest_D22 = 0;
//ZZ    vex_state->guest_D23 = 0;
//ZZ    vex_state->guest_D24 = 0;
//ZZ    vex_state->guest_D25 = 0;
//ZZ    vex_state->guest_D26 = 0;
//ZZ    vex_state->guest_D27 = 0;
//ZZ    vex_state->guest_D28 = 0;
//ZZ    vex_state->guest_D29 = 0;
//ZZ    vex_state->guest_D30 = 0;
//ZZ    vex_state->guest_D31 = 0;
//ZZ
//ZZ    /* ARM encoded; zero is the default as it happens (result flags
//ZZ       (NZCV) cleared, FZ disabled, round to nearest, non-vector mode,
//ZZ       all exns masked, all exn sticky bits cleared). */
//ZZ    vex_state->guest_FPSCR = 0;
//ZZ
//ZZ    vex_state->guest_TPIDRURO = 0;
//ZZ
//ZZ    /* Not in a Thumb IT block. */
//ZZ    vex_state->guest_ITSTATE = 0;
//ZZ
//ZZ    vex_state->padding1 = 0;
//ZZ    vex_state->padding2 = 0;
//ZZ    vex_state->padding3 = 0;
//ZZ    vex_state->padding4 = 0;
//ZZ    vex_state->padding5 = 0;
}


/*-----------------------------------------------------------*/
/*--- Describing the arm guest state, for the benefit     ---*/
/*--- of iropt and instrumenters.                         ---*/
/*-----------------------------------------------------------*/

/* Figure out if any part of the guest state contained in minoff
   .. maxoff requires precise memory exceptions.  If in doubt return
   True (but this generates significantly slower code).

   We enforce precise exns for guest SP, PC, 29(FP), 30(LR).
   That might be overkill (for 29 and 30); I don't know.
*/
Bool guest_arm64_state_requires_precise_mem_exns ( Int minoff,
                                                   Int maxoff)
{
   Int xsp_min = offsetof(VexGuestARM64State, guest_XSP);
   Int xsp_max = xsp_min + 8 - 1;
   Int pc_min  = offsetof(VexGuestARM64State, guest_PC);
   Int pc_max  = pc_min + 8 - 1;

   if (maxoff < xsp_min || minoff > xsp_max) {
      /* no overlap with xsp */
      if (vex_control.iropt_register_updates == VexRegUpdSpAtMemAccess)
         return False; // We only need to check stack pointer.
   } else {
      return True;
   }

   if (maxoff < pc_min || minoff > pc_max) {
      /* no overlap with pc */
   } else {
      return True;
   }

   /* Guessing that we need PX for FP, but I don't really know. */
   Int x29_min = offsetof(VexGuestARM64State, guest_X29);
   Int x29_max = x29_min + 8 - 1;

   if (maxoff < x29_min || minoff > x29_max) {
      /* no overlap with x29 */
   } else {
      return True;
   }

   /* Guessing that we need PX for LR, but I don't really know. */
   Int x30_min = offsetof(VexGuestARM64State, guest_X30);
   Int x30_max = x30_min + 8 - 1;

   if (maxoff < x30_min || minoff > x30_max) {
      /* no overlap with r30 */
   } else {
      return True;
   }

   return False;
}


#define ALWAYSDEFD(field)                             \
    { offsetof(VexGuestARM64State, field),            \
      (sizeof ((VexGuestARM64State*)0)->field) }
VexGuestLayout
   arm64Guest_layout
      = {
          /* Total size of the guest state, in bytes. */
          .total_sizeB = sizeof(VexGuestARM64State),

          /* Describe the stack pointer. */
          .offset_SP = offsetof(VexGuestARM64State,guest_XSP),
          .sizeof_SP = 8,

          /* Describe the instruction pointer. */
          .offset_IP = offsetof(VexGuestARM64State,guest_PC),
          .sizeof_IP = 8,

          /* Describe any sections to be regarded by Memcheck as
             'always-defined'. */
          .n_alwaysDefd = 10,

          /* flags thunk: OP is always defd, whereas DEP1 and DEP2
             have to be tracked.  See detailed comment in gdefs.h on
             meaning of thunk fields. */
          .alwaysDefd
             = { /* 0 */ ALWAYSDEFD(guest_PC),
                 /* 1 */ ALWAYSDEFD(guest_CC_OP),
                 /* 2 */ ALWAYSDEFD(guest_CC_NDEP),
                 /* 3 */ ALWAYSDEFD(guest_EMNOTE),
                 /* 4 */ ALWAYSDEFD(guest_CMSTART),
                 /* 5 */ ALWAYSDEFD(guest_CMLEN),
                 /* 6 */ ALWAYSDEFD(guest_NRADDR),
                 /* 7 */ ALWAYSDEFD(guest_IP_AT_SYSCALL),
                 /* 8 */ ALWAYSDEFD(guest_FPCR),
                 /* 9 */ ALWAYSDEFD(guest_FPSR)
               }
        };


/*---------------------------------------------------------------*/
/*--- end                               guest_arm64_helpers.c ---*/
/*---------------------------------------------------------------*/