toir.c

The Valgrind distribution has multiple tools. The most popular is the memory checking tool (called M

   /* xer_ov MUST denote either 0 or 1, no other value allowed */
   putXER_OV( unop(Iop_32to8, xer_ov) );

   /* Update the summary overflow */
   putXER_SO( binop(Iop_Or8, getXER_SO(), getXER_OV()) );

#  undef INT32_MIN
#  undef AND3
#  undef XOR3
#  undef XOR2
#  undef NOT
}

static void set_XER_OV_64( UInt op, IRExpr* res,
                           IRExpr* argL, IRExpr* argR )
{
   IRExpr* xer_ov;
   vassert(op < PPCG_FLAG_OP_NUMBER);
   vassert(typeOfIRExpr(irbb->tyenv,res)  == Ity_I64);
   vassert(typeOfIRExpr(irbb->tyenv,argL) == Ity_I64);
   vassert(typeOfIRExpr(irbb->tyenv,argR) == Ity_I64);

#  define INT64_MIN 0x8000000000000000ULL

#  define XOR2(_aa,_bb) \
      binop(Iop_Xor64,(_aa),(_bb))

#  define XOR3(_cc,_dd,_ee) \
      binop(Iop_Xor64,binop(Iop_Xor64,(_cc),(_dd)),(_ee))

#  define AND3(_ff,_gg,_hh) \
      binop(Iop_And64,binop(Iop_And64,(_ff),(_gg)),(_hh))

#define NOT(_jj) \
      unop(Iop_Not64, (_jj))

   switch (op) {
   case /* 0  */ PPCG_FLAG_OP_ADD:
   case /* 1  */ PPCG_FLAG_OP_ADDE:
      /* (argL^argR^-1) & (argL^res) & (1<<63)  ? 1:0 */
      // i.e. ((both_same_sign) & (sign_changed) & (sign_mask))
      xer_ov 
         = AND3( XOR3(argL,argR,mkU64(-1)),
                 XOR2(argL,res),
                 mkU64(INT64_MIN) );
      /* xer_ov can only be 0 or 1<<63 */
      xer_ov 
         = unop(Iop_64to1, binop(Iop_Shr64, xer_ov, mkU8(63)));
      break;
      
   case /* 2  */ PPCG_FLAG_OP_DIVW:
      /* (argL == INT64_MIN && argR == -1) || argR == 0 */
      xer_ov
         = mkOR1(
              mkAND1( 
                 binop(Iop_CmpEQ64, argL, mkU64(INT64_MIN)),
                 binop(Iop_CmpEQ64, argR, mkU64(-1)) 
              ),
              binop(Iop_CmpEQ64, argR, mkU64(0) ) 
           );
      break;

   case /* 3  */ PPCG_FLAG_OP_DIVWU:
      /* argR == 0 */
      xer_ov 
         = binop(Iop_CmpEQ64, argR, mkU64(0));
      break;
      
   case /* 4  */ PPCG_FLAG_OP_MULLW: {
      /* OV true if result can't be represented in 64 bits
         i.e sHi != sign extension of sLo */
      xer_ov 
         = binop( Iop_CmpNE32,
                  unop(Iop_64HIto32, res),
                  binop( Iop_Sar32, 
                         unop(Iop_64to32, res), 
                         mkU8(31))
                  );
      break;
   }
      
   case /* 5  */ PPCG_FLAG_OP_NEG:
      /* argL == INT64_MIN */
      xer_ov
         = binop(Iop_CmpEQ64, argL, mkU64(INT64_MIN));
      break;
      
   case /* 6  */ PPCG_FLAG_OP_SUBF:
   case /* 7  */ PPCG_FLAG_OP_SUBFC:
   case /* 8  */ PPCG_FLAG_OP_SUBFE:
      /* ((~argL)^argR^-1) & ((~argL)^res) & (1<<63) ?1:0; */
      xer_ov 
         = AND3( XOR3(NOT(argL),argR,mkU64(-1)),
                 XOR2(NOT(argL),res),
                 mkU64(INT64_MIN) );
      /* xer_ov can only be 0 or 1<<63 */
      xer_ov 
         = unop(Iop_64to1, binop(Iop_Shr64, xer_ov, mkU8(63)));
      break;
      
   default: 
      vex_printf("set_XER_OV: op = %u\n", op);
      vpanic("set_XER_OV(ppc64)");
   }
   
   /* xer_ov MUST denote either 0 or 1, no other value allowed */
   putXER_OV( unop(Iop_1Uto8, xer_ov) );

   /* Update the summary overflow */
   putXER_SO( binop(Iop_Or8, getXER_SO(), getXER_OV()) );

#  undef INT64_MIN
#  undef AND3
#  undef XOR3
#  undef XOR2
#  undef NOT
}

static void set_XER_OV ( IRType ty, UInt op, IRExpr* res,
                         IRExpr* argL, IRExpr* argR )
{
   if (ty == Ity_I32)
      set_XER_OV_32( op, res, argL, argR );
   else
      set_XER_OV_64( op, res, argL, argR );
}



/* RES is the result of doing OP on ARGL and ARGR with the old %XER.CA
   value being OLDCA.  Set %XER.CA accordingly. */

static void set_XER_CA_32 ( UInt op, IRExpr* res,
                            IRExpr* argL, IRExpr* argR, IRExpr* oldca )
{
   IRExpr* xer_ca;
   vassert(op < PPCG_FLAG_OP_NUMBER);
   vassert(typeOfIRExpr(irbb->tyenv,res)   == Ity_I32);
   vassert(typeOfIRExpr(irbb->tyenv,argL)  == Ity_I32);
   vassert(typeOfIRExpr(irbb->tyenv,argR)  == Ity_I32);
   vassert(typeOfIRExpr(irbb->tyenv,oldca) == Ity_I32);

   /* Incoming oldca is assumed to hold the values 0 or 1 only.  This
      seems reasonable given that it's always generated by
      getXER_CA32(), which masks it accordingly.  In any case it being
      0 or 1 is an invariant of the ppc guest state representation;
      if it has any other value, that invariant has been violated. */

   switch (op) {
   case /* 0 */ PPCG_FLAG_OP_ADD:
      /* res <u argL */
      xer_ca
         = unop(Iop_1Uto32, binop(Iop_CmpLT32U, res, argL));
      break;
      
   case /* 1 */ PPCG_FLAG_OP_ADDE:
      /* res <u argL || (old_ca==1 && res==argL) */
      xer_ca 
         = mkOR1( 
              binop(Iop_CmpLT32U, res, argL),
              mkAND1( 
                 binop(Iop_CmpEQ32, oldca, mkU32(1)),
                 binop(Iop_CmpEQ32, res, argL) 
              ) 
           );
      xer_ca 
         = unop(Iop_1Uto32, xer_ca);
      break;
      
   case /* 8 */ PPCG_FLAG_OP_SUBFE:
      /* res <u argR || (old_ca==1 && res==argR) */
      xer_ca 
         = mkOR1( 
              binop(Iop_CmpLT32U, res, argR),
              mkAND1( 
                 binop(Iop_CmpEQ32, oldca, mkU32(1)),
                 binop(Iop_CmpEQ32, res, argR) 
              ) 
           );
      xer_ca 
         = unop(Iop_1Uto32, xer_ca);
      break;
      
   case /* 7 */ PPCG_FLAG_OP_SUBFC:
   case /* 9 */ PPCG_FLAG_OP_SUBFI:
      /* res <=u argR */
      xer_ca
         = unop(Iop_1Uto32, binop(Iop_CmpLE32U, res, argR));
      break;
      
   case /* 10 */ PPCG_FLAG_OP_SRAW:
      /* The shift amount is guaranteed to be in 0 .. 63 inclusive.
         If it is <= 31, behave like SRAWI; else XER.CA is the sign
         bit of argL. */
      /* This term valid for shift amount < 32 only */
      xer_ca
         = binop(
              Iop_And32,
              binop(Iop_Sar32, argL, mkU8(31)),
              binop( Iop_And32,
                     argL,
                     binop( Iop_Sub32,
                            binop(Iop_Shl32, mkU32(1),
                                             unop(Iop_32to8,argR)),
                            mkU32(1) )
                     )
              );
      xer_ca 
         = IRExpr_Mux0X(
              /* shift amt > 31 ? */
              unop(Iop_1Uto8, binop(Iop_CmpLT32U, mkU32(31), argR)),
              /* no -- be like srawi */
              unop(Iop_1Uto32, binop(Iop_CmpNE32, xer_ca, mkU32(0))),
              /* yes -- get sign bit of argL */
              binop(Iop_Shr32, argL, mkU8(31))
           );
      break;

   case /* 11 */ PPCG_FLAG_OP_SRAWI:
      /* xer_ca is 1 iff src was negative and bits_shifted_out != 
         0.  Since the shift amount is known to be in the range
         0 .. 31 inclusive the following seems viable:
         xer.ca == 1 iff the following is nonzero:
         (argL >>s 31)           -- either all 0s or all 1s
         & (argL & (1<<argR)-1)  -- the stuff shifted out */
      xer_ca
         = binop(
              Iop_And32,
              binop(Iop_Sar32, argL, mkU8(31)),
              binop( Iop_And32,
                     argL,
                     binop( Iop_Sub32,
                            binop(Iop_Shl32, mkU32(1),
                                             unop(Iop_32to8,argR)),
                            mkU32(1) )
                     )
              );
      xer_ca 
         = unop(Iop_1Uto32, binop(Iop_CmpNE32, xer_ca, mkU32(0)));
      break;
      
   default: 
      vex_printf("set_XER_CA: op = %u\n", op);
      vpanic("set_XER_CA(ppc)");
   }

   /* xer_ca MUST denote either 0 or 1, no other value allowed */
   putXER_CA( unop(Iop_32to8, xer_ca) );
}

static void set_XER_CA_64 ( UInt op, IRExpr* res,
                            IRExpr* argL, IRExpr* argR, IRExpr* oldca )
{
   IRExpr* xer_ca;
   vassert(op < PPCG_FLAG_OP_NUMBER);
   vassert(typeOfIRExpr(irbb->tyenv,res)   == Ity_I64);
   vassert(typeOfIRExpr(irbb->tyenv,argL)  == Ity_I64);
   vassert(typeOfIRExpr(irbb->tyenv,argR)  == Ity_I64);
   vassert(typeOfIRExpr(irbb->tyenv,oldca) == Ity_I64);

   /* Incoming oldca is assumed to hold the values 0 or 1 only.  This
      seems reasonable given that it's always generated by
      getXER_CA32(), which masks it accordingly.  In any case it being
      0 or 1 is an invariant of the ppc guest state representation;
      if it has any other value, that invariant has been violated. */

   switch (op) {
   case /* 0 */ PPCG_FLAG_OP_ADD:
      /* res <u argL */
      xer_ca
         = unop(Iop_1Uto32, binop(Iop_CmpLT64U, res, argL));
      break;
      
   case /* 1 */ PPCG_FLAG_OP_ADDE:
      /* res <u argL || (old_ca==1 && res==argL) */
      xer_ca 
         = mkOR1( 
              binop(Iop_CmpLT64U, res, argL),
              mkAND1( 
                 binop(Iop_CmpEQ64, oldca, mkU64(1)),
                 binop(Iop_CmpEQ64, res, argL) 
                 ) 
              );
      xer_ca 
         = unop(Iop_1Uto32, xer_ca);
      break;
      
   case /* 8 */ PPCG_FLAG_OP_SUBFE:
      /* res <u argR || (old_ca==1 && res==argR) */
      xer_ca 
         = mkOR1( 
              binop(Iop_CmpLT64U, res, argR),
              mkAND1( 
                 binop(Iop_CmpEQ64, oldca, mkU64(1)),
                 binop(Iop_CmpEQ64, res, argR) 
              ) 
           );
      xer_ca 
         = unop(Iop_1Uto32, xer_ca);
      break;
      
   case /* 7 */ PPCG_FLAG_OP_SUBFC:
   case /* 9 */ PPCG_FLAG_OP_SUBFI:
      /* res <=u argR */
      xer_ca
         = unop(Iop_1Uto32, binop(Iop_CmpLE64U, res, argR));
      break;
      
      
   case /* 10 */ PPCG_FLAG_OP_SRAW:
      /* The shift amount is guaranteed to be in 0 .. 31 inclusive.
         If it is <= 31, behave like SRAWI; else XER.CA is the sign
         bit of argL. */
         /* This term valid for shift amount < 31 only */

      xer_ca
         = binop(
              Iop_And64,
              binop(Iop_Sar64, argL, mkU8(31)),
              binop( Iop_And64,
                     argL,
                     binop( Iop_Sub64,
                            binop(Iop_Shl64, mkU64(1),
                                             unop(Iop_64to8,argR)),
                            mkU64(1) )
              )
           );
      xer_ca 
         = IRExpr_Mux0X(
              /* shift amt > 31 ? */
              unop(Iop_1Uto8, binop(Iop_CmpLT64U, mkU64(31), argR)),
              /* no -- be like srawi */
              unop(Iop_1Uto32, binop(Iop_CmpNE64, xer_ca, mkU64(0))),
              /* yes -- get sign bit of argL */
              unop(Iop_64to32, binop(Iop_Shr64, argL, mkU8(63)))
           );
      break;
      
   case /* 11 */ PPCG_FLAG_OP_SRAWI:
      /* xer_ca is 1 iff src was negative and bits_shifted_out != 0.
         Since the shift amount is known to be in the range 0 .. 31
         inclusive the following seems viable:
         xer.ca == 1 iff the following is nonzero:
         (argL >>s 31)           -- either all 0s or all 1s
         & (argL & (1<<argR)-1)  -- the stuff shifted out */

      xer_ca
         = binop(
              Iop_And64,
              binop(Iop_Sar64, argL, mkU8(31)),
              binop( Iop_And64,
                     argL,
                     binop( Iop_Sub64,
                            binop(Iop_Shl64, mkU64(1),
                                             unop(Iop_64to8,argR)),
                            mkU64(1) )
              )
           );
      xer_ca 
         = unop(Iop_1Uto32, binop(Iop_CmpNE64, xer_ca, mkU64(0)));
      break;
      

   case /* 12 */ PPCG_FLAG_OP_SRAD:
      /* The shift amount is guaranteed to be in 0 .. 63 inclusive.
         If it is <= 63, behave like SRADI; else XER.CA is the sign
         bit of argL. */
         /* This term valid for shift amount < 63 only */

      xer_ca
         = binop(
              Iop_And64,
              binop(Iop_Sar64, argL, mkU8(63)),
              binop( Iop_And64,
                     argL,
                     binop( Iop_Sub64,
                            binop(Iop_Shl64, mkU64(1),
                                             unop(Iop_64to8,argR)),
                            mkU64(1) )
              )
           );
      xer_ca 
         = IRExpr_Mux0X(
              /* shift amt > 63 ? */
              unop(Iop_1Uto8, binop(Iop_CmpLT64U, mkU64(63), argR)),
              /* no -- be like sradi */
              unop(Iop_1Uto32, binop(Iop_CmpNE64, xer_ca, mkU64(0))),
              /* yes -- get sign bit of argL */
              unop(Iop_64to32, binop(Iop_Shr64, argL, mkU8(63)))
           );
      break;


   case /* 13 */ PPCG_FLAG_OP_SRADI:
      /* xer_ca is 1 iff src was negative and bits_shifted_out != 0.
         Since the shift amount is known to be in the range 0 .. 63
         inclusive, the following seems viable:
         xer.ca == 1 iff the following is nonzero:
         (argL >>s 63)           -- either all 0s or all