toir.c

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

   register references, we need to take the host endianness into
   account.  Supplied value is 0 .. 7 and in the Intel instruction
   encoding. */

static IRType szToITy ( Int n )
{
   switch (n) {
      case 1: return Ity_I8;
      case 2: return Ity_I16;
      case 4: return Ity_I32;
      default: vpanic("szToITy(x86)");
   }
}

/* On a little-endian host, less significant bits of the guest
   registers are at lower addresses.  Therefore, if a reference to a
   register low half has the safe guest state offset as a reference to
   the full register.
*/
static Int integerGuestRegOffset ( Int sz, UInt archreg )
{
   vassert(archreg < 8);

   /* Correct for little-endian host only. */
   vassert(!host_is_bigendian);

   if (sz == 4 || sz == 2 || (sz == 1 && archreg < 4)) {
      switch (archreg) {
         case R_EAX: return OFFB_EAX;
         case R_EBX: return OFFB_EBX;
         case R_ECX: return OFFB_ECX;
         case R_EDX: return OFFB_EDX;
         case R_ESI: return OFFB_ESI;
         case R_EDI: return OFFB_EDI;
         case R_ESP: return OFFB_ESP;
         case R_EBP: return OFFB_EBP;
         default: vpanic("integerGuestRegOffset(x86,le)(4,2)");
      }
   }

   vassert(archreg >= 4 && archreg < 8 && sz == 1);
   switch (archreg-4) {
      case R_EAX: return 1+ OFFB_EAX;
      case R_EBX: return 1+ OFFB_EBX;
      case R_ECX: return 1+ OFFB_ECX;
      case R_EDX: return 1+ OFFB_EDX;
      default: vpanic("integerGuestRegOffset(x86,le)(1h)");
   }

   /* NOTREACHED */
   vpanic("integerGuestRegOffset(x86,le)");
}

static Int segmentGuestRegOffset ( UInt sreg )
{
   switch (sreg) {
      case R_ES: return OFFB_ES;
      case R_CS: return OFFB_CS;
      case R_SS: return OFFB_SS;
      case R_DS: return OFFB_DS;
      case R_FS: return OFFB_FS;
      case R_GS: return OFFB_GS;
      default: vpanic("segmentGuestRegOffset(x86)");
   }
}

static Int xmmGuestRegOffset ( UInt xmmreg )
{
   switch (xmmreg) {
      case 0: return OFFB_XMM0;
      case 1: return OFFB_XMM1;
      case 2: return OFFB_XMM2;
      case 3: return OFFB_XMM3;
      case 4: return OFFB_XMM4;
      case 5: return OFFB_XMM5;
      case 6: return OFFB_XMM6;
      case 7: return OFFB_XMM7;
      default: vpanic("xmmGuestRegOffset");
   }
}

/* Lanes of vector registers are always numbered from zero being the
   least significant lane (rightmost in the register).  */

static Int xmmGuestRegLane16offset ( UInt xmmreg, Int laneno )
{
   /* Correct for little-endian host only. */
   vassert(!host_is_bigendian);
   vassert(laneno >= 0 && laneno < 8);
   return xmmGuestRegOffset( xmmreg ) + 2 * laneno;
}

static Int xmmGuestRegLane32offset ( UInt xmmreg, Int laneno )
{
   /* Correct for little-endian host only. */
   vassert(!host_is_bigendian);
   vassert(laneno >= 0 && laneno < 4);
   return xmmGuestRegOffset( xmmreg ) + 4 * laneno;
}

static Int xmmGuestRegLane64offset ( UInt xmmreg, Int laneno )
{
   /* Correct for little-endian host only. */
   vassert(!host_is_bigendian);
   vassert(laneno >= 0 && laneno < 2);
   return xmmGuestRegOffset( xmmreg ) + 8 * laneno;
}

static IRExpr* getIReg ( Int sz, UInt archreg )
{
   vassert(sz == 1 || sz == 2 || sz == 4);
   vassert(archreg < 8);
   return IRExpr_Get( integerGuestRegOffset(sz,archreg),
                      szToITy(sz) );
}

/* Ditto, but write to a reg instead. */
static void putIReg ( Int sz, UInt archreg, IRExpr* e )
{
   IRType ty = typeOfIRExpr(irbb->tyenv, e);
   switch (sz) {
      case 1: vassert(ty == Ity_I8); break;
      case 2: vassert(ty == Ity_I16); break;
      case 4: vassert(ty == Ity_I32); break;
      default: vpanic("putIReg(x86)");
   }
   vassert(archreg < 8);
   stmt( IRStmt_Put(integerGuestRegOffset(sz,archreg), e) );
}

static IRExpr* getSReg ( UInt sreg )
{
   return IRExpr_Get( segmentGuestRegOffset(sreg), Ity_I16 );
}

static void putSReg ( UInt sreg, IRExpr* e )
{
   vassert(typeOfIRExpr(irbb->tyenv,e) == Ity_I16);
   stmt( IRStmt_Put( segmentGuestRegOffset(sreg), e ) );
}

static IRExpr* getXMMReg ( UInt xmmreg )
{
   return IRExpr_Get( xmmGuestRegOffset(xmmreg), Ity_V128 );
}

static IRExpr* getXMMRegLane64 ( UInt xmmreg, Int laneno )
{
   return IRExpr_Get( xmmGuestRegLane64offset(xmmreg,laneno), Ity_I64 );
}

static IRExpr* getXMMRegLane64F ( UInt xmmreg, Int laneno )
{
   return IRExpr_Get( xmmGuestRegLane64offset(xmmreg,laneno), Ity_F64 );
}

static IRExpr* getXMMRegLane32 ( UInt xmmreg, Int laneno )
{
   return IRExpr_Get( xmmGuestRegLane32offset(xmmreg,laneno), Ity_I32 );
}

static IRExpr* getXMMRegLane32F ( UInt xmmreg, Int laneno )
{
   return IRExpr_Get( xmmGuestRegLane32offset(xmmreg,laneno), Ity_F32 );
}

static void putXMMReg ( UInt xmmreg, IRExpr* e )
{
   vassert(typeOfIRExpr(irbb->tyenv,e) == Ity_V128);
   stmt( IRStmt_Put( xmmGuestRegOffset(xmmreg), e ) );
}

static void putXMMRegLane64 ( UInt xmmreg, Int laneno, IRExpr* e )
{
   vassert(typeOfIRExpr(irbb->tyenv,e) == Ity_I64);
   stmt( IRStmt_Put( xmmGuestRegLane64offset(xmmreg,laneno), e ) );
}

static void putXMMRegLane64F ( UInt xmmreg, Int laneno, IRExpr* e )
{
   vassert(typeOfIRExpr(irbb->tyenv,e) == Ity_F64);
   stmt( IRStmt_Put( xmmGuestRegLane64offset(xmmreg,laneno), e ) );
}

static void putXMMRegLane32F ( UInt xmmreg, Int laneno, IRExpr* e )
{
   vassert(typeOfIRExpr(irbb->tyenv,e) == Ity_F32);
   stmt( IRStmt_Put( xmmGuestRegLane32offset(xmmreg,laneno), e ) );
}

static void putXMMRegLane32 ( UInt xmmreg, Int laneno, IRExpr* e )
{
   vassert(typeOfIRExpr(irbb->tyenv,e) == Ity_I32);
   stmt( IRStmt_Put( xmmGuestRegLane32offset(xmmreg,laneno), e ) );
}

static void putXMMRegLane16 ( UInt xmmreg, Int laneno, IRExpr* e )
{
   vassert(typeOfIRExpr(irbb->tyenv,e) == Ity_I16);
   stmt( IRStmt_Put( xmmGuestRegLane16offset(xmmreg,laneno), e ) );
}

static void assign ( IRTemp dst, IRExpr* e )
{
   stmt( IRStmt_Tmp(dst, e) );
}

static void storeLE ( IRExpr* addr, IRExpr* data )
{
   stmt( IRStmt_Store(Iend_LE,addr,data) );
}

static IRExpr* unop ( IROp op, IRExpr* a )
{
   return IRExpr_Unop(op, a);
}

static IRExpr* binop ( IROp op, IRExpr* a1, IRExpr* a2 )
{
   return IRExpr_Binop(op, a1, a2);
}

static IRExpr* triop ( IROp op, IRExpr* a1, IRExpr* a2, IRExpr* a3 )
{
   return IRExpr_Triop(op, a1, a2, a3);
}

static IRExpr* mkexpr ( IRTemp tmp )
{
   return IRExpr_Tmp(tmp);
}

static IRExpr* mkU8 ( UInt i )
{
   vassert(i < 256);
   return IRExpr_Const(IRConst_U8( (UChar)i ));
}

static IRExpr* mkU16 ( UInt i )
{
   vassert(i < 65536);
   return IRExpr_Const(IRConst_U16( (UShort)i ));
}

static IRExpr* mkU32 ( UInt i )
{
   return IRExpr_Const(IRConst_U32(i));
}

static IRExpr* mkU64 ( ULong i )
{
   return IRExpr_Const(IRConst_U64(i));
}

static IRExpr* mkU ( IRType ty, UInt i )
{
   if (ty == Ity_I8)  return mkU8(i);
   if (ty == Ity_I16) return mkU16(i);
   if (ty == Ity_I32) return mkU32(i);
   /* If this panics, it usually means you passed a size (1,2,4)
      value as the IRType, rather than a real IRType. */
   vpanic("mkU(x86)");
}

static IRExpr* mkV128 ( UShort mask )
{
   return IRExpr_Const(IRConst_V128(mask));
}

static IRExpr* loadLE ( IRType ty, IRExpr* data )
{
   return IRExpr_Load(Iend_LE,ty,data);
}

static IROp mkSizedOp ( IRType ty, IROp op8 )
{
   Int adj;
   vassert(ty == Ity_I8 || ty == Ity_I16 || ty == Ity_I32);
   vassert(op8 == Iop_Add8 || op8 == Iop_Sub8 
           || op8 == Iop_Mul8 
           || op8 == Iop_Or8 || op8 == Iop_And8 || op8 == Iop_Xor8
           || op8 == Iop_Shl8 || op8 == Iop_Shr8 || op8 == Iop_Sar8
           || op8 == Iop_CmpEQ8 || op8 == Iop_CmpNE8
           || op8 == Iop_Not8 || op8 == Iop_Neg8);
   adj = ty==Ity_I8 ? 0 : (ty==Ity_I16 ? 1 : 2);
   return adj + op8;
}

static IROp mkWidenOp ( Int szSmall, Int szBig, Bool signd )
{
   if (szSmall == 1 && szBig == 4) {
      return signd ? Iop_8Sto32 : Iop_8Uto32;
   }
   if (szSmall == 1 && szBig == 2) {
      return signd ? Iop_8Sto16 : Iop_8Uto16;
   }
   if (szSmall == 2 && szBig == 4) {
      return signd ? Iop_16Sto32 : Iop_16Uto32;
   }
   vpanic("mkWidenOp(x86,guest)");
}

static IRExpr* mkAnd1 ( IRExpr* x, IRExpr* y )
{
   vassert(typeOfIRExpr(irbb->tyenv,x) == Ity_I1);
   vassert(typeOfIRExpr(irbb->tyenv,y) == Ity_I1);
   return unop(Iop_32to1, 
               binop(Iop_And32, 
                     unop(Iop_1Uto32,x), 
                     unop(Iop_1Uto32,y)));
}


/*------------------------------------------------------------*/
/*--- Helpers for %eflags.                                 ---*/
/*------------------------------------------------------------*/

/* -------------- Evaluating the flags-thunk. -------------- */

/* Build IR to calculate all the eflags from stored
   CC_OP/CC_DEP1/CC_DEP2/CC_NDEP.  Returns an expression ::
   Ity_I32. */
static IRExpr* mk_x86g_calculate_eflags_all ( void )
{
   IRExpr** args
      = mkIRExprVec_4( IRExpr_Get(OFFB_CC_OP,   Ity_I32),
                       IRExpr_Get(OFFB_CC_DEP1, Ity_I32),
                       IRExpr_Get(OFFB_CC_DEP2, Ity_I32),
                       IRExpr_Get(OFFB_CC_NDEP, Ity_I32) );
   IRExpr* call
      = mkIRExprCCall(
           Ity_I32,
           0/*regparm*/, 
           "x86g_calculate_eflags_all", &x86g_calculate_eflags_all,
           args
        );
   /* Exclude OP and NDEP from definedness checking.  We're only
      interested in DEP1 and DEP2. */
   call->Iex.CCall.cee->mcx_mask = (1<<0) | (1<<3);
   return call;
}

/* Build IR to calculate some particular condition from stored
   CC_OP/CC_DEP1/CC_DEP2/CC_NDEP.  Returns an expression ::
   Ity_Bit. */
static IRExpr* mk_x86g_calculate_condition ( X86Condcode cond )
{
   IRExpr** args
      = mkIRExprVec_5( mkU32(cond),
                       IRExpr_Get(OFFB_CC_OP,  Ity_I32),
                       IRExpr_Get(OFFB_CC_DEP1, Ity_I32),
                       IRExpr_Get(OFFB_CC_DEP2, Ity_I32),
                       IRExpr_Get(OFFB_CC_NDEP, Ity_I32) );
   IRExpr* call
      = mkIRExprCCall(
           Ity_I32,
           0/*regparm*/, 
           "x86g_calculate_condition", &x86g_calculate_condition,
           args
        );
   /* Exclude the requested condition, OP and NDEP from definedness
      checking.  We're only interested in DEP1 and DEP2. */
   call->Iex.CCall.cee->mcx_mask = (1<<0) | (1<<1) | (1<<4);
   return unop(Iop_32to1, call);
}

/* Build IR to calculate just the carry flag from stored
   CC_OP/CC_DEP1/CC_DEP2/CC_NDEP.  Returns an expression :: Ity_I32. */
static IRExpr* mk_x86g_calculate_eflags_c ( void )
{
   IRExpr** args
      = mkIRExprVec_4( IRExpr_Get(OFFB_CC_OP,   Ity_I32),
                       IRExpr_Get(OFFB_CC_DEP1, Ity_I32),
                       IRExpr_Get(OFFB_CC_DEP2, Ity_I32),
                       IRExpr_Get(OFFB_CC_NDEP, Ity_I32) );
   IRExpr* call
      = mkIRExprCCall(
           Ity_I32,
           3/*regparm*/, 
           "x86g_calculate_eflags_c", &x86g_calculate_eflags_c,
           args
        );
   /* Exclude OP and NDEP from definedness checking.  We're only
      interested in DEP1 and DEP2. */
   call->Iex.CCall.cee->mcx_mask = (1<<0) | (1<<3);
   return call;
}


/* -------------- Building the flags-thunk. -------------- */

/* The machinery in this section builds the flag-thunk following a
   flag-setting operation.  Hence the various setFlags_* functions.
*/

static Bool isAddSub ( IROp op8 )
{
   return toBool(op8 == Iop_Add8 || op8 == Iop_Sub8);
}

static Bool isLogic ( IROp op8 )
{
   return toBool(op8 == Iop_And8 || op8 == Iop_Or8 || op8 == Iop_Xor8);
}

/* U-widen 8/16/32 bit int expr to 32. */
static IRExpr* widenUto32 ( IRExpr* e )
{
   switch (typeOfIRExpr(irbb->tyenv,e)) {
      case Ity_I32: return e;
      case Ity_I16: return unop(Iop_16Uto32,e);