instruction *rCLRHI_R( instruction *ins )
/********************************************/
{
instruction *new_ins;
instruction *and_ins;
type_class_def type_class;
hw_reg_set high;
name *res;
signed_32 value;
type_class_def half_type_class;
name *op;
half_type_class = HalfClass[ins->type_class];
op = ins->operands[0];
type_class = ins->base_type_class;
res = ins->result;
high = HighReg( res->r.reg );
if( op->n.class == N_INDEXED
&& ( ( op->i.index->n.class == N_REGISTER && HW_Ovlap( op->i.index->r.reg, res->r.reg ) ) /* (1) */
|| ( CheckIndecies( ins, res->r.reg, HW_EMPTY, NULL ) == MB_MAYBE ) /* 2 */
)
) {
/* (1) would have gen'd movzd eax,[eax]
* (2) avoid incorrect reduction of "cnv [foo] => BX" to
* xor bx,bx / mov bx, [foo] / mov bl, [bx]
* (zoiks register allocator)
*/
new_ins = NULL;
} else if( !HW_CEqual( high, HW_EMPTY ) && half_type_class == type_class ) {
bool ScConvert( instruction *ins )
/********************************************
Get rid of instructions like CBW if the high part is not used in the
next instruction.
*/
{
hw_reg_set tmp;
if( G( ins ) == G_SIGNEX ) {
tmp = HighReg( ins->result->r.reg );
if( !HW_Ovlap( ins->head.next->head.live.regs, tmp ) ) {
FreeIns( ins ); /* get rid of the pesky cwd or cbw instruction!*/
return( true );
}
}
return( false );
}
extern bool DoVerify( vertype kind, instruction *ins ) {
/**********************************************************/
name *op1;
name *op2;
name *result;
hw_reg_set tmp;
result = ins->result;
if( ins->num_operands != 0 ) {
op1 = ins->operands[ 0 ];
if( ins->num_operands != 1 ) {
op2 = ins->operands[ 1 ];
}
}
switch( kind ) {
case V_OP2I2:
/*
* U2 is OK too. A U2 operand wouldn't be present in the instruction
* unless the tree code decided it was ok for a halfword instruction
* Kludgey? Maybe just a little.
*/
if( op2->n.name_class == U2 ) return( TRUE );
if( op2->n.name_class == I2 ) return( TRUE );
return( FALSE );
case V_OP1SMALL:
if( op1->c.const_type != CONS_ABSOLUTE ) return( FALSE );
if( op1->c.int_value < 0 ) return( FALSE );
if( op1->c.int_value > 4095 ) return( FALSE );
return( TRUE );
case V_OP1TEMP:
if( op1->n.class == N_TEMP ) return( TRUE );
return( FALSE );
case V_OP1ADDR:
case V_OP1LOC:
if( op1->n.class == N_MEMORY ) return( TRUE );
return( FALSE );
case V_OP2I2CON:
if( op2->c.const_type == CONS_ABSOLUTE
&& CFIsI16( op2->c.value ) ) return( TRUE );
return( FALSE );
case V_LA2:
if( HW_CEqual( op1->r.reg, HW_G0 ) ) return( FALSE );
/* fall through ! */
case V_OP2SMALL:
if( op2->c.const_type != CONS_ABSOLUTE ) return( FALSE );
if( op2->c.int_value < 0 ) return( FALSE );
if( op2->c.int_value > 4095 ) return( FALSE );
return( TRUE );
case V_MULPAIR:
if( !IsRegPair( result->r.reg ) ) return( FALSE );
tmp = LowReg( result->r.reg );
if( !HW_Equal( tmp, op1->r.reg ) ) return( FALSE );
return( TRUE );
case V_CONVPAIR:
if( !IsRegPair( result->r.reg ) ) return( FALSE );
tmp = HighReg( result->r.reg );
if( !HW_Equal( tmp, op1->r.reg ) ) return( FALSE );
return( TRUE );
case V_SIZE_SMALL:
if( op1->n.size > 256 ) return( FALSE );
return( TRUE );
case V_OP2BYTE4CONS:
if( !CFIsI32( op2->c.value ) ) return( FALSE );
if( ( op2->c.int_value & 0xFFFFFF00 ) == 0 ) return( TRUE );
if( ( op2->c.int_value & 0xFFFF00FF ) == 0 ) return( TRUE );
if( ( op2->c.int_value & 0xFF00FFFF ) == 0 ) return( TRUE );
if( ( op2->c.int_value & 0x00FFFFFF ) == 0 ) return( TRUE );
return( FALSE );
case V_OP2BYTE2CONS:
if( !CFIsI16( op2->c.value ) ) return( FALSE );
if( ( op2->c.int_value & 0xFFFFFF00 ) == 0 ) return( TRUE );
if( ( op2->c.int_value & 0xFFFF00FF ) == 0 ) return( TRUE );
return( FALSE );
case V_CMPEQ_OP2ZERO:
if( !OtherVerify( V_CMPEQ, ins, op1, op2, result ) ) return( FALSE );
if( !OtherVerify( V_OP2ZERO, ins, op1, op2, result ) ) return( FALSE );
return( TRUE );
default:
return( OtherVerify( kind, ins, op1, op2, result ) );
}
return( FALSE );
}
extern void DumpOperand( name *operand ) {
/********************************************/
char buffer[20];
hw_reg_set reg;
name *base;
if( operand->n.class == N_INDEXED ) {
if( operand->i.base != NULL ) {
if( !( operand->i.index_flags & X_FAKE_BASE ) ) {
if( operand->i.index_flags & X_LOW_ADDR_BASE ) {
DumpLiteral( "l^" );
}
DumpOperand( operand->i.base );
if( operand->i.constant > 0 ) {
DumpChar( '+' );
}
}
}
if( operand->i.constant != 0 ) {
DumpLong( operand->i.constant );
}
DumpChar( '[' );
if( operand->i.index_flags & X_BASE ) {
reg = operand->i.index->r.reg;
#if _TARGET & ( _TARG_IAPX86 | _TARG_80386 )
if( HW_COvlap( reg, HW_SEGS ) ) {
hw_reg_set tmp;
tmp = reg;
HW_COnlyOn( tmp, HW_SEGS );
DumpRegName( tmp );
DumpChar( ':' );
HW_CTurnOff( reg, HW_SEGS );
}
#endif
if( operand->i.index_flags & X_HIGH_BASE ) {
DumpRegName( HighReg( reg ) );
DumpChar( '+' );
DumpRegName( LowReg( reg ) );
} else {
DumpRegName( LowReg( reg ) );
DumpChar( '+' );
DumpRegName( HighReg( reg ) );
}
} else {
DumpOperand( operand->i.index );
}
if( operand->i.scale != 0 ) {
DumpChar( '*' );
DumpInt( 1 << operand->i.scale );
}
if( operand->i.index_flags & ( X_ALIGNED_1 | X_ALIGNED_2 | X_ALIGNED_4 | X_ALIGNED_8 ) ) {
DumpChar( '$' );
DumpInt( FlagsToAlignment( operand->i.index_flags ) );
}
DumpChar( ']' );
base = operand->i.base;
if( base != NULL ) {
if( operand->i.index_flags & X_FAKE_BASE ) {
DumpChar( '{' );
if( base->n.class == N_MEMORY ) {
DumpXString( AskName(base->v.symbol, base->m.memory_type) );
} else if( base->n.class == N_TEMP ) {
if( _FrontEndTmp( base ) ) {
DumpXString( FEName( base->v.symbol ) );
} else {
DumpOperand( base );
}
}
DumpChar( '}' );
}
}