extern instruction *NeedIndex( instruction *ins ) {
/*******************************************************
Mark conflicts for any name used in instruction as as segment as
NEEDS_SEGMENT, or split out the segment if it is marked as
NEEDS_SEGMENT_SPLIT (move the segment operand to a temp and use the
temp as the segment override). Also, if any index conflicts are
marked as NEEDS_INDEX_SPLIT, split them out into a temp as well.
*/
name *temp;
name *index;
conflict_node *conf;
name *name;
if( ins->num_operands > NumOperands( ins ) ) {
name = ins->operands[ins->num_operands - 1];
conf = NameConflict( ins, name );
if( conf != NULL && _Isnt( conf, CST_NEEDS_SEGMENT_SPLIT ) ) {
_SetTrue( conf, CST_NEEDS_SEGMENT );
MarkSegment( ins, name );
} else if( name->n.class != N_REGISTER ) {
if( conf != NULL ) {
_SetFalse( conf, CST_NEEDS_SEGMENT );
_SetTrue( conf, CST_WAS_SEGMENT );
}
temp = AllocTemp( U2 );
ins->operands[ins->num_operands - 1] = temp;
PrefixIns( ins, MakeMove( name, temp, U2 ) );
MarkSegment( ins, temp );
_SetTrue( NameConflict( ins, temp ), CST_SEGMENT_SPLIT );
ins = ins->head.prev;
}
}
extern bool IndexOkay( instruction *ins, name *index ) {
/**********************************************************/
name *name;
conflict_node *conf;
name = index->i.index;
if( name->n.class == N_REGISTER ) {
return( IsIndexReg( name->r.reg, name->n.name_class, 0 ) );
}
if( name->v.conflict == NULL ) return( FALSE );
if( name->v.usage & USE_MEMORY ) return( FALSE );
if( name->n.class != N_TEMP ) return( FALSE );
conf = NameConflict( ins, name );
if( conf == NULL ) return( FALSE );
if( _Is( conf, NEEDS_INDEX_SPLIT ) ) {
_SetFalse( conf, NEEDS_INDEX );
return( FALSE );
} else {
_SetTrue( conf, NEEDS_INDEX );
ins->head.state = OPERANDS_NEED_WORK;
ins->t.index_needs = MarkIndex( ins, name, 0 );
return( TRUE );
}
}
extern void SplitVars( void )
/*******************************/
/* For each variable, find out if it can be split into two separate variables.*/
/* This often happens when programmers re-use variables rather than defining*/
/* a new one.*/
{
name *op;
conflict_node *conf;
for( ;; ) {
for( conf = ConfList; conf != NULL; conf = conf->next_conflict ) {
op = conf->name;
if( (op->v.usage & USE_IN_ANOTHER_BLOCK) == 0 )
continue;
if( op->n.class != N_TEMP )
continue;
if( _Is( conf, CST_CONF_VISITED ) )
continue;
_SetFalse( conf, CST_CONFLICT_ON_HOLD );
if( _GBitEmpty( conf->id.out_of_block ) )
continue;
if( op->t.alias == op )
Split1Var( conf );
_GBitInit( conf->id.out_of_block, EMPTY );
_SetTrue( conf, CST_CONFLICT_ON_HOLD | CST_CONF_VISITED );
}
if( !MoreConflicts() ) {
break;
}
}
CleanUp();
FreeConflicts();
InsDead();
NullConflicts( EMPTY );
FindReferences();
MakeConflicts();
}