/*
* xfold will remove constant nodes and return the values to
* the calling routines.
*/
__int64 xfold(ENODE *node)
{
__int64 i;
if( node == NULL )
return 0;
switch( node->nodetype )
{
case en_icon:
i = node->i;
node->i = 0;
return i;
case en_add:
return xfold(node->p[0]) + xfold(node->p[1]);
case en_sub:
return xfold(node->p[0]) - xfold(node->p[1]);
case en_mul:
case en_mulu:
if( node->p[0]->nodetype == en_icon )
return xfold(node->p[1]) * node->p[0]->i;
else if( node->p[1]->nodetype == en_icon )
return xfold(node->p[0]) * node->p[1]->i;
else return 0;
case en_shl:
if( node->p[0]->nodetype == en_icon )
return xfold(node->p[1]) << node->p[0]->i;
else if( node->p[1]->nodetype == en_icon )
return xfold(node->p[0]) << node->p[1]->i;
else return 0;
case en_uminus:
return - xfold(node->p[0]);
case en_shr: case en_div: case en_udiv: case en_shru:
case en_mod: case en_asadd:
case en_assub: case en_asmul:
case en_asdiv: case en_asmod:
case en_and: case en_land:
case en_or: case en_lor:
case en_xor: case en_asand:
case en_asor: case en_void:
case en_fcall: case en_assign:
fold_const(&node->p[0]);
fold_const(&node->p[1]);
return 0;
case en_ub_ref: case en_uw_ref:
case en_uc_ref: case en_uh_ref:
case en_b_ref: case en_w_ref:
case en_c_ref: case en_h_ref:
case en_compl:
case en_not:
fold_const(&node->p[0]);
return 0;
}
return 0;
}
/*
* reorganize an expression for optimal constant grouping.
*/
static void fold_const(ENODE **node)
{
ENODE *ep;
int64_t i;
ep = *node;
if( ep == 0 )
return;
if( ep->nodetype == en_add )
{
if( ep->p[0]->nodetype == en_icon )
{
ep->p[0]->i += xfold(ep->p[1]);
return;
}
else if( ep->p[1]->nodetype == en_icon )
{
ep->p[1]->i += xfold(ep->p[0]);
return;
}
}
else if( ep->nodetype == en_sub )
{
if( ep->p[0]->nodetype == en_icon )
{
ep->p[0]->i -= xfold(ep->p[1]);
return;
}
else if( ep->p[1]->nodetype == en_icon )
{
ep->p[1]->i -= xfold(ep->p[0]); // ??? other order ??? xfold - p[1]
return;
}
}
i = xfold(ep);
if( i != 0 )
{
ep = makeinode(en_icon,i);
ep->etype = (*node)->etype;
ep->tp = (*node)->tp;
ep = makenode(en_add,ep,*node);
ep->etype = (*node)->etype;
ep->tp = (*node)->tp;
*node = ep;
}
}
/*
* reorganize an expression for optimal constant grouping.
*/
void fold_const(ENODE **node)
{ ENODE *ep;
__int64 i;
ep = *node;
if( ep == 0 )
return;
if( ep->nodetype == en_add )
{
if( ep->p[0]->nodetype == en_icon )
{
ep->p[0]->i += xfold(ep->p[1]);
return;
}
else if( ep->p[1]->nodetype == en_icon )
{
ep->p[1]->i += xfold(ep->p[0]);
return;
}
}
else if( ep->nodetype == en_sub )
{
if( ep->p[0]->nodetype == en_icon )
{
ep->p[0]->i -= xfold(ep->p[1]);
return;
}
else if( ep->p[1]->nodetype == en_icon )
{
ep->p[1]->i -= xfold(ep->p[0]);
return;
}
}
i = xfold(ep);
if( i != 0 )
{
ep = makeinode(en_icon,i);
ep = makenode(en_add,ep,*node);
*node = ep;
}
}
/*
* xfold will remove constant nodes and return the values to
* the calling routines.
*/
static int64_t xfold(ENODE *node)
{
int64_t i;
if( node == NULL )
return 0;
switch( node->nodetype )
{
case en_icon:
i = node->i;
node->i = 0;
return i;
case en_sxb: case en_sxc: case en_sxh:
case en_zxb: case en_zxc: case en_zxh:
case en_abs:
case en_isnullptr:
return (0);
return xfold(node->p[0]);
case en_add:
return xfold(node->p[0]) + xfold(node->p[1]);
case en_sub:
return xfold(node->p[0]) - xfold(node->p[1]);
case en_mulf:
case en_mul:
case en_mulu:
return (0);
if( node->p[0]->nodetype == en_icon )
return xfold(node->p[1]) * node->p[0]->i;
else if( node->p[1]->nodetype == en_icon )
return xfold(node->p[0]) * node->p[1]->i;
else return 0;
case en_asl:
case en_shl: case en_shlu:
if( node->p[0]->nodetype == en_icon )
return xfold(node->p[1]) << node->p[0]->i;
else if( node->p[1]->nodetype == en_icon )
return xfold(node->p[0]) << node->p[1]->i;
else return 0;
case en_uminus:
return - xfold(node->p[0]);
case en_shr: case en_div: case en_udiv: case en_shru: case en_asr:
case en_mod: case en_asadd:
case en_assub: case en_asmul:
case en_asdiv: case en_asmod:
case en_and: case en_land: case en_land_safe:
case en_or: case en_lor: case en_lor_safe:
case en_xor: case en_asand:
case en_asor: case en_void:
case en_fcall: case en_assign:
fold_const(&node->p[0]);
fold_const(&node->p[1]);
return 0;
case en_ref32: case en_ref32u:
case en_ub_ref: case en_uw_ref:
case en_uc_ref: case en_uh_ref:
case en_b_ref: case en_w_ref:
case en_c_ref: case en_h_ref:
case en_wp_ref: case en_hp_ref:
case en_vector_ref:
case en_compl:
case en_not:
fold_const(&node->p[0]);
return 0;
}
return 0;
}
