/*
* calculate addressability as follows
* REGISTER ==> 12 register
* NAME ==> 11 name+value(SB/SP)
* note that 10 is no longer generated
* CONST ==> 20 $value
* *(20) ==> 21 value
* &(10) ==> 12 $name+value(SB)
* &(11) ==> 1 $name+value(SP)
* (12) + (20) ==> 12 fold constants
* (1) + (20) ==> 1 fold constants
* *(12) ==> 10 back to name
* *(1) ==> 11 back to name
*
* (2,10,11) + (20) ==> 2 indirect w offset
* (2) ==> &13
* *(10,11) ==> 13 indirect, no index
*
* (20) * (X) ==> 7 multiplier in indexing
* (X,7) + (12,1) ==> 8 adder in indexing (addresses)
* (X,7) + (10,11,2) ==> 8 adder in indexing (names)
* (8) ==> &9 index, almost addressable
*
* (X)++ ==> X fake addressability
*
* calculate complexity (number of registers)
*/
void
xcom(Node *n)
{
Node *l, *r;
int g;
if(n == Z)
return;
l = n->left;
r = n->right;
n->complex = 0;
n->addable = 0;
switch(n->op) {
case OCONST:
n->addable = 20;
break;
case ONAME:
n->addable = 11; /* difference to make relocatable */
break;
case OREGISTER:
n->addable = 12;
break;
case OADDR:
xcom(l);
if(l->addable == 10)
n->addable = 12;
else
if(l->addable == 11)
n->addable = 1;
break;
case OADD:
xcom(l);
xcom(r);
if(n->type->etype != TIND)
break;
if(l->addable == 20)
switch(r->addable) {
case 12:
case 1:
n->addable = r->addable;
goto brk;
}
if(r->addable == 20)
switch(l->addable) {
case 12:
case 1:
n->addable = l->addable;
goto brk;
}
break;
case OIND:
xcom(l);
if(l->op == OADDR) {
l = l->left;
l->type = n->type;
*n = *l;
return;
}
switch(l->addable) {
case 20:
n->addable = 21;
break;
case 1:
n->addable = 11;
break;
case 12:
n->addable = 10;
break;
}
break;
case OASHL:
xcom(l);
xcom(r);
if(typev[n->type->etype])
break;
g = vconst(r);
if(g >= 0 && g < 4)
n->addable = 7;
break;
case OMUL:
case OLMUL:
xcom(l);
xcom(r);
if(typev[n->type->etype])
break;
g = vlog(r);
if(g >= 0) {
n->op = OASHL;
r->vconst = g;
if(g < 4)
n->addable = 7;
break;
}
g = vlog(l);
if(g >= 0) {
n->left = r;
n->right = l;
l = r;
r = n->right;
n->op = OASHL;
r->vconst = g;
if(g < 4)
n->addable = 7;
break;
}
break;
case ODIV:
case OLDIV:
xcom(l);
xcom(r);
if(typev[n->type->etype])
break;
g = vlog(r);
if(g >= 0) {
if(n->op == ODIV)
n->op = OASHR;
else
n->op = OLSHR;
r->vconst = g;
}
break;
case OSUB:
xcom(l);
xcom(r);
if(typev[n->type->etype])
break;
if(vconst(l) == 0) {
n->op = ONEG;
n->left = r;
n->right = Z;
}
break;
case OXOR:
xcom(l);
xcom(r);
if(typev[n->type->etype])
break;
if(vconst(l) == -1) {
n->op = OCOM;
n->left = r;
n->right = Z;
}
break;
case OASMUL:
case OASLMUL:
xcom(l);
xcom(r);
if(typev[n->type->etype])
break;
g = vlog(r);
if(g >= 0) {
n->op = OASASHL;
r->vconst = g;
}
goto aseae;
case OASDIV:
case OASLDIV:
xcom(l);
xcom(r);
if(typev[n->type->etype])
break;
g = vlog(r);
if(g >= 0) {
if(n->op == OASDIV)
n->op = OASASHR;
else
n->op = OASLSHR;
r->vconst = g;
}
goto aseae;
case OASLMOD:
case OASMOD:
xcom(l);
xcom(r);
if(typev[n->type->etype])
break;
aseae: /* hack that there are no byte/short mul/div operators */
if(n->type->etype == TCHAR || n->type->etype == TSHORT) {
n->right = new1(OCAST, n->right, Z);
n->right->type = types[TLONG];
n->type = types[TLONG];
}
if(n->type->etype == TUCHAR || n->type->etype == TUSHORT) {
n->right = new1(OCAST, n->right, Z);
n->right->type = types[TULONG];
n->type = types[TULONG];
}
goto asop;
case OASXOR:
case OASOR:
case OASADD:
case OASSUB:
case OASLSHR:
case OASASHR:
case OASASHL:
case OASAND:
case OAS:
xcom(l);
xcom(r);
if(typev[n->type->etype])
break;
asop:
if(l->addable > INDEXED &&
l->complex < FNX &&
r && r->complex < FNX)
n->addable = l->addable;
break;
case OPOSTINC:
case OPREINC:
case OPOSTDEC:
case OPREDEC:
xcom(l);
if(typev[n->type->etype])
break;
if(l->addable > INDEXED &&
l->complex < FNX)
n->addable = l->addable;
break;
default:
if(l != Z)
xcom(l);
if(r != Z)
xcom(r);
break;
}
brk:
n->complex = 0;
if(n->addable >= 10)
return;
if(l != Z)
n->complex = l->complex;
if(r != Z) {
if(r->complex == n->complex)
n->complex = r->complex+1;
else
if(r->complex > n->complex)
n->complex = r->complex;
}
if(n->complex == 0)
n->complex++;
if(com64(n))
return;
switch(n->op) {
case OFUNC:
n->complex = FNX;
break;
case OADD:
case OMUL:
case OLMUL:
case OXOR:
case OAND:
case OOR:
/*
* symmetric operators, make right side simple
* if same, put constant on left to get movq
*/
if(r->complex > l->complex ||
(r->complex == l->complex && r->addable == 20)) {
n->left = r;
n->right = l;
}
break;
case OLE:
case OLT:
case OGE:
case OGT:
case OEQ:
case ONE:
/*
* relational operators, make right side simple
* if same, put constant on left to get movq
*/
if(r->complex > l->complex || r->addable == 20) {
n->left = r;
n->right = l;
n->op = invrel[relindex(n->op)];
}
break;
}
}
/*
* calculate addressability as follows
* CONST ==> 20 $value
* NAME ==> 10 name
* REGISTER ==> 11 register
* INDREG ==> 12 *[(reg)+offset]
* &10 ==> 2 $name
* ADD(2, 20) ==> 2 $name+offset
* ADD(3, 20) ==> 3 $(reg)+offset
* &12 ==> 3 $(reg)+offset
* *11 ==> 11 ??
* *2 ==> 10 name
* *3 ==> 12 *(reg)+offset
* calculate complexity (number of registers)
*/
void
xcom(Node *n)
{
Node *l, *r;
int t;
if(n == Z)
return;
l = n->left;
r = n->right;
n->addable = 0;
n->complex = 0;
switch(n->op) {
case OCONST:
n->addable = 20;
return;
case OREGISTER:
n->addable = 11;
return;
case OINDREG:
n->addable = 12;
return;
case ONAME:
n->addable = 10;
return;
case OADDR:
xcom(l);
if(l->addable == 10)
n->addable = 2;
if(l->addable == 12)
n->addable = 3;
break;
case OIND:
xcom(l);
if(l->addable == 11)
n->addable = 12;
if(l->addable == 3)
n->addable = 12;
if(l->addable == 2)
n->addable = 10;
break;
case OADD:
xcom(l);
xcom(r);
if(l->addable == 20) {
if(r->addable == 2)
n->addable = 2;
if(r->addable == 3)
n->addable = 3;
}
if(r->addable == 20) {
if(l->addable == 2)
n->addable = 2;
if(l->addable == 3)
n->addable = 3;
}
break;
/*
case OSUB:
xcom(l);
xcom(r);
if(typefd[n->type->etype] || typev[n->type->etype])
break;
if(vconst(l) == 0)
n->op = ONEG;
n->left = l;
n->right = Z;
}
break;
*/
case OASHL:
case OASHR:
case OLSHR:
case OASASHL:
case OASASHR:
case OASLSHR:
xcom(l);
xcom(r);
if(sconst(r) && r->vconst < 0){
r->vconst = -r->vconst;
switch(n->op){
case OASHL: n->op = OASHR; break;
case OASHR: n->op = OASHL; break;
case OLSHR: n->op = OASHL; break;
case OASASHL: n->op = OASASHR; break;
case OASASHR: n->op = OASASHL; break;
case OASLSHR: n->op = OASASHL; break;
}
}
break;
case OASLMUL:
case OASMUL:
xcom(l);
xcom(r);
t = vlog(r);
if(t >= 0) {
n->op = OASASHL;
r->vconst = t;
r->type = types[TINT];
}
break;
case OMUL:
case OLMUL:
xcom(l);
xcom(r);
t = vlog(r);
if(t >= 0) {
n->op = OASHL;
r->vconst = t;
r->type = types[TINT];
}
t = vlog(l);
if(t >= 0) {
n->op = OASHL;
n->left = r;
n->right = l;
r = l;
l = n->left;
r->vconst = t;
r->type = types[TINT];
}
break;
case OASLDIV:
xcom(l);
xcom(r);
t = vlog(r);
if(t >= 0) {
n->op = OASLSHR;
r->vconst = t;
r->type = types[TINT];
}
break;
case OLDIV:
xcom(l);
xcom(r);
t = vlog(r);
if(t >= 0) {
n->op = OLSHR;
r->vconst = t;
r->type = types[TINT];
}
break;
case OASLMOD:
xcom(l);
xcom(r);
t = vlog(r);
if(t >= 0) {
n->op = OASAND;
r->vconst--;
}
break;
case OLMOD:
xcom(l);
xcom(r);
t = vlog(r);
if(t >= 0) {
n->op = OAND;
r->vconst--;
}
break;
default:
if(l != Z)
xcom(l);
if(r != Z)
xcom(r);
break;
}
if(n->addable >= 10)
return;
if(l != Z)
n->complex = l->complex;
if(r != Z) {
if(r->complex == n->complex)
n->complex = r->complex+1;
else
if(r->complex > n->complex)
n->complex = r->complex;
}
if(n->complex == 0)
n->complex++;
if(com64(n))
return;
switch(n->op) {
case OFUNC:
n->complex = FNX;
break;
case OLE:
case OLT:
case OGE:
case OGT:
case OHI:
case OHS:
case OLO:
case OLS:
/*
* immediate operators, make const on right
*/
if(l->op == OCONST) {
n->left = r;
n->right = l;
n->op = invrel[relindex(n->op)];
}
break;
case OADD:
case OXOR:
case OAND:
case OOR:
case OEQ:
case ONE:
/*
* immediate operators, make const on right
*/
if(l->op == OCONST) {
n->left = r;
n->right = l;
}
break;
}
}
