// Inferno utils/8c/sgen.c
// http://code.google.com/p/inferno-os/source/browse/utils/8c/sgen.c
//
// Copyright © 1994-1999 Lucent Technologies Inc. All rights reserved.
// Portions Copyright © 1995-1997 C H Forsyth (forsyth@terzarima.net)
// Portions Copyright © 1997-1999 Vita Nuova Limited
// Portions Copyright © 2000-2007 Vita Nuova Holdings Limited (www.vitanuova.com)
// Portions Copyright © 2004,2006 Bruce Ellis
// Portions Copyright © 2005-2007 C H Forsyth (forsyth@terzarima.net)
// Revisions Copyright © 2000-2007 Lucent Technologies Inc. and others
// Portions Copyright © 2009 The Go Authors. All rights reserved.
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.
#include "gc.h"
Prog*
gtext(Sym *s, int32 stkoff)
{
int32 a;
a = argsize();
if((textflag & NOSPLIT) != 0 && stkoff >= 128)
yyerror("stack frame too large for NOSPLIT function");
gpseudo(ATEXT, s, nodconst(stkoff));
p->to.type = D_CONST2;
p->to.offset2 = a;
return p;
}
void
noretval(int n)
{
if(n & 1) {
gins(ANOP, Z, Z);
p->to.type = REGRET;
}
if(n & 2) {
gins(ANOP, Z, Z);
p->to.type = FREGRET;
}
}
/* welcome to commute */
static void
commute(Node *n)
{
Node *l, *r;
l = n->left;
r = n->right;
if(r->complex > l->complex) {
n->left = r;
n->right = l;
}
}
void
indexshift(Node *n)
{
int g;
if(!typechlp[n->type->etype])
return;
simplifyshift(n);
if(n->op == OASHL && n->right->op == OCONST){
g = vconst(n->right);
if(g >= 0 && g < 4)
n->addable = 7;
}
}
/*
* calculate addressability as follows
* NAME ==> 10/11 name+value(SB/SP)
* REGISTER ==> 12 register
* CONST ==> 20 $value
* *(20) ==> 21 value
* &(10) ==> 13 $name+value(SB)
* &(11) ==> 1 $name+value(SP)
* (13) + (20) ==> 13 fold constants
* (1) + (20) ==> 1 fold constants
* *(13) ==> 10 back to name
* *(1) ==> 11 back to name
*
* (20) * (X) ==> 7 multiplier in indexing
* (X,7) + (13,1) ==> 8 adder in indexing (addresses)
* (8) ==> &9(OINDEX) index, almost addressable
* 100 extern register
*
* 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 = 10;
if(n->class == CPARAM || n->class == CAUTO)
n->addable = 11;
break;
case OEXREG:
n->addable = 0;
break;
case OREGISTER:
n->addable = 12;
break;
case OINDREG:
n->addable = 12;
break;
case OADDR:
xcom(l);
if(l->addable == 10)
n->addable = 13;
else
if(l->addable == 11)
n->addable = 1;
break;
case OADD:
xcom(l);
xcom(r);
if(n->type->etype != TIND)
break;
switch(r->addable) {
case 20:
switch(l->addable) {
case 1:
case 13:
commadd:
l->type = n->type;
*n = *l;
l = new(0, Z, Z);
*l = *(n->left);
l->xoffset += r->vconst;
n->left = l;
r = n->right;
goto brk;
}
break;
case 1:
case 13:
case 10:
case 11:
/* l is the base, r is the index */
if(l->addable != 20)
n->addable = 8;
break;
}
switch(l->addable) {
case 20:
switch(r->addable) {
case 13:
case 1:
r = n->left;
l = n->right;
n->left = l;
n->right = r;
goto commadd;
}
break;
case 13:
case 1:
case 10:
case 11:
/* r is the base, l is the index */
if(r->addable != 20)
n->addable = 8;
break;
}
if(n->addable == 8 && !side(n)) {
indx(n);
l = new1(OINDEX, idx.basetree, idx.regtree);
l->scale = idx.scale;
l->addable = 9;
l->complex = l->right->complex;
l->type = l->left->type;
n->op = OADDR;
n->left = l;
n->right = Z;
n->addable = 8;
break;
}
break;
case OINDEX:
xcom(l);
xcom(r);
n->addable = 9;
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 13:
n->addable = 10;
break;
}
break;
case OASHL:
xcom(l);
xcom(r);
indexshift(n);
break;
case OMUL:
case OLMUL:
xcom(l);
xcom(r);
g = vlog(l);
if(g >= 0) {
n->left = r;
n->right = l;
l = r;
r = n->right;
}
g = vlog(r);
if(g >= 0) {
n->op = OASHL;
r->vconst = g;
r->type = types[TINT];
indexshift(n);
break;
}
commute(n);
break;
case OASLDIV:
xcom(l);
xcom(r);
g = vlog(r);
if(g >= 0) {
n->op = OASLSHR;
r->vconst = g;
r->type = types[TINT];
}
break;
case OLDIV:
xcom(l);
xcom(r);
g = vlog(r);
if(g >= 0) {
n->op = OLSHR;
r->vconst = g;
r->type = types[TINT];
indexshift(n);
break;
}
break;
case OASLMOD:
xcom(l);
xcom(r);
g = vlog(r);
if(g >= 0) {
n->op = OASAND;
r->vconst--;
}
break;
case OLMOD:
xcom(l);
xcom(r);
g = vlog(r);
if(g >= 0) {
n->op = OAND;
r->vconst--;
}
break;
case OASMUL:
case OASLMUL:
xcom(l);
xcom(r);
g = vlog(r);
if(g >= 0) {
n->op = OASASHL;
r->vconst = g;
}
break;
case OLSHR:
case OASHR:
xcom(l);
xcom(r);
indexshift(n);
break;
default:
if(l != Z)
xcom(l);
if(r != Z)
xcom(r);
break;
}
brk:
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 OLMOD:
case OMOD:
case OLMUL:
case OLDIV:
case OMUL:
case ODIV:
case OASLMUL:
case OASLDIV:
case OASLMOD:
case OASMUL:
case OASDIV:
case OASMOD:
if(r->complex >= l->complex) {
n->complex = l->complex + 3;
if(r->complex > n->complex)
n->complex = r->complex;
} else {
n->complex = r->complex + 3;
if(l->complex > n->complex)
n->complex = l->complex;
}
break;
case OLSHR:
case OASHL:
case OASHR:
case OASLSHR:
case OASASHL:
case OASASHR:
if(r->complex >= l->complex) {
n->complex = l->complex + 2;
if(r->complex > n->complex)
n->complex = r->complex;
} else {
n->complex = r->complex + 2;
if(l->complex > n->complex)
n->complex = l->complex;
}
break;
case OADD:
case OXOR:
case OAND:
case OOR:
/*
* immediate operators, make const on right
*/
if(l->op == OCONST) {
n->left = r;
n->right = l;
}
break;
case OEQ:
case ONE:
case OLE:
case OLT:
case OGE:
case OGT:
case OHI:
case OHS:
case OLO:
case OLS:
/*
* compare operators, make const on left
*/
if(r->op == OCONST) {
n->left = r;
n->right = l;
n->op = invrel[relindex(n->op)];
}
break;
}
}
void
indx(Node *n)
{
Node *l, *r;
if(debug['x'])
prtree(n, "indx");
l = n->left;
r = n->right;
if(l->addable == 1 || l->addable == 13 || r->complex > l->complex) {
n->right = l;
n->left = r;
l = r;
r = n->right;
}
if(l->addable != 7) {
idx.regtree = l;
idx.scale = 1;
} else
if(l->right->addable == 20) {
idx.regtree = l->left;
idx.scale = 1 << l->right->vconst;
} else
if(l->left->addable == 20) {
idx.regtree = l->right;
idx.scale = 1 << l->left->vconst;
} else
diag(n, "bad index");
idx.basetree = r;
if(debug['x']) {
print("scale = %d\n", idx.scale);
prtree(idx.regtree, "index");
prtree(idx.basetree, "base");
}
}