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- #include "gc.h"
- void
- codgen(Node *n, Node *nn)
- {
- Prog *sp;
- Node *n1, nod, nod1;
- cursafe = 0;
- curarg = 0;
- maxargsafe = 0;
- /*
- * isolate name
- */
- for(n1 = nn;; n1 = n1->left) {
- if(n1 == Z) {
- diag(nn, "cant find function name");
- return;
- }
- if(n1->op == ONAME)
- break;
- }
- nearln = nn->lineno;
- gpseudo(ATEXT, n1->sym, nodconst(stkoff));
- sp = p;
- /*
- * isolate first argument
- */
- if(REGARG) {
- if(typesuv[thisfn->link->etype]) {
- nod1 = *nodret->left;
- nodreg(&nod, &nod1, REGARG);
- gopcode(OAS, &nod, Z, &nod1);
- } else
- if(firstarg && typechlp[firstargtype->etype]) {
- nod1 = *nodret->left;
- nod1.sym = firstarg;
- nod1.type = firstargtype;
- nod1.xoffset = align(0, firstargtype, Aarg1);
- nod1.etype = firstargtype->etype;
- nodreg(&nod, &nod1, REGARG);
- gopcode(OAS, &nod, Z, &nod1);
- }
- }
- retok = 0;
- gen(n);
- if(!retok)
- if(thisfn->link->etype != TVOID)
- warn(Z, "no return at end of function: %s", n1->sym->name);
- noretval(3);
- gbranch(ORETURN);
- if(!debug['N'] || debug['R'] || debug['P'])
- regopt(sp);
- sp->to.offset += maxargsafe;
- }
- void
- gen(Node *n)
- {
- Node *l, nod;
- Prog *sp, *spc, *spb;
- Case *cn;
- long sbc, scc;
- int o;
- loop:
- if(n == Z)
- return;
- nearln = n->lineno;
- o = n->op;
- if(debug['G'])
- if(o != OLIST)
- print("%L %O\n", nearln, o);
- retok = 0;
- switch(o) {
- default:
- complex(n);
- cgen(n, Z);
- break;
- case OLIST:
- gen(n->left);
- rloop:
- n = n->right;
- goto loop;
- case ORETURN:
- retok = 1;
- complex(n);
- if(n->type == T)
- break;
- l = n->left;
- if(l == Z) {
- noretval(3);
- gbranch(ORETURN);
- break;
- }
- if(typesuv[n->type->etype]) {
- sugen(l, nodret, n->type->width);
- noretval(3);
- gbranch(ORETURN);
- break;
- }
- regret(&nod, n);
- cgen(l, &nod);
- regfree(&nod);
- if(typefd[n->type->etype])
- noretval(1);
- else
- noretval(2);
- gbranch(ORETURN);
- break;
- case OLABEL:
- l = n->left;
- if(l) {
- l->pc = pc;
- if(l->label)
- patch(l->label, pc);
- }
- gbranch(OGOTO); /* prevent self reference in reg */
- patch(p, pc);
- goto rloop;
- case OGOTO:
- retok = 1;
- n = n->left;
- if(n == Z)
- return;
- if(n->complex == 0) {
- diag(Z, "label undefined: %s", n->sym->name);
- return;
- }
- gbranch(OGOTO);
- if(n->pc) {
- patch(p, n->pc);
- return;
- }
- if(n->label)
- patch(n->label, pc-1);
- n->label = p;
- return;
- case OCASE:
- l = n->left;
- if(cases == C)
- diag(n, "case/default outside a switch");
- if(l == Z) {
- cas();
- cases->val = 0;
- cases->def = 1;
- cases->label = pc;
- goto rloop;
- }
- complex(l);
- if(l->type == T)
- goto rloop;
- if(l->op == OCONST)
- if(typechl[l->type->etype]) {
- cas();
- cases->val = l->vconst;
- cases->def = 0;
- cases->label = pc;
- goto rloop;
- }
- diag(n, "case expression must be integer constant");
- goto rloop;
- case OSWITCH:
- l = n->left;
- complex(l);
- if(l->type == T)
- break;
- if(!typechl[l->type->etype]) {
- diag(n, "switch expression must be integer");
- break;
- }
- gbranch(OGOTO); /* entry */
- sp = p;
- cn = cases;
- cases = C;
- cas();
- sbc = breakpc;
- breakpc = pc;
- gbranch(OGOTO);
- spb = p;
- gen(n->right);
- gbranch(OGOTO);
- patch(p, breakpc);
- patch(sp, pc);
- regalloc(&nod, l, Z);
- nod.type = types[TLONG];
- cgen(l, &nod);
- doswit(&nod);
- regfree(&nod);
- patch(spb, pc);
- cases = cn;
- breakpc = sbc;
- break;
- case OWHILE:
- case ODWHILE:
- l = n->left;
- gbranch(OGOTO); /* entry */
- sp = p;
- scc = continpc;
- continpc = pc;
- gbranch(OGOTO);
- spc = p;
- sbc = breakpc;
- breakpc = pc;
- gbranch(OGOTO);
- spb = p;
- patch(spc, pc);
- if(n->op == OWHILE)
- patch(sp, pc);
- bcomplex(l); /* test */
- patch(p, breakpc);
- if(n->op == ODWHILE)
- patch(sp, pc);
- gen(n->right); /* body */
- gbranch(OGOTO);
- patch(p, continpc);
- patch(spb, pc);
- continpc = scc;
- breakpc = sbc;
- break;
- case OFOR:
- l = n->left;
- gen(l->right->left); /* init */
- gbranch(OGOTO); /* entry */
- sp = p;
- scc = continpc;
- continpc = pc;
- gbranch(OGOTO);
- spc = p;
- sbc = breakpc;
- breakpc = pc;
- gbranch(OGOTO);
- spb = p;
- patch(spc, pc);
- gen(l->right->right); /* inc */
- patch(sp, pc);
- if(l->left != Z) { /* test */
- bcomplex(l->left);
- patch(p, breakpc);
- }
- gen(n->right); /* body */
- gbranch(OGOTO);
- patch(p, continpc);
- patch(spb, pc);
- continpc = scc;
- breakpc = sbc;
- break;
- case OCONTINUE:
- if(continpc < 0) {
- diag(n, "continue not in a loop");
- break;
- }
- gbranch(OGOTO);
- patch(p, continpc);
- break;
- case OBREAK:
- if(breakpc < 0) {
- diag(n, "break not in a loop");
- break;
- }
- gbranch(OGOTO);
- patch(p, breakpc);
- break;
- case OIF:
- l = n->left;
- bcomplex(l);
- sp = p;
- if(n->right->left != Z)
- gen(n->right->left);
- if(n->right->right != Z) {
- gbranch(OGOTO);
- patch(sp, pc);
- sp = p;
- gen(n->right->right);
- }
- patch(sp, pc);
- break;
- case OSET:
- case OUSED:
- usedset(n->left, o);
- break;
- }
- }
- void
- usedset(Node *n, int o)
- {
- if(n->op == OLIST) {
- usedset(n->left, o);
- usedset(n->right, o);
- return;
- }
- complex(n);
- switch(n->op) {
- case OADDR: /* volatile */
- gins(ANOP, n, Z);
- break;
- case ONAME:
- if(o == OSET)
- gins(ANOP, Z, n);
- else
- gins(ANOP, n, Z);
- break;
- }
- }
- void
- noretval(int n)
- {
- if(n & 1) {
- gins(ANOP, Z, Z);
- p->to.type = D_REG;
- p->to.reg = REGRET;
- }
- if(n & 2) {
- gins(ANOP, Z, Z);
- p->to.type = D_REG;
- p->to.reg = FREGRET;
- }
- }
- /*
- * 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 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 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;
- }
- }
- void
- bcomplex(Node *n)
- {
- complex(n);
- if(n->type != T)
- if(tcompat(n, T, n->type, tnot))
- n->type = T;
- if(n->type != T) {
- bool64(n);
- boolgen(n, 1, Z);
- } else
- gbranch(OGOTO);
- }
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