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-rw-r--r--src/cmd/8g/cgen.c1233
1 files changed, 1233 insertions, 0 deletions
diff --git a/src/cmd/8g/cgen.c b/src/cmd/8g/cgen.c
new file mode 100644
index 000000000..b316e6e34
--- /dev/null
+++ b/src/cmd/8g/cgen.c
@@ -0,0 +1,1233 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// TODO(rsc):
+// assume CLD?
+
+#include "gg.h"
+
+void
+mgen(Node *n, Node *n1, Node *rg)
+{
+ Node n2;
+
+ n1->op = OEMPTY;
+
+ if(n->addable) {
+ *n1 = *n;
+ if(n1->op == OREGISTER || n1->op == OINDREG)
+ reg[n->val.u.reg]++;
+ return;
+ }
+ tempname(n1, n->type);
+ cgen(n, n1);
+ if(n->type->width <= widthptr || isfloat[n->type->etype]) {
+ n2 = *n1;
+ regalloc(n1, n->type, rg);
+ gmove(&n2, n1);
+ }
+}
+
+void
+mfree(Node *n)
+{
+ if(n->op == OREGISTER)
+ regfree(n);
+}
+
+/*
+ * generate:
+ * res = n;
+ * simplifies and calls gmove.
+ *
+ * TODO:
+ * sudoaddable
+ */
+void
+cgen(Node *n, Node *res)
+{
+ Node *nl, *nr, *r, n1, n2, nt, f0, f1;
+ Prog *p1, *p2, *p3;
+ int a;
+
+ if(debug['g']) {
+ dump("\ncgen-n", n);
+ dump("cgen-res", res);
+ }
+
+ if(n == N || n->type == T)
+ fatal("cgen: n nil");
+ if(res == N || res->type == T)
+ fatal("cgen: res nil");
+
+ // inline slices
+ if(cgen_inline(n, res))
+ return;
+
+ while(n->op == OCONVNOP)
+ n = n->left;
+
+ // function calls on both sides? introduce temporary
+ if(n->ullman >= UINF && res->ullman >= UINF) {
+ tempname(&n1, n->type);
+ cgen(n, &n1);
+ cgen(&n1, res);
+ return;
+ }
+
+ // structs etc get handled specially
+ if(isfat(n->type)) {
+ if(n->type->width < 0)
+ fatal("forgot to compute width for %T", n->type);
+ sgen(n, res, n->type->width);
+ return;
+ }
+
+ // update addressability for string, slice
+ // can't do in walk because n->left->addable
+ // changes if n->left is an escaping local variable.
+ switch(n->op) {
+ case OLEN:
+ if(isslice(n->left->type) || istype(n->left->type, TSTRING))
+ n->addable = n->left->addable;
+ break;
+ case OCAP:
+ if(isslice(n->left->type))
+ n->addable = n->left->addable;
+ break;
+ }
+
+ // if both are addressable, move
+ if(n->addable && res->addable) {
+ gmove(n, res);
+ return;
+ }
+
+ // if both are not addressable, use a temporary.
+ if(!n->addable && !res->addable) {
+ // could use regalloc here sometimes,
+ // but have to check for ullman >= UINF.
+ tempname(&n1, n->type);
+ cgen(n, &n1);
+ cgen(&n1, res);
+ return;
+ }
+
+ // if result is not addressable directly but n is,
+ // compute its address and then store via the address.
+ if(!res->addable) {
+ igen(res, &n1, N);
+ cgen(n, &n1);
+ regfree(&n1);
+ return;
+ }
+
+ // complex types
+ if(complexop(n, res)) {
+ complexgen(n, res);
+ return;
+ }
+
+ // otherwise, the result is addressable but n is not.
+ // let's do some computation.
+
+ // use ullman to pick operand to eval first.
+ nl = n->left;
+ nr = n->right;
+ if(nl != N && nl->ullman >= UINF)
+ if(nr != N && nr->ullman >= UINF) {
+ // both are hard
+ tempname(&n1, nl->type);
+ cgen(nl, &n1);
+ n2 = *n;
+ n2.left = &n1;
+ cgen(&n2, res);
+ return;
+ }
+
+ // 64-bit ops are hard on 32-bit machine.
+ if(is64(n->type) || is64(res->type) || n->left != N && is64(n->left->type)) {
+ switch(n->op) {
+ // math goes to cgen64.
+ case OMINUS:
+ case OCOM:
+ case OADD:
+ case OSUB:
+ case OMUL:
+ case OLSH:
+ case ORSH:
+ case OAND:
+ case OOR:
+ case OXOR:
+ cgen64(n, res);
+ return;
+ }
+ }
+
+ if(nl != N && isfloat[n->type->etype] && isfloat[nl->type->etype])
+ goto flt;
+
+ switch(n->op) {
+ default:
+ dump("cgen", n);
+ fatal("cgen %O", n->op);
+ break;
+
+ case OREAL:
+ case OIMAG:
+ case OCOMPLEX:
+ fatal("unexpected complex");
+ return;
+
+ // these call bgen to get a bool value
+ case OOROR:
+ case OANDAND:
+ case OEQ:
+ case ONE:
+ case OLT:
+ case OLE:
+ case OGE:
+ case OGT:
+ case ONOT:
+ p1 = gbranch(AJMP, T);
+ p2 = pc;
+ gmove(nodbool(1), res);
+ p3 = gbranch(AJMP, T);
+ patch(p1, pc);
+ bgen(n, 1, p2);
+ gmove(nodbool(0), res);
+ patch(p3, pc);
+ return;
+
+ case OPLUS:
+ cgen(nl, res);
+ return;
+
+ case OMINUS:
+ case OCOM:
+ a = optoas(n->op, nl->type);
+ goto uop;
+
+ // symmetric binary
+ case OAND:
+ case OOR:
+ case OXOR:
+ case OADD:
+ case OMUL:
+ a = optoas(n->op, nl->type);
+ if(a == AIMULB) {
+ cgen_bmul(n->op, nl, nr, res);
+ break;
+ }
+ goto sbop;
+
+ // asymmetric binary
+ case OSUB:
+ a = optoas(n->op, nl->type);
+ goto abop;
+
+ case OCONV:
+ if(eqtype(n->type, nl->type) || noconv(n->type, nl->type)) {
+ cgen(nl, res);
+ break;
+ }
+
+ tempname(&n2, n->type);
+ mgen(nl, &n1, res);
+ gmove(&n1, &n2);
+ gmove(&n2, res);
+ mfree(&n1);
+ break;
+
+ case ODOT:
+ case ODOTPTR:
+ case OINDEX:
+ case OIND:
+ case ONAME: // PHEAP or PPARAMREF var
+ igen(n, &n1, res);
+ gmove(&n1, res);
+ regfree(&n1);
+ break;
+
+ case OLEN:
+ if(istype(nl->type, TMAP) || istype(nl->type, TCHAN)) {
+ // map has len in the first 32-bit word.
+ // a zero pointer means zero length
+ tempname(&n1, types[tptr]);
+ cgen(nl, &n1);
+ regalloc(&n2, types[tptr], N);
+ gmove(&n1, &n2);
+ n1 = n2;
+
+ nodconst(&n2, types[tptr], 0);
+ gins(optoas(OCMP, types[tptr]), &n1, &n2);
+ p1 = gbranch(optoas(OEQ, types[tptr]), T);
+
+ n2 = n1;
+ n2.op = OINDREG;
+ n2.type = types[TINT32];
+ gmove(&n2, &n1);
+
+ patch(p1, pc);
+
+ gmove(&n1, res);
+ regfree(&n1);
+ break;
+ }
+ if(istype(nl->type, TSTRING) || isslice(nl->type)) {
+ // both slice and string have len one pointer into the struct.
+ igen(nl, &n1, res);
+ n1.type = types[TUINT32];
+ n1.xoffset += Array_nel;
+ gmove(&n1, res);
+ regfree(&n1);
+ break;
+ }
+ fatal("cgen: OLEN: unknown type %lT", nl->type);
+ break;
+
+ case OCAP:
+ if(istype(nl->type, TCHAN)) {
+ // chan has cap in the second 32-bit word.
+ // a zero pointer means zero length
+ regalloc(&n1, types[tptr], res);
+ cgen(nl, &n1);
+
+ nodconst(&n2, types[tptr], 0);
+ gins(optoas(OCMP, types[tptr]), &n1, &n2);
+ p1 = gbranch(optoas(OEQ, types[tptr]), T);
+
+ n2 = n1;
+ n2.op = OINDREG;
+ n2.xoffset = 4;
+ n2.type = types[TINT32];
+ gmove(&n2, &n1);
+
+ patch(p1, pc);
+
+ gmove(&n1, res);
+ regfree(&n1);
+ break;
+ }
+ if(isslice(nl->type)) {
+ igen(nl, &n1, res);
+ n1.op = OINDREG;
+ n1.type = types[TUINT32];
+ n1.xoffset = Array_cap;
+ gmove(&n1, res);
+ regfree(&n1);
+ break;
+ }
+ fatal("cgen: OCAP: unknown type %lT", nl->type);
+ break;
+
+ case OADDR:
+ agen(nl, res);
+ break;
+
+ case OCALLMETH:
+ cgen_callmeth(n, 0);
+ cgen_callret(n, res);
+ break;
+
+ case OCALLINTER:
+ cgen_callinter(n, res, 0);
+ cgen_callret(n, res);
+ break;
+
+ case OCALLFUNC:
+ cgen_call(n, 0);
+ cgen_callret(n, res);
+ break;
+
+ case OMOD:
+ case ODIV:
+ cgen_div(n->op, nl, nr, res);
+ break;
+
+ case OLSH:
+ case ORSH:
+ cgen_shift(n->op, nl, nr, res);
+ break;
+ }
+ return;
+
+sbop: // symmetric binary
+ if(nl->ullman < nr->ullman) {
+ r = nl;
+ nl = nr;
+ nr = r;
+ }
+
+abop: // asymmetric binary
+ if(nl->ullman >= nr->ullman) {
+ tempname(&nt, nl->type);
+ cgen(nl, &nt);
+ mgen(nr, &n2, N);
+ regalloc(&n1, nl->type, res);
+ gmove(&nt, &n1);
+ gins(a, &n2, &n1);
+ gmove(&n1, res);
+ regfree(&n1);
+ mfree(&n2);
+ } else {
+ regalloc(&n2, nr->type, res);
+ cgen(nr, &n2);
+ regalloc(&n1, nl->type, N);
+ cgen(nl, &n1);
+ gins(a, &n2, &n1);
+ regfree(&n2);
+ gmove(&n1, res);
+ regfree(&n1);
+ }
+ return;
+
+uop: // unary
+ tempname(&n1, nl->type);
+ cgen(nl, &n1);
+ gins(a, N, &n1);
+ gmove(&n1, res);
+ return;
+
+flt: // floating-point. 387 (not SSE2) to interoperate with 8c
+ nodreg(&f0, nl->type, D_F0);
+ nodreg(&f1, n->type, D_F0+1);
+ if(nr != N)
+ goto flt2;
+
+ // unary
+ cgen(nl, &f0);
+ if(n->op != OCONV && n->op != OPLUS)
+ gins(foptoas(n->op, n->type, 0), N, N);
+ gmove(&f0, res);
+ return;
+
+flt2: // binary
+ if(nl->ullman >= nr->ullman) {
+ cgen(nl, &f0);
+ if(nr->addable)
+ gins(foptoas(n->op, n->type, 0), nr, &f0);
+ else {
+ cgen(nr, &f0);
+ gins(foptoas(n->op, n->type, Fpop), &f0, &f1);
+ }
+ } else {
+ cgen(nr, &f0);
+ if(nl->addable)
+ gins(foptoas(n->op, n->type, Frev), nl, &f0);
+ else {
+ cgen(nl, &f0);
+ gins(foptoas(n->op, n->type, Frev|Fpop), &f0, &f1);
+ }
+ }
+ gmove(&f0, res);
+ return;
+}
+
+/*
+ * generate array index into res.
+ * n might be any size; res is 32-bit.
+ * returns Prog* to patch to panic call.
+ */
+Prog*
+cgenindex(Node *n, Node *res)
+{
+ Node tmp, lo, hi, zero;
+
+ if(!is64(n->type)) {
+ cgen(n, res);
+ return nil;
+ }
+
+ tempname(&tmp, types[TINT64]);
+ cgen(n, &tmp);
+ split64(&tmp, &lo, &hi);
+ gmove(&lo, res);
+ if(debug['B']) {
+ splitclean();
+ return nil;
+ }
+ nodconst(&zero, types[TINT32], 0);
+ gins(ACMPL, &hi, &zero);
+ splitclean();
+ return gbranch(AJNE, T);
+}
+
+/*
+ * address gen
+ * res = &n;
+ */
+void
+agen(Node *n, Node *res)
+{
+ Node *nl, *nr;
+ Node n1, n2, n3, n4, tmp;
+ Type *t;
+ uint32 w;
+ uint64 v;
+ Prog *p1, *p2;
+
+ if(debug['g']) {
+ dump("\nagen-res", res);
+ dump("agen-r", n);
+ }
+ if(n == N || n->type == T || res == N || res->type == T)
+ fatal("agen");
+
+ while(n->op == OCONVNOP)
+ n = n->left;
+
+ // addressable var is easy
+ if(n->addable) {
+ if(n->op == OREGISTER)
+ fatal("agen OREGISTER");
+ regalloc(&n1, types[tptr], res);
+ gins(ALEAL, n, &n1);
+ gmove(&n1, res);
+ regfree(&n1);
+ return;
+ }
+
+ // let's compute
+ nl = n->left;
+ nr = n->right;
+
+ switch(n->op) {
+ default:
+ fatal("agen %O", n->op);
+
+ case OCALLMETH:
+ cgen_callmeth(n, 0);
+ cgen_aret(n, res);
+ break;
+
+ case OCALLINTER:
+ cgen_callinter(n, res, 0);
+ cgen_aret(n, res);
+ break;
+
+ case OCALLFUNC:
+ cgen_call(n, 0);
+ cgen_aret(n, res);
+ break;
+
+ case OINDEX:
+ p2 = nil; // to be patched to panicindex.
+ w = n->type->width;
+ if(nr->addable) {
+ if(!isconst(nr, CTINT))
+ tempname(&tmp, types[TINT32]);
+ if(!isconst(nl, CTSTR))
+ agenr(nl, &n3, res);
+ if(!isconst(nr, CTINT)) {
+ p2 = cgenindex(nr, &tmp);
+ regalloc(&n1, tmp.type, N);
+ gmove(&tmp, &n1);
+ }
+ } else if(nl->addable) {
+ if(!isconst(nr, CTINT)) {
+ tempname(&tmp, types[TINT32]);
+ p2 = cgenindex(nr, &tmp);
+ regalloc(&n1, tmp.type, N);
+ gmove(&tmp, &n1);
+ }
+ if(!isconst(nl, CTSTR)) {
+ regalloc(&n3, types[tptr], res);
+ agen(nl, &n3);
+ }
+ } else {
+ tempname(&tmp, types[TINT32]);
+ p2 = cgenindex(nr, &tmp);
+ nr = &tmp;
+ if(!isconst(nl, CTSTR))
+ agenr(nl, &n3, res);
+ regalloc(&n1, tmp.type, N);
+ gins(optoas(OAS, tmp.type), &tmp, &n1);
+ }
+
+ // &a is in &n3 (allocated in res)
+ // i is in &n1 (if not constant)
+ // w is width
+
+ // explicit check for nil if array is large enough
+ // that we might derive too big a pointer.
+ if(isfixedarray(nl->type) && nl->type->width >= unmappedzero) {
+ regalloc(&n4, types[tptr], &n3);
+ gmove(&n3, &n4);
+ n4.op = OINDREG;
+ n4.type = types[TUINT8];
+ n4.xoffset = 0;
+ gins(ATESTB, nodintconst(0), &n4);
+ regfree(&n4);
+ }
+
+ // constant index
+ if(isconst(nr, CTINT)) {
+ if(isconst(nl, CTSTR))
+ fatal("constant string constant index");
+ v = mpgetfix(nr->val.u.xval);
+ if(isslice(nl->type) || nl->type->etype == TSTRING) {
+ if(!debug['B'] && !n->etype) {
+ n1 = n3;
+ n1.op = OINDREG;
+ n1.type = types[tptr];
+ n1.xoffset = Array_nel;
+ nodconst(&n2, types[TUINT32], v);
+ gins(optoas(OCMP, types[TUINT32]), &n1, &n2);
+ p1 = gbranch(optoas(OGT, types[TUINT32]), T);
+ ginscall(panicindex, 0);
+ patch(p1, pc);
+ }
+
+ n1 = n3;
+ n1.op = OINDREG;
+ n1.type = types[tptr];
+ n1.xoffset = Array_array;
+ gmove(&n1, &n3);
+ }
+
+ if (v*w != 0) {
+ nodconst(&n2, types[tptr], v*w);
+ gins(optoas(OADD, types[tptr]), &n2, &n3);
+ }
+ gmove(&n3, res);
+ regfree(&n3);
+ break;
+ }
+
+ regalloc(&n2, types[TINT32], &n1); // i
+ gmove(&n1, &n2);
+ regfree(&n1);
+
+ if(!debug['B'] && !n->etype) {
+ // check bounds
+ if(isconst(nl, CTSTR))
+ nodconst(&n1, types[TUINT32], nl->val.u.sval->len);
+ else if(isslice(nl->type) || nl->type->etype == TSTRING) {
+ n1 = n3;
+ n1.op = OINDREG;
+ n1.type = types[tptr];
+ n1.xoffset = Array_nel;
+ } else
+ nodconst(&n1, types[TUINT32], nl->type->bound);
+ gins(optoas(OCMP, types[TUINT32]), &n2, &n1);
+ p1 = gbranch(optoas(OLT, types[TUINT32]), T);
+ if(p2)
+ patch(p2, pc);
+ ginscall(panicindex, 0);
+ patch(p1, pc);
+ }
+
+ if(isconst(nl, CTSTR)) {
+ regalloc(&n3, types[tptr], res);
+ p1 = gins(ALEAL, N, &n3);
+ datastring(nl->val.u.sval->s, nl->val.u.sval->len, &p1->from);
+ p1->from.scale = 1;
+ p1->from.index = n2.val.u.reg;
+ goto indexdone;
+ }
+
+ if(isslice(nl->type) || nl->type->etype == TSTRING) {
+ n1 = n3;
+ n1.op = OINDREG;
+ n1.type = types[tptr];
+ n1.xoffset = Array_array;
+ gmove(&n1, &n3);
+ }
+
+ if(w == 0) {
+ // nothing to do
+ } else if(w == 1 || w == 2 || w == 4 || w == 8) {
+ p1 = gins(ALEAL, &n2, &n3);
+ p1->from.scale = w;
+ p1->from.index = p1->from.type;
+ p1->from.type = p1->to.type + D_INDIR;
+ } else {
+ nodconst(&n1, types[TUINT32], w);
+ gins(optoas(OMUL, types[TUINT32]), &n1, &n2);
+ gins(optoas(OADD, types[tptr]), &n2, &n3);
+ }
+
+ indexdone:
+ gmove(&n3, res);
+ regfree(&n2);
+ regfree(&n3);
+ break;
+
+ case ONAME:
+ // should only get here with names in this func.
+ if(n->funcdepth > 0 && n->funcdepth != funcdepth) {
+ dump("bad agen", n);
+ fatal("agen: bad ONAME funcdepth %d != %d",
+ n->funcdepth, funcdepth);
+ }
+
+ // should only get here for heap vars or paramref
+ if(!(n->class & PHEAP) && n->class != PPARAMREF) {
+ dump("bad agen", n);
+ fatal("agen: bad ONAME class %#x", n->class);
+ }
+ cgen(n->heapaddr, res);
+ if(n->xoffset != 0) {
+ nodconst(&n1, types[tptr], n->xoffset);
+ gins(optoas(OADD, types[tptr]), &n1, res);
+ }
+ break;
+
+ case OIND:
+ cgen(nl, res);
+ break;
+
+ case ODOT:
+ t = nl->type;
+ agen(nl, res);
+ if(n->xoffset != 0) {
+ nodconst(&n1, types[tptr], n->xoffset);
+ gins(optoas(OADD, types[tptr]), &n1, res);
+ }
+ break;
+
+ case ODOTPTR:
+ t = nl->type;
+ if(!isptr[t->etype])
+ fatal("agen: not ptr %N", n);
+ cgen(nl, res);
+ if(n->xoffset != 0) {
+ // explicit check for nil if struct is large enough
+ // that we might derive too big a pointer.
+ if(nl->type->type->width >= unmappedzero) {
+ regalloc(&n1, types[tptr], res);
+ gmove(res, &n1);
+ n1.op = OINDREG;
+ n1.type = types[TUINT8];
+ n1.xoffset = 0;
+ gins(ATESTB, nodintconst(0), &n1);
+ regfree(&n1);
+ }
+ nodconst(&n1, types[tptr], n->xoffset);
+ gins(optoas(OADD, types[tptr]), &n1, res);
+ }
+ break;
+ }
+}
+
+/*
+ * generate:
+ * newreg = &n;
+ * res = newreg
+ *
+ * on exit, a has been changed to be *newreg.
+ * caller must regfree(a).
+ */
+void
+igen(Node *n, Node *a, Node *res)
+{
+ Node n1;
+ Type *fp;
+ Iter flist;
+
+ switch(n->op) {
+ case ONAME:
+ if((n->class&PHEAP) || n->class == PPARAMREF)
+ break;
+ *a = *n;
+ return;
+
+ case OCALLFUNC:
+ fp = structfirst(&flist, getoutarg(n->left->type));
+ cgen_call(n, 0);
+ memset(a, 0, sizeof *a);
+ a->op = OINDREG;
+ a->val.u.reg = D_SP;
+ a->addable = 1;
+ a->xoffset = fp->width;
+ a->type = n->type;
+ return;
+ }
+ // release register for now, to avoid
+ // confusing tempname.
+ if(res != N && res->op == OREGISTER)
+ reg[res->val.u.reg]--;
+ tempname(&n1, types[tptr]);
+ agen(n, &n1);
+ if(res != N && res->op == OREGISTER)
+ reg[res->val.u.reg]++;
+ regalloc(a, types[tptr], res);
+ gmove(&n1, a);
+ a->op = OINDREG;
+ a->type = n->type;
+}
+
+/*
+ * generate:
+ * newreg = &n;
+ *
+ * caller must regfree(a).
+ */
+void
+agenr(Node *n, Node *a, Node *res)
+{
+ Node n1;
+
+ tempname(&n1, types[tptr]);
+ agen(n, &n1);
+ regalloc(a, types[tptr], res);
+ gmove(&n1, a);
+}
+
+/*
+ * branch gen
+ * if(n == true) goto to;
+ */
+void
+bgen(Node *n, int true, Prog *to)
+{
+ int et, a;
+ Node *nl, *nr, *r;
+ Node n1, n2, tmp, t1, t2, ax;
+ Prog *p1, *p2;
+
+ if(debug['g']) {
+ dump("\nbgen", n);
+ }
+
+ if(n == N)
+ n = nodbool(1);
+
+ if(n->ninit != nil)
+ genlist(n->ninit);
+
+ nl = n->left;
+ nr = n->right;
+
+ if(n->type == T) {
+ convlit(&n, types[TBOOL]);
+ if(n->type == T)
+ return;
+ }
+
+ et = n->type->etype;
+ if(et != TBOOL) {
+ yyerror("cgen: bad type %T for %O", n->type, n->op);
+ patch(gins(AEND, N, N), to);
+ return;
+ }
+ nl = N;
+ nr = N;
+
+ switch(n->op) {
+ default:
+ def:
+ regalloc(&n1, n->type, N);
+ cgen(n, &n1);
+ nodconst(&n2, n->type, 0);
+ gins(optoas(OCMP, n->type), &n1, &n2);
+ a = AJNE;
+ if(!true)
+ a = AJEQ;
+ patch(gbranch(a, n->type), to);
+ regfree(&n1);
+ return;
+
+ case OLITERAL:
+ // need to ask if it is bool?
+ if(!true == !n->val.u.bval)
+ patch(gbranch(AJMP, T), to);
+ return;
+
+ case ONAME:
+ if(!n->addable)
+ goto def;
+ nodconst(&n1, n->type, 0);
+ gins(optoas(OCMP, n->type), n, &n1);
+ a = AJNE;
+ if(!true)
+ a = AJEQ;
+ patch(gbranch(a, n->type), to);
+ return;
+
+ case OANDAND:
+ if(!true)
+ goto caseor;
+
+ caseand:
+ p1 = gbranch(AJMP, T);
+ p2 = gbranch(AJMP, T);
+ patch(p1, pc);
+ bgen(n->left, !true, p2);
+ bgen(n->right, !true, p2);
+ p1 = gbranch(AJMP, T);
+ patch(p1, to);
+ patch(p2, pc);
+ return;
+
+ case OOROR:
+ if(!true)
+ goto caseand;
+
+ caseor:
+ bgen(n->left, true, to);
+ bgen(n->right, true, to);
+ return;
+
+ case OEQ:
+ case ONE:
+ case OLT:
+ case OGT:
+ case OLE:
+ case OGE:
+ nr = n->right;
+ if(nr == N || nr->type == T)
+ return;
+
+ case ONOT: // unary
+ nl = n->left;
+ if(nl == N || nl->type == T)
+ return;
+ }
+
+ switch(n->op) {
+ case ONOT:
+ bgen(nl, !true, to);
+ break;
+
+ case OEQ:
+ case ONE:
+ case OLT:
+ case OGT:
+ case OLE:
+ case OGE:
+ a = n->op;
+ if(!true) {
+ if(isfloat[nl->type->etype]) {
+ // brcom is not valid on floats when NaN is involved.
+ p1 = gbranch(AJMP, T);
+ p2 = gbranch(AJMP, T);
+ patch(p1, pc);
+ bgen(n, 1, p2);
+ patch(gbranch(AJMP, T), to);
+ patch(p2, pc);
+ break;
+ }
+ a = brcom(a);
+ true = !true;
+ }
+
+ // make simplest on right
+ if(nl->op == OLITERAL || (nl->ullman < nr->ullman && nl->ullman < UINF)) {
+ a = brrev(a);
+ r = nl;
+ nl = nr;
+ nr = r;
+ }
+
+ if(isslice(nl->type)) {
+ // front end should only leave cmp to literal nil
+ if((a != OEQ && a != ONE) || nr->op != OLITERAL) {
+ yyerror("illegal array comparison");
+ break;
+ }
+ a = optoas(a, types[tptr]);
+ regalloc(&n1, types[tptr], N);
+ agen(nl, &n1);
+ n2 = n1;
+ n2.op = OINDREG;
+ n2.xoffset = Array_array;
+ n2.type = types[tptr];
+ nodconst(&tmp, types[tptr], 0);
+ gins(optoas(OCMP, types[tptr]), &n2, &tmp);
+ patch(gbranch(a, types[tptr]), to);
+ regfree(&n1);
+ break;
+ }
+
+ if(isinter(nl->type)) {
+ // front end should only leave cmp to literal nil
+ if((a != OEQ && a != ONE) || nr->op != OLITERAL) {
+ yyerror("illegal interface comparison");
+ break;
+ }
+ a = optoas(a, types[tptr]);
+ regalloc(&n1, types[tptr], N);
+ agen(nl, &n1);
+ n2 = n1;
+ n2.op = OINDREG;
+ n2.xoffset = 0;
+ nodconst(&tmp, types[tptr], 0);
+ gins(optoas(OCMP, types[tptr]), &n2, &tmp);
+ patch(gbranch(a, types[tptr]), to);
+ regfree(&n1);
+ break;
+ }
+
+ if(isfloat[nr->type->etype]) {
+ a = brrev(a); // because the args are stacked
+ if(a == OGE || a == OGT) {
+ // only < and <= work right with NaN; reverse if needed
+ r = nr;
+ nr = nl;
+ nl = r;
+ a = brrev(a);
+ }
+ nodreg(&tmp, nr->type, D_F0);
+ nodreg(&n2, nr->type, D_F0 + 1);
+ nodreg(&ax, types[TUINT16], D_AX);
+ et = simsimtype(nr->type);
+ if(et == TFLOAT64) {
+ if(nl->ullman > nr->ullman) {
+ cgen(nl, &tmp);
+ cgen(nr, &tmp);
+ gins(AFXCHD, &tmp, &n2);
+ } else {
+ cgen(nr, &tmp);
+ cgen(nl, &tmp);
+ }
+ gins(AFUCOMIP, &tmp, &n2);
+ gins(AFMOVDP, &tmp, &tmp); // annoying pop but still better than STSW+SAHF
+ } else {
+ // TODO(rsc): The moves back and forth to memory
+ // here are for truncating the value to 32 bits.
+ // This handles 32-bit comparison but presumably
+ // all the other ops have the same problem.
+ // We need to figure out what the right general
+ // solution is, besides telling people to use float64.
+ tempname(&t1, types[TFLOAT32]);
+ tempname(&t2, types[TFLOAT32]);
+ cgen(nr, &t1);
+ cgen(nl, &t2);
+ gmove(&t2, &tmp);
+ gins(AFCOMFP, &t1, &tmp);
+ gins(AFSTSW, N, &ax);
+ gins(ASAHF, N, N);
+ }
+ if(a == OEQ) {
+ // neither NE nor P
+ p1 = gbranch(AJNE, T);
+ p2 = gbranch(AJPS, T);
+ patch(gbranch(AJMP, T), to);
+ patch(p1, pc);
+ patch(p2, pc);
+ } else if(a == ONE) {
+ // either NE or P
+ patch(gbranch(AJNE, T), to);
+ patch(gbranch(AJPS, T), to);
+ } else
+ patch(gbranch(optoas(a, nr->type), T), to);
+ break;
+ }
+ if(iscomplex[nl->type->etype]) {
+ complexbool(a, nl, nr, true, to);
+ break;
+ }
+
+ if(is64(nr->type)) {
+ if(!nl->addable) {
+ tempname(&n1, nl->type);
+ cgen(nl, &n1);
+ nl = &n1;
+ }
+ if(!nr->addable) {
+ tempname(&n2, nr->type);
+ cgen(nr, &n2);
+ nr = &n2;
+ }
+ cmp64(nl, nr, a, to);
+ break;
+ }
+
+ a = optoas(a, nr->type);
+
+ if(nr->ullman >= UINF) {
+ tempname(&n1, nl->type);
+ tempname(&tmp, nr->type);
+ cgen(nl, &n1);
+ cgen(nr, &tmp);
+ regalloc(&n2, nr->type, N);
+ cgen(&tmp, &n2);
+ goto cmp;
+ }
+
+ tempname(&n1, nl->type);
+ cgen(nl, &n1);
+
+ if(smallintconst(nr)) {
+ gins(optoas(OCMP, nr->type), &n1, nr);
+ patch(gbranch(a, nr->type), to);
+ break;
+ }
+
+ tempname(&tmp, nr->type);
+ cgen(nr, &tmp);
+ regalloc(&n2, nr->type, N);
+ gmove(&tmp, &n2);
+
+cmp:
+ gins(optoas(OCMP, nr->type), &n1, &n2);
+ patch(gbranch(a, nr->type), to);
+ regfree(&n2);
+ break;
+ }
+}
+
+/*
+ * n is on stack, either local variable
+ * or return value from function call.
+ * return n's offset from SP.
+ */
+int32
+stkof(Node *n)
+{
+ Type *t;
+ Iter flist;
+ int32 off;
+
+ switch(n->op) {
+ case OINDREG:
+ return n->xoffset;
+
+ case ODOT:
+ t = n->left->type;
+ if(isptr[t->etype])
+ break;
+ off = stkof(n->left);
+ if(off == -1000 || off == 1000)
+ return off;
+ return off + n->xoffset;
+
+ case OINDEX:
+ t = n->left->type;
+ if(!isfixedarray(t))
+ break;
+ off = stkof(n->left);
+ if(off == -1000 || off == 1000)
+ return off;
+ if(isconst(n->right, CTINT))
+ return off + t->type->width * mpgetfix(n->right->val.u.xval);
+ return 1000;
+
+ case OCALLMETH:
+ case OCALLINTER:
+ case OCALLFUNC:
+ t = n->left->type;
+ if(isptr[t->etype])
+ t = t->type;
+
+ t = structfirst(&flist, getoutarg(t));
+ if(t != T)
+ return t->width;
+ break;
+ }
+
+ // botch - probably failing to recognize address
+ // arithmetic on the above. eg INDEX and DOT
+ return -1000;
+}
+
+/*
+ * struct gen
+ * memmove(&res, &n, w);
+ */
+void
+sgen(Node *n, Node *res, int32 w)
+{
+ Node dst, src, tdst, tsrc;
+ int32 c, q, odst, osrc;
+
+ if(debug['g']) {
+ print("\nsgen w=%d\n", w);
+ dump("r", n);
+ dump("res", res);
+ }
+ if(w == 0)
+ return;
+ if(n->ullman >= UINF && res->ullman >= UINF) {
+ fatal("sgen UINF");
+ }
+
+ if(w < 0)
+ fatal("sgen copy %d", w);
+
+ // offset on the stack
+ osrc = stkof(n);
+ odst = stkof(res);
+
+ if(osrc != -1000 && odst != -1000 && (osrc == 1000 || odst == 1000)) {
+ // osrc and odst both on stack, and at least one is in
+ // an unknown position. Could generate code to test
+ // for forward/backward copy, but instead just copy
+ // to a temporary location first.
+ tempname(&tsrc, n->type);
+ sgen(n, &tsrc, w);
+ sgen(&tsrc, res, w);
+ return;
+ }
+
+ nodreg(&dst, types[tptr], D_DI);
+ nodreg(&src, types[tptr], D_SI);
+
+ tempname(&tsrc, types[tptr]);
+ tempname(&tdst, types[tptr]);
+ if(!n->addable)
+ agen(n, &tsrc);
+ if(!res->addable)
+ agen(res, &tdst);
+ if(n->addable)
+ agen(n, &src);
+ else
+ gmove(&tsrc, &src);
+ if(res->addable)
+ agen(res, &dst);
+ else
+ gmove(&tdst, &dst);
+
+ c = w % 4; // bytes
+ q = w / 4; // doublewords
+
+ // if we are copying forward on the stack and
+ // the src and dst overlap, then reverse direction
+ if(osrc < odst && odst < osrc+w) {
+ // reverse direction
+ gins(ASTD, N, N); // set direction flag
+ if(c > 0) {
+ gconreg(AADDL, w-1, D_SI);
+ gconreg(AADDL, w-1, D_DI);
+
+ gconreg(AMOVL, c, D_CX);
+ gins(AREP, N, N); // repeat
+ gins(AMOVSB, N, N); // MOVB *(SI)-,*(DI)-
+ }
+
+ if(q > 0) {
+ if(c > 0) {
+ gconreg(AADDL, -3, D_SI);
+ gconreg(AADDL, -3, D_DI);
+ } else {
+ gconreg(AADDL, w-4, D_SI);
+ gconreg(AADDL, w-4, D_DI);
+ }
+ gconreg(AMOVL, q, D_CX);
+ gins(AREP, N, N); // repeat
+ gins(AMOVSL, N, N); // MOVL *(SI)-,*(DI)-
+ }
+ // we leave with the flag clear
+ gins(ACLD, N, N);
+ } else {
+ gins(ACLD, N, N); // paranoia. TODO(rsc): remove?
+ // normal direction
+ if(q >= 4) {
+ gconreg(AMOVL, q, D_CX);
+ gins(AREP, N, N); // repeat
+ gins(AMOVSL, N, N); // MOVL *(SI)+,*(DI)+
+ } else
+ while(q > 0) {
+ gins(AMOVSL, N, N); // MOVL *(SI)+,*(DI)+
+ q--;
+ }
+ while(c > 0) {
+ gins(AMOVSB, N, N); // MOVB *(SI)+,*(DI)+
+ c--;
+ }
+ }
+}
+
generated by cgit v1.2.3 (git 2.39.1) at 2025-07-25 20:47:02 +0000