// 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.
#include <u.h>
#include <libc.h>
#include "gg.h"
/*
* generate:
* res = n;
* simplifies and calls gmove.
*/
void
cgen(Node *n, Node *res)
{
Node *nl, *nr, *r;
Node n1, n2, f0, f1;
int a, w, rg;
Prog *p1, *p2, *p3;
Addr addr;
if(debug['g']) {
dump("\ncgen-n", n);
dump("cgen-res", res);
}
if(n == N || n->type == T)
goto ret;
if(res == N || res->type == T)
fatal("cgen: res nil");
switch(n->op) {
case OSLICE:
case OSLICEARR:
case OSLICESTR:
case OSLICE3:
case OSLICE3ARR:
if (res->op != ONAME || !res->addable) {
tempname(&n1, n->type);
cgen_slice(n, &n1);
cgen(&n1, res);
} else
cgen_slice(n, res);
return;
case OEFACE:
if (res->op != ONAME || !res->addable) {
tempname(&n1, n->type);
cgen_eface(n, &n1);
cgen(&n1, res);
} else
cgen_eface(n, res);
return;
}
while(n->op == OCONVNOP)
n = n->left;
if(n->ullman >= UINF) {
if(n->op == OINDREG)
fatal("cgen: this is going to misscompile");
if(res->ullman >= UINF) {
tempname(&n1, n->type);
cgen(n, &n1);
cgen(&n1, res);
goto ret;
}
}
if(isfat(n->type)) {
if(n->type->width < 0)
fatal("forgot to compute width for %T", n->type);
sgen(n, res, n->type->width);
goto ret;
}
// 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 OSPTR:
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;
case OITAB:
n->addable = n->left->addable;
break;
}
// if both are addressable, move
if(n->addable && res->addable) {
if(is64(n->type) || is64(res->type) ||
n->op == OREGISTER || res->op == OREGISTER ||
iscomplex[n->type->etype] || iscomplex[res->type->etype]) {
gmove(n, res);
} else {
regalloc(&n1, n->type, N);
gmove(n, &n1);
cgen(&n1, res);
regfree(&n1);
}
goto ret;
}
// 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;
}
if(complexop(n, res)) {
complexgen(n, res);
return;
}
// if n is sudoaddable generate addr and move
if (!is64(n->type) && !is64(res->type) && !iscomplex[n->type->etype] && !iscomplex[res->type->etype]) {
a = optoas(OAS, n->type);
if(sudoaddable(a, n, &addr, &w)) {
if (res->op != OREGISTER) {
regalloc(&n2, res->type, N);
p1 = gins(a, N, &n2);
p1->from = addr;
if(debug['g'])
print("%P [ignore previous line]\n", p1);
gmove(&n2, res);
regfree(&n2);
} else {
p1 = gins(a, N, res);
p1->from = addr;
if(debug['g'])
print("%P [ignore previous line]\n", p1);
}
sudoclean();
goto ret;
}
}
// otherwise, the result is addressable but n is not.
// let's do some computation.
nl = n->left;
nr = n->right;
if(nl != N && nl->ullman >= UINF)
if(nr != N && nr->ullman >= UINF) {
tempname(&n1, nl->type);
cgen(nl, &n1);
n2 = *n;
n2.left = &n1;
cgen(&n2, res);
goto ret;
}
// 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 OLROT:
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: unknown op %+hN", n);
break;
case OREAL:
case OIMAG:
case OCOMPLEX:
fatal("unexpected complex");
break;
// 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(AB, T, 0);
p2 = pc;
gmove(nodbool(1), res);
p3 = gbranch(AB, T, 0);
patch(p1, pc);
bgen(n, 1, 0, p2);
gmove(nodbool(0), res);
patch(p3, pc);
goto ret;
case OPLUS:
cgen(nl, res);
goto ret;
// unary
case OCOM:
a = optoas(OXOR, nl->type);
regalloc(&n1, nl->type, N);
cgen(nl, &n1);
nodconst(&n2, nl->type, -1);
gins(a, &n2, &n1);
gmove(&n1, res);
regfree(&n1);
goto ret;
case OMINUS:
regalloc(&n1, nl->type, N);
cgen(nl, &n1);
nodconst(&n2, nl->type, 0);
gins(optoas(OMINUS, nl->type), &n2, &n1);
gmove(&n1, res);
regfree(&n1);
goto ret;
// symmetric binary
case OAND:
case OOR:
case OXOR:
case OADD:
case OADDPTR:
case OMUL:
a = optoas(n->op, nl->type);
goto sbop;
// asymmetric binary
case OSUB:
a = optoas(n->op, nl->type);
goto abop;
case OHMUL:
cgen_hmul(nl, nr, res);
break;
case OLROT:
case OLSH:
case ORSH:
cgen_shift(n->op, n->bounded, nl, nr, res);
break;
case OCONV:
if(eqtype(n->type, nl->type) || noconv(n->type, nl->type)) {
cgen(nl, res);
break;
}
if(nl->addable && !is64(nl->type)) {
regalloc(&n1, nl->type, res);
gmove(nl, &n1);
} else {
if(n->type->width > widthptr || is64(nl->type) || isfloat[nl->type->etype])
tempname(&n1, nl->type);
else
regalloc(&n1, nl->type, res);
cgen(nl, &n1);
}
if(n->type->width > widthptr || is64(n->type) || isfloat[n->type->etype])
tempname(&n2, n->type);
else
regalloc(&n2, n->type, N);
gmove(&n1, &n2);
gmove(&n2, res);
if(n1.op == OREGISTER)
regfree(&n1);
if(n2.op == OREGISTER)
regfree(&n2);
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 OITAB:
// interface table is first word of interface value
igen(nl, &n1, res);
n1.type = n->type;
gmove(&n1, res);
regfree(&n1);
break;
case OSPTR:
// pointer is the first word of string or slice.
if(isconst(nl, CTSTR)) {
regalloc(&n1, types[tptr], res);
p1 = gins(AMOVW, N, &n1);
datastring(nl->val.u.sval->s, nl->val.u.sval->len, &p1->from);
gmove(&n1, res);
regfree(&n1);
break;
}
igen(nl, &n1, res);
n1.type = n->type;
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
regalloc(&n1, types[tptr], res);
cgen(nl, &n1);
nodconst(&n2, types[tptr], 0);
gcmp(optoas(OCMP, types[tptr]), &n1, &n2);
p1 = gbranch(optoas(OEQ, types[tptr]), T, -1);
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);
gcmp(optoas(OCMP, types[tptr]), &n1, &n2);
p1 = gbranch(optoas(OEQ, types[tptr]), T, -1);
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.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:
case OCALLFUNC:
// Release res so that it is available for cgen_call.
// Pick it up again after the call.
rg = -1;
if(n->ullman >= UINF) {
if(res != N && (res->op == OREGISTER || res->op == OINDREG)) {
rg = res->val.u.reg;
reg[rg]--;
}
}
if(n->op == OCALLMETH)
cgen_callmeth(n, 0);
else
cgen_call(n, 0);
if(rg >= 0)
reg[rg]++;
cgen_callret(n, res);
break;
case OCALLINTER:
cgen_callinter(n, res, 0);
cgen_callret(n, res);
break;
case OMOD:
case ODIV:
a = optoas(n->op, nl->type);
goto abop;
}
goto ret;
sbop: // symmetric binary
if(nl->ullman < nr->ullman) {
r = nl;
nl = nr;
nr = r;
}
abop: // asymmetric binary
// TODO(kaib): use fewer registers here.
if(nl->ullman >= nr->ullman) {
regalloc(&n1, nl->type, res);
cgen(nl, &n1);
switch(n->op) {
case OADD:
case OSUB:
case OAND:
case OOR:
case OXOR:
if(smallintconst(nr)) {
n2 = *nr;
break;
}
default:
regalloc(&n2, nr->type, N);
cgen(nr, &n2);
}
} else {
switch(n->op) {
case OADD:
case OSUB:
case OAND:
case OOR:
case OXOR:
if(smallintconst(nr)) {
n2 = *nr;
break;
}
default:
regalloc(&n2, nr->type, res);
cgen(nr, &n2);
}
regalloc(&n1, nl->type, N);
cgen(nl, &n1);
}
gins(a, &n2, &n1);
// Normalize result for types smaller than word.
if(n->type->width < widthptr) {
switch(n->op) {
case OADD:
case OSUB:
case OMUL:
gins(optoas(OAS, n->type), &n1, &n1);
break;
}
}
gmove(&n1, res);
regfree(&n1);
if(n2.op != OLITERAL)
regfree(&n2);
goto ret;
flt: // floating-point.
regalloc(&f0, nl->type, res);
if(nr != N)
goto flt2;
if(n->op == OMINUS) {
nr = nodintconst(-1);
convlit(&nr, n->type);
n->op = OMUL;
goto flt2;
}
// unary
cgen(nl, &f0);
if(n->op != OCONV && n->op != OPLUS)
gins(optoas(n->op, n->type), &f0, &f0);
gmove(&f0, res);
regfree(&f0);
goto ret;
flt2: // binary
if(nl->ullman >= nr->ullman) {
cgen(nl, &f0);
regalloc(&f1, n->type, N);
gmove(&f0, &f1);
cgen(nr, &f0);
gins(optoas(n->op, n->type), &f0, &f1);
} else {
cgen(nr, &f0);
regalloc(&f1, n->type, N);
cgen(nl, &f1);
gins(optoas(n->op, n->type), &f0, &f1);
}
gmove(&f1, res);
regfree(&f0);
regfree(&f1);
goto ret;
ret:
;
}
/*
* 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, int bounded)
{
Node tmp, lo, hi, zero, n1, n2;
if(!is64(n->type)) {
cgen(n, res);
return nil;
}
tempname(&tmp, types[TINT64]);
cgen(n, &tmp);
split64(&tmp, &lo, &hi);
gmove(&lo, res);
if(bounded) {
splitclean();
return nil;
}
regalloc(&n1, types[TINT32], N);
regalloc(&n2, types[TINT32], N);
nodconst(&zero, types[TINT32], 0);
gmove(&hi, &n1);
gmove(&zero, &n2);
gcmp(ACMP, &n1, &n2);
regfree(&n2);
regfree(&n1);
splitclean();
return gbranch(ABNE, T, -1);
}
/*
* generate:
* res = &n;
* The generated code checks that the result is not nil.
*/
void
agen(Node *n, Node *res)
{
Node *nl;
Node n1, n2, n3;
int r;
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;
if(isconst(n, CTNIL) && n->type->width > widthptr) {
// Use of a nil interface or nil slice.
// Create a temporary we can take the address of and read.
// The generated code is just going to panic, so it need not
// be terribly efficient. See issue 3670.
tempname(&n1, n->type);
gvardef(&n1);
clearfat(&n1);
regalloc(&n2, types[tptr], res);
gins(AMOVW, &n1, &n2);
gmove(&n2, res);
regfree(&n2);
goto ret;
}
if(n->addable) {
memset(&n1, 0, sizeof n1);
n1.op = OADDR;
n1.left = n;
regalloc(&n2, types[tptr], res);
gins(AMOVW, &n1, &n2);
gmove(&n2, res);
regfree(&n2);
goto ret;
}
nl = n->left;
switch(n->op) {
default:
fatal("agen: unknown op %+hN", n);
break;
case OCALLMETH:
case OCALLFUNC:
// Release res so that it is available for cgen_call.
// Pick it up again after the call.
r = -1;
if(n->ullman >= UINF) {
if(res->op == OREGISTER || res->op == OINDREG) {
r = res->val.u.reg;
reg[r]--;
}
}
if(n->op == OCALLMETH)
cgen_callmeth(n, 0);
else
cgen_call(n, 0);
if(r >= 0)
reg[r]++;
cgen_aret(n, res);
break;
case OCALLINTER:
cgen_callinter(n, res, 0);
cgen_aret(n, res);
break;
case OSLICE:
case OSLICEARR:
case OSLICESTR:
case OSLICE3:
case OSLICE3ARR:
tempname(&n1, n->type);
cgen_slice(n, &n1);
agen(&n1, res);
break;
case OEFACE:
tempname(&n1, n->type);
cgen_eface(n, &n1);
agen(&n1, res);
break;
case OINDEX:
agenr(n, &n1, res);
gmove(&n1, res);
regfree(&n1);
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[TINT32], n->xoffset);
regalloc(&n2, n1.type, N);
regalloc(&n3, types[TINT32], N);
gmove(&n1, &n2);
gmove(res, &n3);
gins(optoas(OADD, types[tptr]), &n2, &n3);
gmove(&n3, res);
regfree(&n2);
regfree(&n3);
}
break;
case OIND:
cgen(nl, res);
cgen_checknil(res);
break;
case ODOT:
agen(nl, res);
if(n->xoffset != 0) {
nodconst(&n1, types[TINT32], n->xoffset);
regalloc(&n2, n1.type, N);
regalloc(&n3, types[TINT32], N);
gmove(&n1, &n2);
gmove(res, &n3);
gins(optoas(OADD, types[tptr]), &n2, &n3);
gmove(&n3, res);
regfree(&n2);
regfree(&n3);
}
break;
case ODOTPTR:
cgen(nl, res);
cgen_checknil(res);
if(n->xoffset != 0) {
nodconst(&n1, types[TINT32], n->xoffset);
regalloc(&n2, n1.type, N);
regalloc(&n3, types[tptr], N);
gmove(&n1, &n2);
gmove(res, &n3);
gins(optoas(OADD, types[tptr]), &n2, &n3);
gmove(&n3, res);
regfree(&n2);
regfree(&n3);
}
break;
}
ret:
;
}
/*
* generate:
* newreg = &n;
* res = newreg
*
* on exit, a has been changed to be *newreg.
* caller must regfree(a).
* The generated code checks that the result is not *nil.
*/
void
igen(Node *n, Node *a, Node *res)
{
Node n1;
int r;
if(debug['g']) {
dump("\nigen-n", n);
}
switch(n->op) {
case ONAME:
if((n->class&PHEAP) || n->class == PPARAMREF)
break;
*a = *n;
return;
case OINDREG:
// Increase the refcount of the register so that igen's caller
// has to call regfree.
if(n->val.u.reg != REGSP)
reg[n->val.u.reg]++;
*a = *n;
return;
case ODOT:
igen(n->left, a, res);
a->xoffset += n->xoffset;
a->type = n->type;
return;
case ODOTPTR:
if(n->left->addable
|| n->left->op == OCALLFUNC
|| n->left->op == OCALLMETH
|| n->left->op == OCALLINTER) {
// igen-able nodes.
igen(n->left, &n1, res);
regalloc(a, types[tptr], &n1);
gmove(&n1, a);
regfree(&n1);
} else {
regalloc(a, types[tptr], res);
cgen(n->left, a);
}
cgen_checknil(a);
a->op = OINDREG;
a->xoffset = n->xoffset;
a->type = n->type;
return;
case OCALLMETH:
case OCALLFUNC:
case OCALLINTER:
// Release res so that it is available for cgen_call.
// Pick it up again after the call.
r = -1;
if(n->ullman >= UINF) {
if(res != N && (res->op == OREGISTER || res->op == OINDREG)) {
r = res->val.u.reg;
reg[r]--;
}
}
switch(n->op) {
case OCALLMETH:
cgen_callmeth(n, 0);
break;
case OCALLFUNC:
cgen_call(n, 0);
break;
case OCALLINTER:
cgen_callinter(n, N, 0);
break;
}
if(r >= 0)
reg[r]++;
regalloc(a, types[tptr], res);
cgen_aret(n, a);
a->op = OINDREG;
a->type = n->type;
return;
}
agenr(n, a, res);
a->op = OINDREG;
a->type = n->type;
}
/*
* allocate a register in res and generate
* newreg = &n
* The caller must call regfree(a).
*/
void
cgenr(Node *n, Node *a, Node *res)
{
Node n1;
if(debug['g'])
dump("cgenr-n", n);
if(isfat(n->type))
fatal("cgenr on fat node");
if(n->addable) {
regalloc(a, types[tptr], res);
gmove(n, a);
return;
}
switch(n->op) {
case ONAME:
case ODOT:
case ODOTPTR:
case OINDEX:
case OCALLFUNC:
case OCALLMETH:
case OCALLINTER:
igen(n, &n1, res);
regalloc(a, types[tptr], &n1);
gmove(&n1, a);
regfree(&n1);
break;
default:
regalloc(a, n->type, res);
cgen(n, a);
break;
}
}
/*
* generate:
* newreg = &n;
*
* caller must regfree(a).
* The generated code checks that the result is not nil.
*/
void
agenr(Node *n, Node *a, Node *res)
{
Node *nl, *nr;
Node n1, n2, n3, n4, tmp;
Prog *p1, *p2;
uint32 w;
uint64 v;
int bounded;
if(debug['g'])
dump("agenr-n", n);
nl = n->left;
nr = n->right;
switch(n->op) {
case ODOT:
case ODOTPTR:
case OCALLFUNC:
case OCALLMETH:
case OCALLINTER:
igen(n, &n1, res);
regalloc(a, types[tptr], &n1);
agen(&n1, a);
regfree(&n1);
break;
case OIND:
cgenr(n->left, a, res);
cgen_checknil(a);
break;
case OINDEX:
p2 = nil; // to be patched to panicindex.
w = n->type->width;
bounded = debug['B'] || n->bounded;
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, bounded);
regalloc(&n1, tmp.type, N);
gmove(&tmp, &n1);
}
} else
if(nl->addable) {
if(!isconst(nr, CTINT)) {
tempname(&tmp, types[TINT32]);
p2 = cgenindex(nr, &tmp, bounded);
regalloc(&n1, tmp.type, N);
gmove(&tmp, &n1);
}
if(!isconst(nl, CTSTR)) {
agenr(nl, &n3, res);
}
} else {
tempname(&tmp, types[TINT32]);
p2 = cgenindex(nr, &tmp, bounded);
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
// 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->bounded) {
n1 = n3;
n1.op = OINDREG;
n1.type = types[tptr];
n1.xoffset = Array_nel;
regalloc(&n4, n1.type, N);
gmove(&n1, &n4);
nodconst(&n2, types[TUINT32], v);
gcmp(optoas(OCMP, types[TUINT32]), &n4, &n2);
regfree(&n4);
p1 = gbranch(optoas(OGT, types[TUINT32]), T, +1);
ginscall(panicindex, 0);
patch(p1, pc);
}
n1 = n3;
n1.op = OINDREG;
n1.type = types[tptr];
n1.xoffset = Array_array;
gmove(&n1, &n3);
}
nodconst(&n2, types[tptr], v*w);
gins(optoas(OADD, types[tptr]), &n2, &n3);
*a = n3;
break;
}
regalloc(&n2, types[TINT32], &n1); // i
gmove(&n1, &n2);
regfree(&n1);
if(!debug['B'] && !n->bounded) {
// check bounds
if(isconst(nl, CTSTR)) {
nodconst(&n4, 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;
regalloc(&n4, types[TUINT32], N);
gmove(&n1, &n4);
} else {
nodconst(&n4, types[TUINT32], nl->type->bound);
}
gcmp(optoas(OCMP, types[TUINT32]), &n2, &n4);
if(n4.op == OREGISTER)
regfree(&n4);
p1 = gbranch(optoas(OLT, types[TUINT32]), T, +1);
if(p2)
patch(p2, pc);
ginscall(panicindex, 0);
patch(p1, pc);
}
if(isconst(nl, CTSTR)) {
regalloc(&n3, types[tptr], res);
p1 = gins(AMOVW, N, &n3);
datastring(nl->val.u.sval->s, nl->val.u.sval->len, &p1->from);
p1->from.type = D_CONST;
} else
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) {
memset(&n4, 0, sizeof n4);
n4.op = OADDR;
n4.left = &n2;
cgen(&n4, &n3);
if (w == 1)
gins(AADD, &n2, &n3);
else if(w == 2)
gshift(AADD, &n2, SHIFT_LL, 1, &n3);
else if(w == 4)
gshift(AADD, &n2, SHIFT_LL, 2, &n3);
else if(w == 8)
gshift(AADD, &n2, SHIFT_LL, 3, &n3);
} else {
regalloc(&n4, types[TUINT32], N);
nodconst(&n1, types[TUINT32], w);
gmove(&n1, &n4);
gins(optoas(OMUL, types[TUINT32]), &n4, &n2);
gins(optoas(OADD, types[tptr]), &n2, &n3);
regfree(&n4);
}
*a = n3;
regfree(&n2);
break;
default:
regalloc(a, types[tptr], res);
agen(n, a);
break;
}
}
void
gencmp0(Node *n, Type *t, int o, int likely, Prog *to)
{
Node n1, n2, n3;
int a;
regalloc(&n1, t, N);
cgen(n, &n1);
a = optoas(OCMP, t);
if(a != ACMP) {
nodconst(&n2, t, 0);
regalloc(&n3, t, N);
gmove(&n2, &n3);
gcmp(a, &n1, &n3);
regfree(&n3);
} else
gins(ATST, &n1, N);
a = optoas(o, t);
patch(gbranch(a, t, likely), to);
regfree(&n1);
}
/*
* generate:
* if(n == true) goto to;
*/
void
bgen(Node *n, int true, int likely, Prog *to)
{
int et, a;
Node *nl, *nr, *r;
Node n1, n2, n3, n4, tmp;
NodeList *ll;
Prog *p1, *p2;
USED(n4); // in unreachable code below
if(debug['g']) {
dump("\nbgen", n);
}
if(n == N)
n = nodbool(1);
if(n->ninit != nil)
genlist(n->ninit);
if(n->type == T) {
convlit(&n, types[TBOOL]);
if(n->type == T)
goto ret;
}
et = n->type->etype;
if(et != TBOOL) {
yyerror("cgen: bad type %T for %O", n->type, n->op);
patch(gins(AEND, N, N), to);
goto ret;
}
nr = N;
switch(n->op) {
default:
a = ONE;
if(!true)
a = OEQ;
gencmp0(n, n->type, a, likely, to);
goto ret;
case OLITERAL:
// need to ask if it is bool?
if(!true == !n->val.u.bval)
patch(gbranch(AB, T, 0), to);
goto ret;
case OANDAND:
if(!true)
goto caseor;
caseand:
p1 = gbranch(AB, T, 0);
p2 = gbranch(AB, T, 0);
patch(p1, pc);
bgen(n->left, !true, -likely, p2);
bgen(n->right, !true, -likely, p2);
p1 = gbranch(AB, T, 0);
patch(p1, to);
patch(p2, pc);
goto ret;
case OOROR:
if(!true)
goto caseand;
caseor:
bgen(n->left, true, likely, to);
bgen(n->right, true, likely, to);
goto ret;
case OEQ:
case ONE:
case OLT:
case OGT:
case OLE:
case OGE:
nr = n->right;
if(nr == N || nr->type == T)
goto ret;
case ONOT: // unary
nl = n->left;
if(nl == N || nl->type == T)
goto ret;
}
switch(n->op) {
case ONOT:
bgen(nl, !true, likely, to);
goto ret;
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(AB, T, 0);
p2 = gbranch(AB, T, 0);
patch(p1, pc);
ll = n->ninit;
n->ninit = nil;
bgen(n, 1, -likely, p2);
n->ninit = ll;
patch(gbranch(AB, T, 0), to);
patch(p2, pc);
goto ret;
}
a = brcom(a);
true = !true;
}
// make simplest on right
if(nl->op == OLITERAL || (nl->ullman < UINF && nl->ullman < nr->ullman)) {
a = brrev(a);
r = nl;
nl = nr;
nr = r;
}
if(isslice(nl->type)) {
// only valid to cmp darray to literal nil
if((a != OEQ && a != ONE) || nr->op != OLITERAL) {
yyerror("illegal array comparison");
break;
}
igen(nl, &n1, N);
n1.xoffset += Array_array;
n1.type = types[tptr];
gencmp0(&n1, types[tptr], a, likely, to);
regfree(&n1);
break;
}
if(isinter(nl->type)) {
// front end shold only leave cmp to literal nil
if((a != OEQ && a != ONE) || nr->op != OLITERAL) {
yyerror("illegal interface comparison");
break;
}
igen(nl, &n1, N);
n1.type = types[tptr];
n1.xoffset += 0;
gencmp0(&n1, types[tptr], a, likely, to);
regfree(&n1);
break;
}
if(iscomplex[nl->type->etype]) {
complexbool(a, nl, nr, true, likely, 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, likely, to);
break;
}
if(nr->op == OLITERAL) {
if(isconst(nr, CTINT) && mpgetfix(nr->val.u.xval) == 0) {
gencmp0(nl, nl->type, a, likely, to);
break;
}
if(nr->val.ctype == CTNIL) {
gencmp0(nl, nl->type, a, likely, to);
break;
}
}
a = optoas(a, nr->type);
if(nr->ullman >= UINF) {
regalloc(&n1, nl->type, N);
cgen(nl, &n1);
tempname(&tmp, nl->type);
gmove(&n1, &tmp);
regfree(&n1);
regalloc(&n2, nr->type, N);
cgen(nr, &n2);
regalloc(&n1, nl->type, N);
cgen(&tmp, &n1);
gcmp(optoas(OCMP, nr->type), &n1, &n2);
patch(gbranch(a, nr->type, likely), to);
regfree(&n1);
regfree(&n2);
break;
}
tempname(&n3, nl->type);
cgen(nl, &n3);
tempname(&tmp, nr->type);
cgen(nr, &tmp);
regalloc(&n1, nl->type, N);
gmove(&n3, &n1);
regalloc(&n2, nr->type, N);
gmove(&tmp, &n2);
gcmp(optoas(OCMP, nr->type), &n1, &n2);
if(isfloat[nl->type->etype]) {
if(n->op == ONE) {
p1 = gbranch(ABVS, nr->type, likely);
patch(gbranch(a, nr->type, likely), to);
patch(p1, to);
} else {
p1 = gbranch(ABVS, nr->type, -likely);
patch(gbranch(a, nr->type, likely), to);
patch(p1, pc);
}
} else {
patch(gbranch(a, nr->type, likely), to);
}
regfree(&n1);
regfree(&n2);
break;
}
goto ret;
ret:
;
}
/*
* 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 + 4; // correct for LR
break;
}
// botch - probably failing to recognize address
// arithmetic on the above. eg INDEX and DOT
return -1000;
}
/*
* block copy:
* memmove(&res, &n, w);
* NB: character copy assumed little endian architecture
*/
void
sgen(Node *n, Node *res, int64 w)
{
Node dst, src, tmp, nend, r0, r1, r2, *f;
int32 c, odst, osrc;
int dir, align, op;
Prog *p, *ploop;
NodeList *l;
if(debug['g']) {
print("\nsgen w=%lld\n", w);
dump("r", n);
dump("res", res);
}
if(n->ullman >= UINF && res->ullman >= UINF)
fatal("sgen UINF");
if(w < 0 || (int32)w != w)
fatal("sgen copy %lld", w);
if(n->type == T)
fatal("sgen: missing type");
if(w == 0) {
// evaluate side effects only.
regalloc(&dst, types[tptr], N);
agen(res, &dst);
agen(n, &dst);
regfree(&dst);
return;
}
// If copying .args, that's all the results, so record definition sites
// for them for the liveness analysis.
if(res->op == ONAME && strcmp(res->sym->name, ".args") == 0)
for(l = curfn->dcl; l != nil; l = l->next)
if(l->n->class == PPARAMOUT)
gvardef(l->n);
// Avoid taking the address for simple enough types.
if(componentgen(n, res))
return;
// determine alignment.
// want to avoid unaligned access, so have to use
// smaller operations for less aligned types.
// for example moving [4]byte must use 4 MOVB not 1 MOVW.
align = n->type->align;
switch(align) {
default:
fatal("sgen: invalid alignment %d for %T", align, n->type);
case 1:
op = AMOVB;
break;
case 2:
op = AMOVH;
break;
case 4:
op = AMOVW;
break;
}
if(w%align)
fatal("sgen: unaligned size %lld (align=%d) for %T", w, align, n->type);
c = w / align;
// 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(&tmp, n->type);
sgen(n, &tmp, w);
sgen(&tmp, res, w);
return;
}
if(osrc%align != 0 || odst%align != 0)
fatal("sgen: unaligned offset src %d or dst %d (align %d)", osrc, odst, align);
// if we are copying forward on the stack and
// the src and dst overlap, then reverse direction
dir = align;
if(osrc < odst && odst < osrc+w)
dir = -dir;
if(op == AMOVW && dir > 0 && c >= 4 && c <= 128) {
r0.op = OREGISTER;
r0.val.u.reg = REGALLOC_R0;
r1.op = OREGISTER;
r1.val.u.reg = REGALLOC_R0 + 1;
r2.op = OREGISTER;
r2.val.u.reg = REGALLOC_R0 + 2;
regalloc(&src, types[tptr], &r1);
regalloc(&dst, types[tptr], &r2);
if(n->ullman >= res->ullman) {
// eval n first
agen(n, &src);
if(res->op == ONAME)
gvardef(res);
agen(res, &dst);
} else {
// eval res first
if(res->op == ONAME)
gvardef(res);
agen(res, &dst);
agen(n, &src);
}
regalloc(&tmp, types[tptr], &r0);
f = sysfunc("duffcopy");
p = gins(ADUFFCOPY, N, f);
afunclit(&p->to, f);
// 8 and 128 = magic constants: see ../../pkg/runtime/asm_arm.s
p->to.offset = 8*(128-c);
regfree(&tmp);
regfree(&src);
regfree(&dst);
return;
}
if(n->ullman >= res->ullman) {
agenr(n, &dst, res); // temporarily use dst
regalloc(&src, types[tptr], N);
gins(AMOVW, &dst, &src);
if(res->op == ONAME)
gvardef(res);
agen(res, &dst);
} else {
if(res->op == ONAME)
gvardef(res);
agenr(res, &dst, res);
agenr(n, &src, N);
}
regalloc(&tmp, types[TUINT32], N);
// set up end marker
memset(&nend, 0, sizeof nend);
if(c >= 4) {
regalloc(&nend, types[TUINT32], N);
p = gins(AMOVW, &src, &nend);
p->from.type = D_CONST;
if(dir < 0)
p->from.offset = dir;
else
p->from.offset = w;
}
// move src and dest to the end of block if necessary
if(dir < 0) {
p = gins(AMOVW, &src, &src);
p->from.type = D_CONST;
p->from.offset = w + dir;
p = gins(AMOVW, &dst, &dst);
p->from.type = D_CONST;
p->from.offset = w + dir;
}
// move
if(c >= 4) {
p = gins(op, &src, &tmp);
p->from.type = D_OREG;
p->from.offset = dir;
p->scond |= C_PBIT;
ploop = p;
p = gins(op, &tmp, &dst);
p->to.type = D_OREG;
p->to.offset = dir;
p->scond |= C_PBIT;
p = gins(ACMP, &src, N);
raddr(&nend, p);
patch(gbranch(ABNE, T, 0), ploop);
regfree(&nend);
} else {
while(c-- > 0) {
p = gins(op, &src, &tmp);
p->from.type = D_OREG;
p->from.offset = dir;
p->scond |= C_PBIT;
p = gins(op, &tmp, &dst);
p->to.type = D_OREG;
p->to.offset = dir;
p->scond |= C_PBIT;
}
}
regfree(&dst);
regfree(&src);
regfree(&tmp);
}
static int
cadable(Node *n)
{
if(!n->addable) {
// dont know how it happens,
// but it does
return 0;
}
switch(n->op) {
case ONAME:
return 1;
}
return 0;
}
/*
* copy a composite value by moving its individual components.
* Slices, strings and interfaces are supported.
* nr is N when assigning a zero value.
* return 1 if can do, 0 if cant.
*/
int
componentgen(Node *nr, Node *nl)
{
Node nodl, nodr, tmp;
int freel, freer;
freel = 0;
freer = 0;
switch(nl->type->etype) {
default:
goto no;
case TARRAY:
if(!isslice(nl->type))
goto no;
case TSTRING:
case TINTER:
break;
}
nodl = *nl;
if(!cadable(nl)) {
if(nr == N || !cadable(nr))
goto no;
igen(nl, &nodl, N);
freel = 1;
}
if(nr != N) {
nodr = *nr;
if(!cadable(nr)) {
igen(nr, &nodr, N);
freer = 1;
}
} else {
// When zeroing, prepare a register containing zero.
nodconst(&tmp, nl->type, 0);
regalloc(&nodr, types[TUINT], N);
gmove(&tmp, &nodr);
freer = 1;
}
// nl and nr are 'cadable' which basically means they are names (variables) now.
// If they are the same variable, don't generate any code, because the
// VARDEF we generate will mark the old value as dead incorrectly.
// (And also the assignments are useless.)
if(nr != N && nl->op == ONAME && nr->op == ONAME && nl == nr)
goto yes;
switch(nl->type->etype) {
case TARRAY:
if(nl->op == ONAME)
gvardef(nl);
nodl.xoffset += Array_array;
nodl.type = ptrto(nl->type->type);
if(nr != N) {
nodr.xoffset += Array_array;
nodr.type = nodl.type;
}
gmove(&nodr, &nodl);
nodl.xoffset += Array_nel-Array_array;
nodl.type = types[simtype[TUINT]];
if(nr != N) {
nodr.xoffset += Array_nel-Array_array;
nodr.type = nodl.type;
}
gmove(&nodr, &nodl);
nodl.xoffset += Array_cap-Array_nel;
nodl.type = types[simtype[TUINT]];
if(nr != N) {
nodr.xoffset += Array_cap-Array_nel;
nodr.type = nodl.type;
}
gmove(&nodr, &nodl);
goto yes;
case TSTRING:
if(nl->op == ONAME)
gvardef(nl);
nodl.xoffset += Array_array;
nodl.type = ptrto(types[TUINT8]);
if(nr != N) {
nodr.xoffset += Array_array;
nodr.type = nodl.type;
}
gmove(&nodr, &nodl);
nodl.xoffset += Array_nel-Array_array;
nodl.type = types[simtype[TUINT]];
if(nr != N) {
nodr.xoffset += Array_nel-Array_array;
nodr.type = nodl.type;
}
gmove(&nodr, &nodl);
goto yes;
case TINTER:
if(nl->op == ONAME)
gvardef(nl);
nodl.xoffset += Array_array;
nodl.type = ptrto(types[TUINT8]);
if(nr != N) {
nodr.xoffset += Array_array;
nodr.type = nodl.type;
}
gmove(&nodr, &nodl);
nodl.xoffset += Array_nel-Array_array;
nodl.type = ptrto(types[TUINT8]);
if(nr != N) {
nodr.xoffset += Array_nel-Array_array;
nodr.type = nodl.type;
}
gmove(&nodr, &nodl);
goto yes;
}
no:
if(freer)
regfree(&nodr);
if(freel)
regfree(&nodl);
return 0;
yes:
if(freer)
regfree(&nodr);
if(freel)
regfree(&nodl);
return 1;
}