diff options
Diffstat (limited to 'src/cmd/9g/cgen.c')
| -rw-r--r-- | src/cmd/9g/cgen.c | 1763 |
1 files changed, 1763 insertions, 0 deletions
diff --git a/src/cmd/9g/cgen.c b/src/cmd/9g/cgen.c new file mode 100644 index 000000000..e38936001 --- /dev/null +++ b/src/cmd/9g/cgen.c @@ -0,0 +1,1763 @@ +// 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; + int a, f; + Prog *p1, *p2, *p3; + Addr addr; + +//print("cgen %N(%d) -> %N(%d)\n", n, n->addable, res, res->addable); + 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"); + + while(n->op == OCONVNOP) + n = n->left; + + 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); + goto ret; + case OEFACE: + if (res->op != ONAME || !res->addable) { + tempname(&n1, n->type); + cgen_eface(n, &n1); + cgen(&n1, res); + } else + cgen_eface(n, res); + goto ret; + } + + 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; + } + + if(!res->addable) { + if(n->ullman > res->ullman) { + regalloc(&n1, n->type, res); + cgen(n, &n1); + if(n1.ullman > res->ullman) { + dump("n1", &n1); + dump("res", res); + fatal("loop in cgen"); + } + cgen(&n1, res); + regfree(&n1); + goto ret; + } + + if(res->ullman >= UINF) + goto gen; + + if(complexop(n, res)) { + complexgen(n, res); + goto ret; + } + + f = 1; // gen thru register + switch(n->op) { + case OLITERAL: + if(smallintconst(n)) + f = 0; + break; + case OREGISTER: + f = 0; + break; + } + + if(!iscomplex[n->type->etype]) { + a = optoas(OAS, res->type); + if(sudoaddable(a, res, &addr)) { + if(f) { + regalloc(&n2, res->type, N); + cgen(n, &n2); + p1 = gins(a, &n2, N); + regfree(&n2); + } else + p1 = gins(a, n, N); + p1->to = addr; + if(debug['g']) + print("%P [ignore previous line]\n", p1); + sudoclean(); + goto ret; + } + } + + gen: + igen(res, &n1, N); + cgen(n, &n1); + regfree(&n1); + 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(complexop(n, res)) { + complexgen(n, res); + goto ret; + } + + // if both are addressable, move + if(n->addable) { + if(n->op == OREGISTER || res->op == OREGISTER) { + gmove(n, res); + } else { + regalloc(&n1, n->type, N); + gmove(n, &n1); + cgen(&n1, res); + regfree(&n1); + } + goto ret; + } + + 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; + } + + if(!iscomplex[n->type->etype]) { + a = optoas(OAS, n->type); + if(sudoaddable(a, n, &addr)) { + if(res->op == OREGISTER) { + p1 = gins(a, N, res); + p1->from = addr; + } else { + regalloc(&n2, n->type, N); + p1 = gins(a, N, &n2); + p1->from = addr; + gins(a, &n2, res); + regfree(&n2); + } + sudoclean(); + goto ret; + } + } + + // TODO(minux): we shouldn't reverse FP comparisons, but then we need to synthesize + // OGE, OLE, and ONE ourselves. + // 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; + + // 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(ABR, T, 0); + p2 = pc; + gmove(nodbool(1), res); + p3 = gbranch(ABR, 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: + if(isfloat[nl->type->etype]) { + nr = nodintconst(-1); + convlit(&nr, n->type); + a = optoas(OMUL, nl->type); + goto sbop; + } + 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); + goto sbop; + + // asymmetric binary + case OSUB: + a = optoas(n->op, nl->type); + goto abop; + + case OHMUL: + cgen_hmul(nl, nr, res); + break; + + case OCONV: + if(n->type->width > nl->type->width) { + // If loading from memory, do conversion during load, + // so as to avoid use of 8-bit register in, say, int(*byteptr). + switch(nl->op) { + case ODOT: + case ODOTPTR: + case OINDEX: + case OIND: + case ONAME: + igen(nl, &n1, res); + regalloc(&n2, n->type, res); + gmove(&n1, &n2); + gmove(&n2, res); + regfree(&n2); + regfree(&n1); + goto ret; + } + } + + regalloc(&n1, nl->type, res); + regalloc(&n2, n->type, &n1); + cgen(nl, &n1); + + // if we do the conversion n1 -> n2 here + // reusing the register, then gmove won't + // have to allocate its own register. + gmove(&n1, &n2); + gmove(&n2, res); + regfree(&n2); + regfree(&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 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(AMOVD, 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 and chan have len in the first int-sized 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, 0); + + n2 = n1; + n2.op = OINDREG; + n2.type = types[simtype[TINT]]; + 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. + // a zero pointer means zero length + igen(nl, &n1, res); + n1.type = types[simtype[TUINT]]; + 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 int-sized 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, 0); + + n2 = n1; + n2.op = OINDREG; + n2.xoffset = widthint; + n2.type = types[simtype[TINT]]; + gmove(&n2, &n1); + + patch(p1, pc); + + gmove(&n1, res); + regfree(&n1); + break; + } + if(isslice(nl->type)) { + igen(nl, &n1, res); + n1.type = types[simtype[TUINT]]; + n1.xoffset += Array_cap; + gmove(&n1, res); + regfree(&n1); + break; + } + fatal("cgen: OCAP: unknown type %lT", nl->type); + break; + + case OADDR: + if(n->bounded) // let race detector avoid nil checks + disable_checknil++; + agen(nl, res); + if(n->bounded) + disable_checknil--; + 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: + if(isfloat[n->type->etype]) { + a = optoas(n->op, nl->type); + goto abop; + } + + if(nl->ullman >= nr->ullman) { + regalloc(&n1, nl->type, res); + cgen(nl, &n1); + cgen_div(n->op, &n1, nr, res); + regfree(&n1); + } else { + if(!smallintconst(nr)) { + regalloc(&n2, nr->type, res); + cgen(nr, &n2); + } else { + n2 = *nr; + } + cgen_div(n->op, nl, &n2, res); + if(n2.op != OLITERAL) + regfree(&n2); + } + break; + + case OLSH: + case ORSH: + case OLROT: + cgen_shift(n->op, n->bounded, nl, nr, res); + break; + } + goto ret; + +sbop: // symmetric binary + /* + * put simplest on right - we'll generate into left + * and then adjust it using the computation of right. + * constants and variables have the same ullman + * count, so look for constants specially. + * + * an integer constant we can use as an immediate + * is simpler than a variable - we can use the immediate + * in the adjustment instruction directly - so it goes + * on the right. + * + * other constants, like big integers or floating point + * constants, require a mov into a register, so those + * might as well go on the left, so we can reuse that + * register for the computation. + */ + if(nl->ullman < nr->ullman || + (nl->ullman == nr->ullman && + (smallintconst(nl) || (nr->op == OLITERAL && !smallintconst(nr))))) { + r = nl; + nl = nr; + nr = r; + } + +abop: // asymmetric binary + if(nl->ullman >= nr->ullman) { + regalloc(&n1, nl->type, res); + cgen(nl, &n1); + /* + * This generates smaller code - it avoids a MOV - but it's + * easily 10% slower due to not being able to + * optimize/manipulate the move. + * To see, run: go test -bench . crypto/md5 + * with and without. + * + if(sudoaddable(a, nr, &addr)) { + p1 = gins(a, N, &n1); + p1->from = addr; + gmove(&n1, res); + sudoclean(); + regfree(&n1); + goto ret; + } + * + */ + // TODO(minux): enable using constants directly in certain instructions. + //if(smallintconst(nr)) + // n2 = *nr; + //else { + regalloc(&n2, nr->type, N); + cgen(nr, &n2); + //} + } else { + //if(smallintconst(nr)) + // n2 = *nr; + //else { + 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 < widthreg) { + switch(n->op) { + case OADD: + case OSUB: + case OMUL: + case OLSH: + gins(optoas(OAS, n->type), &n1, &n1); + break; + } + } + gmove(&n1, res); + regfree(&n1); + if(n2.op != OLITERAL) + regfree(&n2); + goto ret; + +uop: // unary + regalloc(&n1, nl->type, res); + cgen(nl, &n1); + gins(a, N, &n1); + gmove(&n1, res); + regfree(&n1); + goto ret; + +ret: + ; +} + +/* + * allocate a register (reusing res if possible) and generate + * a = 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, n->type, 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; + } +} + +/* + * allocate a register (reusing res if possible) and generate + * a = &n + * The caller must call 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; + + 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[TINT64]); + if(!isconst(nl, CTSTR)) + agenr(nl, &n3, res); + if(!isconst(nr, CTINT)) { + cgen(nr, &tmp); + regalloc(&n1, tmp.type, N); + gmove(&tmp, &n1); + } + } else if(nl->addable) { + if(!isconst(nr, CTINT)) { + tempname(&tmp, types[TINT64]); + cgen(nr, &tmp); + regalloc(&n1, tmp.type, N); + gmove(&tmp, &n1); + } + if(!isconst(nl, CTSTR)) { + agenr(nl, &n3, res); + } + } else { + tempname(&tmp, types[TINT64]); + cgen(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 + + // 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); + ginscon2(optoas(OCMP, types[TUINT64]), &n4, v); + regfree(&n4); + p1 = gbranch(optoas(OGT, types[TUINT64]), T, +1); + 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) { + ginscon(optoas(OADD, types[tptr]), v*w, &n3); + } + *a = n3; + break; + } + + regalloc(&n2, types[TINT64], &n1); // i + gmove(&n1, &n2); + regfree(&n1); + + if(!debug['B'] && !n->bounded) { + // check bounds + if(isconst(nl, CTSTR)) { + nodconst(&n4, types[TUINT64], 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[TUINT64], N); + gmove(&n1, &n4); + } else { + if(nl->type->bound < (1<<15)-1) + nodconst(&n4, types[TUINT64], nl->type->bound); + else { + regalloc(&n4, types[TUINT64], N); + p1 = gins(AMOVD, N, &n4); + p1->from.type = D_CONST; + p1->from.offset = nl->type->bound; + } + } + gins(optoas(OCMP, types[TUINT64]), &n2, &n4); + if(n4.op == OREGISTER) + regfree(&n4); + p1 = gbranch(optoas(OLT, types[TUINT64]), T, +1); + if(p2) + patch(p2, pc); + ginscall(panicindex, 0); + patch(p1, pc); + } + + if(isconst(nl, CTSTR)) { + regalloc(&n3, types[tptr], res); + p1 = gins(AMOVD, 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 already scaled */ + gins(optoas(OADD, types[tptr]), &n2, &n3); + } /* else if(w == 2 || w == 4 || w == 8) { + // TODO(minux): scale using shift + } */ else { + regalloc(&n4, types[TUINT64], N); + nodconst(&n1, types[TUINT64], w); + gmove(&n1, &n4); + gins(optoas(OMUL, types[TUINT64]), &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; + } +} + +static void +ginsadd(int as, vlong off, Node *dst) +{ + Node n1; + + regalloc(&n1, types[tptr], dst); + gmove(dst, &n1); + ginscon(as, off, &n1); + gmove(&n1, dst); + regfree(&n1); +} + +/* + * generate: + * res = &n; + * The generated code checks that the result is not nil. + */ +void +agen(Node *n, Node *res) +{ + Node *nl, *nr; + Node n1, n2, n3; + + if(debug['g']) { + dump("\nagen-res", res); + dump("agen-r", n); + } + if(n == N || n->type == T) + return; + + 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); + memset(&n3, 0, sizeof n3); + n3.op = OADDR; + n3.left = &n1; + gins(AMOVD, &n3, &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(AMOVD, &n1, &n2); + gmove(&n2, res); + regfree(&n2); + goto ret; + } + + nl = n->left; + nr = n->right; + USED(nr); + + switch(n->op) { + default: + fatal("agen: unknown op %+hN", n); + break; + + case OCALLMETH: + // TODO(minux): 5g has this: Release res so that it is available for cgen_call. + // Pick it up again after the call for OCALLMETH and OCALLFUNC. + 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 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) { + ginsadd(optoas(OADD, types[tptr]), n->xoffset, res); + } + break; + + case OIND: + cgen(nl, res); + cgen_checknil(res); + break; + + case ODOT: + agen(nl, res); + if(n->xoffset != 0) { + ginsadd(optoas(OADD, types[tptr]), n->xoffset, res); + } + break; + + case ODOTPTR: + cgen(nl, res); + cgen_checknil(res); + if(n->xoffset != 0) { + ginsadd(optoas(OADD, types[tptr]), n->xoffset, res); + } + 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) +{ + Type *fp; + Iter flist; + Node n1; + + 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 != D_R0+REGSP) + reg[n->val.u.reg]++; + *a = *n; + return; + + case ODOT: + igen(n->left, a, res); + a->xoffset += n->xoffset; + a->type = n->type; + fixlargeoffset(a); + return; + + case ODOTPTR: + cgenr(n->left, a, res); + cgen_checknil(a); + a->op = OINDREG; + a->xoffset += n->xoffset; + a->type = n->type; + fixlargeoffset(a); + return; + + case OCALLFUNC: + case OCALLMETH: + case OCALLINTER: + switch(n->op) { + case OCALLFUNC: + cgen_call(n, 0); + break; + case OCALLMETH: + cgen_callmeth(n, 0); + break; + case OCALLINTER: + cgen_callinter(n, N, 0); + break; + } + fp = structfirst(&flist, getoutarg(n->left->type)); + memset(a, 0, sizeof *a); + a->op = OINDREG; + a->val.u.reg = D_R0+REGSP; + a->addable = 1; + a->xoffset = fp->width + widthptr; // +widthptr: saved lr at 0(SP) + a->type = n->type; + return; + + case OINDEX: + // Index of fixed-size array by constant can + // put the offset in the addressing. + // Could do the same for slice except that we need + // to use the real index for the bounds checking. + if(isfixedarray(n->left->type) || + (isptr[n->left->type->etype] && isfixedarray(n->left->left->type))) + if(isconst(n->right, CTINT)) { + // Compute &a. + if(!isptr[n->left->type->etype]) + igen(n->left, a, res); + else { + igen(n->left, &n1, res); + cgen_checknil(&n1); + regalloc(a, types[tptr], res); + gmove(&n1, a); + regfree(&n1); + a->op = OINDREG; + } + + // Compute &a[i] as &a + i*width. + a->type = n->type; + a->xoffset += mpgetfix(n->right->val.u.xval)*n->type->width; + fixlargeoffset(a); + return; + } + break; + } + + agenr(n, a, res); + a->op = OINDREG; + a->type = n->type; +} + +/* + * generate: + * if(n == true) goto to; + */ +void +bgen(Node *n, int true, int likely, Prog *to) +{ + int et, a; + Node *nl, *nr, *l, *r; + Node n1, n2, tmp; + NodeList *ll; + Prog *p1, *p2; + + 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; + + while(n->op == OCONVNOP) { + n = n->left; + if(n->ninit != nil) + genlist(n->ninit); + } + + switch(n->op) { + default: + regalloc(&n1, n->type, N); + cgen(n, &n1); + nodconst(&n2, n->type, 0); + gins(optoas(OCMP, n->type), &n1, &n2); + a = ABNE; + if(!true) + a = ABEQ; + patch(gbranch(a, n->type, likely), to); + regfree(&n1); + goto ret; + + case OLITERAL: + // need to ask if it is bool? + if(!true == !n->val.u.bval) + patch(gbranch(ABR, T, likely), to); + goto ret; + + case OANDAND: + if(!true) + goto caseor; + + caseand: + p1 = gbranch(ABR, T, 0); + p2 = gbranch(ABR, T, 0); + patch(p1, pc); + bgen(n->left, !true, -likely, p2); + bgen(n->right, !true, -likely, p2); + p1 = gbranch(ABR, 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; + break; + } + + 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[nr->type->etype]) { + // brcom is not valid on floats when NaN is involved. + p1 = gbranch(ABR, T, 0); + p2 = gbranch(ABR, T, 0); + patch(p1, pc); + ll = n->ninit; // avoid re-genning ninit + n->ninit = nil; + bgen(n, 1, -likely, p2); + n->ninit = ll; + patch(gbranch(ABR, T, 0), to); + patch(p2, pc); + goto ret; + } + 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 slice comparison"); + break; + } + a = optoas(a, types[tptr]); + igen(nl, &n1, N); + n1.xoffset += Array_array; + n1.type = types[tptr]; + nodconst(&tmp, types[tptr], 0); + regalloc(&n2, types[tptr], &n1); + gmove(&n1, &n2); + gins(optoas(OCMP, types[tptr]), &n2, &tmp); + regfree(&n2); + patch(gbranch(a, types[tptr], likely), 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]); + igen(nl, &n1, N); + n1.type = types[tptr]; + nodconst(&tmp, types[tptr], 0); + regalloc(&n2, types[tptr], &n1); + gmove(&n1, &n2); + gins(optoas(OCMP, types[tptr]), &n2, &tmp); + regfree(&n2); + patch(gbranch(a, types[tptr], likely), to); + regfree(&n1); + break; + } + if(iscomplex[nl->type->etype]) { + complexbool(a, nl, nr, true, likely, to); + break; + } + + 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); + + goto cmp; + } + + regalloc(&n1, nl->type, N); + cgen(nl, &n1); + + // TODO(minux): cmpi does accept 16-bit signed immediate as p->to. + // and cmpli accepts 16-bit unsigned immediate. + //if(smallintconst(nr)) { + // gins(optoas(OCMP, nr->type), &n1, nr); + // patch(gbranch(optoas(a, nr->type), nr->type, likely), to); + // regfree(&n1); + // break; + //} + + regalloc(&n2, nr->type, N); + cgen(nr, &n2); + cmp: + l = &n1; + r = &n2; + gins(optoas(OCMP, nr->type), l, r); + if(isfloat[nr->type->etype] && (a == OLE || a == OGE)) { + // To get NaN right, must rewrite x <= y into separate x < y or x = y. + switch(a) { + case OLE: + a = OLT; + break; + case OGE: + a = OGT; + break; + } + patch(gbranch(optoas(a, nr->type), nr->type, likely), to); + patch(gbranch(optoas(OEQ, nr->type), nr->type, likely), to); + } else { + patch(gbranch(optoas(a, nr->type), 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. + */ +int64 +stkof(Node *n) +{ + Type *t; + Iter flist; + int64 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 + widthptr; // +widthptr: correct for saved LR + break; + } + + // botch - probably failing to recognize address + // arithmetic on the above. eg INDEX and DOT + return -1000; +} + +/* + * block copy: + * memmove(&ns, &n, w); + */ +void +sgen(Node *n, Node *ns, int64 w) +{ + Node dst, src, tmp, nend; + int32 c, odst, osrc; + int dir, align, op; + Prog *p, *ploop; + NodeList *l; + Node *res = ns; + + if(debug['g']) { + print("\nsgen w=%lld\n", w); + dump("r", n); + dump("res", ns); + } + + if(n->ullman >= UINF && ns->ullman >= UINF) + fatal("sgen UINF"); + + if(w < 0) + fatal("sgen copy %lld", w); + + // If copying .args, that's all the results, so record definition sites + // for them for the liveness analysis. + if(ns->op == ONAME && strcmp(ns->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, ns)) + // return; + + if(w == 0) { + // evaluate side effects only. + regalloc(&dst, types[tptr], N); + agen(res, &dst); + agen(n, &dst); + regfree(&dst); + 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 = AMOVBU; + break; + case 2: + op = AMOVHU; + break; + case 4: + op = AMOVWZU; // there is no lwau, only lwaux + break; + case 8: + op = AMOVDU; + 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(n->ullman >= res->ullman) { + agenr(n, &dst, res); // temporarily use dst + regalloc(&src, types[tptr], N); + gins(AMOVD, &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[tptr], N); + + // set up end marker + memset(&nend, 0, sizeof nend); + + // move src and dest to the end of block if necessary + if(dir < 0) { + if(c >= 4) { + regalloc(&nend, types[tptr], N); + p = gins(AMOVD, &src, &nend); + } + + p = gins(AADD, N, &src); + p->from.type = D_CONST; + p->from.offset = w; + + p = gins(AADD, N, &dst); + p->from.type = D_CONST; + p->from.offset = w; + } else { + p = gins(AADD, N, &src); + p->from.type = D_CONST; + p->from.offset = -dir; + + p = gins(AADD, N, &dst); + p->from.type = D_CONST; + p->from.offset = -dir; + + if(c >= 4) { + regalloc(&nend, types[tptr], N); + p = gins(AMOVD, &src, &nend); + p->from.type = D_CONST; + p->from.offset = w; + } + } + + + // move + // TODO: enable duffcopy for larger copies. + if(c >= 4) { + p = gins(op, &src, &tmp); + p->from.type = D_OREG; + p->from.offset = dir; + ploop = p; + + p = gins(op, &tmp, &dst); + p->to.type = D_OREG; + p->to.offset = dir; + + p = gins(ACMP, &src, &nend); + + 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 = gins(op, &tmp, &dst); + p->to.type = D_OREG; + p->to.offset = dir; + } + } + + 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. + * Small structs or arrays with elements of basic type are + * also supported. + * nr is N when assigning a zero value. + * return 1 if can do, 0 if can't. + */ +int +componentgen(Node *nr, Node *nl) +{ + Node nodl, nodr; + Type *t; + int freel, freer; + vlong fldcount; + vlong loffset, roffset; + + freel = 0; + freer = 0; + + switch(nl->type->etype) { + default: + goto no; + + case TARRAY: + t = nl->type; + + // Slices are ok. + if(isslice(t)) + break; + // Small arrays are ok. + if(t->bound > 0 && t->bound <= 3 && !isfat(t->type)) + break; + + goto no; + + case TSTRUCT: + // Small structs with non-fat types are ok. + // Zero-sized structs are treated separately elsewhere. + fldcount = 0; + for(t=nl->type->type; t; t=t->down) { + if(isfat(t->type)) + goto no; + if(t->etype != TFIELD) + fatal("componentgen: not a TFIELD: %lT", t); + fldcount++; + } + if(fldcount == 0 || fldcount > 4) + goto no; + + break; + + 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; + } + } + + // 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: + // componentgen for arrays. + if(nl->op == ONAME) + gvardef(nl); + t = nl->type; + if(!isslice(t)) { + nodl.type = t->type; + nodr.type = nodl.type; + for(fldcount=0; fldcount < t->bound; fldcount++) { + if(nr == N) + clearslim(&nodl); + else + gmove(&nodr, &nodl); + nodl.xoffset += t->type->width; + nodr.xoffset += t->type->width; + } + goto yes; + } + + // componentgen for slices. + nodl.xoffset += Array_array; + nodl.type = ptrto(nl->type->type); + + if(nr != N) { + nodr.xoffset += Array_array; + nodr.type = nodl.type; + } else + nodconst(&nodr, nodl.type, 0); + 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; + } else + nodconst(&nodr, nodl.type, 0); + 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; + } else + nodconst(&nodr, nodl.type, 0); + 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; + } else + nodconst(&nodr, nodl.type, 0); + 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; + } else + nodconst(&nodr, nodl.type, 0); + 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; + } else + nodconst(&nodr, nodl.type, 0); + 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; + } else + nodconst(&nodr, nodl.type, 0); + gmove(&nodr, &nodl); + + goto yes; + + case TSTRUCT: + if(nl->op == ONAME) + gvardef(nl); + loffset = nodl.xoffset; + roffset = nodr.xoffset; + // funarg structs may not begin at offset zero. + if(nl->type->etype == TSTRUCT && nl->type->funarg && nl->type->type) + loffset -= nl->type->type->width; + if(nr != N && nr->type->etype == TSTRUCT && nr->type->funarg && nr->type->type) + roffset -= nr->type->type->width; + + for(t=nl->type->type; t; t=t->down) { + nodl.xoffset = loffset + t->width; + nodl.type = t->type; + + if(nr == N) + clearslim(&nodl); + else { + nodr.xoffset = roffset + t->width; + 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; +} |