// Inferno utils/5l/noop.c // http://code.google.com/p/inferno-os/source/browse/utils/5l/noop.c // // Copyright © 1994-1999 Lucent Technologies Inc. All rights reserved. // Portions Copyright © 1995-1997 C H Forsyth (forsyth@terzarima.net) // Portions Copyright © 1997-1999 Vita Nuova Limited // Portions Copyright © 2000-2007 Vita Nuova Holdings Limited (www.vitanuova.com) // Portions Copyright © 2004,2006 Bruce Ellis // Portions Copyright © 2005-2007 C H Forsyth (forsyth@terzarima.net) // Revisions Copyright © 2000-2007 Lucent Technologies Inc. and others // Portions Copyright © 2009 The Go Authors. All rights reserved. // // Permission is hereby granted, free of charge, to any person obtaining a copy // of this software and associated documentation files (the "Software"), to deal // in the Software without restriction, including without limitation the rights // to use, copy, modify, merge, publish, distribute, sublicense, and/or sell // copies of the Software, and to permit persons to whom the Software is // furnished to do so, subject to the following conditions: // // The above copyright notice and this permission notice shall be included in // all copies or substantial portions of the Software. // // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN // THE SOFTWARE. #include "l.h" // see ../../runtime/proc.c:/StackGuard enum { StackBig = 4096, }; static Sym* sym_div; static Sym* sym_divu; static Sym* sym_mod; static Sym* sym_modu; static void setdiv(int); static Prog * movrr(Prog *q, int rs, int rd, Prog *p) { if(q == nil) q = prg(); q->as = AMOVW; q->line = p->line; q->from.type = D_REG; q->from.reg = rs; q->to.type = D_REG; q->to.reg = rd; q->link = p->link; return q; } static Prog * fnret(Prog *q, int rs, int foreign, Prog *p) { q = movrr(q, rs, REGPC, p); if(foreign){ // BX rs q->as = ABXRET; q->from.type = D_NONE; q->from.reg = NREG; q->to.reg = rs; } return q; } static Prog * aword(int32 w, Prog *p) { Prog *q; q = prg(); q->as = AWORD; q->line = p->line; q->from.type = D_NONE; q->reg = NREG; q->to.type = D_CONST; q->to.offset = w; q->link = p->link; p->link = q; return q; } static Prog * adword(int32 w1, int32 w2, Prog *p) { Prog *q; q = prg(); q->as = ADWORD; q->line = p->line; q->from.type = D_CONST; q->from.offset = w1; q->reg = NREG; q->to.type = D_CONST; q->to.offset = w2; q->link = p->link; p->link = q; return q; } void noops(void) { Prog *p, *q, *q1, *q2; int o, curframe, curbecome, maxbecome, foreign; Prog *pmorestack; Sym *symmorestack; /* * find leaf subroutines * become sizes * frame sizes * strip NOPs * expand RET * expand BECOME pseudo */ if(debug['v']) Bprint(&bso, "%5.2f noops\n", cputime()); Bflush(&bso); pmorestack = P; symmorestack = lookup("runtime·morestack", 0); if(symmorestack->type == STEXT) for(p = firstp; p != P; p = p->link) { if(p->as == ATEXT) { if(p->from.sym == symmorestack) { pmorestack = p; p->reg |= NOSPLIT; break; } } } // TODO(kaib): make lack of morestack an error // if(pmorestack == P) // diag("runtime·morestack not defined"); curframe = 0; curbecome = 0; maxbecome = 0; curtext = 0; q = P; for(p = firstp; p != P; p = p->link) { setarch(p); /* find out how much arg space is used in this TEXT */ if(p->to.type == D_OREG && p->to.reg == REGSP) if(p->to.offset > curframe) curframe = p->to.offset; switch(p->as) { case ATEXT: if(curtext && curtext->from.sym) { curtext->from.sym->frame = curframe; curtext->from.sym->become = curbecome; if(curbecome > maxbecome) maxbecome = curbecome; } curframe = 0; curbecome = 0; p->mark |= LEAF; curtext = p; break; case ARET: /* special form of RET is BECOME */ if(p->from.type == D_CONST) if(p->from.offset > curbecome) curbecome = p->from.offset; break; case ADIV: case ADIVU: case AMOD: case AMODU: q = p; if(prog_div == P) initdiv(); if(curtext != P) curtext->mark &= ~LEAF; setdiv(p->as); continue; case ANOP: q1 = p->link; q->link = q1; /* q is non-nop */ q1->mark |= p->mark; continue; case ABL: case ABX: if(curtext != P) curtext->mark &= ~LEAF; case ABCASE: case AB: case ABEQ: case ABNE: case ABCS: case ABHS: case ABCC: case ABLO: case ABMI: case ABPL: case ABVS: case ABVC: case ABHI: case ABLS: case ABGE: case ABLT: case ABGT: case ABLE: q1 = p->cond; if(q1 != P) { while(q1->as == ANOP) { q1 = q1->link; p->cond = q1; } } break; } q = p; } if(curtext && curtext->from.sym) { curtext->from.sym->frame = curframe; curtext->from.sym->become = curbecome; if(curbecome > maxbecome) maxbecome = curbecome; } if(debug['b']) print("max become = %d\n", maxbecome); xdefine("ALEFbecome", STEXT, maxbecome); curtext = 0; for(p = firstp; p != P; p = p->link) { setarch(p); switch(p->as) { case ATEXT: curtext = p; break; case ABL: // case ABX: if(curtext != P && curtext->from.sym != S && curtext->to.offset >= 0) { o = maxbecome - curtext->from.sym->frame; if(o <= 0) break; /* calling a become or calling a variable */ if(p->to.sym == S || p->to.sym->become) { curtext->to.offset += o; if(debug['b']) { curp = p; print("%D calling %D increase %d\n", &curtext->from, &p->to, o); } } } break; } } for(p = firstp; p != P; p = p->link) { setarch(p); o = p->as; switch(o) { case ATEXT: curtext = p; autosize = p->to.offset + 4; if(autosize <= 4) if(curtext->mark & LEAF) { p->to.offset = -4; autosize = 0; } if(!autosize && !(curtext->mark & LEAF)) { if(debug['v']) Bprint(&bso, "save suppressed in: %s\n", curtext->from.sym->name); Bflush(&bso); curtext->mark |= LEAF; } #ifdef CALLEEBX if(p->from.sym->foreign){ if(thumb) // don't allow literal pool to seperate these p = adword(0xe28f7001, 0xe12fff17, p); // arm add 1, pc, r7 and bx r7 // p = aword(0xe12fff17, aword(0xe28f7001, p)); // arm add 1, pc, r7 and bx r7 else p = aword(0x4778, p); // thumb bx pc and 2 bytes padding } #endif if(curtext->mark & LEAF) { if(curtext->from.sym) curtext->from.sym->type = SLEAF; if(!autosize) break; } if(thumb){ if(!(p->reg & NOSPLIT)) diag("stack splitting not supported in thumb"); if(!(curtext->mark & LEAF)){ q = movrr(nil, REGLINK, REGTMPT-1, p); p->link = q; q1 = prg(); q1->as = AMOVW; q1->line = p->line; q1->from.type = D_REG; q1->from.reg = REGTMPT-1; q1->to.type = D_OREG; q1->to.name = D_NONE; q1->to.reg = REGSP; q1->to.offset = 0; q1->link = q->link; q->link = q1; } if(autosize){ q2 = prg(); q2->as = ASUB; q2->line = p->line; q2->from.type = D_CONST; q2->from.offset = autosize; q2->to.type = D_REG; q2->to.reg = REGSP; q2->link = p->link; p->link = q2; } break; } if(p->reg & NOSPLIT) { q1 = prg(); q1->as = AMOVW; q1->scond |= C_WBIT; q1->line = p->line; q1->from.type = D_REG; q1->from.reg = REGLINK; q1->to.type = D_OREG; q1->to.offset = -autosize; q1->to.reg = REGSP; q1->link = p->link; p->link = q1; } else if (autosize < StackBig) { // split stack check for small functions // MOVW g_stackguard(g), R1 // CMP R1, $-autosize(SP) // MOVW.LO $autosize, R1 // MOVW.LO $args, R2 // MOVW.LO R14, R3 // BL.LO runtime·morestack(SB) // modifies LR // MOVW.W R14,$-autosize(SP) // TODO(kaib): add more trampolines // TODO(kaib): put stackguard in register // TODO(kaib): add support for -K and underflow detection // MOVW g_stackguard(g), R1 p = appendp(p); p->as = AMOVW; p->from.type = D_OREG; p->from.reg = REGG; p->to.type = D_REG; p->to.reg = 1; // CMP R1, $-autosize(SP) p = appendp(p); p->as = ACMP; p->from.type = D_REG; p->from.reg = 1; p->from.offset = -autosize; p->reg = REGSP; // MOVW.LO $autosize, R1 p = appendp(p); p->as = AMOVW; p->scond = C_SCOND_LO; p->from.type = D_CONST; p->from.offset = 0; p->to.type = D_REG; p->to.reg = 1; // MOVW.LO $args +4, R2 // also need to store the extra 4 bytes. p = appendp(p); p->as = AMOVW; p->scond = C_SCOND_LO; p->from.type = D_CONST; p->from.offset = (curtext->to.offset2 & ~7) + 4; p->to.type = D_REG; p->to.reg = 2; // MOVW.LO R14, R3 p = appendp(p); p->as = AMOVW; p->scond = C_SCOND_LO; p->from.type = D_REG; p->from.reg = REGLINK; p->to.type = D_REG; p->to.reg = 3; // BL.LO runtime·morestack(SB) // modifies LR p = appendp(p); p->as = ABL; p->scond = C_SCOND_LO; p->to.type = D_BRANCH; p->to.sym = symmorestack; p->cond = pmorestack; // MOVW.W R14,$-autosize(SP) p = appendp(p); p->as = AMOVW; p->scond |= C_WBIT; p->from.type = D_REG; p->from.reg = REGLINK; p->to.type = D_OREG; p->to.offset = -autosize; p->to.reg = REGSP; } else { // > StackBig // MOVW $autosize, R1 // MOVW $args, R2 // MOVW R14, R3 // BL runtime·morestack(SB) // modifies LR // MOVW.W R14,$-autosize(SP) // MOVW $autosize, R1 p = appendp(p); p->as = AMOVW; p->from.type = D_CONST; p->from.offset = autosize; p->to.type = D_REG; p->to.reg = 1; // MOVW $args +4, R2 // also need to store the extra 4 bytes. p = appendp(p); p->as = AMOVW; p->from.type = D_CONST; p->from.offset = (curtext->to.offset2 & ~7) + 4; p->to.type = D_REG; p->to.reg = 2; // MOVW R14, R3 p = appendp(p); p->as = AMOVW; p->from.type = D_REG; p->from.reg = REGLINK; p->to.type = D_REG; p->to.reg = 3; // BL runtime·morestack(SB) // modifies LR p = appendp(p); p->as = ABL; p->to.type = D_BRANCH; p->to.sym = symmorestack; p->cond = pmorestack; // MOVW.W R14,$-autosize(SP) p = appendp(p); p->as = AMOVW; p->scond |= C_WBIT; p->from.type = D_REG; p->from.reg = REGLINK; p->to.type = D_OREG; p->to.offset = -autosize; p->to.reg = REGSP; } break; case ARET: nocache(p); foreign = seenthumb && curtext->from.sym != S && (curtext->from.sym->foreign || curtext->from.sym->fnptr); // print("%s %d %d\n", curtext->from.sym->name, curtext->from.sym->foreign, curtext->from.sym->fnptr); if(p->from.type == D_CONST) goto become; if(curtext->mark & LEAF) { if(!autosize) { if(thumb){ p = fnret(p, REGLINK, foreign, p); break; } // if(foreign) print("ABXRET 1 %s\n", curtext->from.sym->name); p->as = foreign ? ABXRET : AB; p->from = zprg.from; p->to.type = D_OREG; p->to.offset = 0; p->to.reg = REGLINK; break; } } if(thumb){ if(curtext->mark & LEAF){ if(autosize){ p->as = AADD; p->from.type = D_CONST; p->from.offset = autosize; p->to.type = D_REG; p->to.reg = REGSP; q = nil; } else q = p; q = fnret(q, REGLINK, foreign, p); if(q != p) p->link = q; } else{ p->as = AMOVW; p->from.type = D_OREG; p->from.name = D_NONE; p->from.reg = REGSP; p->from.offset = 0; p->to.type = D_REG; p->to.reg = REGTMPT-1; if(autosize){ q = prg(); q->as = AADD; q->from.type = D_CONST; q->from.offset = autosize; q->to.type = D_REG; q->to.reg = REGSP; q->link = p->link; p->link = q; } else q = p; q1 = fnret(nil, REGTMPT-1, foreign, p); q1->link = q->link; q->link = q1; } break; } if(foreign) { // if(foreign) print("ABXRET 3 %s\n", curtext->from.sym->name); #define R 1 p->as = AMOVW; p->from.type = D_OREG; p->from.name = D_NONE; p->from.reg = REGSP; p->from.offset = 0; p->to.type = D_REG; p->to.reg = R; q = prg(); q->as = AADD; q->scond = p->scond; q->line = p->line; q->from.type = D_CONST; q->from.offset = autosize; q->to.type = D_REG; q->to.reg = REGSP; q->link = p->link; p->link = q; q1 = prg(); q1->as = ABXRET; q1->scond = p->scond; q1->line = p->line; q1->to.type = D_OREG; q1->to.offset = 0; q1->to.reg = R; q1->link = q->link; q->link = q1; #undef R } else { p->as = AMOVW; p->scond |= C_PBIT; p->from.type = D_OREG; p->from.offset = autosize; p->from.reg = REGSP; p->to.type = D_REG; p->to.reg = REGPC; } break; become: if(foreign){ diag("foreign become - help"); break; } if(thumb){ diag("thumb become - help"); break; } print("arm become\n"); if(curtext->mark & LEAF) { if(!autosize) { p->as = AB; p->from = zprg.from; break; } } q = prg(); q->scond = p->scond; q->line = p->line; q->as = AB; q->from = zprg.from; q->to = p->to; q->cond = p->cond; q->link = p->link; p->link = q; if(thumb){ q1 = prg(); q1->line = p->line; q1->as = AADD; q1->from.type = D_CONST; q1->from.offset = autosize; q1->to.type = D_REG; q1->to.reg = REGSP; p->as = AMOVW; p->line = p->line; p->from.type = D_OREG; p->from.name = D_NONE; p->from.reg = REGSP; p->from.offset = 0; p->to.type = D_REG; p->to.reg = REGTMPT-1; q1->link = q; p->link = q1; q2 = movrr(nil, REGTMPT-1, REGLINK, p); q2->link = q; q1->link = q2; break; } p->as = AMOVW; p->scond |= C_PBIT; p->from = zprg.from; p->from.type = D_OREG; p->from.offset = autosize; p->from.reg = REGSP; p->to = zprg.to; p->to.type = D_REG; p->to.reg = REGLINK; break; case ADIV: case ADIVU: case AMOD: case AMODU: if(debug['M']) break; if(p->from.type != D_REG) break; if(p->to.type != D_REG) break; q1 = p; /* MOV a,4(SP) */ q = prg(); q->link = p->link; p->link = q; p = q; p->as = AMOVW; p->line = q1->line; p->from.type = D_REG; p->from.reg = q1->from.reg; p->to.type = D_OREG; p->to.reg = REGSP; p->to.offset = 4; /* MOV b,REGTMP */ q = prg(); q->link = p->link; p->link = q; p = q; p->as = AMOVW; p->line = q1->line; p->from.type = D_REG; p->from.reg = q1->reg; if(q1->reg == NREG) p->from.reg = q1->to.reg; p->to.type = D_REG; p->to.reg = prog_div != UP && prog_div->from.sym->thumb ? REGTMPT : REGTMP; p->to.offset = 0; /* CALL appropriate */ q = prg(); q->link = p->link; p->link = q; p = q; #ifdef CALLEEBX p->as = ABL; #else if(prog_div != UP && prog_div->from.sym->thumb) p->as = thumb ? ABL : ABX; else p->as = thumb ? ABX : ABL; #endif p->line = q1->line; p->to.type = D_BRANCH; p->cond = p; switch(o) { case ADIV: p->cond = prog_div; p->to.sym = sym_div; break; case ADIVU: p->cond = prog_divu; p->to.sym = sym_divu; break; case AMOD: p->cond = prog_mod; p->to.sym = sym_mod; break; case AMODU: p->cond = prog_modu; p->to.sym = sym_modu; break; } /* MOV REGTMP, b */ q = prg(); q->link = p->link; p->link = q; p = q; p->as = AMOVW; p->line = q1->line; p->from.type = D_REG; p->from.reg = prog_div != UP && prog_div->from.sym->thumb ? REGTMPT : REGTMP; p->from.offset = 0; p->to.type = D_REG; p->to.reg = q1->to.reg; /* ADD $8,SP */ q = prg(); q->link = p->link; p->link = q; p = q; p->as = AADD; p->from.type = D_CONST; p->from.reg = NREG; p->from.offset = 8; p->reg = NREG; p->to.type = D_REG; p->to.reg = REGSP; /* SUB $8,SP */ q1->as = ASUB; q1->from.type = D_CONST; q1->from.offset = 8; q1->from.reg = NREG; q1->reg = NREG; q1->to.type = D_REG; q1->to.reg = REGSP; break; case AMOVW: if(thumb){ Adr *a = &p->from; if(a->type == D_CONST && ((a->name == D_NONE && a->reg == REGSP) || a->name == D_AUTO || a->name == D_PARAM) && (a->offset & 3)) diag("SP offset not multiple of 4"); } break; case AMOVB: case AMOVBU: case AMOVH: case AMOVHU: if(thumb){ if(p->from.type == D_OREG && (p->from.name == D_AUTO || p->from.name == D_PARAM || (p->from.name == D_CONST && p->from.reg == REGSP))){ q = prg(); *q = *p; if(p->from.name == D_AUTO) q->from.offset += autosize; else if(p->from.name == D_PARAM) q->from.offset += autosize+4; q->from.name = D_NONE; q->from.reg = REGTMPT; p = movrr(p, REGSP, REGTMPT, p); q->link = p->link; p->link = q; } if(p->to.type == D_OREG && (p->to.name == D_AUTO || p->to.name == D_PARAM || (p->to.name == D_CONST && p->to.reg == REGSP))){ q = prg(); *q = *p; if(p->to.name == D_AUTO) q->to.offset += autosize; else if(p->to.name == D_PARAM) q->to.offset += autosize+4; q->to.name = D_NONE; q->to.reg = REGTMPT; p = movrr(p, REGSP, REGTMPT, p); q->link = p->link; p->link = q; if(q->to.offset < 0 || q->to.offset > 255){ // complicated p->to.reg = REGTMPT+1; // mov sp, r8 q1 = prg(); q1->line = p->line; q1->as = AMOVW; q1->from.type = D_CONST; q1->from.offset = q->to.offset; q1->to.type = D_REG; q1->to.reg = REGTMPT; // mov $o, r7 p->link = q1; q1->link = q; q1 = prg(); q1->line = p->line; q1->as = AADD; q1->from.type = D_REG; q1->from.reg = REGTMPT+1; q1->to.type = D_REG; q1->to.reg = REGTMPT; // add r8, r7 p->link->link = q1; q1->link = q; q->to.offset = 0; // mov* r, 0(r7) /* phew */ } } } break; case AMOVM: if(thumb){ if(p->from.type == D_OREG){ if(p->from.offset == 0) p->from.type = D_REG; else diag("non-zero AMOVM offset"); } else if(p->to.type == D_OREG){ if(p->to.offset == 0) p->to.type = D_REG; else diag("non-zero AMOVM offset"); } } break; case AB: if(thumb && p->to.type == D_OREG){ if(p->to.offset == 0){ p->as = AMOVW; p->from.type = D_REG; p->from.reg = p->to.reg; p->to.type = D_REG; p->to.reg = REGPC; } else{ p->as = AADD; p->from.type = D_CONST; p->from.offset = p->to.offset; p->reg = p->to.reg; p->to.type = D_REG; p->to.reg = REGTMPT-1; q = prg(); q->as = AMOVW; q->line = p->line; q->from.type = D_REG; q->from.reg = REGTMPT-1; q->to.type = D_REG; q->to.reg = REGPC; q->link = p->link; p->link = q; } } if(seenthumb && !thumb && p->to.type == D_OREG && p->to.reg == REGLINK){ // print("warn %s: b (R%d) assuming a return\n", curtext->from.sym->name, p->to.reg); p->as = ABXRET; } break; case ABL: case ABX: if(thumb && p->to.type == D_OREG){ if(p->to.offset == 0){ p->as = o; p->from.type = D_NONE; p->to.type = D_REG; } else{ p->as = AADD; p->from.type = D_CONST; p->from.offset = p->to.offset; p->reg = p->to.reg; p->to.type = D_REG; p->to.reg = REGTMPT-1; q = prg(); q->as = o; q->line = p->line; q->from.type = D_NONE; q->to.type = D_REG; q->to.reg = REGTMPT-1; q->link = p->link; p->link = q; } } break; } } } static void sigdiv(char *n) { Sym *s; s = lookup(n, 0); if(s->type == STEXT){ if(s->sig == 0) s->sig = SIGNINTERN; } else if(s->type == 0 || s->type == SXREF) s->type = SUNDEF; } void divsig(void) { sigdiv("_div"); sigdiv("_divu"); sigdiv("_mod"); sigdiv("_modu"); } static void sdiv(Sym *s) { if(s->type == 0 || s->type == SXREF){ /* undefsym(s); */ s->type = SXREF; if(s->sig == 0) s->sig = SIGNINTERN; s->subtype = SIMPORT; } else if(s->type != STEXT) diag("undefined: %s", s->name); } void initdiv(void) { Sym *s2, *s3, *s4, *s5; Prog *p; if(prog_div != P) return; sym_div = s2 = lookup("_div", 0); sym_divu = s3 = lookup("_divu", 0); sym_mod = s4 = lookup("_mod", 0); sym_modu = s5 = lookup("_modu", 0); if(dlm) { sdiv(s2); if(s2->type == SXREF) prog_div = UP; sdiv(s3); if(s3->type == SXREF) prog_divu = UP; sdiv(s4); if(s4->type == SXREF) prog_mod = UP; sdiv(s5); if(s5->type == SXREF) prog_modu = UP; } for(p = firstp; p != P; p = p->link) if(p->as == ATEXT) { if(p->from.sym == s2) prog_div = p; if(p->from.sym == s3) prog_divu = p; if(p->from.sym == s4) prog_mod = p; if(p->from.sym == s5) prog_modu = p; } if(prog_div == P) { diag("undefined: %s", s2->name); prog_div = curtext; } if(prog_divu == P) { diag("undefined: %s", s3->name); prog_divu = curtext; } if(prog_mod == P) { diag("undefined: %s", s4->name); prog_mod = curtext; } if(prog_modu == P) { diag("undefined: %s", s5->name); prog_modu = curtext; } } static void setdiv(int as) { Prog *p = nil; switch(as){ case ADIV: p = prog_div; break; case ADIVU: p = prog_divu; break; case AMOD: p = prog_mod; break; case AMODU: p = prog_modu; break; } if(p != UP && thumb != p->from.sym->thumb) p->from.sym->foreign = 1; } void nocache(Prog *p) { p->optab = 0; p->from.class = 0; p->to.class = 0; }