ref: c881e33e8ed668f4d5a2102c113e3edb1ea80d44
dir: /sys/src/cmd/5l/noop.c/
#include "l.h" static Sym* sym_div; static Sym* sym_divu; static Sym* sym_mod; static Sym* sym_modu; void noops(void) { Prog *p, *q, *q1; int o, curframe, curbecome, maxbecome; /* * 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); curframe = 0; curbecome = 0; maxbecome = 0; curtext = 0; q = P; for(p = firstp; p != P; p = p->link) { /* 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; continue; case ANOP: q1 = p->link; q->link = q1; /* q is non-nop */ q1->mark |= p->mark; continue; case ABL: 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) { switch(p->as) { case ATEXT: curtext = p; break; case ABL: 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) { 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; } if(curtext->mark & LEAF) { if(curtext->from.sym) curtext->from.sym->type = SLEAF; #ifdef optimise_time if(autosize) { q = prg(); q->as = ASUB; 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; } break; #else if(!autosize) break; #endif } 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; break; case ARET: nocache(p); if(p->from.type == D_CONST) goto become; if(curtext->mark & LEAF) { if(!autosize) { p->as = AB; p->from = zprg.from; p->to.type = D_OREG; p->to.offset = 0; p->to.reg = REGLINK; break; } #ifdef optimise_time p->as = AADD; p->from.type = D_CONST; p->from.offset = autosize; p->to.type = D_REG; p->to.reg = REGSP; q = prg(); q->as = AB; q->scond = p->scond; q->line = p->line; q->to.type = D_OREG; q->to.offset = 0; q->to.reg = REGLINK; q->link = p->link; p->link = q; break; #endif } 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(curtext->mark & LEAF) { if(!autosize) { p->as = AB; p->from = zprg.from; break; } #ifdef optimise_time 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; p->as = AADD; p->from = zprg.from; p->from.type = D_CONST; p->from.offset = autosize; p->to = zprg.to; p->to.type = D_REG; p->to.reg = REGSP; break; #endif } 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; 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; /* * 5c code generation for unsigned -> double made the * unfortunate assumption that single and double floating * point registers are aliased - true for emulated 7500 * but not for vfp. Now corrected, but this test is * insurance against old 5c compiled code in libraries. */ case AMOVWD: if((q = p->link) != P && q->as == ACMP) if((q = q->link) != P && q->as == AMOVF) if((q1 = q->link) != P && q1->as == AADDF) if(q1->to.type == D_FREG && q1->to.reg == p->to.reg) { q1->as = AADDD; q1 = prg(); q1->scond = q->scond; q1->line = q->line; q1->as = AMOVFD; q1->from = q->to; q1->to = q1->from; q1->link = q->link; q->link = q1; } 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 = REGTMP; p->to.offset = 0; /* CALL appropriate */ q = prg(); q->link = p->link; p->link = q; p = q; p->as = ABL; 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 = 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; } } } 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; } } void nocache(Prog *p) { p->optab = 0; p->from.class = 0; p->to.class = 0; }