ref: 5d202d345616907d511b46e395226958fe66a2c3
dir: /sys/src/cmd/ql/noop.c/
#include "l.h" void noops(void) { Prog *p, *p1, *q, *q1; int o, mov, aoffset, 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) { /* too hard, just leave alone */ 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; q = p; p->mark |= LABEL|LEAF|SYNC; if(p->link) p->link->mark |= LABEL; curtext = p; break; case ANOR: q = p; if(p->to.type == D_REG) if(p->to.reg == REGZERO) p->mark |= LABEL|SYNC; break; case ALWAR: case ASTWCCC: case AECIWX: case AECOWX: case AEIEIO: case AICBI: case AISYNC: case ATLBIE: case ADCBF: case ADCBI: case ADCBST: case ADCBT: case ADCBTST: case ADCBZ: case ASYNC: case ATW: case AWORD: case ARFI: case ARFCI: q = p; p->mark |= LABEL|SYNC; continue; case AMOVW: q = p; switch(p->from.type) { case D_MSR: case D_SREG: case D_SPR: case D_FPSCR: case D_CREG: case D_DCR: p->mark |= LABEL|SYNC; } switch(p->to.type) { case D_MSR: case D_SREG: case D_SPR: case D_FPSCR: case D_CREG: case D_DCR: p->mark |= LABEL|SYNC; } continue; case AFABS: case AFABSCC: case AFADD: case AFADDCC: case AFCTIW: case AFCTIWCC: case AFCTIWZ: case AFCTIWZCC: case AFDIV: case AFDIVCC: case AFMADD: case AFMADDCC: case AFMOVD: case AFMOVDU: /* case AFMOVDS: */ case AFMOVS: case AFMOVSU: /* case AFMOVSD: */ case AFMSUB: case AFMSUBCC: case AFMUL: case AFMULCC: case AFNABS: case AFNABSCC: case AFNEG: case AFNEGCC: case AFNMADD: case AFNMADDCC: case AFNMSUB: case AFNMSUBCC: case AFRSP: case AFRSPCC: case AFSUB: case AFSUBCC: q = p; p->mark |= FLOAT; continue; case ABL: case ABCL: if(curtext != P) curtext->mark &= ~LEAF; case ABC: case ABEQ: case ABGE: case ABGT: case ABLE: case ABLT: case ABNE: case ABR: case ABVC: case ABVS: p->mark |= BRANCH; q = p; q1 = p->cond; if(q1 != P) { while(q1->as == ANOP) { q1 = q1->link; p->cond = q1; } if(!(q1->mark & LEAF)) q1->mark |= LABEL; } else p->mark |= LABEL; q1 = p->link; if(q1 != P) q1->mark |= LABEL; continue; case AFCMPO: case AFCMPU: q = p; p->mark |= FCMP|FLOAT; continue; case ARETURN: /* special form of RETURN is BECOME */ if(p->from.type == D_CONST) if(p->from.offset > curbecome) curbecome = p->from.offset; q = p; if(p->link != P) p->link->mark |= LABEL; continue; case ANOP: q1 = p->link; q->link = q1; /* q is non-nop */ q1->mark |= p->mark; continue; default: q = p; continue; } } 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: /* ABCL? */ 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; } } curtext = P; for(p = firstp; p != P; p = p->link) { o = p->as; switch(o) { case ATEXT: mov = AMOVW; aoffset = 0; curtext = p; autosize = p->to.offset + 4; if((p->mark & LEAF) && autosize <= 4) autosize = 0; else if(autosize & 4) autosize += 4; p->to.offset = autosize - 4; q = p; if(autosize) { /* use MOVWU to adjust R1 when saving R31, if autosize is small */ if(!(curtext->mark & LEAF) && autosize >= -BIG && autosize <= BIG) { mov = AMOVWU; aoffset = -autosize; } else { q = prg(); q->as = AADD; 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; } } else if(!(curtext->mark & LEAF)) { if(debug['v']) Bprint(&bso, "save suppressed in: %s\n", curtext->from.sym->name); curtext->mark |= LEAF; } if(curtext->mark & LEAF) { if(curtext->from.sym) curtext->from.sym->type = SLEAF; break; } q1 = prg(); q1->as = mov; q1->line = p->line; q1->from.type = D_REG; q1->from.reg = REGTMP; q1->to.type = D_OREG; q1->to.offset = aoffset; q1->to.reg = REGSP; q1->link = q->link; q->link = q1; q1 = prg(); q1->as = AMOVW; q1->line = p->line; q1->from.type = D_SPR; q1->from.offset = D_LR; q1->to.type = D_REG; q1->to.reg = REGTMP; q1->link = q->link; q->link = q1; break; case ARETURN: if(p->from.type == D_CONST) goto become; if(curtext->mark & LEAF) { if(!autosize) { p->as = ABR; p->from = zprg.from; p->to.type = D_SPR; p->to.offset = D_LR; p->mark |= BRANCH; break; } 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 = ABR; q->line = p->line; q->to.type = D_SPR; q->to.offset = D_LR; q->mark |= BRANCH; q->link = p->link; p->link = q; break; } p->as = AMOVW; p->from.type = D_OREG; p->from.offset = 0; p->from.reg = REGSP; p->to.type = D_REG; p->to.reg = REGTMP; q = prg(); q->as = AMOVW; q->line = p->line; q->from.type = D_REG; q->from.reg = REGTMP; q->to.type = D_SPR; q->to.offset = D_LR; q->link = p->link; p->link = q; p = q; if(autosize) { q = prg(); q->as = AADD; 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 = ABR; q1->line = p->line; q1->to.type = D_SPR; q1->to.offset = D_LR; q1->mark |= BRANCH; q1->link = q->link; q->link = q1; break; become: if(curtext->mark & LEAF) { q = prg(); q->line = p->line; q->as = ABR; q->from = zprg.from; q->to = p->to; q->cond = p->cond; q->link = p->link; q->mark |= BRANCH; 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; } q = prg(); q->line = p->line; q->as = ABR; q->from = zprg.from; q->to = p->to; q->cond = p->cond; q->mark |= BRANCH; q->link = p->link; p->link = q; q = prg(); q->line = p->line; 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; q = prg(); q->line = p->line; q->as = AMOVW; q->line = p->line; q->from.type = D_REG; q->from.reg = REGTMP; q->to.type = D_SPR; q->to.offset = D_LR; q->link = p->link; p->link = q; p->as = AMOVW; p->from = zprg.from; p->from.type = D_OREG; p->from.offset = 0; p->from.reg = REGSP; p->to = zprg.to; p->to.type = D_REG; p->to.reg = REGTMP; break; } } if(debug['Q'] == 0) return; curtext = P; q = P; /* p - 1 */ q1 = firstp; /* top of block */ o = 0; /* count of instructions */ for(p = firstp; p != P; p = p1) { p1 = p->link; o++; if(p->mark & NOSCHED){ if(q1 != p){ sched(q1, q); } for(; p != P; p = p->link){ if(!(p->mark & NOSCHED)) break; q = p; } p1 = p; q1 = p; o = 0; continue; } if(p->mark & (LABEL|SYNC)) { if(q1 != p) sched(q1, q); q1 = p; o = 1; } if(p->mark & (BRANCH|SYNC)) { sched(q1, p); q1 = p1; o = 0; } if(o >= NSCHED) { sched(q1, p); q1 = p1; o = 0; } q = p; } } void addnop(Prog *p) { Prog *q; q = prg(); q->as = ANOR; q->line = p->line; q->from.type = D_REG; q->from.reg = REGZERO; q->to.type = D_REG; q->to.reg = REGZERO; q->link = p->link; p->link = q; }