ref: 06912e53e491dedb495ca4e6a308831ef7af544f
dir: /sys/src/cmd/5l/asm.c/
#include "l.h" long OFFSET; static Prog *PP; long entryvalue(void) { char *a; Sym *s; a = INITENTRY; if(*a >= '0' && *a <= '9') return atolwhex(a); s = lookup(a, 0); if(s->type == 0) return INITTEXT; switch(s->type) { case STEXT: case SLEAF: break; case SDATA: if(dlm) return s->value+INITDAT; default: diag("entry not text: %s", s->name); } return s->value; } void asmb(void) { Prog *p; long t, etext; Optab *o; if(debug['v']) Bprint(&bso, "%5.2f asm\n", cputime()); Bflush(&bso); OFFSET = HEADR; seek(cout, OFFSET, 0); pc = INITTEXT; for(p = firstp; p != P; p = p->link) { if(p->as == ATEXT) { curtext = p; autosize = p->to.offset + 4; } if(p->pc != pc) { diag("phase error %lux sb %lux", p->pc, pc); if(!debug['a']) prasm(curp); pc = p->pc; } curp = p; o = oplook(p); /* could probably avoid this call */ asmout(p, o); pc += o->size; } if(debug['a']) Bprint(&bso, "\n"); Bflush(&bso); cflush(); /* output strings in text segment */ etext = INITTEXT + textsize; for(t = pc; t < etext; t += sizeof(buf)-100) { if(etext-t > sizeof(buf)-100) datblk(t, sizeof(buf)-100, 1); else datblk(t, etext-t, 1); } curtext = P; switch(HEADTYPE) { case 0: case 1: case 2: case 5: case 7: OFFSET = HEADR+textsize; seek(cout, OFFSET, 0); break; case 3: case 6: /* no header, padded segments */ OFFSET = rnd(HEADR+textsize, 4096); seek(cout, OFFSET, 0); break; } if(dlm){ char buf[8]; write(cout, buf, INITDAT-textsize); textsize = INITDAT; } for(t = 0; t < datsize; t += sizeof(buf)-100) { if(datsize-t > sizeof(buf)-100) datblk(t, sizeof(buf)-100, 0); else datblk(t, datsize-t, 0); } symsize = 0; lcsize = 0; if(!debug['s']) { if(debug['v']) Bprint(&bso, "%5.2f sym\n", cputime()); Bflush(&bso); switch(HEADTYPE) { case 0: case 1: case 4: case 5: debug['s'] = 1; break; case 2: OFFSET = HEADR+textsize+datsize; seek(cout, OFFSET, 0); break; case 3: case 6: /* no header, padded segments */ OFFSET += rnd(datsize, 4096); seek(cout, OFFSET, 0); break; case 7: break; } if(!debug['s']) asmsym(); if(debug['v']) Bprint(&bso, "%5.2f pc\n", cputime()); Bflush(&bso); if(!debug['s']) asmlc(); if(dlm) asmdyn(); cflush(); } else if(dlm){ seek(cout, HEADR+textsize+datsize, 0); asmdyn(); cflush(); } if(debug['v']) Bprint(&bso, "%5.2f header\n", cputime()); Bflush(&bso); OFFSET = 0; seek(cout, OFFSET, 0); switch(HEADTYPE) { case 0: /* no header */ case 6: /* no header, padded segments */ break; case 1: /* aif for risc os */ lputl(0xe1a00000); /* NOP - decompress code */ lputl(0xe1a00000); /* NOP - relocation code */ lputl(0xeb000000 + 12); /* BL - zero init code */ lputl(0xeb000000 + (entryvalue() - INITTEXT + HEADR - 12 - 8) / 4); /* BL - entry code */ lputl(0xef000011); /* SWI - exit code */ lputl(textsize+HEADR); /* text size */ lputl(datsize); /* data size */ lputl(0); /* sym size */ lputl(bsssize); /* bss size */ lputl(0); /* sym type */ lputl(INITTEXT-HEADR); /* text addr */ lputl(0); /* workspace - ignored */ lputl(32); /* addr mode / data addr flag */ lputl(0); /* data addr */ for(t=0; t<2; t++) lputl(0); /* reserved */ for(t=0; t<15; t++) lputl(0xe1a00000); /* NOP - zero init code */ lputl(0xe1a0f00e); /* B (R14) - zero init return */ break; case 2: /* plan 9 */ if(dlm) lput(0x80000000|0x647); /* magic */ else lput(0x647); /* magic */ lput(textsize); /* sizes */ lput(datsize); lput(bsssize); lput(symsize); /* nsyms */ lput(entryvalue()); /* va of entry */ lput(0L); lput(lcsize); break; case 3: /* boot for NetBSD */ lput((143<<16)|0413); /* magic */ lputl(rnd(HEADR+textsize, 4096)); lputl(rnd(datsize, 4096)); lputl(bsssize); lputl(symsize); /* nsyms */ lputl(entryvalue()); /* va of entry */ lputl(0L); lputl(0L); break; case 4: /* boot for IXP1200 */ break; case 5: /* boot for ipaq */ lputl(0xe3300000); /* nop */ lputl(0xe3300000); /* nop */ lputl(0xe3300000); /* nop */ lputl(0xe3300000); /* nop */ break; case 7: /* elf */ strnput("\177ELF", 4); /* e_ident */ cput(1); /* class = 32 bit */ cput(2); /* data = MSB */ cput(1); /* version = CURRENT */ strnput("", 9); lput((2L<<16)|40); /* type = EXEC; machine = ARM */ lput(1L); /* version = CURRENT */ lput(entryvalue()); /* entry vaddr */ lput(52L); /* offset to first phdr */ debug['S'] = 1; /* no symbol table */ if(debug['S']){ lput(HEADR+textsize+datsize+symsize); /* offset to first shdr */ lput(0L); /* flags = PPC */ lput((52L<<16)|32L); /* Ehdr & Phdr sizes*/ lput((4L<<16)|40L); /* # Phdrs & Shdr size */ lput((4L<<16)|2L); /* # Shdrs & shdr string size */ } else{ lput(0L); lput(0L); /* flags = PPC */ lput((52L<<16)|32L); /* Ehdr & Phdr sizes*/ lput((4L<<16)|0L); /* # Phdrs & Shdr size */ lput((4L<<16)|0L); /* # Shdrs & shdr string size */ } lput(1L); /* text - type = PT_LOAD */ lput(HEADR); /* file offset */ lput(INITTEXT); /* vaddr */ lput(INITTEXT); /* paddr */ lput(textsize); /* file size */ lput(textsize); /* memory size */ lput(0x05L); /* protections = RX */ lput(0); /* alignment */ lput(1L); /* data - type = PT_LOAD */ lput(HEADR+textsize); /* file offset */ lput(INITDAT); /* vaddr */ lput(INITDAT); /* paddr */ lput(datsize); /* file size */ lput(datsize+bsssize); /* memory size */ lput(0x07L); /* protections = RWX */ lput(0); /* alignment */ lput(0L); /* data - type = PT_NULL */ lput(HEADR+textsize+datsize); /* file offset */ lput(0L); /* vaddr */ lput(0L); /* paddr */ lput(symsize); /* symbol table size */ lput(lcsize); /* line number size */ lput(0x04L); /* protections = R */ lput(0x04L); /* alignment code?? */ break; } cflush(); } void strnput(char *s, int n) { for(; *s; s++){ cput(*s); n--; } for(; n > 0; n--) cput(0); } void cput(int c) { cbp[0] = c; cbp++; cbc--; if(cbc <= 0) cflush(); } void wput(long l) { cbp[0] = l>>8; cbp[1] = l; cbp += 2; cbc -= 2; if(cbc <= 0) cflush(); } void lput(long l) { cbp[0] = l>>24; cbp[1] = l>>16; cbp[2] = l>>8; cbp[3] = l; cbp += 4; cbc -= 4; if(cbc <= 0) cflush(); } void lputl(long l) { cbp[3] = l>>24; cbp[2] = l>>16; cbp[1] = l>>8; cbp[0] = l; cbp += 4; cbc -= 4; if(cbc <= 0) cflush(); } void cflush(void) { int n; n = sizeof(buf.cbuf) - cbc; if(n) write(cout, buf.cbuf, n); cbp = buf.cbuf; cbc = sizeof(buf.cbuf); } void nopstat(char *f, Count *c) { if(c->outof) Bprint(&bso, "%s delay %ld/%ld (%.2f)\n", f, c->outof - c->count, c->outof, (double)(c->outof - c->count)/c->outof); } void asmsym(void) { Prog *p; Auto *a; Sym *s; int h; s = lookup("etext", 0); if(s->type == STEXT) putsymb(s->name, 'T', s->value, s->version); for(h=0; h<NHASH; h++) for(s=hash[h]; s!=S; s=s->link) switch(s->type) { case SCONST: putsymb(s->name, 'D', s->value, s->version); continue; case SDATA: putsymb(s->name, 'D', s->value+INITDAT, s->version); continue; case SBSS: putsymb(s->name, 'B', s->value+INITDAT, s->version); continue; case SSTRING: putsymb(s->name, 'T', s->value, s->version); continue; case SFILE: putsymb(s->name, 'f', s->value, s->version); continue; } for(p=textp; p!=P; p=p->cond) { s = p->from.sym; if(s->type != STEXT && s->type != SLEAF) continue; /* filenames first */ for(a=p->to.autom; a; a=a->link) if(a->type == D_FILE) putsymb(a->asym->name, 'z', a->aoffset, 0); else if(a->type == D_FILE1) putsymb(a->asym->name, 'Z', a->aoffset, 0); if(s->type == STEXT) putsymb(s->name, 'T', s->value, s->version); else putsymb(s->name, 'L', s->value, s->version); /* frame, auto and param after */ putsymb(".frame", 'm', p->to.offset+4, 0); for(a=p->to.autom; a; a=a->link) if(a->type == D_AUTO) putsymb(a->asym->name, 'a', -a->aoffset, 0); else if(a->type == D_PARAM) putsymb(a->asym->name, 'p', a->aoffset, 0); } if(debug['v'] || debug['n']) Bprint(&bso, "symsize = %lud\n", symsize); Bflush(&bso); } void putsymb(char *s, int t, long v, int ver) { int i, f; if(t == 'f') s++; lput(v); if(ver) t += 'a' - 'A'; cput(t+0x80); /* 0x80 is variable length */ if(t == 'Z' || t == 'z') { cput(s[0]); for(i=1; s[i] != 0 || s[i+1] != 0; i += 2) { cput(s[i]); cput(s[i+1]); } cput(0); cput(0); i++; } else { for(i=0; s[i]; i++) cput(s[i]); cput(0); } symsize += 4 + 1 + i + 1; if(debug['n']) { if(t == 'z' || t == 'Z') { Bprint(&bso, "%c %.8lux ", t, v); for(i=1; s[i] != 0 || s[i+1] != 0; i+=2) { f = ((s[i]&0xff) << 8) | (s[i+1]&0xff); Bprint(&bso, "/%x", f); } Bprint(&bso, "\n"); return; } if(ver) Bprint(&bso, "%c %.8lux %s<%d>\n", t, v, s, ver); else Bprint(&bso, "%c %.8lux %s\n", t, v, s); } } #define MINLC 4 void asmlc(void) { long oldpc, oldlc; Prog *p; long v, s; oldpc = INITTEXT; oldlc = 0; for(p = firstp; p != P; p = p->link) { if(p->line == oldlc || p->as == ATEXT || p->as == ANOP) { if(p->as == ATEXT) curtext = p; if(debug['V']) Bprint(&bso, "%6lux %P\n", p->pc, p); continue; } if(debug['V']) Bprint(&bso, "\t\t%6ld", lcsize); v = (p->pc - oldpc) / MINLC; while(v) { s = 127; if(v < 127) s = v; cput(s+128); /* 129-255 +pc */ if(debug['V']) Bprint(&bso, " pc+%ld*%d(%ld)", s, MINLC, s+128); v -= s; lcsize++; } s = p->line - oldlc; oldlc = p->line; oldpc = p->pc + MINLC; if(s > 64 || s < -64) { cput(0); /* 0 vv +lc */ cput(s>>24); cput(s>>16); cput(s>>8); cput(s); if(debug['V']) { if(s > 0) Bprint(&bso, " lc+%ld(%d,%ld)\n", s, 0, s); else Bprint(&bso, " lc%ld(%d,%ld)\n", s, 0, s); Bprint(&bso, "%6lux %P\n", p->pc, p); } lcsize += 5; continue; } if(s > 0) { cput(0+s); /* 1-64 +lc */ if(debug['V']) { Bprint(&bso, " lc+%ld(%ld)\n", s, 0+s); Bprint(&bso, "%6lux %P\n", p->pc, p); } } else { cput(64-s); /* 65-128 -lc */ if(debug['V']) { Bprint(&bso, " lc%ld(%ld)\n", s, 64-s); Bprint(&bso, "%6lux %P\n", p->pc, p); } } lcsize++; } while(lcsize & 1) { s = 129; cput(s); lcsize++; } if(debug['v'] || debug['V']) Bprint(&bso, "lcsize = %ld\n", lcsize); Bflush(&bso); } void datblk(long s, long n, int str) { Sym *v; Prog *p; char *cast; long a, l, fl, j, d; int i, c; memset(buf.dbuf, 0, n+100); for(p = datap; p != P; p = p->link) { if(str != (p->from.sym->type == SSTRING)) continue; curp = p; a = p->from.sym->value + p->from.offset; l = a - s; c = p->reg; i = 0; if(l < 0) { if(l+c <= 0) continue; while(l < 0) { l++; i++; } } if(l >= n) continue; if(p->as != AINIT && p->as != ADYNT && !p->from.sym->dupok) { for(j=l+(c-i)-1; j>=l; j--) if(buf.dbuf[j]) { print("%P\n", p); diag("multiple initialization"); break; } } switch(p->to.type) { default: diag("unknown mode in initialization%P", p); break; case D_FCONST: switch(c) { default: case 4: fl = ieeedtof(p->to.ieee); cast = (char*)&fl; for(; i<c; i++) { buf.dbuf[l] = cast[fnuxi4[i]]; l++; } break; case 8: cast = (char*)p->to.ieee; for(; i<c; i++) { buf.dbuf[l] = cast[fnuxi8[i]]; l++; } break; } break; case D_SCONST: for(; i<c; i++) { buf.dbuf[l] = p->to.sval[i]; l++; } break; case D_CONST: d = p->to.offset; v = p->to.sym; if(v) { switch(v->type) { case SUNDEF: ckoff(v, d); case STEXT: case SLEAF: case SSTRING: d += p->to.sym->value; break; case SDATA: case SBSS: d += p->to.sym->value + INITDAT; } if(dlm) dynreloc(v, a+INITDAT, 1); } cast = (char*)&d; switch(c) { default: diag("bad nuxi %d %d%P", c, i, curp); break; case 1: for(; i<c; i++) { buf.dbuf[l] = cast[inuxi1[i]]; l++; } break; case 2: for(; i<c; i++) { buf.dbuf[l] = cast[inuxi2[i]]; l++; } break; case 4: for(; i<c; i++) { buf.dbuf[l] = cast[inuxi4[i]]; l++; } break; } break; } } write(cout, buf.dbuf, n); } void asmout(Prog *p, Optab *o) { long o1, o2, o3, o4, o5, o6, v; int r, rf, rt, rt2; Sym *s; PP = p; o1 = 0; o2 = 0; o3 = 0; o4 = 0; o5 = 0; o6 = 0; switch(o->type) { default: diag("unknown asm %d", o->type); prasm(p); break; case 0: /* pseudo ops */ break; case 1: /* op R,[R],R */ o1 = oprrr(p->as, p->scond); rf = p->from.reg; rt = p->to.reg; r = p->reg; if(p->to.type == D_NONE) rt = 0; if(p->as == AMOVW || p->as == AMVN) r = 0; else if(r == NREG) r = rt; o1 |= rf | (r<<16) | (rt<<12); break; case 2: /* movbu $I,[R],R */ aclass(&p->from); o1 = oprrr(p->as, p->scond); o1 |= immrot(instoffset); rt = p->to.reg; r = p->reg; if(p->to.type == D_NONE) rt = 0; if(p->as == AMOVW || p->as == AMVN) r = 0; else if(r == NREG) r = rt; o1 |= (r<<16) | (rt<<12); break; case 3: /* add R<<[IR],[R],R */ mov: aclass(&p->from); o1 = oprrr(p->as, p->scond); o1 |= p->from.offset; rt = p->to.reg; r = p->reg; if(p->to.type == D_NONE) rt = 0; if(p->as == AMOVW || p->as == AMVN) r = 0; else if(r == NREG) r = rt; o1 |= (r<<16) | (rt<<12); break; case 4: /* add $I,[R],R */ aclass(&p->from); o1 = oprrr(AADD, p->scond); o1 |= immrot(instoffset); r = p->from.reg; if(r == NREG) r = o->param; o1 |= r << 16; o1 |= p->to.reg << 12; break; case 5: /* bra s */ v = -8; if(p->cond == UP) { s = p->to.sym; if(s->type != SUNDEF) diag("bad branch sym type"); v = (ulong)s->value >> (Roffset-2); dynreloc(s, p->pc, 0); } else if(p->cond != P) v = (p->cond->pc - pc) - 8; o1 = opbra(p->as, p->scond); o1 |= (v >> 2) & 0xffffff; break; case 6: /* b ,O(R) -> add $O,R,PC */ aclass(&p->to); o1 = oprrr(AADD, p->scond); o1 |= immrot(instoffset); o1 |= p->to.reg << 16; o1 |= REGPC << 12; break; case 7: /* bl ,O(R) -> mov PC,link; add $O,R,PC */ aclass(&p->to); o1 = oprrr(AADD, p->scond); o1 |= immrot(0); o1 |= REGPC << 16; o1 |= REGLINK << 12; o2 = oprrr(AADD, p->scond); o2 |= immrot(instoffset); o2 |= p->to.reg << 16; o2 |= REGPC << 12; break; case 8: /* sll $c,[R],R -> mov (R<<$c),R */ aclass(&p->from); o1 = oprrr(p->as, p->scond); r = p->reg; if(r == NREG) r = p->to.reg; o1 |= r; o1 |= (instoffset&31) << 7; o1 |= p->to.reg << 12; break; case 9: /* sll R,[R],R -> mov (R<<R),R */ o1 = oprrr(p->as, p->scond); r = p->reg; if(r == NREG) r = p->to.reg; o1 |= r; o1 |= (p->from.reg << 8) | (1<<4); o1 |= p->to.reg << 12; break; case 10: /* swi [$con] */ o1 = oprrr(p->as, p->scond); if(p->to.type != D_NONE) { aclass(&p->to); o1 |= instoffset & 0xffffff; } break; case 11: /* word */ switch(aclass(&p->to)) { case C_LCON: if(!dlm) break; if(p->to.name != D_EXTERN && p->to.name != D_STATIC) break; case C_ADDR: if(p->to.sym->type == SUNDEF) ckoff(p->to.sym, p->to.offset); dynreloc(p->to.sym, p->pc, 1); } o1 = instoffset; break; case 12: /* movw $lcon, reg */ o1 = omvl(p, &p->from, p->to.reg); break; case 13: /* op $lcon, [R], R */ o1 = omvl(p, &p->from, REGTMP); if(!o1) break; o2 = oprrr(p->as, p->scond); o2 |= REGTMP; r = p->reg; if(p->as == AMOVW || p->as == AMVN) r = 0; else if(r == NREG) r = p->to.reg; o2 |= r << 16; if(p->to.type != D_NONE) o2 |= p->to.reg << 12; break; case 14: /* movb/movbu/movh/movhu R,R */ o1 = oprrr(ASLL, p->scond); if(p->as == AMOVBU || p->as == AMOVHU) o2 = oprrr(ASRL, p->scond); else o2 = oprrr(ASRA, p->scond); r = p->to.reg; o1 |= (p->from.reg)|(r<<12); o2 |= (r)|(r<<12); if(p->as == AMOVB || p->as == AMOVBU) { o1 |= (24<<7); o2 |= (24<<7); } else { o1 |= (16<<7); o2 |= (16<<7); } break; case 15: /* mul r,[r,]r */ o1 = oprrr(p->as, p->scond); rf = p->from.reg; rt = p->to.reg; r = p->reg; if(r == NREG) r = rt; if(rt == r) { r = rf; rf = rt; } if(0) if(rt == r || rf == REGPC || r == REGPC || rt == REGPC) { diag("bad registers in MUL"); prasm(p); } o1 |= (rf<<8) | r | (rt<<16); break; case 16: /* div r,[r,]r */ o1 = 0xf << 28; o2 = 0; break; case 17: o1 = oprrr(p->as, p->scond); rf = p->from.reg; rt = p->to.reg; rt2 = p->to.offset; r = p->reg; o1 |= (rf<<8) | r | (rt<<16) | (rt2<<12); break; case 20: /* mov/movb/movbu R,O(R) */ aclass(&p->to); r = p->to.reg; if(r == NREG) r = o->param; o1 = osr(p->as, p->from.reg, instoffset, r, p->scond); break; case 21: /* mov/movbu O(R),R -> lr */ aclass(&p->from); r = p->from.reg; if(r == NREG) r = o->param; o1 = olr(instoffset, r, p->to.reg, p->scond); if(p->as != AMOVW) o1 |= 1<<22; break; case 22: /* movb/movh/movhu O(R),R -> lr,shl,shr */ aclass(&p->from); r = p->from.reg; if(r == NREG) r = o->param; o1 = olr(instoffset, r, p->to.reg, p->scond); o2 = oprrr(ASLL, p->scond); o3 = oprrr(ASRA, p->scond); r = p->to.reg; if(p->as == AMOVB) { o2 |= (24<<7)|(r)|(r<<12); o3 |= (24<<7)|(r)|(r<<12); } else { o2 |= (16<<7)|(r)|(r<<12); if(p->as == AMOVHU) o3 = oprrr(ASRL, p->scond); o3 |= (16<<7)|(r)|(r<<12); } break; case 23: /* movh/movhu R,O(R) -> sb,sb */ aclass(&p->to); r = p->to.reg; if(r == NREG) r = o->param; o1 = osr(AMOVH, p->from.reg, instoffset, r, p->scond); o2 = oprrr(ASRL, p->scond); o2 |= (8<<7)|(p->from.reg)|(REGTMP<<12); o3 = osr(AMOVH, REGTMP, instoffset+1, r, p->scond); break; case 30: /* mov/movb/movbu R,L(R) */ o1 = omvl(p, &p->to, REGTMP); if(!o1) break; r = p->to.reg; if(r == NREG) r = o->param; o2 = osrr(p->from.reg, REGTMP,r, p->scond); if(p->as != AMOVW) o2 |= 1<<22; break; case 31: /* mov/movbu L(R),R -> lr[b] */ case 32: /* movh/movb L(R),R -> lr[b] */ o1 = omvl(p, &p->from, REGTMP); if(!o1) break; r = p->from.reg; if(r == NREG) r = o->param; o2 = olrr(REGTMP,r, p->to.reg, p->scond); if(p->as == AMOVBU || p->as == AMOVB) o2 |= 1<<22; if(o->type == 31) break; o3 = oprrr(ASLL, p->scond); if(p->as == AMOVBU || p->as == AMOVHU) o4 = oprrr(ASRL, p->scond); else o4 = oprrr(ASRA, p->scond); r = p->to.reg; o3 |= (r)|(r<<12); o4 |= (r)|(r<<12); if(p->as == AMOVB || p->as == AMOVBU) { o3 |= (24<<7); o4 |= (24<<7); } else { o3 |= (16<<7); o4 |= (16<<7); } break; case 33: /* movh/movhu R,L(R) -> sb, sb */ o1 = omvl(p, &p->to, REGTMP); if(!o1) break; r = p->to.reg; if(r == NREG) r = o->param; o2 = osrr(p->from.reg, REGTMP, r, p->scond); o2 |= (1<<22) ; o3 = oprrr(ASRL, p->scond); o3 |= (8<<7)|(p->from.reg)|(p->from.reg<<12); o3 |= (1<<6); /* ROR 8 */ o4 = oprrr(AADD, p->scond); o4 |= (REGTMP << 12) | (REGTMP << 16); o4 |= immrot(1); o5 = osrr(p->from.reg, REGTMP,r,p->scond); o5 |= (1<<22); o6 = oprrr(ASRL, p->scond); o6 |= (24<<7)|(p->from.reg)|(p->from.reg<<12); o6 |= (1<<6); /* ROL 8 */ break; case 34: /* mov $lacon,R */ o1 = omvl(p, &p->from, REGTMP); if(!o1) break; o2 = oprrr(AADD, p->scond); o2 |= REGTMP; r = p->from.reg; if(r == NREG) r = o->param; o2 |= r << 16; if(p->to.type != D_NONE) o2 |= p->to.reg << 12; break; case 35: /* mov PSR,R */ o1 = (2<<23) | (0xf<<16) | (0<<0); o1 |= (p->scond & C_SCOND) << 28; o1 |= (p->from.reg & 1) << 22; o1 |= p->to.reg << 12; break; case 36: /* mov R,PSR */ o1 = (2<<23) | (0x29f<<12) | (0<<4); if(p->scond & C_FBIT) o1 ^= 0x010 << 12; o1 |= (p->scond & C_SCOND) << 28; o1 |= (p->to.reg & 1) << 22; o1 |= p->from.reg << 0; break; case 37: /* mov $con,PSR */ aclass(&p->from); o1 = (2<<23) | (0x29f<<12) | (0<<4); if(p->scond & C_FBIT) o1 ^= 0x010 << 12; o1 |= (p->scond & C_SCOND) << 28; o1 |= immrot(instoffset); o1 |= (p->to.reg & 1) << 22; o1 |= p->from.reg << 0; break; case 38: /* movm $con,oreg -> stm */ o1 = (0x4 << 25); o1 |= p->from.offset & 0xffff; o1 |= p->to.reg << 16; aclass(&p->to); goto movm; case 39: /* movm oreg,$con -> ldm */ o1 = (0x4 << 25) | (1 << 20); o1 |= p->to.offset & 0xffff; o1 |= p->from.reg << 16; aclass(&p->from); movm: if(instoffset != 0) diag("offset must be zero in MOVM"); o1 |= (p->scond & C_SCOND) << 28; if(p->scond & C_PBIT) o1 |= 1 << 24; if(p->scond & C_UBIT) o1 |= 1 << 23; if(p->scond & C_SBIT) o1 |= 1 << 22; if(p->scond & C_WBIT) o1 |= 1 << 21; break; case 40: /* swp oreg,reg,reg */ if(p->as != ASTREX){ aclass(&p->from); if(instoffset != 0) diag("offset must be zero in SWP"); } o1 = (0x2<<23) | (0x9<<4); if(p->as == ASWPBU) o1 |= (1 << 22); else if(p->as == ALDREX || p->as == ASTREX){ o1 |= (1 << 23) | 0xf00; if(p->as == ALDREX) o1 |= (1 << 20) | 0xf; } o1 |= p->from.reg << 16; o1 |= p->reg << 0; o1 |= p->to.reg << 12; o1 |= (p->scond & C_SCOND) << 28; break; case 41: /* rfe -> movm.s.w.u 0(r13),[r15] */ o1 = 0xe8fd8000; break; case 42: /* clrex */ o1 = 0xf57ff01f; break; case 50: /* floating point store */ v = regoff(&p->to); r = p->to.reg; if(r == NREG) r = o->param; o1 = ofsr(p->as, p->from.reg, v, r, p->scond, p); break; case 51: /* floating point load */ v = regoff(&p->from); r = p->from.reg; if(r == NREG) r = o->param; o1 = ofsr(p->as, p->to.reg, v, r, p->scond, p) | (1<<20); break; case 52: /* floating point store, long offset UGLY */ o1 = omvl(p, &p->to, REGTMP); if(!o1) break; r = p->to.reg; if(r == NREG) r = o->param; o2 = oprrr(AADD, p->scond) | (REGTMP << 12) | (REGTMP << 16) | r; o3 = ofsr(p->as, p->from.reg, 0, REGTMP, p->scond, p); break; case 53: /* floating point load, long offset UGLY */ o1 = omvl(p, &p->from, REGTMP); if(!o1) break; r = p->from.reg; if(r == NREG) r = o->param; o2 = oprrr(AADD, p->scond) | (REGTMP << 12) | (REGTMP << 16) | r; o3 = ofsr(p->as, p->to.reg, 0, REGTMP, p->scond, p) | (1<<20); break; case 54: /* floating point arith */ o1 = oprrr(p->as, p->scond); if(p->from.type == D_FCONST) { rf = chipfloat(p->from.ieee); if(rf < 0){ diag("invalid floating-point immediate\n%P", p); rf = 0; } rf |= (1<<3); } else rf = p->from.reg; rt = p->to.reg; r = p->reg; if(p->to.type == D_NONE) rt = 0; /* CMP[FD] */ else if(o1 & (1<<15)) r = 0; /* monadic */ else if(r == NREG) r = rt; o1 |= rf | (r<<16) | (rt<<12); break; case 55: /* floating point fix and float */ o1 = oprrr(p->as, p->scond); rf = p->from.reg; rt = p->to.reg; if(p->to.type == D_NONE){ rt = 0; diag("to.type==D_NONE (asm/fp)"); } if(p->from.type == D_REG) o1 |= (rf<<12) | (rt<<16); else o1 |= rf | (rt<<12); break; /* old arm 7500 fp using coproc 1 (1<<8) */ case 56: /* move to FP[CS]R */ o1 = ((p->scond & C_SCOND) << 28) | (0xe << 24) | (1<<8) | (1<<4); o1 |= ((p->to.reg+1)<<21) | (p->from.reg << 12); break; case 57: /* move from FP[CS]R */ o1 = ((p->scond & C_SCOND) << 28) | (0xe << 24) | (1<<8) | (1<<4); o1 |= ((p->from.reg+1)<<21) | (p->to.reg<<12) | (1<<20); break; case 58: /* movbu R,R */ o1 = oprrr(AAND, p->scond); o1 |= immrot(0xff); rt = p->to.reg; r = p->from.reg; if(p->to.type == D_NONE) rt = 0; if(r == NREG) r = rt; o1 |= (r<<16) | (rt<<12); break; case 59: /* movw/bu R<<I(R),R -> ldr indexed */ if(p->from.reg == NREG) { if(p->as != AMOVW) diag("byte MOV from shifter operand"); goto mov; } if(p->from.offset&(1<<4)) diag("bad shift in LDR"); o1 = olrr(p->from.offset, p->from.reg, p->to.reg, p->scond); if(p->as == AMOVBU) o1 |= 1<<22; break; case 60: /* movb R(R),R -> ldrsb indexed */ if(p->from.reg == NREG) { diag("byte MOV from shifter operand"); goto mov; } if(p->from.offset&(~0xf)) diag("bad shift in LDRSB"); o1 = olhrr(p->from.offset, p->from.reg, p->to.reg, p->scond); o1 ^= (1<<5)|(1<<6); break; case 61: /* movw/b/bu R,R<<[IR](R) -> str indexed */ if(p->to.reg == NREG) diag("MOV to shifter operand"); o1 = osrr(p->from.reg, p->to.offset, p->to.reg, p->scond); if(p->as == AMOVB || p->as == AMOVBU) o1 |= 1<<22; break; case 62: /* case R -> movw R<<2(PC),PC */ o1 = olrr(p->from.reg, REGPC, REGPC, p->scond); o1 |= 2<<7; break; case 63: /* bcase */ if(p->cond != P) { o1 = p->cond->pc; if(dlm) dynreloc(S, p->pc, 1); } break; /* reloc ops */ case 64: /* mov/movb/movbu R,addr */ o1 = omvl(p, &p->to, REGTMP); if(!o1) break; o2 = osr(p->as, p->from.reg, 0, REGTMP, p->scond); break; case 65: /* mov/movbu addr,R */ case 66: /* movh/movhu/movb addr,R */ o1 = omvl(p, &p->from, REGTMP); if(!o1) break; o2 = olr(0, REGTMP, p->to.reg, p->scond); if(p->as == AMOVBU || p->as == AMOVB) o2 |= 1<<22; if(o->type == 65) break; o3 = oprrr(ASLL, p->scond); if(p->as == AMOVBU || p->as == AMOVHU) o4 = oprrr(ASRL, p->scond); else o4 = oprrr(ASRA, p->scond); r = p->to.reg; o3 |= (r)|(r<<12); o4 |= (r)|(r<<12); if(p->as == AMOVB || p->as == AMOVBU) { o3 |= (24<<7); o4 |= (24<<7); } else { o3 |= (16<<7); o4 |= (16<<7); } break; case 67: /* movh/movhu R,addr -> sb, sb */ o1 = omvl(p, &p->to, REGTMP); if(!o1) break; o2 = osr(p->as, p->from.reg, 0, REGTMP, p->scond); o3 = oprrr(ASRL, p->scond); o3 |= (8<<7)|(p->from.reg)|(p->from.reg<<12); o3 |= (1<<6); /* ROR 8 */ o4 = oprrr(AADD, p->scond); o4 |= (REGTMP << 12) | (REGTMP << 16); o4 |= immrot(1); o5 = osr(p->as, p->from.reg, 0, REGTMP, p->scond); o6 = oprrr(ASRL, p->scond); o6 |= (24<<7)|(p->from.reg)|(p->from.reg<<12); o6 |= (1<<6); /* ROL 8 */ break; case 68: /* floating point store -> ADDR */ o1 = omvl(p, &p->to, REGTMP); if(!o1) break; o2 = ofsr(p->as, p->from.reg, 0, REGTMP, p->scond, p); break; case 69: /* floating point load <- ADDR */ o1 = omvl(p, &p->from, REGTMP); if(!o1) break; o2 = ofsr(p->as, p->to.reg, 0, REGTMP, p->scond, p) | (1<<20); break; /* ArmV4 ops: */ case 70: /* movh/movhu R,O(R) -> strh */ aclass(&p->to); r = p->to.reg; if(r == NREG) r = o->param; o1 = oshr(p->from.reg, instoffset, r, p->scond); break; case 71: /* movb/movh/movhu O(R),R -> ldrsb/ldrsh/ldrh */ aclass(&p->from); r = p->from.reg; if(r == NREG) r = o->param; o1 = olhr(instoffset, r, p->to.reg, p->scond); if(p->as == AMOVB) o1 ^= (1<<5)|(1<<6); else if(p->as == AMOVH) o1 ^= (1<<6); break; case 72: /* movh/movhu R,L(R) -> strh */ o1 = omvl(p, &p->to, REGTMP); if(!o1) break; r = p->to.reg; if(r == NREG) r = o->param; o2 = oshrr(p->from.reg, REGTMP,r, p->scond); break; case 73: /* movb/movh/movhu L(R),R -> ldrsb/ldrsh/ldrh */ o1 = omvl(p, &p->from, REGTMP); if(!o1) break; r = p->from.reg; if(r == NREG) r = o->param; o2 = olhrr(REGTMP, r, p->to.reg, p->scond); if(p->as == AMOVB) o2 ^= (1<<5)|(1<<6); else if(p->as == AMOVH) o2 ^= (1<<6); break; /* VFP ops: */ case 74: /* vfp floating point arith */ o1 = opvfprrr(p->as, p->scond); rf = p->from.reg; if(p->from.type == D_FCONST) { diag("invalid floating-point immediate\n%P", p); rf = 0; } rt = p->to.reg; r = p->reg; if(r == NREG) r = rt; o1 |= rt<<12; if(((o1>>20)&0xf) == 0xb) o1 |= rf<<0; else o1 |= r<<16 | rf<<0; break; case 75: /* vfp floating point compare */ o1 = opvfprrr(p->as, p->scond); rf = p->from.reg; if(p->from.type == D_FCONST) { if(p->from.ieee->h != 0 || p->from.ieee->l != 0) diag("invalid floating-point immediate\n%P", p); o1 |= 1<<16; rf = 0; } rt = p->reg; o1 |= rt<<12 | rf<<0; o2 = 0x0ef1fa10; /* MRS APSR_nzcv, FPSCR */ o2 |= (p->scond & C_SCOND) << 28; break; case 76: /* vfp floating point fix and float */ o1 = opvfprrr(p->as, p->scond); rf = p->from.reg; rt = p->to.reg; if(p->from.type == D_REG) { o2 = o1 | rt<<12 | rt<<0; o1 = 0x0e000a10; /* VMOV F,R */ o1 |= (p->scond & C_SCOND) << 28 | rt<<16 | rf<<12; } else { o1 |= FREGTMP<<12 | rf<<0; o2 = 0x0e100a10; /* VMOV R,F */ o2 |= (p->scond & C_SCOND) << 28 | FREGTMP<<16 | rt<<12; } break; } if(debug['a'] > 1) Bprint(&bso, "%2d ", o->type); v = p->pc; switch(o->size) { default: if(debug['a']) Bprint(&bso, " %.8lux:\t\t%P\n", v, p); break; case 4: if(debug['a']) Bprint(&bso, " %.8lux: %.8lux\t%P\n", v, o1, p); lputl(o1); break; case 8: if(debug['a']) Bprint(&bso, " %.8lux: %.8lux %.8lux%P\n", v, o1, o2, p); lputl(o1); lputl(o2); break; case 12: if(debug['a']) Bprint(&bso, " %.8lux: %.8lux %.8lux %.8lux%P\n", v, o1, o2, o3, p); lputl(o1); lputl(o2); lputl(o3); break; case 16: if(debug['a']) Bprint(&bso, " %.8lux: %.8lux %.8lux %.8lux %.8lux%P\n", v, o1, o2, o3, o4, p); lputl(o1); lputl(o2); lputl(o3); lputl(o4); break; case 20: if(debug['a']) Bprint(&bso, " %.8lux: %.8lux %.8lux %.8lux %.8lux %.8lux%P\n", v, o1, o2, o3, o4, o5, p); lputl(o1); lputl(o2); lputl(o3); lputl(o4); lputl(o5); break; case 24: if(debug['a']) Bprint(&bso, " %.8lux: %.8lux %.8lux %.8lux %.8lux %.8lux %.8lux%P\n", v, o1, o2, o3, o4, o5, o6, p); lputl(o1); lputl(o2); lputl(o3); lputl(o4); lputl(o5); lputl(o6); break; } } long oprrr(int a, int sc) { long o; o = (sc & C_SCOND) << 28; if(sc & C_SBIT) o |= 1 << 20; if(sc & (C_PBIT|C_WBIT)) diag(".P/.W on dp instruction"); switch(a) { case AMULU: case AMUL: return o | (0x0<<21) | (0x9<<4); case AMULA: return o | (0x1<<21) | (0x9<<4); case AMULLU: return o | (0x4<<21) | (0x9<<4); case AMULL: return o | (0x6<<21) | (0x9<<4); case AMULALU: return o | (0x5<<21) | (0x9<<4); case AMULAL: return o | (0x7<<21) | (0x9<<4); case AAND: return o | (0x0<<21); case AEOR: return o | (0x1<<21); case ASUB: return o | (0x2<<21); case ARSB: return o | (0x3<<21); case AADD: return o | (0x4<<21); case AADC: return o | (0x5<<21); case ASBC: return o | (0x6<<21); case ARSC: return o | (0x7<<21); case ATST: return o | (0x8<<21) | (1<<20); case ATEQ: return o | (0x9<<21) | (1<<20); case ACMP: return o | (0xa<<21) | (1<<20); case ACMN: return o | (0xb<<21) | (1<<20); case AORR: return o | (0xc<<21); case AMOVW: return o | (0xd<<21); case ABIC: return o | (0xe<<21); case AMVN: return o | (0xf<<21); case ASLL: return o | (0xd<<21) | (0<<5); case ASRL: return o | (0xd<<21) | (1<<5); case ASRA: return o | (0xd<<21) | (2<<5); case AROR: return o | (0xd<<21) | (3<<5); case ASWI: return o | (0xf<<24); /* old arm 7500 fp using coproc 1 (1<<8) */ case AADDD: return o | (0xe<<24) | (0x0<<20) | (1<<8) | (1<<7); case AADDF: return o | (0xe<<24) | (0x0<<20) | (1<<8); case AMULD: return o | (0xe<<24) | (0x1<<20) | (1<<8) | (1<<7); case AMULF: return o | (0xe<<24) | (0x1<<20) | (1<<8); case ASUBD: return o | (0xe<<24) | (0x2<<20) | (1<<8) | (1<<7); case ASUBF: return o | (0xe<<24) | (0x2<<20) | (1<<8); case ADIVD: return o | (0xe<<24) | (0x4<<20) | (1<<8) | (1<<7); case ADIVF: return o | (0xe<<24) | (0x4<<20) | (1<<8); case ACMPD: case ACMPF: return o | (0xe<<24) | (0x9<<20) | (0xF<<12) | (1<<8) | (1<<4); /* arguably, ACMPF should expand to RNDF, CMPD */ case AMOVF: case AMOVDF: return o | (0xe<<24) | (0x0<<20) | (1<<15) | (1<<8); case AMOVD: case AMOVFD: return o | (0xe<<24) | (0x0<<20) | (1<<15) | (1<<8) | (1<<7); case AMOVWF: return o | (0xe<<24) | (0<<20) | (1<<8) | (1<<4); case AMOVWD: return o | (0xe<<24) | (0<<20) | (1<<8) | (1<<4) | (1<<7); case AMOVFW: return o | (0xe<<24) | (1<<20) | (1<<8) | (1<<4); case AMOVDW: return o | (0xe<<24) | (1<<20) | (1<<8) | (1<<4) | (1<<7); } diag("bad rrr %d", a); prasm(curp); return 0; } long opvfprrr(int a, int sc) { long o; o = (sc & C_SCOND) << 28; if(sc & (C_SBIT|C_PBIT|C_WBIT)) diag(".S/.P/.W on vfp instruction"); o |= 0xe<<24; switch(a) { case AMOVWD: return o | 0xb<<8 | 0xb<<20 | 1<<6 | 0x8<<16 | 1<<7; case AMOVWF: return o | 0xa<<8 | 0xb<<20 | 1<<6 | 0x8<<16 | 1<<7; case AMOVDW: return o | 0xb<<8 | 0xb<<20 | 1<<6 | 0xD<<16 | 1<<7; case AMOVFW: return o | 0xa<<8 | 0xb<<20 | 1<<6 | 0xD<<16 | 1<<7; case AMOVFD: return o | 0xa<<8 | 0xb<<20 | 1<<6 | 0x7<<16 | 1<<7; case AMOVDF: return o | 0xb<<8 | 0xb<<20 | 1<<6 | 0x7<<16 | 1<<7; case AMOVF: return o | 0xa<<8 | 0xb<<20 | 1<<6 | 0x0<<16 | 0<<7; case AMOVD: return o | 0xb<<8 | 0xb<<20 | 1<<6 | 0x0<<16 | 0<<7; case ACMPF: return o | 0xa<<8 | 0xb<<20 | 1<<6 | 0x4<<16 | 0<<7; case ACMPD: return o | 0xb<<8 | 0xb<<20 | 1<<6 | 0x4<<16 | 0<<7; case AADDF: return o | 0xa<<8 | 0x3<<20; case AADDD: return o | 0xb<<8 | 0x3<<20; case ASUBF: return o | 0xa<<8 | 0x3<<20 | 1<<6; case ASUBD: return o | 0xb<<8 | 0x3<<20 | 1<<6; case AMULF: return o | 0xa<<8 | 0x2<<20; case AMULD: return o | 0xb<<8 | 0x2<<20; case ADIVF: return o | 0xa<<8 | 0x8<<20; case ADIVD: return o | 0xb<<8 | 0x8<<20; } diag("bad vfp rrr %d", a); prasm(curp); return 0; } long opbra(int a, int sc) { if(sc & (C_SBIT|C_PBIT|C_WBIT)) diag(".S/.P/.W on bra instruction"); sc &= C_SCOND; if(a == ABL) return (sc<<28)|(0x5<<25)|(0x1<<24); if(sc != 0xe) diag(".COND on bcond instruction"); switch(a) { case ABEQ: return (0x0<<28)|(0x5<<25); case ABNE: return (0x1<<28)|(0x5<<25); case ABCS: return (0x2<<28)|(0x5<<25); case ABHS: return (0x2<<28)|(0x5<<25); case ABCC: return (0x3<<28)|(0x5<<25); case ABLO: return (0x3<<28)|(0x5<<25); case ABMI: return (0x4<<28)|(0x5<<25); case ABPL: return (0x5<<28)|(0x5<<25); case ABVS: return (0x6<<28)|(0x5<<25); case ABVC: return (0x7<<28)|(0x5<<25); case ABHI: return (0x8<<28)|(0x5<<25); case ABLS: return (0x9<<28)|(0x5<<25); case ABGE: return (0xa<<28)|(0x5<<25); case ABLT: return (0xb<<28)|(0x5<<25); case ABGT: return (0xc<<28)|(0x5<<25); case ABLE: return (0xd<<28)|(0x5<<25); case AB: return (0xe<<28)|(0x5<<25); } diag("bad bra %A", a); prasm(curp); return 0; } long olr(long v, int b, int r, int sc) { long o; if(sc & C_SBIT) diag(".S on LDR/STR instruction"); o = (sc & C_SCOND) << 28; if(!(sc & C_PBIT)) o |= 1 << 24; if(!(sc & C_UBIT)) o |= 1 << 23; if(sc & C_WBIT) o |= 1 << 21; o |= (0x1<<26) | (1<<20); if(v < 0) { v = -v; o ^= 1 << 23; } if(v >= (1<<12)) diag("literal span too large: %ld (R%d)\n%P", v, b, PP); o |= v; o |= b << 16; o |= r << 12; return o; } long olhr(long v, int b, int r, int sc) { long o; if(sc & C_SBIT) diag(".S on LDRH/STRH instruction"); o = (sc & C_SCOND) << 28; if(!(sc & C_PBIT)) o |= 1 << 24; if(sc & C_WBIT) o |= 1 << 21; o |= (1<<23) | (1<<20)|(0xb<<4); if(v < 0) { v = -v; o ^= 1 << 23; } if(v >= (1<<8)) diag("literal span too large: %ld (R%d)\n%P", v, b, PP); o |= (v&0xf)|((v>>4)<<8)|(1<<22); o |= b << 16; o |= r << 12; return o; } long osr(int a, int r, long v, int b, int sc) { long o; o = olr(v, b, r, sc) ^ (1<<20); if(a != AMOVW) o |= 1<<22; return o; } long oshr(int r, long v, int b, int sc) { long o; o = olhr(v, b, r, sc) ^ (1<<20); return o; } long osrr(int r, int i, int b, int sc) { return olr(i, b, r, sc) ^ ((1<<25) | (1<<20)); } long oshrr(int r, int i, int b, int sc) { return olhr(i, b, r, sc) ^ ((1<<22) | (1<<20)); } long olrr(int i, int b, int r, int sc) { return olr(i, b, r, sc) ^ (1<<25); } long olhrr(int i, int b, int r, int sc) { return olhr(i, b, r, sc) ^ (1<<22); } long ovfpmem(int a, int r, long v, int b, int sc, Prog *p) { long o; if(sc & (C_SBIT|C_PBIT|C_WBIT)) diag(".S/.P/.W on VLDR/VSTR instruction"); o = (sc & C_SCOND) << 28; o |= 0xd<<24 | (1<<23); if(v < 0) { v = -v; o ^= 1 << 23; } if(v & 3) diag("odd offset for floating point op: %ld\n%P", v, p); else if(v >= (1<<10)) diag("literal span too large: %ld\n%P", v, p); o |= (v>>2) & 0xFF; o |= b << 16; o |= r << 12; switch(a) { default: diag("bad fst %A", a); case AMOVD: o |= 0xb<<8; break; case AMOVF: o |= 0xa<<8; break; } return o; } long ofsr(int a, int r, long v, int b, int sc, Prog *p) { long o; if(vfp) return ovfpmem(a, r, v, b, sc, p); if(sc & C_SBIT) diag(".S on FLDR/FSTR instruction"); o = (sc & C_SCOND) << 28; if(!(sc & C_PBIT)) o |= 1 << 24; if(sc & C_WBIT) o |= 1 << 21; o |= (6<<25) | (1<<24) | (1<<23); if(v < 0) { v = -v; o ^= 1 << 23; } if(v & 3) diag("odd offset for floating point op: %ld\n%P", v, p); else if(v >= (1<<10)) diag("literal span too large: %ld\n%P", v, p); o |= (v>>2) & 0xFF; o |= b << 16; o |= r << 12; o |= 1 << 8; switch(a) { default: diag("bad fst %A", a); case AMOVD: o |= 1<<15; case AMOVF: break; } return o; } long omvl(Prog *p, Adr *a, int dr) { long v, o1; if(!p->cond) { aclass(a); v = immrot(~instoffset); if(v == 0) { diag("missing literal"); prasm(p); return 0; } o1 = oprrr(AMVN, p->scond&C_SCOND); o1 |= v; o1 |= dr << 12; } else { v = p->cond->pc - p->pc - 8; o1 = olr(v, REGPC, dr, p->scond&C_SCOND); } return o1; } static Ieee chipfloats[] = { {0x00000000, 0x00000000}, /* 0 */ {0x00000000, 0x3ff00000}, /* 1 */ {0x00000000, 0x40000000}, /* 2 */ {0x00000000, 0x40080000}, /* 3 */ {0x00000000, 0x40100000}, /* 4 */ {0x00000000, 0x40140000}, /* 5 */ {0x00000000, 0x3fe00000}, /* .5 */ {0x00000000, 0x40240000}, /* 10 */ }; int chipfloat(Ieee *e) { Ieee *p; int n; if(vfp) return -1; for(n = sizeof(chipfloats)/sizeof(chipfloats[0]); --n >= 0;){ p = &chipfloats[n]; if(p->l == e->l && p->h == e->h) return n; } return -1; }