Esempio n. 1
0
/* Helper for FORI. Coercion. */
void LJ_FASTCALL lj_meta_for(lua_State *L, TValue *o)
{
  if (!lj_strscan_numberobj(o)) lj_err_msg(L, LJ_ERR_FORINIT);
  if (!lj_strscan_numberobj(o+1)) lj_err_msg(L, LJ_ERR_FORLIM);
  if (!lj_strscan_numberobj(o+2)) lj_err_msg(L, LJ_ERR_FORSTEP);
  if (LJ_DUALNUM) {
    /* Ensure all slots are integers or all slots are numbers. */
    int32_t k[3];
    int nint = 0;
    ptrdiff_t i;
    for (i = 0; i <= 2; i++) {
      if (tvisint(o+i)) {
	k[i] = intV(o+i); nint++;
      } else {
	k[i] = lj_num2int(numV(o+i)); nint += ((lua_Number)k[i] == numV(o+i));
      }
    }
    if (nint == 3) {  /* Narrow to integers. */
      setintV(o, k[0]);
      setintV(o+1, k[1]);
      setintV(o+2, k[2]);
    } else if (nint != 0) {  /* Widen to numbers. */
      if (tvisint(o)) setnumV(o, (lua_Number)intV(o));
      if (tvisint(o+1)) setnumV(o+1, (lua_Number)intV(o+1));
      if (tvisint(o+2)) setnumV(o+2, (lua_Number)intV(o+2));
    }
  }
}
Esempio n. 2
0
/* Restore a value from the trace exit state. */
static void snap_restoreval(jit_State *J, GCtrace *T, ExitState *ex,
			    SnapNo snapno, BloomFilter rfilt,
			    IRRef ref, TValue *o)
{
  IRIns *ir = &T->ir[ref];
  IRType1 t = ir->t;
  RegSP rs = ir->prev;
  if (irref_isk(ref)) {  /* Restore constant slot. */
    lj_ir_kvalue(J->L, o, ir);
    return;
  }
  if (LJ_UNLIKELY(bloomtest(rfilt, ref)))
    rs = snap_renameref(T, snapno, ref, rs);
  lua_assert(!LJ_GC64);  /* TODO_GC64: handle 64 bit references. */
  if (ra_hasspill(regsp_spill(rs))) {  /* Restore from spill slot. */
    int32_t *sps = &ex->spill[regsp_spill(rs)];
    if (irt_isinteger(t)) {
      setintV(o, *sps);
#if !LJ_SOFTFP
    } else if (irt_isnum(t)) {
      o->u64 = *(uint64_t *)sps;
#endif
    } else if (LJ_64 && irt_islightud(t)) {
      /* 64 bit lightuserdata which may escape already has the tag bits. */
      o->u64 = *(uint64_t *)sps;
    } else {
      lua_assert(!irt_ispri(t));  /* PRI refs never have a spill slot. */
      setgcV(J->L, o, (GCobj *)(uintptr_t)*(GCSize *)sps, irt_toitype(t));
    }
  } else {  /* Restore from register. */
    Reg r = regsp_reg(rs);
    if (ra_noreg(r)) {
      lua_assert(ir->o == IR_CONV && ir->op2 == IRCONV_NUM_INT);
      snap_restoreval(J, T, ex, snapno, rfilt, ir->op1, o);
      if (LJ_DUALNUM) setnumV(o, (lua_Number)intV(o));
      return;
    } else if (irt_isinteger(t)) {
      setintV(o, (int32_t)ex->gpr[r-RID_MIN_GPR]);
#if !LJ_SOFTFP
    } else if (irt_isnum(t)) {
      setnumV(o, ex->fpr[r-RID_MIN_FPR]);
#endif
    } else if (LJ_64 && irt_is64(t)) {
      /* 64 bit values that already have the tag bits. */
      o->u64 = ex->gpr[r-RID_MIN_GPR];
    } else if (irt_ispri(t)) {
      setpriV(o, irt_toitype(t));
    } else {
      setgcV(J->L, o, (GCobj *)ex->gpr[r-RID_MIN_GPR], irt_toitype(t));
    }
  }
}
Esempio n. 3
0
LUALIB_API int luaL_execresult(lua_State *L, int stat)
{
  if (stat != -1) {
#if LJ_TARGET_POSIX
    if (WIFSIGNALED(stat)) {
      stat = WTERMSIG(stat);
      setnilV(L->top++);
      lua_pushliteral(L, "signal");
    } else {
      if (WIFEXITED(stat))
	stat = WEXITSTATUS(stat);
      if (stat == 0)
	setboolV(L->top++, 1);
      else
	setnilV(L->top++);
      lua_pushliteral(L, "exit");
    }
#else
    if (stat == 0)
      setboolV(L->top++, 1);
    else
      setnilV(L->top++);
    lua_pushliteral(L, "exit");
#endif
    setintV(L->top++, stat);
    return 3;
  }
  return luaL_fileresult(L, 0, NULL);
}
static void LJ_FASTCALL recff_table_remove(jit_State *J, RecordFFData *rd)
{
  TRef tab = J->base[0];
  rd->nres = 0;
  if (tref_istab(tab)) {
    if (!J->base[1] || tref_isnil(J->base[1])) {  /* Simple pop: t[#t] = nil */
      TRef trlen = lj_ir_call(J, IRCALL_lj_tab_len, tab);
      GCtab *t = tabV(&rd->argv[0]);
      MSize len = lj_tab_len(t);
      emitir(IRTGI(len ? IR_NE : IR_EQ), trlen, lj_ir_kint(J, 0));
      if (len) {
	RecordIndex ix;
	ix.tab = tab;
	ix.key = trlen;
	settabV(J->L, &ix.tabv, t);
	setintV(&ix.keyv, len);
	ix.idxchain = 0;
	if (results_wanted(J) != 0) {  /* Specialize load only if needed. */
	  ix.val = 0;
	  J->base[0] = lj_record_idx(J, &ix);  /* Load previous value. */
	  rd->nres = 1;
	  /* Assumes ix.key/ix.tab is not modified for raw lj_record_idx(). */
	}
	ix.val = TREF_NIL;
	lj_record_idx(J, &ix);  /* Remove value. */
      }
    } else {  /* Complex case: remove in the middle. */
      recff_nyiu(J);
    }
  }  /* else: Interpreter will throw. */
}
Esempio n. 5
0
int32_t lj_lib_checkbit(lua_State *L, int narg)
{
  TValue *o = L->base + narg-1;
  if (!(o < L->top && lj_strscan_numberobj(o)))
    lj_err_argt(L, narg, LUA_TNUMBER);
  if (LJ_LIKELY(tvisint(o))) {
    return intV(o);
  } else {
    int32_t i = lj_num2bit(numV(o));
    if (LJ_DUALNUM) setintV(o, i);
    return i;
  }
}
Esempio n. 6
0
/* Index a C library by name. */
TValue *lj_clib_index(lua_State *L, CLibrary *cl, GCstr *name)
{
  TValue *tv = lj_tab_setstr(L, cl->cache, name);
  if (LJ_UNLIKELY(tvisnil(tv))) {
    CTState *cts = ctype_cts(L);
    CType *ct;
    CTypeID id = lj_ctype_getname(cts, &ct, name, CLNS_INDEX);
    if (!id)
      lj_err_callerv(L, LJ_ERR_FFI_NODECL, strdata(name));
    if (ctype_isconstval(ct->info)) {
      CType *ctt = ctype_child(cts, ct);
      lua_assert(ctype_isinteger(ctt->info) && ctt->size <= 4);
      if ((ctt->info & CTF_UNSIGNED) && (int32_t)ct->size < 0)
	setnumV(tv, (lua_Number)(uint32_t)ct->size);
      else
	setintV(tv, (int32_t)ct->size);
    } else {
      const char *sym = clib_extsym(cts, ct, name);
#if LJ_TARGET_WINDOWS
      DWORD oldwerr = GetLastError();
#endif
      void *p = clib_getsym(cl, sym);
      GCcdata *cd;
      lua_assert(ctype_isfunc(ct->info) || ctype_isextern(ct->info));
#if LJ_TARGET_X86 && LJ_ABI_WIN
      /* Retry with decorated name for fastcall/stdcall functions. */
      if (!p && ctype_isfunc(ct->info)) {
	CTInfo cconv = ctype_cconv(ct->info);
	if (cconv == CTCC_FASTCALL || cconv == CTCC_STDCALL) {
	  CTSize sz = clib_func_argsize(cts, ct);
	  const char *symd = lj_str_pushf(L,
			       cconv == CTCC_FASTCALL ? "@%s@%d" : "_%s@%d",
			       sym, sz);
	  L->top--;
	  p = clib_getsym(cl, symd);
	}
      }
#endif
      if (!p)
	clib_error(L, "cannot resolve symbol " LUA_QS ": %s", sym);
#if LJ_TARGET_WINDOWS
      SetLastError(oldwerr);
#endif
      cd = lj_cdata_new(cts, id, CTSIZE_PTR);
      *(void **)cdataptr(cd) = p;
      setcdataV(L, tv, cd);
    }
  }
  return tv;
}
static void LJ_FASTCALL recff_ipairs_aux(jit_State *J, RecordFFData *rd)
{
  RecordIndex ix;
  ix.tab = J->base[0];
  if (tref_istab(ix.tab)) {
    if (!tvisnumber(&rd->argv[1]))  /* No support for string coercion. */
      lj_trace_err(J, LJ_TRERR_BADTYPE);
    setintV(&ix.keyv, numberVint(&rd->argv[1])+1);
    settabV(J->L, &ix.tabv, tabV(&rd->argv[0]));
    ix.val = 0; ix.idxchain = 0;
    ix.key = lj_opt_narrow_toint(J, J->base[1]);
    J->base[0] = ix.key = emitir(IRTI(IR_ADD), ix.key, lj_ir_kint(J, 1));
    J->base[1] = lj_record_idx(J, &ix);
    rd->nres = tref_isnil(J->base[1]) ? 0 : 2;
  }  /* else: Interpreter will throw. */
}
Esempio n. 8
0
LUALIB_API int luaL_fileresult(lua_State *L, int stat, const char *fname)
{
  if (stat) {
    setboolV(L->top++, 1);
    return 1;
  } else {
    int en = errno;  /* Lua API calls may change this value. */
    setnilV(L->top++);
    if (fname)
      lua_pushfstring(L, "%s: %s", fname, strerror(en));
    else
      lua_pushfstring(L, "%s", strerror(en));
    setintV(L->top++, en);
    lj_trace_abort(G(L));
    return 3;
  }
}
Esempio n. 9
0
/* Convert C type to TValue. Caveat: expects to get the raw CType! */
int lj_cconv_tv_ct(CTState *cts, CType *s, CTypeID sid,
		   TValue *o, uint8_t *sp)
{
  CTInfo sinfo = s->info;
  lua_assert(!ctype_isenum(sinfo));
  if (ctype_isnum(sinfo)) {
    if (!ctype_isbool(sinfo)) {
      if (ctype_isinteger(sinfo) && s->size > 4) goto copyval;
      if (LJ_DUALNUM && ctype_isinteger(sinfo)) {
	int32_t i;
	lj_cconv_ct_ct(cts, ctype_get(cts, CTID_INT32), s,
		       (uint8_t *)&i, sp, 0);
	if ((sinfo & CTF_UNSIGNED) && i < 0)
	  setnumV(o, (lua_Number)(uint32_t)i);
	else
	  setintV(o, i);
      } else {
	lj_cconv_ct_ct(cts, ctype_get(cts, CTID_DOUBLE), s,
		       (uint8_t *)&o->n, sp, 0);
	/* Numbers are NOT canonicalized here! Beware of uninitialized data. */
	lua_assert(tvisnum(o));
      }
    } else {
      uint32_t b = ((*sp) & 1);
      setboolV(o, b);
      setboolV(&cts->g->tmptv2, b);  /* Remember for trace recorder. */
    }
    return 0;
  } else if (ctype_isrefarray(sinfo) || ctype_isstruct(sinfo)) {
    /* Create reference. */
    setcdataV(cts->L, o, lj_cdata_newref(cts, sp, sid));
    return 1;  /* Need GC step. */
  } else {
    GCcdata *cd;
    CTSize sz;
  copyval:  /* Copy value. */
    sz = s->size;
    lua_assert(sz != CTSIZE_INVALID);
    /* Attributes are stripped, qualifiers are kept (but mostly ignored). */
    cd = lj_cdata_new(cts, ctype_typeid(cts, s), sz);
    setcdataV(cts->L, o, cd);
    memcpy(cdataptr(cd), sp, sz);
    return 1;  /* Need GC step. */
  }
}
Esempio n. 10
0
static int io_file_readnum(lua_State *L, FILE *fp)
{
  lua_Number d;
  if (fscanf(fp, LUA_NUMBER_SCAN, &d) == 1) {
    if (LJ_DUALNUM) {
      int32_t i = lj_num2int(d);
      if (d == (lua_Number)i && !tvismzero((cTValue *)&d)) {
	setintV(L->top++, i);
	return 1;
      }
    }
    setnumV(L->top++, d);
    return 1;
  } else {
    setnilV(L->top++);
    return 0;
  }
}
Esempio n. 11
0
LJLIB_ASM(bit_lshift)		LJLIB_REC(bit_shift IR_BSHL)
{
#if LJ_HASFFI
  CTypeID id = 0, id2 = 0;
  uint64_t x = lj_carith_check64(L, 1, &id);
  int32_t sh = (int32_t)lj_carith_check64(L, 2, &id2);
  if (id) {
    x = lj_carith_shift64(x, sh, curr_func(L)->c.ffid - (int)FF_bit_lshift);
    return bit_result64(L, id, x);
  }
  if (id2) setintV(L->base+1, sh);
  return FFH_RETRY;
#else
  lj_lib_checknumber(L, 1);
  bit_checkbit(L, 2);
  return FFH_RETRY;
#endif
}
static void LJ_FASTCALL recff_table_insert(jit_State *J, RecordFFData *rd)
{
  RecordIndex ix;
  ix.tab = J->base[0];
  ix.val = J->base[1];
  rd->nres = 0;
  if (tref_istab(ix.tab) && ix.val) {
    if (!J->base[2]) {  /* Simple push: t[#t+1] = v */
      TRef trlen = lj_ir_call(J, IRCALL_lj_tab_len, ix.tab);
      GCtab *t = tabV(&rd->argv[0]);
      ix.key = emitir(IRTI(IR_ADD), trlen, lj_ir_kint(J, 1));
      settabV(J->L, &ix.tabv, t);
      setintV(&ix.keyv, lj_tab_len(t) + 1);
      ix.idxchain = 0;
      lj_record_idx(J, &ix);  /* Set new value. */
    } else {  /* Complex case: insert in the middle. */
      recff_nyiu(J);
    }
  }  /* else: Interpreter will throw. */
}
Esempio n. 13
0
/* Parse a number literal. */
static void lex_number(LexState *ls, TValue *tv)
{
  int c;
  lua_assert(lj_char_isdigit(ls->current));
  do {
    c = ls->current;
    save_and_next(ls);
  } while (lj_char_isident(ls->current) || ls->current == '.' ||
	   ((ls->current == '-' || ls->current == '+') &&
	    ((c & ~0x20) == 'E' || (c & ~0x20) == 'P')));
#if LJ_HASFFI
  c &= ~0x20;
  if ((c == 'I' || c == 'L' || c == 'U') && !ctype_ctsG(G(ls->L)))
    lex_loadffi(ls->L);
  if (c == 'I')  /* Parse imaginary part of complex number. */
    ls->sb.n--;
#endif
  save(ls, '\0');
#if LJ_HASFFI
  if ((c == 'L' || c == 'U') && lex_number64(ls, tv)) {  /* Parse 64 bit int. */
    return;
  } else
#endif
  if (lj_str_numconv(ls->sb.buf, tv)) {
#if LJ_HASFFI
    if (c == 'I') {  /* Return cdata holding a complex number. */
      GCcdata *cd = lj_cdata_new_(ls->L, CTID_COMPLEX_DOUBLE, 2*sizeof(double));
      ((double *)cdataptr(cd))[0] = 0;
      ((double *)cdataptr(cd))[1] = numberVnum(tv);
      lj_parse_keepcdata(ls, tv, cd);
    }
#endif
    if (LJ_DUALNUM && tvisnum(tv)) {
      int32_t k = lj_num2int(numV(tv));
      if ((lua_Number)k == numV(tv))  /* -0 cannot end up here. */
	setintV(tv, k);
    }
    return;
  }
  lj_lex_error(ls, TK_number, LJ_ERR_XNUMBER);
}
Esempio n. 14
0
static void jit_profile_callback(lua_State *L2, lua_State *L, int samples,
				 int vmstate)
{
  TValue key;
  cTValue *tv;
  setlightudV(&key, (void *)&KEY_PROFILE_FUNC);
  tv = lj_tab_get(L, tabV(registry(L)), &key);
  if (tvisfunc(tv)) {
    char vmst = (char)vmstate;
    int status;
    setfuncV(L2, L2->top++, funcV(tv));
    setthreadV(L2, L2->top++, L);
    setintV(L2->top++, samples);
    setstrV(L2, L2->top++, lj_str_new(L2, &vmst, 1));
    status = lua_pcall(L2, 3, 0, 0);  /* callback(thread, samples, vmstate) */
    if (status) {
      if (G(L2)->panic) G(L2)->panic(L2);
      exit(EXIT_FAILURE);
    }
    lj_trace_abort(G(L2));
  }
}
Esempio n. 15
0
/* Synchronous abort with error message. */
void lj_trace_err(jit_State *J, TraceError e)
{
  setnilV(&J->errinfo);  /* No error info. */
  setintV(J->L->top++, (int32_t)e);
  lj_err_throw(J->L, LUA_ERRRUN);
}
Esempio n. 16
0
/* Restore interpreter state from exit state with the help of a snapshot. */
const BCIns *lj_snap_restore(jit_State *J, void *exptr)
{
  ExitState *ex = (ExitState *)exptr;
  SnapNo snapno = J->exitno;  /* For now, snapno == exitno. */
  GCtrace *T = traceref(J, J->parent);
  SnapShot *snap = &T->snap[snapno];
  MSize n, nent = snap->nent;
  SnapEntry *map = &T->snapmap[snap->mapofs];
  SnapEntry *flinks = map + nent + snap->depth;
  int32_t ftsz0;
  BCReg nslots = snap->nslots;
  TValue *frame;
  BloomFilter rfilt = snap_renamefilter(T, snapno);
  const BCIns *pc = snap_pc(map[nent]);
  lua_State *L = J->L;

  /* Set interpreter PC to the next PC to get correct error messages. */
  setcframe_pc(cframe_raw(L->cframe), pc+1);

  /* Make sure the stack is big enough for the slots from the snapshot. */
  if (LJ_UNLIKELY(L->base + nslots > tvref(L->maxstack))) {
    L->top = curr_topL(L);
    lj_state_growstack(L, nslots - curr_proto(L)->framesize);
  }

  /* Fill stack slots with data from the registers and spill slots. */
  frame = L->base-1;
  ftsz0 = frame_ftsz(frame);  /* Preserve link to previous frame in slot #0. */
  for (n = 0; n < nent; n++) {
    SnapEntry sn = map[n];
    IRRef ref = snap_ref(sn);
    BCReg s = snap_slot(sn);
    TValue *o = &frame[s];  /* Stack slots are relative to start frame. */
    IRIns *ir = &T->ir[ref];
    if (irref_isk(ref)) {  /* Restore constant slot. */
      lj_ir_kvalue(L, o, ir);
      if ((sn & (SNAP_CONT|SNAP_FRAME))) {
	/* Overwrite tag with frame link. */
	o->fr.tp.ftsz = s != 0 ? (int32_t)*flinks-- : ftsz0;
	if ((sn & SNAP_FRAME)) {
	  GCfunc *fn = ir_kfunc(ir);
	  if (isluafunc(fn)) {
	    MSize framesize = funcproto(fn)->framesize;
	    L->base = ++o;
	    if (LJ_UNLIKELY(o + framesize > tvref(L->maxstack))) {
	      ptrdiff_t fsave = savestack(L, frame);
	      L->top = o;
	      lj_state_growstack(L, framesize);  /* Grow again. */
	      frame = restorestack(L, fsave);
	    }
	  }
	}
      }
    } else if (!(sn & SNAP_NORESTORE)) {
      IRType1 t = ir->t;
      RegSP rs = ir->prev;
      lua_assert(!(sn & (SNAP_CONT|SNAP_FRAME)));
      if (LJ_UNLIKELY(bloomtest(rfilt, ref)))
	rs = snap_renameref(T, snapno, ref, rs);
      if (ra_hasspill(regsp_spill(rs))) {  /* Restore from spill slot. */
	int32_t *sps = &ex->spill[regsp_spill(rs)];
	if (LJ_SOFTFP && (sn & SNAP_SOFTFPNUM)) {
	  o->u32.lo = (uint32_t)*sps;
	} else if (irt_isinteger(t)) {
	  setintV(o, *sps);
#if !LJ_SOFTFP
	} else if (irt_isnum(t)) {
	  o->u64 = *(uint64_t *)sps;
#endif
#if LJ_64
	} else if (irt_islightud(t)) {
	  /* 64 bit lightuserdata which may escape already has the tag bits. */
	  o->u64 = *(uint64_t *)sps;
#endif
	} else {
	  lua_assert(!irt_ispri(t));  /* PRI refs never have a spill slot. */
	  setgcrefi(o->gcr, *sps);
	  setitype(o, irt_toitype(t));
	}
      } else {  /* Restore from register. */
	Reg r = regsp_reg(rs);
	lua_assert(ra_hasreg(r));
	if (LJ_SOFTFP && (sn & SNAP_SOFTFPNUM)) {
	  o->u32.lo = (uint32_t)ex->gpr[r-RID_MIN_GPR];
	} else if (irt_isinteger(t)) {
	  setintV(o, (int32_t)ex->gpr[r-RID_MIN_GPR]);
#if !LJ_SOFTFP
	} else if (irt_isnum(t)) {
	  setnumV(o, ex->fpr[r-RID_MIN_FPR]);
#endif
#if LJ_64
	} else if (irt_islightud(t)) {
	  /* 64 bit lightuserdata which may escape already has the tag bits. */
	  o->u64 = ex->gpr[r-RID_MIN_GPR];
#endif
	} else {
	  if (!irt_ispri(t))
	    setgcrefi(o->gcr, ex->gpr[r-RID_MIN_GPR]);
	  setitype(o, irt_toitype(t));
	}
      }
      if (LJ_SOFTFP && (sn & SNAP_SOFTFPNUM)) {
	rs = (ir+1)->prev;
	if (LJ_UNLIKELY(bloomtest(rfilt, ref+1)))
	  rs = snap_renameref(T, snapno, ref+1, rs);
	o->u32.hi = (ra_hasspill(regsp_spill(rs))) ?
	    (uint32_t)*&ex->spill[regsp_spill(rs)] :
	    (uint32_t)ex->gpr[regsp_reg(rs)-RID_MIN_GPR];
      }
    }
  }
  switch (bc_op(*pc)) {
  case BC_CALLM: case BC_CALLMT: case BC_RETM: case BC_TSETM:
    L->top = frame + nslots;
    break;
  default:
    L->top = curr_topL(L);
    break;
  }
  lua_assert(map + nent == flinks);
  return pc;
}
Esempio n. 17
0
/* Synchronous abort with error message and error info. */
void lj_trace_err_info(jit_State *J, TraceError e)
{
  setintV(J->L->top++, (int32_t)e);
  lj_err_throw(J->L, LUA_ERRRUN);
}
Esempio n. 18
0
static void setintfield(lua_State *L, GCtab *t, const char *name, int32_t val)
{
    setintV(lj_tab_setstr(L, t, lj_str_newz(L, name)), val);
}
Esempio n. 19
0
/* Restore interpreter state from exit state with the help of a snapshot. */
void lj_snap_restore(jit_State *J, void *exptr)
{
  ExitState *ex = (ExitState *)exptr;
  SnapNo snapno = J->exitno;  /* For now, snapno == exitno. */
  Trace *T = J->trace[J->parent];
  SnapShot *snap = &T->snap[snapno];
  BCReg s, nslots = snap->nslots;
  IRRef2 *map = &T->snapmap[snap->mapofs];
  IRRef2 *flinks = map + nslots + snap->nframelinks;
  TValue *o, *newbase, *ntop;
  BloomFilter rfilt = snap_renamefilter(T, snapno);
  lua_State *L = J->L;

  /* Make sure the stack is big enough for the slots from the snapshot. */
  if (L->base + nslots >= L->maxstack) {
    L->top = curr_topL(L);
    lj_state_growstack(L, nslots - curr_proto(L)->framesize);
  }

  /* Fill stack slots with data from the registers and spill slots. */
  newbase = NULL;
  ntop = L->base;
  for (s = 0, o = L->base-1; s < nslots; s++, o++) {
    IRRef ref = snap_ref(map[s]);
    if (ref) {
      IRIns *ir = &T->ir[ref];
      if (irref_isk(ref)) {  /* Restore constant slot. */
	lj_ir_kvalue(L, o, ir);
      } else {
	IRType1 t = ir->t;
	RegSP rs = ir->prev;
	if (LJ_UNLIKELY(bloomtest(rfilt, ref)))
	  rs = snap_renameref(T, snapno, ref, rs);
	if (ra_hasspill(regsp_spill(rs))) {  /* Restore from spill slot. */
	  int32_t *sps = &ex->spill[regsp_spill(rs)];
	  if (irt_isinteger(t)) {
	    setintV(o, *sps);
	  } else if (irt_isnum(t)) {
	    o->u64 = *(uint64_t *)sps;
	  } else {
	    lua_assert(!irt_ispri(t));  /* PRI refs never have a spill slot. */
	    setgcrefi(o->gcr, *sps);
	    setitype(o, irt_toitype(t));
	  }
	} else if (ra_hasreg(regsp_reg(rs))) {  /* Restore from register. */
	  Reg r = regsp_reg(rs);
	  if (irt_isinteger(t)) {
	    setintV(o, ex->gpr[r-RID_MIN_GPR]);
	  } else if (irt_isnum(t)) {
	    setnumV(o, ex->fpr[r-RID_MIN_FPR]);
	  } else {
	    if (!irt_ispri(t))
	      setgcrefi(o->gcr, ex->gpr[r-RID_MIN_GPR]);
	    setitype(o, irt_toitype(t));
	  }
	} else {  /* Restore frame slot. */
	  lua_assert(ir->o == IR_FRAME);
	  /* This works for both PTR and FUNC IR_FRAME. */
	  setgcrefp(o->fr.func, mref(T->ir[ir->op2].ptr, void));
	  if (s != 0)  /* Do not overwrite link to previous frame. */
	    o->fr.tp.ftsz = (int32_t)*--flinks;
	  if (irt_isfunc(ir->t)) {
	    GCfunc *fn = gco2func(gcref(T->ir[ir->op2].gcr));
	    if (isluafunc(fn)) {
	      TValue *fs;
	      newbase = o+1;
	      fs = newbase + funcproto(fn)->framesize;
	      if (fs > ntop) ntop = fs; /* Update top for newly added frames. */
	    }
	  }
	}
      }
    } else if (newbase) {
      setnilV(o);  /* Clear unreferenced slots of newly added frames. */
    }
  }