Example #1
0
/* Narrowing of power operator or math.pow. */
TRef lj_opt_narrow_pow(jit_State *J, TRef rb, TRef rc, TValue *vc)
{
  lua_Number n;
  if (tvisstr(vc) && !lj_str_tonum(strV(vc), vc))
    lj_trace_err(J, LJ_TRERR_BADTYPE);
  n = numV(vc);
  /* Limit narrowing for pow to small exponents (or for two constants). */
  if ((tref_isk(rc) && tref_isint(rc) && tref_isk(rb)) ||
      ((J->flags & JIT_F_OPT_NARROW) &&
       (numisint(n) && n >= -65536.0 && n <= 65536.0))) {
    TRef tmp;
    if (!tref_isinteger(rc)) {
      if (tref_isstr(rc))
	rc = emitir(IRTG(IR_STRTO, IRT_NUM), rc, 0);
      rc = emitir(IRTGI(IR_TOINT), rc, IRTOINT_CHECK); /* Guarded TOINT! */
    }
    if (!tref_isk(rc)) {  /* Range guard: -65536 <= i <= 65536 */
      tmp = emitir(IRTI(IR_ADD), rc, lj_ir_kint(J, 65536-2147483647-1));
      emitir(IRTGI(IR_LE), tmp, lj_ir_kint(J, 2*65536-2147483647-1));
    }
    return emitir(IRTN(IR_POWI), rb, rc);
  }
  /* FOLD covers most cases, but some are easier to do here. */
  if (tref_isk(rb) && tvispone(ir_knum(IR(tref_ref(rb)))))
    return rb;  /* 1 ^ x ==> 1 */
  rc = lj_ir_tonum(J, rc);
  if (tref_isk(rc) && ir_knum(IR(tref_ref(rc)))->n == 0.5)
    return emitir(IRTN(IR_FPMATH), rb, IRFPM_SQRT);  /* x ^ 0.5 ==> sqrt(x) */
  /* Split up b^c into exp2(c*log2(b)). Assembler may rejoin later. */
  rb = emitir(IRTN(IR_FPMATH), rb, IRFPM_LOG2);
  rc = emitir(IRTN(IR_MUL), rb, rc);
  return emitir(IRTN(IR_FPMATH), rc, IRFPM_EXP2);
}
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. */
}
static void LJ_FASTCALL recff_io_flush(jit_State *J, RecordFFData *rd)
{
  TRef fp = recff_io_fp(J, rd->data);
  TRef tr = lj_ir_call(J, IRCALL_fflush, fp);
  if (results_wanted(J) != 0)  /* Check result only if not ignored. */
    emitir(IRTGI(IR_EQ), tr, lj_ir_kint(J, 0));
  J->base[0] = TREF_TRUE;
}
static void LJ_FASTCALL recff_io_write(jit_State *J, RecordFFData *rd)
{
  TRef fp = recff_io_fp(J, rd->data);
  TRef zero = lj_ir_kint(J, 0);
  TRef one = lj_ir_kint(J, 1);
  ptrdiff_t i = rd->data == 0 ? 1 : 0;
  for (; J->base[i]; i++) {
    TRef str = lj_ir_tostr(J, J->base[i]);
    TRef buf = emitir(IRT(IR_STRREF, IRT_P32), str, zero);
    TRef len = emitir(IRTI(IR_FLOAD), str, IRFL_STR_LEN);
    if (tref_isk(len) && IR(tref_ref(len))->i == 1) {
      TRef tr = emitir(IRT(IR_XLOAD, IRT_U8), buf, IRXLOAD_READONLY);
      tr = lj_ir_call(J, IRCALL_fputc, tr, fp);
      if (results_wanted(J) != 0)  /* Check result only if not ignored. */
	emitir(IRTGI(IR_NE), tr, lj_ir_kint(J, -1));
    } else {
      TRef tr = lj_ir_call(J, IRCALL_fwrite, buf, one, len, fp);
      if (results_wanted(J) != 0)  /* Check result only if not ignored. */
	emitir(IRTGI(IR_EQ), tr, len);
    }
  }
  J->base[0] = TREF_TRUE;
}
/* Record rounding functions math.floor and math.ceil. */
static void LJ_FASTCALL recff_math_round(jit_State *J, RecordFFData *rd)
{
  TRef tr = J->base[0];
  if (!tref_isinteger(tr)) {  /* Pass through integers unmodified. */
    tr = emitir(IRTN(IR_FPMATH), lj_ir_tonum(J, tr), rd->data);
    /* Result is integral (or NaN/Inf), but may not fit an int32_t. */
    if (LJ_DUALNUM) {  /* Try to narrow using a guarded conversion to int. */
      lua_Number n = lj_vm_foldfpm(numberVnum(&rd->argv[0]), rd->data);
      if (n == (lua_Number)lj_num2int(n))
	tr = emitir(IRTGI(IR_CONV), tr, IRCONV_INT_NUM|IRCONV_CHECK);
    }
    J->base[0] = tr;
  }
}
/* Get FILE* for I/O function. Any I/O error aborts recording, so there's
** no need to encode the alternate cases for any of the guards.
*/
static TRef recff_io_fp(jit_State *J, uint32_t id)
{
  TRef tr, ud, fp;
  if (id) {  /* io.func() */
    tr = lj_ir_kptr(J, &J2G(J)->gcroot[id]);
    ud = emitir(IRT(IR_XLOAD, IRT_UDATA), tr, 0);
  } else {  /* fp:method() */
    ud = J->base[0];
    if (!tref_isudata(ud))
      lj_trace_err(J, LJ_TRERR_BADTYPE);
    tr = emitir(IRT(IR_FLOAD, IRT_U8), ud, IRFL_UDATA_UDTYPE);
    emitir(IRTGI(IR_EQ), tr, lj_ir_kint(J, UDTYPE_IO_FILE));
  }
  fp = emitir(IRT(IR_FLOAD, IRT_PTR), ud, IRFL_UDATA_FILE);
  emitir(IRTG(IR_NE, IRT_PTR), fp, lj_ir_knull(J, IRT_PTR));
  return fp;
}
Example #7
0
static TRef crec_tv_ct(jit_State *J, CType *s, CTypeID sid, TRef sp)
{
  CTState *cts = ctype_ctsG(J2G(J));
  CTInfo sinfo = s->info;
  lua_assert(!ctype_isenum(sinfo));
  if (ctype_isnum(sinfo)) {
    IRType t = crec_ct2irt(s);
    TRef tr;
    if (t == IRT_CDATA)
      goto err_nyi;  /* NYI: copyval of >64 bit integers. */
    tr = emitir(IRT(IR_XLOAD, t), sp, 0);
    if (t == IRT_FLOAT || t == IRT_U32) {  /* Keep uint32_t/float as numbers. */
      tr = emitconv(tr, IRT_NUM, t, 0);
    } else if (t == IRT_I64 || t == IRT_U64) {  /* Box 64 bit integer. */
      TRef dp = emitir(IRTG(IR_CNEW, IRT_CDATA), lj_ir_kint(J, sid), TREF_NIL);
      TRef ptr = emitir(IRT(IR_ADD, IRT_PTR), dp,
			lj_ir_kintp(J, sizeof(GCcdata)));
      emitir(IRT(IR_XSTORE, t), ptr, tr);
      return dp;
    } else if ((sinfo & CTF_BOOL)) {
      /* Assume not equal to zero. Fixup and emit pending guard later. */
      lj_ir_set(J, IRTGI(IR_NE), tr, lj_ir_kint(J, 0));
      J->postproc = LJ_POST_FIXGUARD;
      tr = TREF_TRUE;
    }
    return tr;
  } else if (ctype_isptr(sinfo)) {
    IRType t = (LJ_64 && s->size == 8) ? IRT_P64 : IRT_P32;
    sp = emitir(IRT(IR_XLOAD, t), sp, 0);
  } else if (ctype_isrefarray(sinfo) || ctype_isstruct(sinfo)) {
    cts->L = J->L;
    sid = lj_ctype_intern(cts, CTINFO_REF(sid), CTSIZE_PTR);  /* Create ref. */
  } else if (ctype_iscomplex(sinfo)) {  /* Unbox/box complex. */
    IRType t = s->size == 2*sizeof(double) ? IRT_NUM : IRT_FLOAT;
    ptrdiff_t esz = (ptrdiff_t)(s->size >> 1);
    TRef ptr, tr1, tr2, dp;
    dp = emitir(IRTG(IR_CNEW, IRT_CDATA), lj_ir_kint(J, sid), TREF_NIL);
    tr1 = emitir(IRT(IR_XLOAD, t), sp, 0);
    ptr = emitir(IRT(IR_ADD, IRT_PTR), sp, lj_ir_kintp(J, esz));
    tr2 = emitir(IRT(IR_XLOAD, t), ptr, 0);
    ptr = emitir(IRT(IR_ADD, IRT_PTR), dp, lj_ir_kintp(J, sizeof(GCcdata)));
    emitir(IRT(IR_XSTORE, t), ptr, tr1);
    ptr = emitir(IRT(IR_ADD, IRT_PTR), dp, lj_ir_kintp(J, sizeof(GCcdata)+esz));
    emitir(IRT(IR_XSTORE, t), ptr, tr2);
    return dp;
  } else {
/* Emit a (checked) number to integer conversion. */
static IRRef split_num2int(jit_State *J, IRRef lo, IRRef hi, int check)
{
  IRRef tmp, res;
#if LJ_LE
  tmp = split_emit(J, IRT(IR_CARG, IRT_NIL), lo, hi);
#else
  tmp = split_emit(J, IRT(IR_CARG, IRT_NIL), hi, lo);
#endif
  res = split_emit(J, IRTI(IR_CALLN), tmp, IRCALL_softfp_d2i);
  if (check) {
    tmp = split_emit(J, IRTI(IR_CALLN), res, IRCALL_softfp_i2d);
    split_emit(J, IRT(IR_HIOP, IRT_SOFTFP), tmp, tmp);
    split_emit(J, IRTGI(IR_EQ), tmp, lo);
    split_emit(J, IRTG(IR_HIOP, IRT_SOFTFP), tmp+1, hi);
  }
  return res;
}
/* Handle string.byte (rd->data = 0) and string.sub (rd->data = 1). */
static void LJ_FASTCALL recff_string_range(jit_State *J, RecordFFData *rd)
{
  TRef trstr = lj_ir_tostr(J, J->base[0]);
  TRef trlen = emitir(IRTI(IR_FLOAD), trstr, IRFL_STR_LEN);
  TRef tr0 = lj_ir_kint(J, 0);
  TRef trstart, trend;
  GCstr *str = argv2str(J, &rd->argv[0]);
  int32_t start, end;
  if (rd->data) {  /* string.sub(str, start [,end]) */
    start = argv2int(J, &rd->argv[1]);
    trstart = lj_opt_narrow_toint(J, J->base[1]);
    trend = J->base[2];
    if (tref_isnil(trend)) {
      trend = lj_ir_kint(J, -1);
      end = -1;
    } else {
      trend = lj_opt_narrow_toint(J, trend);
      end = argv2int(J, &rd->argv[2]);
    }
  } else {  /* string.byte(str, [,start [,end]]) */
    if (J->base[1]) {
      start = argv2int(J, &rd->argv[1]);
      trstart = lj_opt_narrow_toint(J, J->base[1]);
      trend = J->base[2];
      if (tref_isnil(trend)) {
	trend = trstart;
	end = start;
      } else {
	trend = lj_opt_narrow_toint(J, trend);
	end = argv2int(J, &rd->argv[2]);
      }
    } else {
      trend = trstart = lj_ir_kint(J, 1);
      end = start = 1;
    }
  }
  if (end < 0) {
    emitir(IRTGI(IR_LT), trend, tr0);
    trend = emitir(IRTI(IR_ADD), emitir(IRTI(IR_ADD), trlen, trend),
		   lj_ir_kint(J, 1));
    end = end+(int32_t)str->len+1;
  } else if ((MSize)end <= str->len) {
    emitir(IRTGI(IR_ULE), trend, trlen);
  } else {
    emitir(IRTGI(IR_GT), trend, trlen);
    end = (int32_t)str->len;
    trend = trlen;
  }
  if (start < 0) {
    emitir(IRTGI(IR_LT), trstart, tr0);
    trstart = emitir(IRTI(IR_ADD), trlen, trstart);
    start = start+(int32_t)str->len;
    emitir(start < 0 ? IRTGI(IR_LT) : IRTGI(IR_GE), trstart, tr0);
    if (start < 0) {
      trstart = tr0;
      start = 0;
    }
  } else {
    if (start == 0) {
      emitir(IRTGI(IR_EQ), trstart, tr0);
      trstart = tr0;
    } else {
      trstart = emitir(IRTI(IR_ADD), trstart, lj_ir_kint(J, -1));
      emitir(IRTGI(IR_GE), trstart, tr0);
      start--;
    }
  }
  if (rd->data) {  /* Return string.sub result. */
    if (end - start >= 0) {
      /* Also handle empty range here, to avoid extra traces. */
      TRef trptr, trslen = emitir(IRTI(IR_SUB), trend, trstart);
      emitir(IRTGI(IR_GE), trslen, tr0);
      trptr = emitir(IRT(IR_STRREF, IRT_P32), trstr, trstart);
      J->base[0] = emitir(IRT(IR_SNEW, IRT_STR), trptr, trslen);
    } else {  /* Range underflow: return empty string. */
      emitir(IRTGI(IR_LT), trend, trstart);
      J->base[0] = lj_ir_kstr(J, lj_str_new(J->L, strdata(str), 0));
    }
  } else {  /* Return string.byte result(s). */
    ptrdiff_t i, len = end - start;
    if (len > 0) {
      TRef trslen = emitir(IRTI(IR_SUB), trend, trstart);
      emitir(IRTGI(IR_EQ), trslen, lj_ir_kint(J, (int32_t)len));
      if (J->baseslot + len > LJ_MAX_JSLOTS)
	lj_trace_err_info(J, LJ_TRERR_STACKOV);
      rd->nres = len;
      for (i = 0; i < len; i++) {
	TRef tmp = emitir(IRTI(IR_ADD), trstart, lj_ir_kint(J, (int32_t)i));
	tmp = emitir(IRT(IR_STRREF, IRT_P32), trstr, tmp);
	J->base[i] = emitir(IRT(IR_XLOAD, IRT_U8), tmp, IRXLOAD_READONLY);
      }
    } else {  /* Empty range or range underflow: return no results. */
      emitir(IRTGI(IR_LE), trend, trstart);
      rd->nres = 0;
    }
  }
}
Example #10
0
/* Unroll loop. */
static void loop_unroll(jit_State *J)
{
  IRRef1 phi[LJ_MAX_PHI];
  uint32_t nphi = 0;
  IRRef1 *subst;
  SnapNo onsnap;
  SnapShot *osnap, *loopsnap;
  SnapEntry *loopmap, *psentinel;
  IRRef ins, invar;

  /* Use temp buffer for substitution table.
  ** Only non-constant refs in [REF_BIAS,invar) are valid indexes.
  ** Caveat: don't call into the VM or run the GC or the buffer may be gone.
  */
  invar = J->cur.nins;
  subst = (IRRef1 *)lj_str_needbuf(J->L, &G(J->L)->tmpbuf,
				   (invar-REF_BIAS)*sizeof(IRRef1)) - REF_BIAS;
  subst[REF_BASE] = REF_BASE;

  /* LOOP separates the pre-roll from the loop body. */
  emitir_raw(IRTG(IR_LOOP, IRT_NIL), 0, 0);

  /* Grow snapshot buffer and map for copy-substituted snapshots.
  ** Need up to twice the number of snapshots minus #0 and loop snapshot.
  ** Need up to twice the number of entries plus fallback substitutions
  ** from the loop snapshot entries for each new snapshot.
  ** Caveat: both calls may reallocate J->cur.snap and J->cur.snapmap!
  */
  onsnap = J->cur.nsnap;
  lj_snap_grow_buf(J, 2*onsnap-2);
  lj_snap_grow_map(J, J->cur.nsnapmap*2+(onsnap-2)*J->cur.snap[onsnap-1].nent);

  /* The loop snapshot is used for fallback substitutions. */
  loopsnap = &J->cur.snap[onsnap-1];
  loopmap = &J->cur.snapmap[loopsnap->mapofs];
  /* The PC of snapshot #0 and the loop snapshot must match. */
  psentinel = &loopmap[loopsnap->nent];
  lua_assert(*psentinel == J->cur.snapmap[J->cur.snap[0].nent]);
  *psentinel = SNAP(255, 0, 0);  /* Replace PC with temporary sentinel. */

  /* Start substitution with snapshot #1 (#0 is empty for root traces). */
  osnap = &J->cur.snap[1];

  /* Copy and substitute all recorded instructions and snapshots. */
  for (ins = REF_FIRST; ins < invar; ins++) {
    IRIns *ir;
    IRRef op1, op2;

    if (ins >= osnap->ref)  /* Instruction belongs to next snapshot? */
      loop_subst_snap(J, osnap++, loopmap, subst);  /* Copy-substitute it. */

    /* Substitute instruction operands. */
    ir = IR(ins);
    op1 = ir->op1;
    if (!irref_isk(op1)) op1 = subst[op1];
    op2 = ir->op2;
    if (!irref_isk(op2)) op2 = subst[op2];
    if (irm_kind(lj_ir_mode[ir->o]) == IRM_N &&
	op1 == ir->op1 && op2 == ir->op2) {  /* Regular invariant ins? */
      subst[ins] = (IRRef1)ins;  /* Shortcut. */
    } else {
      /* Re-emit substituted instruction to the FOLD/CSE/etc. pipeline. */
      IRType1 t = ir->t;  /* Get this first, since emitir may invalidate ir. */
      IRRef ref = tref_ref(emitir(ir->ot & ~IRT_ISPHI, op1, op2));
      subst[ins] = (IRRef1)ref;
      if (ref != ins) {
	IRIns *irr = IR(ref);
	if (ref < invar) {  /* Loop-carried dependency? */
	  /* Potential PHI? */
	  if (!irref_isk(ref) && !irt_isphi(irr->t) && !irt_ispri(irr->t)) {
	    irt_setphi(irr->t);
	    if (nphi >= LJ_MAX_PHI)
	      lj_trace_err(J, LJ_TRERR_PHIOV);
	    phi[nphi++] = (IRRef1)ref;
	  }
	  /* Check all loop-carried dependencies for type instability. */
	  if (!irt_sametype(t, irr->t)) {
	    if (irt_isinteger(t) && irt_isinteger(irr->t))
	      continue;
	    else if (irt_isnum(t) && irt_isinteger(irr->t))  /* Fix int->num. */
	      ref = tref_ref(emitir(IRTN(IR_CONV), ref, IRCONV_NUM_INT));
	    else if (irt_isnum(irr->t) && irt_isinteger(t))  /* Fix num->int. */
	      ref = tref_ref(emitir(IRTGI(IR_CONV), ref,
				    IRCONV_INT_NUM|IRCONV_CHECK));
	    else
	      lj_trace_err(J, LJ_TRERR_TYPEINS);
	    subst[ins] = (IRRef1)ref;
	    irr = IR(ref);
	    goto phiconv;
	  }
	} else if (ref != REF_DROP && irr->o == IR_CONV &&
		   ref > invar && irr->op1 < invar) {
	  /* May need an extra PHI for a CONV. */
	  ref = irr->op1;
	  irr = IR(ref);
	phiconv:
	  if (ref < invar && !irref_isk(ref) && !irt_isphi(irr->t)) {
	    irt_setphi(irr->t);
	    if (nphi >= LJ_MAX_PHI)
	      lj_trace_err(J, LJ_TRERR_PHIOV);
	    phi[nphi++] = (IRRef1)ref;
	  }
	}
      }
    }
  }
  if (!irt_isguard(J->guardemit))  /* Drop redundant snapshot. */
    J->cur.nsnapmap = (uint16_t)J->cur.snap[--J->cur.nsnap].mapofs;
  lua_assert(J->cur.nsnapmap <= J->sizesnapmap);
  *psentinel = J->cur.snapmap[J->cur.snap[0].nent];  /* Restore PC. */

  loop_emit_phi(J, subst, phi, nphi, onsnap);
}
/* Transform the old IR to the new IR. */
static void split_ir(jit_State *J)
{
  IRRef nins = J->cur.nins, nk = J->cur.nk;
  MSize irlen = nins - nk;
  MSize need = (irlen+1)*(sizeof(IRIns) + sizeof(IRRef1));
  IRIns *oir = (IRIns *)lj_str_needbuf(J->L, &G(J->L)->tmpbuf, need);
  IRRef1 *hisubst;
  IRRef ref, snref;
  SnapShot *snap;

  /* Copy old IR to buffer. */
  memcpy(oir, IR(nk), irlen*sizeof(IRIns));
  /* Bias hiword substitution table and old IR. Loword kept in field prev. */
  hisubst = (IRRef1 *)&oir[irlen] - nk;
  oir -= nk;

  /* Remove all IR instructions, but retain IR constants. */
  J->cur.nins = REF_FIRST;
  J->loopref = 0;

  /* Process constants and fixed references. */
  for (ref = nk; ref <= REF_BASE; ref++) {
    IRIns *ir = &oir[ref];
    if ((LJ_SOFTFP && ir->o == IR_KNUM) || ir->o == IR_KINT64) {
      /* Split up 64 bit constant. */
      TValue tv = *ir_k64(ir);
      ir->prev = lj_ir_kint(J, (int32_t)tv.u32.lo);
      hisubst[ref] = lj_ir_kint(J, (int32_t)tv.u32.hi);
    } else {
      ir->prev = ref;  /* Identity substitution for loword. */
      hisubst[ref] = 0;
    }
  }

  /* Process old IR instructions. */
  snap = J->cur.snap;
  snref = snap->ref;
  for (ref = REF_FIRST; ref < nins; ref++) {
    IRIns *ir = &oir[ref];
    IRRef nref = lj_ir_nextins(J);
    IRIns *nir = IR(nref);
    IRRef hi = 0;

    if (ref >= snref) {
      snap->ref = nref;
      split_subst_snap(J, snap++, oir);
      snref = snap < &J->cur.snap[J->cur.nsnap] ? snap->ref : ~(IRRef)0;
    }

    /* Copy-substitute old instruction to new instruction. */
    nir->op1 = ir->op1 < nk ? ir->op1 : oir[ir->op1].prev;
    nir->op2 = ir->op2 < nk ? ir->op2 : oir[ir->op2].prev;
    ir->prev = nref;  /* Loword substitution. */
    nir->o = ir->o;
    nir->t.irt = ir->t.irt & ~(IRT_MARK|IRT_ISPHI);
    hisubst[ref] = 0;

    /* Split 64 bit instructions. */
#if LJ_SOFTFP
    if (irt_isnum(ir->t)) {
      nir->t.irt = IRT_INT | (nir->t.irt & IRT_GUARD);  /* Turn into INT op. */
      /* Note: hi ref = lo ref + 1! Required for SNAP_SOFTFPNUM logic. */
      switch (ir->o) {
      case IR_ADD:
	hi = split_call_ll(J, hisubst, oir, ir, IRCALL_softfp_add);
	break;
      case IR_SUB:
	hi = split_call_ll(J, hisubst, oir, ir, IRCALL_softfp_sub);
	break;
      case IR_MUL:
	hi = split_call_ll(J, hisubst, oir, ir, IRCALL_softfp_mul);
	break;
      case IR_DIV:
	hi = split_call_ll(J, hisubst, oir, ir, IRCALL_softfp_div);
	break;
      case IR_POW:
	hi = split_call_li(J, hisubst, oir, ir, IRCALL_lj_vm_powi);
	break;
      case IR_FPMATH:
	/* Try to rejoin pow from EXP2, MUL and LOG2. */
	if (nir->op2 == IRFPM_EXP2 && nir->op1 > J->loopref) {
	  IRIns *irp = IR(nir->op1);
	  if (irp->o == IR_CALLN && irp->op2 == IRCALL_softfp_mul) {
	    IRIns *irm4 = IR(irp->op1);
	    IRIns *irm3 = IR(irm4->op1);
	    IRIns *irm12 = IR(irm3->op1);
	    IRIns *irl1 = IR(irm12->op1);
	    if (irm12->op1 > J->loopref && irl1->o == IR_CALLN &&
		irl1->op2 == IRCALL_lj_vm_log2) {
	      IRRef tmp = irl1->op1;  /* Recycle first two args from LOG2. */
	      IRRef arg3 = irm3->op2, arg4 = irm4->op2;
	      J->cur.nins--;
	      tmp = split_emit(J, IRT(IR_CARG, IRT_NIL), tmp, arg3);
	      tmp = split_emit(J, IRT(IR_CARG, IRT_NIL), tmp, arg4);
	      ir->prev = tmp = split_emit(J, IRTI(IR_CALLN), tmp, IRCALL_pow);
	      hi = split_emit(J, IRT(IR_HIOP, IRT_SOFTFP), tmp, tmp);
	      break;
	    }
	  }
	}
	hi = split_call_l(J, hisubst, oir, ir, IRCALL_lj_vm_floor + ir->op2);
	break;
      case IR_ATAN2:
	hi = split_call_ll(J, hisubst, oir, ir, IRCALL_atan2);
	break;
      case IR_LDEXP:
	hi = split_call_li(J, hisubst, oir, ir, IRCALL_ldexp);
	break;
      case IR_NEG: case IR_ABS:
	nir->o = IR_CONV;  /* Pass through loword. */
	nir->op2 = (IRT_INT << 5) | IRT_INT;
	hi = split_emit(J, IRT(ir->o == IR_NEG ? IR_BXOR : IR_BAND, IRT_SOFTFP),
			hisubst[ir->op1], hisubst[ir->op2]);
	break;
      case IR_SLOAD:
	if ((nir->op2 & IRSLOAD_CONVERT)) {  /* Convert from int to number. */
	  nir->op2 &= ~IRSLOAD_CONVERT;
	  ir->prev = nref = split_emit(J, IRTI(IR_CALLN), nref,
				       IRCALL_softfp_i2d);
	  hi = split_emit(J, IRT(IR_HIOP, IRT_SOFTFP), nref, nref);
	  break;
	}
	/* fallthrough */
      case IR_ALOAD: case IR_HLOAD: case IR_ULOAD: case IR_VLOAD:
      case IR_STRTO:
	hi = split_emit(J, IRT(IR_HIOP, IRT_SOFTFP), nref, nref);
	break;
      case IR_XLOAD: {
	IRIns inslo = *nir;  /* Save/undo the emit of the lo XLOAD. */
	J->cur.nins--;
	hi = split_ptr(J, oir, ir->op1);  /* Insert the hiref ADD. */
	nref = lj_ir_nextins(J);
	nir = IR(nref);
	*nir = inslo;  /* Re-emit lo XLOAD immediately before hi XLOAD. */
	hi = split_emit(J, IRT(IR_XLOAD, IRT_SOFTFP), hi, ir->op2);
#if LJ_LE
	ir->prev = nref;
#else
	ir->prev = hi; hi = nref;
#endif
	break;
	}
      case IR_ASTORE: case IR_HSTORE: case IR_USTORE: case IR_XSTORE:
	split_emit(J, IRT(IR_HIOP, IRT_SOFTFP), nir->op1, hisubst[ir->op2]);
	break;
      case IR_CONV: {  /* Conversion to number. Others handled below. */
	IRType st = (IRType)(ir->op2 & IRCONV_SRCMASK);
	UNUSED(st);
#if LJ_32 && LJ_HASFFI
	if (st == IRT_I64 || st == IRT_U64) {
	  hi = split_call_l(J, hisubst, oir, ir,
		 st == IRT_I64 ? IRCALL_fp64_l2d : IRCALL_fp64_ul2d);
	  break;
	}
#endif
	lua_assert(st == IRT_INT ||
		   (LJ_32 && LJ_HASFFI && (st == IRT_U32 || st == IRT_FLOAT)));
	nir->o = IR_CALLN;
#if LJ_32 && LJ_HASFFI
	nir->op2 = st == IRT_INT ? IRCALL_softfp_i2d :
		   st == IRT_FLOAT ? IRCALL_softfp_f2d :
		   IRCALL_softfp_ui2d;
#else
	nir->op2 = IRCALL_softfp_i2d;
#endif
	hi = split_emit(J, IRT(IR_HIOP, IRT_SOFTFP), nref, nref);
	break;
	}
      case IR_CALLN:
      case IR_CALLL:
      case IR_CALLS:
      case IR_CALLXS:
	goto split_call;
      case IR_PHI:
	if (nir->op1 == nir->op2)
	  J->cur.nins--;  /* Drop useless PHIs. */
	if (hisubst[ir->op1] != hisubst[ir->op2])
	  split_emit(J, IRT(IR_PHI, IRT_SOFTFP),
		     hisubst[ir->op1], hisubst[ir->op2]);
	break;
      case IR_HIOP:
	J->cur.nins--;  /* Drop joining HIOP. */
	ir->prev = nir->op1;
	hi = nir->op2;
	break;
      default:
	lua_assert(ir->o <= IR_NE || ir->o == IR_MIN || ir->o == IR_MAX);
	hi = split_emit(J, IRTG(IR_HIOP, IRT_SOFTFP),
			hisubst[ir->op1], hisubst[ir->op2]);
	break;
      }
    } else
#endif
#if LJ_32 && LJ_HASFFI
    if (irt_isint64(ir->t)) {
      IRRef hiref = hisubst[ir->op1];
      nir->t.irt = IRT_INT | (nir->t.irt & IRT_GUARD);  /* Turn into INT op. */
      switch (ir->o) {
      case IR_ADD:
      case IR_SUB:
	/* Use plain op for hiword if loword cannot produce a carry/borrow. */
	if (irref_isk(nir->op2) && IR(nir->op2)->i == 0) {
	  ir->prev = nir->op1;  /* Pass through loword. */
	  nir->op1 = hiref; nir->op2 = hisubst[ir->op2];
	  hi = nref;
	  break;
	}
	/* fallthrough */
      case IR_NEG:
	hi = split_emit(J, IRTI(IR_HIOP), hiref, hisubst[ir->op2]);
	break;
      case IR_MUL:
	hi = split_call_ll(J, hisubst, oir, ir, IRCALL_lj_carith_mul64);
	break;
      case IR_DIV:
	hi = split_call_ll(J, hisubst, oir, ir,
			   irt_isi64(ir->t) ? IRCALL_lj_carith_divi64 :
					      IRCALL_lj_carith_divu64);
	break;
      case IR_MOD:
	hi = split_call_ll(J, hisubst, oir, ir,
			   irt_isi64(ir->t) ? IRCALL_lj_carith_modi64 :
					      IRCALL_lj_carith_modu64);
	break;
      case IR_POW:
	hi = split_call_ll(J, hisubst, oir, ir,
			   irt_isi64(ir->t) ? IRCALL_lj_carith_powi64 :
					      IRCALL_lj_carith_powu64);
	break;
      case IR_FLOAD:
	lua_assert(ir->op2 == IRFL_CDATA_INT64);
	hi = split_emit(J, IRTI(IR_FLOAD), nir->op1, IRFL_CDATA_INT64_4);
#if LJ_BE
	ir->prev = hi; hi = nref;
#endif
	break;
      case IR_XLOAD:
	hi = split_emit(J, IRTI(IR_XLOAD), split_ptr(J, oir, ir->op1), ir->op2);
#if LJ_BE
	ir->prev = hi; hi = nref;
#endif
	break;
      case IR_XSTORE:
	split_emit(J, IRTI(IR_HIOP), nir->op1, hisubst[ir->op2]);
	break;
      case IR_CONV: {  /* Conversion to 64 bit integer. Others handled below. */
	IRType st = (IRType)(ir->op2 & IRCONV_SRCMASK);
#if LJ_SOFTFP
	if (st == IRT_NUM) {  /* NUM to 64 bit int conv. */
	  hi = split_call_l(J, hisubst, oir, ir,
		 irt_isi64(ir->t) ? IRCALL_fp64_d2l : IRCALL_fp64_d2ul);
	} else if (st == IRT_FLOAT) {  /* FLOAT to 64 bit int conv. */
	  nir->o = IR_CALLN;
	  nir->op2 = irt_isi64(ir->t) ? IRCALL_fp64_f2l : IRCALL_fp64_f2ul;
	  hi = split_emit(J, IRTI(IR_HIOP), nref, nref);
	}
#else
	if (st == IRT_NUM || st == IRT_FLOAT) {  /* FP to 64 bit int conv. */
	  hi = split_emit(J, IRTI(IR_HIOP), nir->op1, nref);
	}
#endif
	else if (st == IRT_I64 || st == IRT_U64) {  /* 64/64 bit cast. */
	  /* Drop cast, since assembler doesn't care. But fwd both parts. */
	  hi = hiref;
	  goto fwdlo;
	} else if ((ir->op2 & IRCONV_SEXT)) {  /* Sign-extend to 64 bit. */
	  IRRef k31 = lj_ir_kint(J, 31);
	  nir = IR(nref);  /* May have been reallocated. */
	  ir->prev = nir->op1;  /* Pass through loword. */
	  nir->o = IR_BSAR;  /* hi = bsar(lo, 31). */
	  nir->op2 = k31;
	  hi = nref;
	} else {  /* Zero-extend to 64 bit. */
	  hi = lj_ir_kint(J, 0);
	  goto fwdlo;
	}
	break;
	}
      case IR_CALLXS:
	goto split_call;
      case IR_PHI: {
	IRRef hiref2;
	if ((irref_isk(nir->op1) && irref_isk(nir->op2)) ||
	    nir->op1 == nir->op2)
	  J->cur.nins--;  /* Drop useless PHIs. */
	hiref2 = hisubst[ir->op2];
	if (!((irref_isk(hiref) && irref_isk(hiref2)) || hiref == hiref2))
	  split_emit(J, IRTI(IR_PHI), hiref, hiref2);
	break;
	}
      case IR_HIOP:
	J->cur.nins--;  /* Drop joining HIOP. */
	ir->prev = nir->op1;
	hi = nir->op2;
	break;
      default:
	lua_assert(ir->o <= IR_NE);  /* Comparisons. */
	split_emit(J, IRTGI(IR_HIOP), hiref, hisubst[ir->op2]);
	break;
      }
    } else
#endif
#if LJ_SOFTFP
    if (ir->o == IR_SLOAD) {
      if ((nir->op2 & IRSLOAD_CONVERT)) {  /* Convert from number to int. */
	nir->op2 &= ~IRSLOAD_CONVERT;
	if (!(nir->op2 & IRSLOAD_TYPECHECK))
	  nir->t.irt = IRT_INT;  /* Drop guard. */
	split_emit(J, IRT(IR_HIOP, IRT_SOFTFP), nref, nref);
	ir->prev = split_num2int(J, nref, nref+1, irt_isguard(ir->t));
      }
    } else if (ir->o == IR_TOBIT) {
      IRRef tmp, op1 = ir->op1;
      J->cur.nins--;
#if LJ_LE
      tmp = split_emit(J, IRT(IR_CARG, IRT_NIL), oir[op1].prev, hisubst[op1]);
#else
      tmp = split_emit(J, IRT(IR_CARG, IRT_NIL), hisubst[op1], oir[op1].prev);
#endif
      ir->prev = split_emit(J, IRTI(IR_CALLN), tmp, IRCALL_lj_vm_tobit);
    } else if (ir->o == IR_TOSTR) {
      if (hisubst[ir->op1]) {
	if (irref_isk(ir->op1))
	  nir->op1 = ir->op1;
	else
	  split_emit(J, IRT(IR_HIOP, IRT_NIL), hisubst[ir->op1], nref);
      }
    } else if (ir->o == IR_HREF || ir->o == IR_NEWREF) {
      if (irref_isk(ir->op2) && hisubst[ir->op2])
	nir->op2 = ir->op2;
    } else
#endif
    if (ir->o == IR_CONV) {  /* See above, too. */
      IRType st = (IRType)(ir->op2 & IRCONV_SRCMASK);
#if LJ_32 && LJ_HASFFI
      if (st == IRT_I64 || st == IRT_U64) {  /* Conversion from 64 bit int. */
#if LJ_SOFTFP
	if (irt_isfloat(ir->t)) {
	  split_call_l(J, hisubst, oir, ir,
		       st == IRT_I64 ? IRCALL_fp64_l2f : IRCALL_fp64_ul2f);
	  J->cur.nins--;  /* Drop unused HIOP. */
	}
#else
	if (irt_isfp(ir->t)) {  /* 64 bit integer to FP conversion. */
	  ir->prev = split_emit(J, IRT(IR_HIOP, irt_type(ir->t)),
				hisubst[ir->op1], nref);
	}
#endif
	else {  /* Truncate to lower 32 bits. */
	fwdlo:
	  ir->prev = nir->op1;  /* Forward loword. */
	  /* Replace with NOP to avoid messing up the snapshot logic. */
	  nir->ot = IRT(IR_NOP, IRT_NIL);
	  nir->op1 = nir->op2 = 0;
	}
      }
#endif
#if LJ_SOFTFP && LJ_32 && LJ_HASFFI
      else if (irt_isfloat(ir->t)) {
	if (st == IRT_NUM) {
	  split_call_l(J, hisubst, oir, ir, IRCALL_softfp_d2f);
	  J->cur.nins--;  /* Drop unused HIOP. */
	} else {
	  nir->o = IR_CALLN;
	  nir->op2 = st == IRT_INT ? IRCALL_softfp_i2f : IRCALL_softfp_ui2f;
	}
      } else if (st == IRT_FLOAT) {
	nir->o = IR_CALLN;
	nir->op2 = irt_isint(ir->t) ? IRCALL_softfp_f2i : IRCALL_softfp_f2ui;
      } else
#endif
#if LJ_SOFTFP
      if (st == IRT_NUM || (LJ_32 && LJ_HASFFI && st == IRT_FLOAT)) {
	if (irt_isguard(ir->t)) {
	  lua_assert(st == IRT_NUM && irt_isint(ir->t));
	  J->cur.nins--;
	  ir->prev = split_num2int(J, nir->op1, hisubst[ir->op1], 1);
	} else {
	  split_call_l(J, hisubst, oir, ir,
#if LJ_32 && LJ_HASFFI
	    st == IRT_NUM ?
	      (irt_isint(ir->t) ? IRCALL_softfp_d2i : IRCALL_softfp_d2ui) :
	      (irt_isint(ir->t) ? IRCALL_softfp_f2i : IRCALL_softfp_f2ui)
#else
	    IRCALL_softfp_d2i
#endif
	  );
	  J->cur.nins--;  /* Drop unused HIOP. */
	}
      }
#endif
    } else if (ir->o == IR_CALLXS) {
      IRRef hiref;
    split_call:
      hiref = hisubst[ir->op1];
      if (hiref) {
	IROpT ot = nir->ot;
	IRRef op2 = nir->op2;
	nir->ot = IRT(IR_CARG, IRT_NIL);
#if LJ_LE
	nir->op2 = hiref;
#else
	nir->op2 = nir->op1; nir->op1 = hiref;
#endif
	ir->prev = nref = split_emit(J, ot, nref, op2);
      }
      if (LJ_SOFTFP ? irt_is64(ir->t) : irt_isint64(ir->t))
	hi = split_emit(J,
	  IRT(IR_HIOP, (LJ_SOFTFP && irt_isnum(ir->t)) ? IRT_SOFTFP : IRT_INT),
	  nref, nref);
    } else if (ir->o == IR_CARG) {
      IRRef hiref = hisubst[ir->op1];
      if (hiref) {
	IRRef op2 = nir->op2;
#if LJ_LE
	nir->op2 = hiref;
#else
	nir->op2 = nir->op1; nir->op1 = hiref;
#endif
	ir->prev = nref = split_emit(J, IRT(IR_CARG, IRT_NIL), nref, op2);
	nir = IR(nref);
      }
      hiref = hisubst[ir->op2];
      if (hiref) {
#if !LJ_TARGET_X86
	int carg = 0;
	IRIns *cir;
	for (cir = IR(nir->op1); cir->o == IR_CARG; cir = IR(cir->op1))
	  carg++;
	if ((carg & 1) == 0) {  /* Align 64 bit arguments. */
	  IRRef op2 = nir->op2;
	  nir->op2 = REF_NIL;
	  nref = split_emit(J, IRT(IR_CARG, IRT_NIL), nref, op2);
	  nir = IR(nref);
	}
#endif
#if LJ_BE
	{ IRRef tmp = nir->op2; nir->op2 = hiref; hiref = tmp; }
#endif
	ir->prev = split_emit(J, IRT(IR_CARG, IRT_NIL), nref, hiref);
      }
    } else if (ir->o == IR_CNEWI) {
      if (hisubst[ir->op2])
	split_emit(J, IRT(IR_HIOP, IRT_NIL), nref, hisubst[ir->op2]);
    } else if (ir->o == IR_LOOP) {
      J->loopref = nref;  /* Needed by assembler. */
    }
    hisubst[ref] = hi;  /* Store hiword substitution. */
  }
  if (snref == nins) {  /* Substitution for last snapshot. */
    snap->ref = J->cur.nins;
    split_subst_snap(J, snap, oir);
  }

  /* Add PHI marks. */
  for (ref = J->cur.nins-1; ref >= REF_FIRST; ref--) {
    IRIns *ir = IR(ref);
    if (ir->o != IR_PHI) break;
    if (!irref_isk(ir->op1)) irt_setphi(IR(ir->op1)->t);
    if (ir->op2 > J->loopref) irt_setphi(IR(ir->op2)->t);
  }
}
Example #12
0
/* Transform the old IR to the new IR. */
static void split_ir(jit_State *J)
{
  IRRef nins = J->cur.nins, nk = J->cur.nk;
  MSize irlen = nins - nk;
  MSize need = (irlen+1)*(sizeof(IRIns) + sizeof(IRRef1));
  IRIns *oir = (IRIns *)lj_str_needbuf(J->L, &G(J->L)->tmpbuf, need);
  IRRef1 *hisubst;
  IRRef ref;

  /* Copy old IR to buffer. */
  memcpy(oir, IR(nk), irlen*sizeof(IRIns));
  /* Bias hiword substitution table and old IR. Loword kept in field prev. */
  hisubst = (IRRef1 *)&oir[irlen] - nk;
  oir -= nk;

  /* Remove all IR instructions, but retain IR constants. */
  J->cur.nins = REF_FIRST;

  /* Process constants and fixed references. */
  for (ref = nk; ref <= REF_BASE; ref++) {
    IRIns *ir = &oir[ref];
    if (ir->o == IR_KINT64) {  /* Split up 64 bit constant. */
      TValue tv = *ir_k64(ir);
      ir->prev = lj_ir_kint(J, (int32_t)tv.u32.lo);
      hisubst[ref] = lj_ir_kint(J, (int32_t)tv.u32.hi);
    } else {
      ir->prev = ref;  /* Identity substitution for loword. */
      hisubst[ref] = 0;
    }
  }

  /* Process old IR instructions. */
  for (ref = REF_FIRST; ref < nins; ref++) {
    IRIns *ir = &oir[ref];
    IRRef nref = lj_ir_nextins(J);
    IRIns *nir = IR(nref);
    IRRef hi = 0;

    /* Copy-substitute old instruction to new instruction. */
    nir->op1 = ir->op1 < nk ? ir->op1 : oir[ir->op1].prev;
    nir->op2 = ir->op2 < nk ? ir->op2 : oir[ir->op2].prev;
    ir->prev = nref;  /* Loword substitution. */
    nir->o = ir->o;
    nir->t.irt = ir->t.irt & ~(IRT_MARK|IRT_ISPHI);
    hisubst[ref] = 0;

    /* Split 64 bit instructions. */
    if (irt_isint64(ir->t)) {
      IRRef hiref = hisubst[ir->op1];
      nir->t.irt = IRT_INT | (nir->t.irt & IRT_GUARD);  /* Turn into INT op. */
      switch (ir->o) {
      case IR_ADD:
      case IR_SUB:
	/* Use plain op for hiword if loword cannot produce a carry/borrow. */
	if (irref_isk(nir->op2) && IR(nir->op2)->i == 0) {
	  ir->prev = nir->op1;  /* Pass through loword. */
	  nir->op1 = hiref; nir->op2 = hisubst[ir->op2];
	  hi = nref;
	  break;
	}
	/* fallthrough */
      case IR_NEG:
	hi = split_emit(J, IRTI(IR_HIOP), hiref, hisubst[ir->op2]);
	break;
      case IR_MUL:
	hi = split_call64(J, hisubst, oir, ir, IRCALL_lj_carith_mul64);
	break;
      case IR_DIV:
	hi = split_call64(J, hisubst, oir, ir,
			  irt_isi64(ir->t) ? IRCALL_lj_carith_divi64 :
					     IRCALL_lj_carith_divu64);
	break;
      case IR_MOD:
	hi = split_call64(J, hisubst, oir, ir,
			  irt_isi64(ir->t) ? IRCALL_lj_carith_modi64 :
					     IRCALL_lj_carith_modu64);
	break;
      case IR_POW:
	hi = split_call64(J, hisubst, oir, ir,
			  irt_isi64(ir->t) ? IRCALL_lj_carith_powi64 :
					     IRCALL_lj_carith_powu64);
	break;
      case IR_FLOAD:
	lua_assert(ir->op2 == IRFL_CDATA_INT64);
	hi = split_emit(J, IRTI(IR_FLOAD), nir->op1, IRFL_CDATA_INT64HI);
#if LJ_BE
	ir->prev = hi; hi = nref;
#endif
	break;
      case IR_XLOAD:
	hi = split_emit(J, IRTI(IR_XLOAD), split_ptr(J, nir->op1), ir->op2);
#if LJ_BE
	ir->prev = hi; hi = nref;
#endif
	break;
      case IR_XSTORE:
#if LJ_LE
	hiref = hisubst[ir->op2];
#else
	hiref = nir->op2; nir->op2 = hisubst[ir->op2];
#endif
	split_emit(J, IRTI(IR_XSTORE), split_ptr(J, nir->op1), hiref);
	break;
      case IR_CONV: {  /* Conversion to 64 bit integer. Others handled below. */
	IRType st = (IRType)(ir->op2 & IRCONV_SRCMASK);
	if (st == IRT_NUM || st == IRT_FLOAT) {  /* FP to 64 bit int conv. */
	  hi = split_emit(J, IRTI(IR_HIOP), nir->op1, nref);
	} else if (st == IRT_I64 || st == IRT_U64) {  /* 64/64 bit cast. */
	  /* Drop cast, since assembler doesn't care. */
	  goto fwdlo;
	} else if ((ir->op2 & IRCONV_SEXT)) {  /* Sign-extend to 64 bit. */
	  IRRef k31 = lj_ir_kint(J, 31);
	  nir = IR(nref);  /* May have been reallocated. */
	  ir->prev = nir->op1;  /* Pass through loword. */
	  nir->o = IR_BSAR;  /* hi = bsar(lo, 31). */
	  nir->op2 = k31;
	  hi = nref;
	} else {  /* Zero-extend to 64 bit. */
	  hi = lj_ir_kint(J, 0);
	  goto fwdlo;
	}
	break;
	}
      case IR_PHI: {
	IRRef hiref2;
	if ((irref_isk(nir->op1) && irref_isk(nir->op2)) ||
	    nir->op1 == nir->op2)
	  J->cur.nins--;  /* Drop useless PHIs. */
	hiref2 = hisubst[ir->op2];
	if (!((irref_isk(hiref) && irref_isk(hiref2)) || hiref == hiref2))
	  split_emit(J, IRTI(IR_PHI), hiref, hiref2);
	break;
	}
      default:
	lua_assert(ir->o <= IR_NE);  /* Comparisons. */
	split_emit(J, IRTGI(IR_HIOP), hiref, hisubst[ir->op2]);
	break;
      }
    } else if (ir->o == IR_CONV) {  /* See above, too. */
      IRType st = (IRType)(ir->op2 & IRCONV_SRCMASK);
      if (st == IRT_I64 || st == IRT_U64) {  /* Conversion from 64 bit int. */
	if (irt_isfp(ir->t)) {  /* 64 bit integer to FP conversion. */
	  ir->prev = split_emit(J, IRT(IR_HIOP, irt_type(ir->t)),
				hisubst[ir->op1], nref);
	} else {  /* Truncate to lower 32 bits. */
	fwdlo:
	  ir->prev = nir->op1;  /* Forward loword. */
	  /* Replace with NOP to avoid messing up the snapshot logic. */
	  nir->ot = IRT(IR_NOP, IRT_NIL);
	  nir->op1 = nir->op2 = 0;
	}
      }
    } else if (ir->o == IR_CNEWI) {
      if (hisubst[ir->op2])
	split_emit(J, IRT(IR_HIOP, IRT_NIL), nref, hisubst[ir->op2]);
    } else if (ir->o == IR_LOOP) {
      J->loopref = nref;  /* Needed by assembler. */
    }
    hisubst[ref] = hi;  /* Store hiword substitution. */
  }

  /* Add PHI marks. */
  for (ref = J->cur.nins-1; ref >= REF_FIRST; ref--) {
    IRIns *ir = IR(ref);
    if (ir->o != IR_PHI) break;
    if (!irref_isk(ir->op1)) irt_setphi(IR(ir->op1)->t);
    if (ir->op2 > J->loopref) irt_setphi(IR(ir->op2)->t);
  }

  /* Substitute snapshot maps. */
  oir[nins].prev = J->cur.nins;  /* Substitution for last snapshot. */
  {
    SnapNo i, nsnap = J->cur.nsnap;
    for (i = 0; i < nsnap; i++) {
      SnapShot *snap = &J->cur.snap[i];
      SnapEntry *map = &J->cur.snapmap[snap->mapofs];
      MSize n, nent = snap->nent;
      snap->ref = oir[snap->ref].prev;
      for (n = 0; n < nent; n++) {
	SnapEntry sn = map[n];
	map[n] = ((sn & 0xffff0000) | oir[snap_ref(sn)].prev);
      }
    }
  }
}