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ffi/target/release/build/mlua-sys-6a99a2ae50f12319/out/luajit-build/build/src/lj_asm_x86.h  view on Meta::CPAN

/* Inlined hash lookup. Specialized for key type and for const keys.
** The equivalent C code is:
**   Node *n = hashkey(t, key);
**   do {
**     if (lj_obj_equal(&n->key, key)) return &n->val;
**   } while ((n = nextnode(n)));
**   return niltv(L);
*/
static void asm_href(ASMState *as, IRIns *ir, IROp merge)
{
  RegSet allow = RSET_GPR;
  int destused = ra_used(ir);
  Reg dest = ra_dest(as, ir, allow);
  Reg tab = ra_alloc1(as, ir->op1, rset_clear(allow, dest));
  Reg key = RID_NONE, tmp = RID_NONE;
  IRIns *irkey = IR(ir->op2);
  int isk = irref_isk(ir->op2);
  IRType1 kt = irkey->t;
  uint32_t khash;
  MCLabel l_end, l_loop, l_next;

  if (!isk) {
    rset_clear(allow, tab);
    key = ra_alloc1(as, ir->op2, irt_isnum(kt) ? RSET_FPR : allow);
    if (LJ_GC64 || !irt_isstr(kt))
      tmp = ra_scratch(as, rset_exclude(allow, key));
  }

  /* Key not found in chain: jump to exit (if merged) or load niltv. */
  l_end = emit_label(as);
  if (merge == IR_NE)
    asm_guardcc(as, CC_E);  /* XI_JMP is not found by lj_asm_patchexit. */
  else if (destused)
    emit_loada(as, dest, niltvg(J2G(as->J)));

  /* Follow hash chain until the end. */
  l_loop = emit_sjcc_label(as, CC_NZ);
  emit_rr(as, XO_TEST, dest|REX_GC64, dest);
  emit_rmro(as, XO_MOV, dest|REX_GC64, dest, offsetof(Node, next));
  l_next = emit_label(as);

  /* Type and value comparison. */
  if (merge == IR_EQ)
    asm_guardcc(as, CC_E);
  else
    emit_sjcc(as, CC_E, l_end);
  checkmclim(as);
  if (irt_isnum(kt)) {
    if (isk) {
      /* Assumes -0.0 is already canonicalized to +0.0. */
      emit_gmroi(as, XG_ARITHi(XOg_CMP), dest, offsetof(Node, key.u32.lo),
		 (int32_t)ir_knum(irkey)->u32.lo);
      emit_sjcc(as, CC_NE, l_next);
      emit_gmroi(as, XG_ARITHi(XOg_CMP), dest, offsetof(Node, key.u32.hi),
		 (int32_t)ir_knum(irkey)->u32.hi);
    } else {
      emit_sjcc(as, CC_P, l_next);
      emit_rmro(as, XO_UCOMISD, key, dest, offsetof(Node, key.n));
      emit_sjcc(as, CC_AE, l_next);
      /* The type check avoids NaN penalties and complaints from Valgrind. */
#if LJ_64 && !LJ_GC64
      emit_u32(as, LJ_TISNUM);
      emit_rmro(as, XO_ARITHi, XOg_CMP, dest, offsetof(Node, key.it));
#else
      emit_i8(as, LJ_TISNUM);
      emit_rmro(as, XO_ARITHi8, XOg_CMP, dest, offsetof(Node, key.it));
#endif
    }
#if LJ_64 && !LJ_GC64
  } else if (irt_islightud(kt)) {
    emit_rmro(as, XO_CMP, key|REX_64, dest, offsetof(Node, key.u64));
#endif
#if LJ_GC64
  } else if (irt_isaddr(kt)) {
    if (isk) {
      TValue k;
      k.u64 = ((uint64_t)irt_toitype(irkey->t) << 47) | irkey[1].tv.u64;
      emit_gmroi(as, XG_ARITHi(XOg_CMP), dest, offsetof(Node, key.u32.lo),
		 k.u32.lo);
      emit_sjcc(as, CC_NE, l_next);
      emit_gmroi(as, XG_ARITHi(XOg_CMP), dest, offsetof(Node, key.u32.hi),
		 k.u32.hi);
    } else {
      emit_rmro(as, XO_CMP, tmp|REX_64, dest, offsetof(Node, key.u64));
    }
  } else {
    lj_assertA(irt_ispri(kt) && !irt_isnil(kt), "bad HREF key type");
    emit_u32(as, (irt_toitype(kt)<<15)|0x7fff);
    emit_rmro(as, XO_ARITHi, XOg_CMP, dest, offsetof(Node, key.it));
#else
  } else {
    if (!irt_ispri(kt)) {
      lj_assertA(irt_isaddr(kt), "bad HREF key type");
      if (isk)
	emit_gmroi(as, XG_ARITHi(XOg_CMP), dest, offsetof(Node, key.gcr),
		   ptr2addr(ir_kgc(irkey)));
      else
	emit_rmro(as, XO_CMP, key, dest, offsetof(Node, key.gcr));
      emit_sjcc(as, CC_NE, l_next);
    }
    lj_assertA(!irt_isnil(kt), "bad HREF key type");
    emit_i8(as, irt_toitype(kt));
    emit_rmro(as, XO_ARITHi8, XOg_CMP, dest, offsetof(Node, key.it));
#endif
  }
  emit_sfixup(as, l_loop);
#if LJ_GC64
  if (!isk && irt_isaddr(kt)) {
    emit_rr(as, XO_OR, tmp|REX_64, key);
    emit_loadu64(as, tmp, (uint64_t)irt_toitype(kt) << 47);
  }
#endif

  /* Load main position relative to tab->node into dest. */
  khash = isk ? ir_khash(as, irkey) : 1;
  if (khash == 0) {
    emit_rmro(as, XO_MOV, dest|REX_GC64, tab, offsetof(GCtab, node));
  } else {
    emit_rmro(as, XO_ARITH(XOg_ADD), dest|REX_GC64, tab, offsetof(GCtab,node));
    emit_shifti(as, XOg_SHL, dest, 3);