// qbe_emit.cm — mcode IR → QBE IL compiler
// Takes mcode IR (from mcode.cm) and uses qbe.cm macros to produce
// a complete QBE IL program ready for the qbe compiler.
// qbe module is passed via env as 'qbe'

var qbe_emit = function(ir, qbe, export_name) {
  var out = []
  var data_out = []
  var str_table = {}
  var str_id = 0
  var uid = 0

  // ============================================================
  // Output helpers
  // ============================================================

  var emit = function(s) {
    push(out, s)
  }

  var fresh = function() {
    uid = uid + 1
    return "u" + text(uid)
  }

  var sanitize = function(lbl) {
    var r = replace(lbl, ".", "_")
    r = replace(r, "-", "_")
    r = replace(r, " ", "_")
    r = replace(r, "/", "_")
    r = replace(r, "<", "")
    r = replace(r, ">", "")
    r = replace(r, "(", "")
    r = replace(r, ")", "")
    return r
  }

  // ============================================================
  // String interning — emit data section entries
  // ============================================================

  var intern_str = function(val) {
    if (str_table[val] != null) return str_table[val]
    var label = "$d_str_" + text(str_id)
    str_id = str_id + 1
    var escaped = replace(val, "\\", "\\\\")
    escaped = replace(escaped, "\"", "\\\"")
    escaped = replace(escaped, "\n", "\\n")
    escaped = replace(escaped, "\r", "\\r")
    escaped = replace(escaped, "\t", "\\t")
    var line = "data " + label + ' = ' + '{ b "' + escaped + '", b 0 }'
    push(data_out, line)
    str_table[val] = label
    return label
  }

  // ============================================================
  // Extract property name from mcode operand
  // ============================================================

  var prop_name = function(a) {
    if (is_text(a)) return a
    if (is_object(a)) {
      if (a.name != null) return a.name
      if (a.value != null) return a.value
    }
    return null
  }

  // ============================================================
  // Compile one function's instructions
  // ============================================================

  var compile_fn = function(fn, fn_idx, is_main) {
    var instrs = fn.instructions
    var nr_slots = fn.nr_slots
    var nr_args = fn.nr_args
    var disruption_pc = fn.disruption_pc != null ? fn.disruption_pc : 0
    var has_handler = disruption_pc > 0
    var name = is_main ? (export_name ? export_name : "cell_main") : "cell_fn_" + text(fn_idx)
    name = sanitize(name)
    var i = 0
    var instr = null
    var op = null
    var a1 = null
    var a2 = null
    var a3 = null
    var a4 = null
    var p = null
    var pn = null
    var sl = null
    var lbl = null
    var fop_id = 0
    var nr_elems = 0
    var ei = 0
    var elem_slot = 0
    var v = null
    var lhs = null
    var rhs = null
    var obj = null
    var chk = null
    var pat_label = null
    var flg_label = null
    var in_handler = false

    // Function signature: (ctx, frame_ptr) → JSValue
    emit(`export function l $${name}(l %ctx, l %fp) {`)
    emit("@entry")

    // GC-safe slot access: every read/write goes through frame memory.
    // %fp may become stale after GC-triggering calls — use refresh_fp().
    var s_read = function(slot) {
      var t = fresh()
      emit(`  %${t} =l add %fp, ${text(slot * 8)}`)
      emit(`  %${t}v =l loadl %${t}`)
      return `%${t}v`
    }

    var s_write = function(slot, val) {
      var t = fresh()
      var sv = val
      if (!starts_with(val, "%")) {
        sv = `%${t}c`
        emit(`  ${sv} =l copy ${val}`)
      }
      emit(`  %${t} =l add %fp, ${text(slot * 8)}`)
      emit(`  storel ${sv}, %${t}`)
    }

    var refresh_fp = function() {
      emit(`  %fp =l call $cell_rt_refresh_fp_checked(l %ctx)`)
      var exc = fresh()
      emit(`  %${exc} =w ceql %fp, 0`)
      if (has_handler && !in_handler) {
        emit(`  jnz %${exc}, @disruption_handler, @${exc}_ok`)
      } else {
        emit(`  jnz %${exc}, @${exc}_exc, @${exc}_ok`)
        emit(`@${exc}_exc`)
        emit(`  ret 15`)
      }
      emit(`@${exc}_ok`)
    }

    // Walk instructions
    var last_was_term = false
    i = 0
    while (i < length(instrs)) {
      instr = instrs[i]

      // Emit @disruption_handler at the right flat index
      // disruption_pc counts all entries (labels + instructions)
      if (has_handler && i == disruption_pc) {
        if (!last_was_term) {
          emit("  jmp @disruption_handler")
        }
        emit("@disruption_handler")
        emit("  call $cell_rt_clear_exception(l %ctx)")
        emit(`  %fp =l call $cell_rt_refresh_fp(l %ctx)`)
        last_was_term = false
        in_handler = true
      }
      i = i + 1

      // Labels are plain strings; skip _nop_ur_ pseudo-labels from streamline
      if (is_text(instr)) {
        if (starts_with(instr, "_nop_ur_")) continue
        lbl = sanitize(instr)
        if (!last_was_term) {
          emit(`  jmp @${lbl}`)
        }
        emit("@" + lbl)
        last_was_term = false
        continue
      }

      // Skip dead code: non-label instructions after a terminator are unreachable
      if (last_was_term) continue

      op = instr[0]
      a1 = instr[1]
      a2 = instr[2]
      a3 = instr[3]
      last_was_term = false

      // --- Constants ---

      if (op == "int") {
        s_write(a1, text(a2 * 2))
        continue
      }
      if (op == "null") {
        s_write(a1, text(qbe.js_null))
        continue
      }
      if (op == "true") {
        s_write(a1, text(qbe.js_true))
        continue
      }
      if (op == "false") {
        s_write(a1, text(qbe.js_false))
        continue
      }
      if (op == "access") {
        p = fresh()
        if (is_number(a2)) {
          if (is_integer(a2)) {
            s_write(a1, text(a2 * 2))
          } else {
            emit(`  %${p} =l call $qbe_new_float64(l %ctx, d d_${text(a2)})`)
            refresh_fp()
            s_write(a1, `%${p}`)
          }
        } else if (is_text(a2)) {
          sl = intern_str(a2)
          emit(`  %${p} =l call $qbe_new_string(l %ctx, l ${sl})`)
          refresh_fp()
          s_write(a1, `%${p}`)
        } else if (is_object(a2)) {
          if (a2.make == "intrinsic") {
            sl = intern_str(a2.name)
            emit(`  %${p} =l call $cell_rt_get_intrinsic(l %ctx, l ${sl})`)
            refresh_fp()
            s_write(a1, `%${p}`)
          } else if (a2.kind == "number") {
            if (a2.number != null && is_integer(a2.number)) {
              s_write(a1, text(a2.number * 2))
            } else if (a2.number != null) {
              emit(`  %${p} =l call $qbe_new_float64(l %ctx, d d_${text(a2.number)})`)
              refresh_fp()
              s_write(a1, `%${p}`)
            } else {
              s_write(a1, text(qbe.js_null))
            }
          } else if (a2.kind == "text") {
            sl = intern_str(a2.value)
            emit(`  %${p} =l call $qbe_new_string(l %ctx, l ${sl})`)
            refresh_fp()
            s_write(a1, `%${p}`)
          } else if (a2.kind == "true") {
            s_write(a1, text(qbe.js_true))
          } else if (a2.kind == "false") {
            s_write(a1, text(qbe.js_false))
          } else if (a2.kind == "null") {
            s_write(a1, text(qbe.js_null))
          } else {
            s_write(a1, text(qbe.js_null))
          }
        } else {
          s_write(a1, text(qbe.js_null))
        }
        continue
      }

      // --- Movement ---

      if (op == "move") {
        v = s_read(a2)
        s_write(a1, v)
        continue
      }

      // --- Generic arithmetic (VM dispatches int/float) ---

      if (op == "add") {
        lhs = s_read(a2)
        rhs = s_read(a3)
        p = fresh()
        emit(`  %${p} =l call $cell_rt_add(l %ctx, l ${lhs}, l ${rhs})`)
        refresh_fp()
        s_write(a1, `%${p}`)
        continue
      }
      if (op == "subtract") {
        lhs = s_read(a2)
        rhs = s_read(a3)
        p = fresh()
        emit(qbe.sub(p, "%ctx", lhs, rhs))
        refresh_fp()
        s_write(a1, `%${p}`)
        continue
      }
      if (op == "multiply") {
        lhs = s_read(a2)
        rhs = s_read(a3)
        p = fresh()
        emit(qbe.mul(p, "%ctx", lhs, rhs))
        refresh_fp()
        s_write(a1, `%${p}`)
        continue
      }
      if (op == "divide") {
        lhs = s_read(a2)
        rhs = s_read(a3)
        p = fresh()
        emit(qbe.div(p, "%ctx", lhs, rhs))
        refresh_fp()
        s_write(a1, `%${p}`)
        continue
      }
      if (op == "modulo") {
        lhs = s_read(a2)
        rhs = s_read(a3)
        p = fresh()
        emit(qbe.mod(p, "%ctx", lhs, rhs))
        refresh_fp()
        s_write(a1, `%${p}`)
        continue
      }
      if (op == "negate") {
        v = s_read(a2)
        p = fresh()
        emit(qbe.neg(p, "%ctx", v))
        refresh_fp()
        s_write(a1, `%${p}`)
        continue
      }

      if (op == "pow") {
        lhs = s_read(a2)
        rhs = s_read(a3)
        p = fresh()
        emit(`  %${p} =l call $qbe_float_pow(l %ctx, l ${lhs}, l ${rhs})`)
        refresh_fp()
        s_write(a1, `%${p}`)
        continue
      }

      // --- String concat ---

      if (op == "concat") {
        lhs = s_read(a2)
        rhs = s_read(a3)
        p = fresh()
        emit(qbe.concat(p, "%ctx", lhs, rhs))
        refresh_fp()
        s_write(a1, `%${p}`)
        continue
      }

      // --- Type checks — use qbe.cm macros (no GC, no refresh) ---

      if (op == "is_int") {
        v = s_read(a2)
        p = fresh()
        emit(qbe.is_int(p, v))
        emit(qbe.new_bool(p + ".r", "%" + p))
        s_write(a1, `%${p}.r`)
        continue
      }
      if (op == "is_text") {
        v = s_read(a2)
        p = fresh()
        emit(`  %${p} =w call $JS_IsText(l ${v})`)
        emit(qbe.new_bool(p + ".r", "%" + p))
        s_write(a1, `%${p}.r`)
        continue
      }
      if (op == "is_num") {
        v = s_read(a2)
        p = fresh()
        emit(qbe.is_number(p, v))
        emit(qbe.new_bool(p + ".r", "%" + p))
        s_write(a1, `%${p}.r`)
        continue
      }
      if (op == "is_bool") {
        v = s_read(a2)
        p = fresh()
        emit(qbe.is_bool(p, v))
        emit(qbe.new_bool(p + ".r", "%" + p))
        s_write(a1, `%${p}.r`)
        continue
      }
      if (op == "is_null") {
        v = s_read(a2)
        p = fresh()
        emit(qbe.is_null(p, v))
        emit(qbe.new_bool(p + ".r", "%" + p))
        s_write(a1, `%${p}.r`)
        continue
      }
      if (op == "is_identical") {
        lhs = s_read(a2)
        rhs = s_read(a3)
        p = fresh()
        emit(qbe.is_identical(p, lhs, rhs))
        s_write(a1, `%${p}`)
        continue
      }
      if (op == "is_array") {
        v = s_read(a2)
        p = fresh()
        emit(`  %${p} =w call $JS_IsArray(l ${v})`)
        emit(qbe.new_bool(p + ".r", "%" + p))
        s_write(a1, `%${p}.r`)
        continue
      }
      if (op == "is_func") {
        v = s_read(a2)
        p = fresh()
        emit(`  %${p} =w call $JS_IsFunction(l ${v})`)
        emit(qbe.new_bool(p + ".r", "%" + p))
        s_write(a1, `%${p}.r`)
        continue
      }
      if (op == "is_record") {
        v = s_read(a2)
        p = fresh()
        emit(`  %${p} =w call $JS_IsRecord(l ${v})`)
        emit(qbe.new_bool(p + ".r", "%" + p))
        s_write(a1, `%${p}.r`)
        continue
      }
      if (op == "is_stone") {
        v = s_read(a2)
        p = fresh()
        emit(`  %${p} =w call $JS_IsStone(l ${v})`)
        emit(qbe.new_bool(p + ".r", "%" + p))
        s_write(a1, `%${p}.r`)
        continue
      }
      if (op == "is_proxy") {
        v = s_read(a2)
        p = fresh()
        emit(`  %${p} =w call $cell_rt_is_proxy(l %ctx, l ${v})`)
        emit(qbe.new_bool(p + ".r", "%" + p))
        s_write(a1, `%${p}.r`)
        continue
      }

      // --- Comparisons (int path, no GC) ---

      if (op == "eq_int") {
        lhs = s_read(a2)
        rhs = s_read(a3)
        p = fresh()
        emit(qbe.eq_int(p, "%ctx", lhs, rhs))
        s_write(a1, `%${p}`)
        continue
      }
      if (op == "ne_int") {
        lhs = s_read(a2)
        rhs = s_read(a3)
        p = fresh()
        emit(qbe.ne_int(p, "%ctx", lhs, rhs))
        s_write(a1, `%${p}`)
        continue
      }
      if (op == "lt_int") {
        lhs = s_read(a2)
        rhs = s_read(a3)
        p = fresh()
        emit(qbe.lt_int(p, "%ctx", lhs, rhs))
        s_write(a1, `%${p}`)
        continue
      }
      if (op == "gt_int") {
        lhs = s_read(a2)
        rhs = s_read(a3)
        p = fresh()
        emit(qbe.gt_int(p, "%ctx", lhs, rhs))
        s_write(a1, `%${p}`)
        continue
      }
      if (op == "le_int") {
        lhs = s_read(a2)
        rhs = s_read(a3)
        p = fresh()
        emit(qbe.le_int(p, "%ctx", lhs, rhs))
        s_write(a1, `%${p}`)
        continue
      }
      if (op == "ge_int") {
        lhs = s_read(a2)
        rhs = s_read(a3)
        p = fresh()
        emit(qbe.ge_int(p, "%ctx", lhs, rhs))
        s_write(a1, `%${p}`)
        continue
      }

      // --- Comparisons (float/text/bool) ---

      if (op == "eq_float") {
        lhs = s_read(a2)
        rhs = s_read(a3)
        p = fresh()
        emit(qbe.eq_float(p, "%ctx", lhs, rhs))
        s_write(a1, `%${p}`)
        continue
      }
      if (op == "ne_float") {
        lhs = s_read(a2)
        rhs = s_read(a3)
        p = fresh()
        emit(qbe.ne_float(p, "%ctx", lhs, rhs))
        s_write(a1, `%${p}`)
        continue
      }
      if (op == "lt_float") {
        lhs = s_read(a2)
        rhs = s_read(a3)
        p = fresh()
        emit(qbe.lt_float(p, "%ctx", lhs, rhs))
        s_write(a1, `%${p}`)
        continue
      }
      if (op == "le_float") {
        lhs = s_read(a2)
        rhs = s_read(a3)
        p = fresh()
        emit(qbe.le_float(p, "%ctx", lhs, rhs))
        s_write(a1, `%${p}`)
        continue
      }
      if (op == "gt_float") {
        lhs = s_read(a2)
        rhs = s_read(a3)
        p = fresh()
        emit(qbe.gt_float(p, "%ctx", lhs, rhs))
        s_write(a1, `%${p}`)
        continue
      }
      if (op == "ge_float") {
        lhs = s_read(a2)
        rhs = s_read(a3)
        p = fresh()
        emit(qbe.ge_float(p, "%ctx", lhs, rhs))
        s_write(a1, `%${p}`)
        continue
      }
      if (op == "eq_text") {
        lhs = s_read(a2)
        rhs = s_read(a3)
        p = fresh()
        emit(qbe.eq_text(p, "%ctx", lhs, rhs))
        s_write(a1, `%${p}`)
        continue
      }
      if (op == "ne_text") {
        lhs = s_read(a2)
        rhs = s_read(a3)
        p = fresh()
        emit(qbe.ne_text(p, "%ctx", lhs, rhs))
        s_write(a1, `%${p}`)
        continue
      }
      if (op == "lt_text" || op == "gt_text" || op == "le_text" || op == "ge_text") {
        lhs = s_read(a2)
        rhs = s_read(a3)
        p = fresh()
        emit(`  %${p} =l call $cell_rt_${op}(l %ctx, l ${lhs}, l ${rhs})`)
        s_write(a1, `%${p}`)
        continue
      }
      if (op == "eq_bool") {
        lhs = s_read(a2)
        rhs = s_read(a3)
        p = fresh()
        emit(qbe.eq_bool(p, lhs, rhs))
        s_write(a1, `%${p}`)
        continue
      }
      if (op == "ne_bool") {
        lhs = s_read(a2)
        rhs = s_read(a3)
        p = fresh()
        emit(qbe.ne_bool(p, lhs, rhs))
        s_write(a1, `%${p}`)
        continue
      }
      if (op == "eq_tol" || op == "ne_tol") {
        lhs = s_read(a2)
        rhs = s_read(a3)
        p = fresh()
        emit(`  %${p} =l call $cell_rt_${op}(l %ctx, l ${lhs}, l ${rhs})`)
        s_write(a1, `%${p}`)
        continue
      }

      // --- Boolean ops ---

      if (op == "not") {
        v = s_read(a2)
        p = fresh()
        emit(qbe.lnot(p, "%ctx", v))
        s_write(a1, `%${p}`)
        continue
      }
      if (op == "and") {
        lhs = s_read(a2)
        rhs = s_read(a3)
        p = fresh()
        emit(`  %${p} =l call $cell_rt_and(l %ctx, l ${lhs}, l ${rhs})`)
        s_write(a1, `%${p}`)
        continue
      }
      if (op == "or") {
        lhs = s_read(a2)
        rhs = s_read(a3)
        p = fresh()
        emit(`  %${p} =l call $cell_rt_or(l %ctx, l ${lhs}, l ${rhs})`)
        s_write(a1, `%${p}`)
        continue
      }

      // --- Bitwise ops — use qbe.cm macros (no GC) ---

      if (op == "bitnot") {
        v = s_read(a2)
        p = fresh()
        emit(qbe.bnot(p, "%ctx", v))
        s_write(a1, `%${p}`)
        continue
      }
      if (op == "bitand") {
        lhs = s_read(a2)
        rhs = s_read(a3)
        p = fresh()
        emit(qbe.band(p, "%ctx", lhs, rhs))
        s_write(a1, `%${p}`)
        continue
      }
      if (op == "bitor") {
        lhs = s_read(a2)
        rhs = s_read(a3)
        p = fresh()
        emit(qbe.bor(p, "%ctx", lhs, rhs))
        s_write(a1, `%${p}`)
        continue
      }
      if (op == "bitxor") {
        lhs = s_read(a2)
        rhs = s_read(a3)
        p = fresh()
        emit(qbe.bxor(p, "%ctx", lhs, rhs))
        s_write(a1, `%${p}`)
        continue
      }
      if (op == "shl") {
        lhs = s_read(a2)
        rhs = s_read(a3)
        p = fresh()
        emit(qbe.shl(p, "%ctx", lhs, rhs))
        s_write(a1, `%${p}`)
        continue
      }
      if (op == "shr") {
        lhs = s_read(a2)
        rhs = s_read(a3)
        p = fresh()
        emit(qbe.shr(p, "%ctx", lhs, rhs))
        s_write(a1, `%${p}`)
        continue
      }
      if (op == "ushr") {
        lhs = s_read(a2)
        rhs = s_read(a3)
        p = fresh()
        emit(qbe.ushr(p, "%ctx", lhs, rhs))
        s_write(a1, `%${p}`)
        continue
      }

      // --- Property access — runtime calls [G] ---

      if (op == "load_field") {
        v = s_read(a2)
        pn = null
        if (is_text(a3)) pn = a3
        else if (is_object(a3) && a3.name != null) pn = a3.name
        else if (is_object(a3) && a3.value != null) pn = a3.value
        p = fresh()
        if (pn != null) {
          sl = intern_str(pn)
          emit(`  %${p} =l call $cell_rt_load_field(l %ctx, l ${v}, l ${sl})`)
        } else {
          lhs = s_read(a3)
          emit(`  %${p} =l call $cell_rt_load_dynamic(l %ctx, l ${v}, l ${lhs})`)
        }
        refresh_fp()
        s_write(a1, `%${p}`)
        continue
      }
      if (op == "load_index") {
        lhs = s_read(a2)
        rhs = s_read(a3)
        p = fresh()
        emit(`  %${p} =l call $cell_rt_load_index(l %ctx, l ${lhs}, l ${rhs})`)
        refresh_fp()
        s_write(a1, `%${p}`)
        continue
      }
      if (op == "load_dynamic") {
        v = s_read(a2)
        pn = null
        if (is_text(a3)) pn = a3
        else if (is_object(a3) && a3.name != null) pn = a3.name
        else if (is_object(a3) && a3.value != null) pn = a3.value
        p = fresh()
        if (pn != null) {
          sl = intern_str(pn)
          emit(`  %${p} =l call $cell_rt_load_field(l %ctx, l ${v}, l ${sl})`)
        } else {
          lhs = s_read(a3)
          emit(`  %${p} =l call $cell_rt_load_dynamic(l %ctx, l ${v}, l ${lhs})`)
        }
        refresh_fp()
        s_write(a1, `%${p}`)
        continue
      }
      if (op == "store_field") {
        // IR: ["store_field", obj, val, prop] → C: (ctx, val, obj, name)
        obj = s_read(a1)
        v = s_read(a2)
        pn = null
        if (is_text(a3)) {
          pn = a3
        } else if (is_object(a3)) {
          if (a3.name != null) pn = a3.name
          else if (a3.value != null) pn = a3.value
        }
        if (pn != null) {
          sl = intern_str(pn)
          emit(`  call $cell_rt_store_field(l %ctx, l ${v}, l ${obj}, l ${sl})`)
        } else {
          lhs = s_read(a3)
          emit(`  call $cell_rt_store_dynamic(l %ctx, l ${v}, l ${obj}, l ${lhs})`)
        }
        refresh_fp()
        continue
      }
      if (op == "store_index") {
        // IR: ["store_index", obj, val, idx] → C: (ctx, val, obj, idx)
        obj = s_read(a1)
        v = s_read(a2)
        lhs = s_read(a3)
        emit(`  call $cell_rt_store_index(l %ctx, l ${v}, l ${obj}, l ${lhs})`)
        refresh_fp()
        continue
      }
      if (op == "store_dynamic") {
        // IR: ["store_dynamic", obj, val, key] → C: (ctx, val, obj, key)
        obj = s_read(a1)
        v = s_read(a2)
        pn = null
        if (is_text(a3)) pn = a3
        else if (is_object(a3) && a3.name != null) pn = a3.name
        else if (is_object(a3) && a3.value != null) pn = a3.value
        if (pn != null) {
          sl = intern_str(pn)
          emit(`  call $cell_rt_store_field(l %ctx, l ${v}, l ${obj}, l ${sl})`)
        } else {
          lhs = s_read(a3)
          emit(`  call $cell_rt_store_dynamic(l %ctx, l ${v}, l ${obj}, l ${lhs})`)
        }
        refresh_fp()
        continue
      }

      // --- Closure access (no GC) ---

      if (op == "get") {
        // mcode: get(dest, slot, depth) — a2=slot, a3=depth
        p = fresh()
        emit(`  %${p} =l call $cell_rt_get_closure(l %ctx, l %fp, l ${text(a3)}, l ${text(a2)})`)
        s_write(a1, `%${p}`)
        continue
      }
      if (op == "put") {
        // mcode: put(val, slot, depth) — a2=slot, a3=depth
        v = s_read(a1)
        emit(`  call $cell_rt_put_closure(l %ctx, l %fp, l ${v}, l ${text(a3)}, l ${text(a2)})`)
        continue
      }

      // --- Control flow ---

      if (op == "jump") {
        emit(`  jmp @${sanitize(a1)}`)
        last_was_term = true
        continue
      }
      if (op == "jump_true") {
        v = s_read(a1)
        p = fresh()
        emit(`  %${p} =w call $JS_ToBool(l %ctx, l ${v})`)
        emit(`  jnz %${p}, @${sanitize(a2)}, @${p}_f`)
        emit(`@${p}_f`)
        continue
      }
      if (op == "jump_false") {
        v = s_read(a1)
        p = fresh()
        emit(`  %${p} =w call $JS_ToBool(l %ctx, l ${v})`)
        emit(`  jnz %${p}, @${p}_t, @${sanitize(a2)}`)
        emit(`@${p}_t`)
        continue
      }
      if (op == "jump_null") {
        v = s_read(a1)
        p = fresh()
        emit(`  %${p} =w ceql ${v}, ${text(qbe.js_null)}`)
        emit(`  jnz %${p}, @${sanitize(a2)}, @${p}_nn`)
        emit(`@${p}_nn`)
        continue
      }
      if (op == "jump_not_null") {
        v = s_read(a1)
        p = fresh()
        emit(`  %${p} =w cnel ${v}, ${text(qbe.js_null)}`)
        emit(`  jnz %${p}, @${sanitize(a2)}, @${p}_n`)
        emit(`@${p}_n`)
        continue
      }

      // --- Function calls [G] ---

      if (op == "frame") {
        v = s_read(a2)
        p = fresh()
        emit(`  %${p} =l call $cell_rt_frame(l %ctx, l ${v}, l ${text(a3)})`)
        refresh_fp()
        s_write(a1, `%${p}`)
        continue
      }
      if (op == "setarg") {
        v = s_read(a1)
        lhs = s_read(a3)
        emit(`  call $cell_rt_setarg(l ${v}, l ${text(a2)}, l ${lhs})`)
        continue
      }
      if (op == "invoke") {
        v = s_read(a1)
        p = fresh()
        emit(`  %${p} =l call $cell_rt_invoke(l %ctx, l ${v})`)
        chk = fresh()
        emit(`  %${chk} =w ceql %${p}, 15`)
        if (has_handler) {
          emit(`  jnz %${chk}, @disruption_handler, @${chk}_ok`)
        } else {
          emit(`  jnz %${chk}, @${chk}_exc, @${chk}_ok`)
          emit(`@${chk}_exc`)
          emit(`  ret 15`)
        }
        emit(`@${chk}_ok`)
        refresh_fp()
        s_write(a2, `%${p}`)
        continue
      }
      if (op == "tail_invoke") {
        v = s_read(a1)
        p = fresh()
        emit(`  %${p} =l call $cell_rt_invoke(l %ctx, l ${v})`)
        chk = fresh()
        emit(`  %${chk} =w ceql %${p}, 15`)
        if (has_handler) {
          emit(`  jnz %${chk}, @disruption_handler, @${chk}_ok`)
        } else {
          emit(`  jnz %${chk}, @${chk}_exc, @${chk}_ok`)
          emit(`@${chk}_exc`)
          emit(`  ret 15`)
        }
        emit(`@${chk}_ok`)
        refresh_fp()
        s_write(a2, `%${p}`)
        continue
      }
      if (op == "goframe") {
        v = s_read(a2)
        p = fresh()
        emit(`  %${p} =l call $cell_rt_goframe(l %ctx, l ${v}, l ${text(a3)})`)
        refresh_fp()
        s_write(a1, `%${p}`)
        continue
      }
      if (op == "goinvoke") {
        v = s_read(a1)
        p = fresh()
        emit(`  %${p} =l call $cell_rt_goinvoke(l %ctx, l ${v})`)
        chk = fresh()
        emit(`  %${chk} =w ceql %${p}, 15`)
        if (has_handler) {
          emit(`  jnz %${chk}, @disruption_handler, @${chk}_ok`)
          emit(`@${chk}_ok`)
          refresh_fp()
          emit(`  ret %${p}`)
        } else {
          emit(`  jnz %${chk}, @${chk}_exc, @${chk}_ok`)
          emit(`@${chk}_exc`)
          emit(`  ret 15`)
          emit(`@${chk}_ok`)
          emit(`  ret %${p}`)
        }
        last_was_term = true
        continue
      }

      // --- Function object creation [G] ---

      if (op == "function") {
        p = fresh()
        emit(`  %${p} =l call $cell_rt_make_function(l %ctx, l ${text(a2)}, l %fp)`)
        refresh_fp()
        s_write(a1, `%${p}`)
        continue
      }

      // --- Record/Array creation [G] ---

      if (op == "record") {
        p = fresh()
        emit(`  %${p} =l call $JS_NewObject(l %ctx)`)
        refresh_fp()
        s_write(a1, `%${p}`)
        continue
      }
      if (op == "array") {
        // a2 is a size hint; elements are pushed via separate push instructions
        p = fresh()
        emit(`  %${p} =l call $JS_NewArray(l %ctx)`)
        refresh_fp()
        s_write(a1, `%${p}`)
        continue
      }

      // --- Array push/pop [G] ---

      if (op == "push") {
        lhs = s_read(a1)
        rhs = s_read(a2)
        emit(`  call $cell_rt_push(l %ctx, l ${lhs}, l ${rhs})`)
        refresh_fp()
        continue
      }
      if (op == "pop") {
        v = s_read(a2)
        p = fresh()
        emit(`  %${p} =l call $cell_rt_pop(l %ctx, l ${v})`)
        refresh_fp()
        s_write(a1, `%${p}`)
        continue
      }

      // --- Length [G] ---

      if (op == "length") {
        v = s_read(a2)
        p = fresh()
        emit(`  %${p} =l call $JS_CellLength(l %ctx, l ${v})`)
        refresh_fp()
        s_write(a1, `%${p}`)
        continue
      }

      // --- Misc ---

      if (op == "return") {
        v = s_read(a1)
        emit(`  ret ${v}`)
        last_was_term = true
        continue
      }
      if (op == "disrupt") {
        emit(`  call $cell_rt_disrupt(l %ctx)`)
        if (has_handler && !in_handler) {
          emit("  jmp @disruption_handler")
        } else {
          emit(`  ret 15`)
        }
        last_was_term = true
        continue
      }
      if (op == "delete") {
        v = s_read(a2)
        pn = null
        if (is_text(a3)) pn = a3
        else if (is_object(a3) && a3.name != null) pn = a3.name
        else if (is_object(a3) && a3.value != null) pn = a3.value
        p = fresh()
        if (pn != null) {
          sl = intern_str(pn)
          emit(`  %${p} =l call $cell_rt_delete(l %ctx, l ${v}, l ${sl})`)
        } else {
          lhs = s_read(a3)
          emit(`  %${p} =l call $cell_rt_delete(l %ctx, l ${v}, l ${lhs})`)
        }
        refresh_fp()
        s_write(a1, `%${p}`)
        continue
      }

      // --- in [G] ---

      if (op == "in") {
        // IR: ["in", dest, key_slot, obj_slot]
        lhs = s_read(a2)
        rhs = s_read(a3)
        p = fresh()
        emit(`  %${p} =l call $cell_rt_in(l %ctx, l ${lhs}, l ${rhs})`)
        refresh_fp()
        s_write(a1, `%${p}`)
        continue
      }

      // --- regexp [G] ---

      if (op == "regexp") {
        // IR: ["regexp", dest_slot, pattern_string, flags_string]
        pat_label = intern_str(a2)
        flg_label = intern_str(a3)
        p = fresh()
        emit(`  %${p} =l call $cell_rt_regexp(l %ctx, l ${pat_label}, l ${flg_label})`)
        refresh_fp()
        s_write(a1, `%${p}`)
        continue
      }

      // --- Unknown opcode ---
      emit(`  # unknown: ${op}`)
    }

    // Emit @disrupt landing pad for arithmetic type-error branches
    if (!last_was_term) {
      emit("  jmp @disrupt")
    }
    emit("@disrupt")
    emit(`  call $cell_rt_disrupt(l %ctx)`)
    emit(`  ret 15`)

    emit("}")
    emit("")
  }

  // ============================================================
  // Main: compile all functions then main
  // ============================================================

  var fi = 0
  while (fi < length(ir.functions)) {
    compile_fn(ir.functions[fi], fi, false)
    fi = fi + 1
  }

  compile_fn(ir.main, -1, true)

  // Assemble: data section first, then function bodies
  var result = []
  var di = 0
  while (di < length(data_out)) {
    push(result, data_out[di])
    di = di + 1
  }
  if (length(data_out) > 0) push(result, "")

  di = 0
  while (di < length(out)) {
    push(result, out[di])
    di = di + 1
  }

  return text(result, "\n")
}

return qbe_emit