(module
  ;; Run with Wasmtime from a directory containing ilo.rom and ilo.blocks:
  ;;   XDG_CACHE_HOME=/tmp /home/crc/.wasmtime/bin/wasmtime --dir=$PWD::. extras/ilo-wasm.wat
  ;;
  ;; The module uses WASI preview1 and fixed guest paths "ilo.rom" and
  ;; "ilo.blocks", matching the default names used by ilo.c.
  (import "wasi_snapshot_preview1" "fd_read"
    (func $fd_read (param i32 i32 i32 i32) (result i32)))
  (import "wasi_snapshot_preview1" "fd_write"
    (func $fd_write (param i32 i32 i32 i32) (result i32)))
  (import "wasi_snapshot_preview1" "fd_close"
    (func $fd_close (param i32) (result i32)))
  (import "wasi_snapshot_preview1" "fd_seek"
    (func $fd_seek (param i32 i64 i32 i32) (result i32)))
  (import "wasi_snapshot_preview1" "path_open"
    (func $path_open (param i32 i32 i32 i32 i32 i64 i64 i32 i32) (result i32)))

  (memory 5)
  (export "memory" (memory 0))
  (export "_start" (func $_start))

  ;; Memory map:
  ;;   0..262143      ilo memory: 65,536 signed 32-bit cells
  ;;   262144..262275 data stack: 33 signed 32-bit cells
  ;;   262276..263303 address stack: 257 signed 32-bit cells
  (global $DS i32 (i32.const 262144))
  (global $AS i32 (i32.const 262276))
  (global $OPENED i32 (i32.const 263304))
  (global $NIO i32 (i32.const 263308))
  (global $IOV i32 (i32.const 263312))
  (global $SEEKED i32 (i32.const 263320))
  (global $BYTE i32 (i32.const 263328))
  (global $NUMBUF i32 (i32.const 263336))
  (global $ROM i32 (i32.const 263384))
  (global $BLOCKS i32 (i32.const 263392))

  (data (i32.const 263384) "ilo.rom\00")
  (data (i32.const 263392) "ilo.blocks\00")

  (global $ip (mut i32) (i32.const 0))
  (global $sp (mut i32) (i32.const 0))
  (global $rp (mut i32) (i32.const 0))

  (func $cell (param $a i32) (result i32)
    local.get $a
    i32.const 2
    i32.shl)

  (func $ds_addr (param $a i32) (result i32)
    global.get $DS
    local.get $a
    i32.const 2
    i32.shl
    i32.add)

  (func $as_addr (param $a i32) (result i32)
    global.get $AS
    local.get $a
    i32.const 2
    i32.shl
    i32.add)

  (func $t_addr (result i32)
    global.get $sp
    call $ds_addr)

  (func $n_addr (result i32)
    global.get $sp
    i32.const 1
    i32.sub
    call $ds_addr)

  (func $r_addr (result i32)
    global.get $rp
    call $as_addr)

  (func $t (result i32)
    call $t_addr
    i32.load)

  (func $n (result i32)
    call $n_addr
    i32.load)

  (func $set_t (param $v i32)
    call $t_addr
    local.get $v
    i32.store)

  (func $set_n (param $v i32)
    call $n_addr
    local.get $v
    i32.store)

  (func $push (param $v i32)
    global.get $sp
    i32.const 1
    i32.add
    call $ds_addr
    local.get $v
    i32.store
    global.get $sp
    i32.const 1
    i32.add
    global.set $sp)

  (func $pop (result i32)
    (local $a i32)
    global.get $sp
    i32.const 1
    i32.sub
    global.set $sp
    global.get $sp
    i32.const 1
    i32.add
    local.tee $a
    call $ds_addr
    i32.load)

  (func $open_ro (param $path i32) (param $len i32) (result i32)
    (local $err i32)
    i32.const 3            ;; cwd preopen
    i32.const 0
    local.get $path
    local.get $len
    i32.const 0
    i64.const 6            ;; FD_READ | FD_SEEK
    i64.const 0
    i32.const 0
    global.get $OPENED
    call $path_open
    local.tee $err
    if
      i32.const -1
      return
    end
    global.get $OPENED
    i32.load)

  (func $open_rw (param $path i32) (param $len i32) (result i32)
    (local $err i32)
    i32.const 3
    i32.const 0
    local.get $path
    local.get $len
    i32.const 0
    i64.const 70           ;; FD_READ | FD_SEEK | FD_WRITE
    i64.const 0
    i32.const 0
    global.get $OPENED
    call $path_open
    local.tee $err
    if
      i32.const -1
      return
    end
    global.get $OPENED
    i32.load)

  (func $load_image
    (local $fd i32)
    global.get $ROM
    i32.const 7
    call $open_ro
    local.set $fd
    local.get $fd
    i32.const 0
    i32.lt_s
    if
      i32.const 0
      global.set $ip
      i32.const 0
      global.set $sp
      i32.const 0
      global.set $rp
      return
    end
    global.get $IOV
    i32.const 0
    i32.store
    global.get $IOV
    i32.const 4
    i32.add
    i32.const 262144
    i32.store
    local.get $fd
    global.get $IOV
    i32.const 1
    global.get $NIO
    call $fd_read
    drop
    local.get $fd
    call $fd_close
    drop
    i32.const 0
    global.set $ip
    i32.const 0
    global.set $sp
    i32.const 0
    global.set $rp)

  (func $save_image
    (local $fd i32)
    global.get $ROM
    i32.const 7
    call $open_rw
    local.set $fd
    local.get $fd
    i32.const 0
    i32.lt_s
    if
      return
    end
    global.get $IOV
    i32.const 0
    i32.store
    global.get $IOV
    i32.const 4
    i32.add
    i32.const 262144
    i32.store
    local.get $fd
    global.get $IOV
    i32.const 1
    global.get $NIO
    call $fd_write
    drop
    local.get $fd
    call $fd_close
    drop)

  (func $read_block
    (local $fd i32) (local $block i32) (local $buffer i32)
    call $pop
    local.set $buffer
    call $pop
    local.set $block
    global.get $BLOCKS
    i32.const 10
    call $open_ro
    local.set $fd
    local.get $fd
    i32.const 0
    i32.lt_s
    if
      return
    end
    local.get $fd
    local.get $block
    i64.extend_i32_s
    i64.const 4096
    i64.mul
    i32.const 0
    global.get $SEEKED
    call $fd_seek
    drop
    global.get $IOV
    local.get $buffer
    call $cell
    i32.store
    global.get $IOV
    i32.const 4
    i32.add
    i32.const 4096
    i32.store
    local.get $fd
    global.get $IOV
    i32.const 1
    global.get $NIO
    call $fd_read
    drop
    local.get $fd
    call $fd_close
    drop)

  (func $write_block
    (local $fd i32) (local $block i32) (local $buffer i32)
    call $pop
    local.set $buffer
    call $pop
    local.set $block
    global.get $BLOCKS
    i32.const 10
    call $open_rw
    local.set $fd
    local.get $fd
    i32.const 0
    i32.lt_s
    if
      return
    end
    local.get $fd
    local.get $block
    i64.extend_i32_s
    i64.const 4096
    i64.mul
    i32.const 0
    global.get $SEEKED
    call $fd_seek
    drop
    global.get $IOV
    local.get $buffer
    call $cell
    i32.store
    global.get $IOV
    i32.const 4
    i32.add
    i32.const 4096
    i32.store
    local.get $fd
    global.get $IOV
    i32.const 1
    global.get $NIO
    call $fd_write
    drop
    local.get $fd
    call $fd_close
    drop)

  (func $save_ip
    global.get $rp
    i32.const 1
    i32.add
    global.set $rp
    call $r_addr
    global.get $ip
    i32.store)

  (func $li
    global.get $ip
    i32.const 1
    i32.add
    global.set $ip
    global.get $ip
    call $cell
    i32.load
    call $push)

  (func $du
    call $t
    call $push)

  (func $dr
    call $t_addr
    i32.const 0
    i32.store
    global.get $sp
    i32.const 1
    i32.sub
    global.set $sp)

  (func $sw
    (local $a i32)
    call $t
    local.set $a
    call $n
    call $set_t
    local.get $a
    call $set_n)

  (func $pu
    global.get $rp
    i32.const 1
    i32.add
    global.set $rp
    call $r_addr
    call $pop
    i32.store)

  (func $po
    call $r_addr
    i32.load
    call $push
    global.get $rp
    i32.const 1
    i32.sub
    global.set $rp)

  (func $ju
    call $pop
    i32.const 1
    i32.sub
    global.set $ip)

  (func $ca
    call $save_ip
    call $pop
    i32.const 1
    i32.sub
    global.set $ip)

  (func $cc
    (local $a i32)
    call $pop
    local.set $a
    call $pop
    if
      call $save_ip
      local.get $a
      i32.const 1
      i32.sub
      global.set $ip
    end)

  (func $cj
    (local $a i32)
    call $pop
    local.set $a
    call $pop
    if
      local.get $a
      i32.const 1
      i32.sub
      global.set $ip
    end)

  (func $re
    call $r_addr
    i32.load
    global.set $ip
    global.get $rp
    i32.const 1
    i32.sub
    global.set $rp)

  (func $eq
    call $n
    call $t
    i32.eq
    i32.const -1
    i32.mul
    call $set_n
    global.get $sp
    i32.const 1
    i32.sub
    global.set $sp)

  (func $ne
    call $n
    call $t
    i32.ne
    i32.const -1
    i32.mul
    call $set_n
    global.get $sp
    i32.const 1
    i32.sub
    global.set $sp)

  (func $lt
    call $n
    call $t
    i32.lt_s
    i32.const -1
    i32.mul
    call $set_n
    global.get $sp
    i32.const 1
    i32.sub
    global.set $sp)

  (func $gt
    call $n
    call $t
    i32.gt_s
    i32.const -1
    i32.mul
    call $set_n
    global.get $sp
    i32.const 1
    i32.sub
    global.set $sp)

  (func $fe
    call $t
    call $cell
    i32.load
    call $set_t)

  (func $st
    call $t
    call $cell
    call $n
    i32.store
    global.get $sp
    i32.const 2
    i32.sub
    global.set $sp)

  (func $ad
    call $n
    call $t
    i32.add
    call $set_n
    global.get $sp
    i32.const 1
    i32.sub
    global.set $sp)

  (func $su
    call $n
    call $t
    i32.sub
    call $set_n
    global.get $sp
    i32.const 1
    i32.sub
    global.set $sp)

  (func $mu
    call $n
    call $t
    i32.mul
    call $set_n
    global.get $sp
    i32.const 1
    i32.sub
    global.set $sp)

  (func $di
    (local $a i32) (local $b i32)
    call $t
    local.set $a
    call $n
    local.set $b
    local.get $b
    local.get $a
    i32.div_s
    call $set_t
    local.get $b
    local.get $a
    i32.rem_s
    call $set_n
    local.get $b
    i32.const 0
    i32.ge_s
    call $n
    i32.const 0
    i32.lt_s
    i32.and
    if
      call $t
      i32.const 1
      i32.add
      call $set_t
      call $n
      local.get $a
      i32.sub
      call $set_n
    end)

  (func $an
    call $t
    call $n
    i32.and
    call $set_n
    global.get $sp
    i32.const 1
    i32.sub
    global.set $sp)

  (func $or
    call $t
    call $n
    i32.or
    call $set_n
    global.get $sp
    i32.const 1
    i32.sub
    global.set $sp)

  (func $xo
    call $t
    call $n
    i32.xor
    call $set_n
    global.get $sp
    i32.const 1
    i32.sub
    global.set $sp)

  (func $sl
    call $n
    call $t
    i32.shl
    call $set_n
    global.get $sp
    i32.const 1
    i32.sub
    global.set $sp)

  (func $sr
    call $n
    call $t
    i32.shr_s
    call $set_n
    global.get $sp
    i32.const 1
    i32.sub
    global.set $sp)

  (func $cp
    (local $l i32) (local $d i32) (local $s i32)
    call $pop
    local.set $l
    call $pop
    local.set $d
    call $t
    local.set $s
    i32.const -1
    call $set_t
    block $done
      loop $again
        local.get $l
        i32.eqz
        br_if $done
        local.get $d
        call $cell
        i32.load
        local.get $s
        call $cell
        i32.load
        i32.ne
        if
          i32.const 0
          call $set_t
        end
        local.get $l
        i32.const 1
        i32.sub
        local.set $l
        local.get $s
        i32.const 1
        i32.add
        local.set $s
        local.get $d
        i32.const 1
        i32.add
        local.set $d
        br $again
      end
    end)

  (func $cy
    (local $l i32) (local $d i32) (local $s i32)
    call $pop
    local.set $l
    call $pop
    local.set $d
    call $pop
    local.set $s
    block $done
      loop $again
        local.get $l
        i32.eqz
        br_if $done
        local.get $d
        call $cell
        local.get $s
        call $cell
        i32.load
        i32.store
        local.get $l
        i32.const 1
        i32.sub
        local.set $l
        local.get $s
        i32.const 1
        i32.add
        local.set $s
        local.get $d
        i32.const 1
        i32.add
        local.set $d
        br $again
      end
    end)

  (func $write_bytes (param $ptr i32) (param $len i32)
    global.get $IOV
    local.get $ptr
    i32.store
    global.get $IOV
    i32.const 4
    i32.add
    local.get $len
    i32.store
    i32.const 1
    global.get $IOV
    i32.const 1
    global.get $NIO
    call $fd_write
    drop)

  (func $write_byte (param $b i32)
    global.get $BYTE
    local.get $b
    i32.store8
    global.get $BYTE
    i32.const 1
    call $write_bytes)

  (func $read_byte (result i32)
    global.get $IOV
    global.get $BYTE
    i32.store
    global.get $IOV
    i32.const 4
    i32.add
    i32.const 1
    i32.store
    i32.const 0
    global.get $IOV
    i32.const 1
    global.get $NIO
    call $fd_read
    drop
    global.get $NIO
    i32.load
    i32.eqz
    if
      i32.const 32
      return
    end
    global.get $BYTE
    i32.load8_u)

  (func $io
    (local $dev i32)
    call $pop
    local.set $dev
    local.get $dev
    i32.eqz
    if
      call $pop
      call $write_byte
      return
    end
    local.get $dev
    i32.const 1
    i32.eq
    if
      call $read_byte
      call $push
      return
    end
    local.get $dev
    i32.const 2
    i32.eq
    if
      call $read_block
      return
    end
    local.get $dev
    i32.const 3
    i32.eq
    if
      call $write_block
      return
    end
    local.get $dev
    i32.const 4
    i32.eq
    if
      call $save_image
      return
    end
    local.get $dev
    i32.const 5
    i32.eq
    if
      call $load_image
      i32.const -1
      global.set $ip
      return
    end
    local.get $dev
    i32.const 6
    i32.eq
    if
      i32.const 65536
      global.set $ip
      return
    end
    local.get $dev
    i32.const 7
    i32.eq
    if
      global.get $sp
      call $push
      global.get $rp
      call $push
    end)

  (func $process (param $o i32)
    local.get $o
    i32.const 1
    i32.eq
    if call $li return end
    local.get $o
    i32.const 2
    i32.eq
    if call $du return end
    local.get $o
    i32.const 3
    i32.eq
    if call $dr return end
    local.get $o
    i32.const 4
    i32.eq
    if call $sw return end
    local.get $o
    i32.const 5
    i32.eq
    if call $pu return end
    local.get $o
    i32.const 6
    i32.eq
    if call $po return end
    local.get $o
    i32.const 7
    i32.eq
    if call $ju return end
    local.get $o
    i32.const 8
    i32.eq
    if call $ca return end
    local.get $o
    i32.const 9
    i32.eq
    if call $cc return end
    local.get $o
    i32.const 10
    i32.eq
    if call $cj return end
    local.get $o
    i32.const 11
    i32.eq
    if call $re return end
    local.get $o
    i32.const 12
    i32.eq
    if call $eq return end
    local.get $o
    i32.const 13
    i32.eq
    if call $ne return end
    local.get $o
    i32.const 14
    i32.eq
    if call $lt return end
    local.get $o
    i32.const 15
    i32.eq
    if call $gt return end
    local.get $o
    i32.const 16
    i32.eq
    if call $fe return end
    local.get $o
    i32.const 17
    i32.eq
    if call $st return end
    local.get $o
    i32.const 18
    i32.eq
    if call $ad return end
    local.get $o
    i32.const 19
    i32.eq
    if call $su return end
    local.get $o
    i32.const 20
    i32.eq
    if call $mu return end
    local.get $o
    i32.const 21
    i32.eq
    if call $di return end
    local.get $o
    i32.const 22
    i32.eq
    if call $an return end
    local.get $o
    i32.const 23
    i32.eq
    if call $or return end
    local.get $o
    i32.const 24
    i32.eq
    if call $xo return end
    local.get $o
    i32.const 25
    i32.eq
    if call $sl return end
    local.get $o
    i32.const 26
    i32.eq
    if call $sr return end
    local.get $o
    i32.const 27
    i32.eq
    if call $cp return end
    local.get $o
    i32.const 28
    i32.eq
    if call $cy return end
    local.get $o
    i32.const 29
    i32.eq
    if call $io return end)

  (func $process_bundle (param $opcode i32)
    local.get $opcode
    i32.const 255
    i32.and
    call $process
    local.get $opcode
    i32.const 8
    i32.shr_u
    i32.const 255
    i32.and
    call $process
    local.get $opcode
    i32.const 16
    i32.shr_u
    i32.const 255
    i32.and
    call $process
    local.get $opcode
    i32.const 24
    i32.shr_u
    i32.const 255
    i32.and
    call $process)

  (func $execute
    block $done
      loop $again
        global.get $ip
        i32.const 65536
        i32.ge_s
        br_if $done
        global.get $ip
        call $cell
        i32.load
        call $process_bundle
        global.get $ip
        i32.const 1
        i32.add
        global.set $ip
        br $again
      end
    end)

  (func $print_i32 (param $v i32)
    (local $u i32) (local $p i32) (local $end i32)
    local.get $v
    i32.eqz
    if
      i32.const 48
      call $write_byte
      return
    end
    local.get $v
    i32.const 0
    i32.lt_s
    if
      i32.const 45
      call $write_byte
      i32.const 0
      local.get $v
      i32.sub
      local.set $u
    else
      local.get $v
      local.set $u
    end
    global.get $NUMBUF
    i32.const 31
    i32.add
    local.tee $p
    local.set $end
    block $done
      loop $digits
        local.get $p
        local.get $u
        i32.const 10
        i32.rem_u
        i32.const 48
        i32.add
        i32.store8
        local.get $u
        i32.const 10
        i32.div_u
        local.set $u
        local.get $u
        i32.eqz
        br_if $done
        local.get $p
        i32.const 1
        i32.sub
        local.set $p
        br $digits
      end
    end
    local.get $p
    local.get $end
    local.get $p
    i32.sub
    i32.const 1
    i32.add
    call $write_bytes)

  (func $dump_stack
    block $done
      loop $again
        global.get $sp
        i32.eqz
        br_if $done
        i32.const 32
        call $write_byte
        call $t
        call $print_i32
        global.get $sp
        i32.const 1
        i32.sub
        global.set $sp
        br $again
      end
    end
    i32.const 10
    call $write_byte)

  (func $_start
    call $load_image
    call $execute
    call $dump_stack))