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# Playing with emitting cool textures.
#
# To run (on Linux):
#   $ git clone https://github.com/akkartik/mu
#   $ cd mu
#   $ ./translate_mu apps/texture.mu
#   $ ./a.elf > a.ppm

fn main -> _/ebx: int {
#?   var width/esi: int <- copy 0x190  # 400
#?   var height/edi: int <- copy 0xe1  # 225; aspect ratio 16:9
  var width/esi: int <- copy 0xff
  var height/edi: int <- copy 0xff
  print-string 0, "P3\n"
  print-int32-decimal 0, width
  print-string 0, " "
  print-int32-decimal 0, height
  print-string 0, "\n"
  print-string 0, "255\n"  # color depth
  var row/ecx: int <- copy 0
  {
    compare row, height
    break-if->=
    var col/edx: int <- copy 0
    {
      compare col, width
      break-if->=
      # r
      var tmp/eax: int <- copy col
      tmp <- multiply row
      tmp <- and 0x7f
      tmp <- add 0x80
      tmp <- copy 0xff
      print-int32-decimal 0, tmp
      print-string 0, " "
      # g
      tmp <- copy row
      tmp <- multiply col
      tmp <- and 0x7f
      tmp <- add 0x80
#?       tmp <- copy 0xcf
      print-int32-decimal 0, tmp
      print-string 0, " "
      # b
      tmp <- copy row
      tmp <- multiply col
      tmp <- and 0x7f
      tmp <- add 0x80
      print-int32-decimal 0, tmp
      print-string 0, "\n"
      col <- increment
      loop
    }
    row <- increment
    loop
  }
  return 0
}
='#n905'>905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 992
# primitives for emitting traces to a 'trace' stream, and for tests to make assertions on its contents
#
# A trace stream looks like a regular stream:
#   write: int  # index at which writes go
#   read: int  # index that we've read until
#   data: (array byte)  # prefixed by size as usual
# Usually the trace stream will be in a separate segment set aside for the purpose.
#
# primitives for operating on traces (arguments in quotes):
#   - initialize-trace-stream: populates Trace-stream with a new segment of the given 'size'
#   - trace: adds a 'line' to Trace-stream
#   - check-trace-contains: scans from Trace-stream's start for a matching 'line', prints a 'message' to stderr on failure
#   - check-trace-scans-to: scans from Trace-stream's read pointer for a matching 'line', prints a 'message' to stderr on failure

== data

# Handles are addresses created on the heap.
# In safe Mu they'll be fat pointers. But in SubX they're just addresses, since
# SubX programs never reclaim memory.

Trace-stream:  # (handle stream byte)
    0/imm32
    # we don't have safe handles (fat pointers) yet

Trace-segment:
    0/imm32/curr
    0/imm32/limit

# Fake trace-stream for tests.
# Also illustrates the layout of the real trace-stream (segment).
_test-trace-stream:  # (stream byte)
    # current write index
    0/imm32
    # current read index
    0/imm32
    # size
    8/imm32
    # data
    00 00 00 00 00 00 00 00  # 8 bytes

== code
#   instruction                     effective address                                                   register    displacement    immediate
# . op          subop               mod             rm32          base        index         scale       r32
# . 1-3 bytes   3 bits              2 bits          3 bits        3 bits      3 bits        2 bits      2 bits      0/1/2/4 bytes   0/1/2/4 bytes

# Allocate a new segment for the trace stream, initialize its size, and save its address to Trace-stream.
# The Trace-stream segment will consist of variable-length lines separated by newlines (0x0a)
initialize-trace-stream:  # n: int
    # . prologue
    55/push-ebp
    89/copy                         3/mod/direct    5/rm32/ebp    .           .             .           4/r32/esp   .               .                 # copy esp to ebp
    # . save registers
    50/push-eax
    51/push-ecx
    # ecx = n
    8b/copy                         1/mod/*+disp8   5/rm32/ebp    .           .             .           1/r32/ecx   8/disp8         .                 # copy *(ebp+8) to ecx
    # Trace-segment = new-segment(n)
    # . . push args
    68/push  Trace-segment/imm32
    51/push-ecx
    # . . call
    e8/call  new-segment/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
    # copy Trace-segment->curr to *Trace-stream
    8b/copy                         0/mod/indirect  5/rm32/.disp32            .             .           0/r32/eax   Trace-segment/disp32              # copy *Trace-segment to eax
#?     # watch point to catch Trace-stream leaks
#? $watch-1:
    89/copy                         0/mod/indirect  5/rm32/.disp32            .             .           0/r32/eax   Trace-stream/disp32               # copy eax to *Trace-stream
    # Trace-stream->size = n - 12
    # . ecx -= 12
    81          5/subop/subtract    3/mod/direct    1/rm32/ecx    .           .             .           .           .               0xc/imm32         # subtract from ecx
    # . Trace-stream->size = ecx
    89/copy                         1/mod/*+disp8   0/rm32/eax    .           .             .           1/r32/ecx   8/disp8         .                 # copy ecx to *(eax+8)
$initialize-trace-stream:end:
    # . restore registers
    59/pop-to-ecx
    58/pop-to-eax
    # . epilogue
    89/copy                         3/mod/direct    4/rm32/esp    .           .             .           5/r32/ebp   .               .                 # copy ebp to esp
    5d/pop-to-ebp
    c3/return

# Append a string to the given trace stream.
# Silently give up if it's already full. Or truncate the string if there isn't enough room.
trace:  # line: (addr array byte)
    # . prologue
    55/push-ebp
    89/copy                         3/mod/direct    5/rm32/ebp    .           .             .           4/r32/esp   .               .                 # copy esp to ebp
    # . save registers
    50/push-eax
    51/push-ecx
    52/push-edx
    53/push-ebx
    56/push-esi
    57/push-edi
    # var edi: (addr stream byte) = *Trace-stream
    8b/copy                         0/mod/indirect  5/rm32/.disp32            .             .           7/r32/edi   Trace-stream/disp32               # copy *Trace-stream to edi
    # esi = line
    8b/copy                         1/mod/*+disp8   5/rm32/ebp    .           .                         6/r32/esi   8/disp8         .                 # copy *(ebp+8) to esi
    # var ecx: int = t->write
    8b/copy                         0/mod/indirect  7/rm32/edi    .           .             .           1/r32/ecx   .               .                 # copy *edi to ecx
    # var edx: int = t->size
    8b/copy                         1/mod/*+disp8   7/rm32/edi    .           .             .           2/r32/edx   8/disp8         .                 # copy *(edi+8) to edx
    # eax = _append-3(&t->data[t->write], &t->data[t->size], line)
    # . . push line
    56/push-esi
    # . . push &t->data[t->size]
    8d/copy-address                 1/mod/*+disp8   4/rm32/sib    7/base/edi  2/index/edx   .           3/r32/ebx   0xc/disp8       .                 # copy edi+edx+12 to ebx
    53/push-ebx
    # . . push &t->data[t->write]
    8d/copy-address                 1/mod/*+disp8   4/rm32/sib    7/base/edi  1/index/ecx   .           3/r32/ebx   0xc/disp8       .                 # copy edi+ecx+12 to ebx
    53/push-ebx
    # . . call
    e8/call  _append-3/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               0xc/imm32         # add to esp
    # if (eax == 0) return
    3d/compare-eax-and  0/imm32
    74/jump-if-=  $trace:end/disp8
    # t->write += eax
    01/add                          0/mod/indirect  7/rm32/edi    .           .             .           0/r32/eax   .               .                 # add eax to *edi
    # refresh ecx = t->write
    8b/copy                         0/mod/indirect  7/rm32/edi    .           .             .           1/r32/ecx   .               .                 # copy *edi to ecx
    # eax = _append-3(&t->data[t->write], &t->data[t->size], line)
    # . . push line
    68/push  Newline/imm32
    # . . push &t->data[t->size]
    8d/copy-address                 1/mod/*+disp8   4/rm32/sib    7/base/edi  2/index/edx   .           3/r32/ebx   0xc/disp8       .                 # copy edi+edx+12 to ebx
    53/push-ebx
    # . . push &t->data[t->write]
    8d/copy-address                 1/mod/*+disp8   4/rm32/sib    7/base/edi  1/index/ecx   .           3/r32/ebx   0xc/disp8       .                 # copy edi+ecx+12 to ebx
    53/push-ebx
    # . . call
    e8/call  _append-3/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               0xc/imm32         # add to esp
    # t->write += eax
    01/add                          0/mod/indirect  7/rm32/edi    .           .             .           0/r32/eax   .               .                 # add eax to *edi
$trace:end:
    # . restore registers
    5f/pop-to-edi
    5e/pop-to-esi
    5b/pop-to-ebx
    5a/pop-to-edx
    59/pop-to-ecx
    58/pop-to-eax
    # . epilogue
    89/copy                         3/mod/direct    4/rm32/esp    .           .             .           5/r32/ebp   .               .                 # copy ebp to esp
    5d/pop-to-ebp
    c3/return

test-trace-single:
    # push *Trace-stream
    ff          6/subop/push        0/mod/indirect  5/rm32/.disp32            .             .           .           Trace-stream/disp32               # push *Trace-stream
    # *Trace-stream = _test-trace-stream
    b8/copy-to-eax  _test-trace-stream/imm32
    89/copy                         0/mod/indirect  5/rm32/.disp32            .             .           0/r32/eax   Trace-stream/disp32               # copy eax to *Trace-stream
    # clear-trace-stream()
    e8/call  clear-trace-stream/disp32
    # trace("Ab")
    # . . push args
    68/push  "Ab"/imm32
    # . . call
    e8/call  trace/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               4/imm32           # add to esp
    # check-ints-equal(*_test-trace-stream->data, 41/A 62/b 0a/newline 00, msg)
    # . . push args
    68/push  "F - test-trace-single"/imm32
    68/push  0x0a6241/imm32/Ab-newline
    # . . push *_test-trace-stream->data
    b8/copy-to-eax  _test-trace-stream/imm32
    ff          6/subop/push        1/mod/*+disp8   0/rm32/eax    .           .             .           .           0xc/disp8       .                 # push *(eax+12)
    # . . call
    e8/call  check-ints-equal/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               0xc/imm32         # add to esp
    # pop into *Trace-stream
    8f          0/subop/pop         0/mod/indirect  5/rm32/.disp32            .             .           .           Trace-stream/disp32               # pop into *Trace-stream
    # end
    c3/return

test-trace-appends:
    # push *Trace-stream
    ff          6/subop/push        0/mod/indirect  5/rm32/.disp32            .             .           .           Trace-stream/disp32               # push *Trace-stream
    # *Trace-stream = _test-trace-stream
    b8/copy-to-eax  _test-trace-stream/imm32
    89/copy                         0/mod/indirect  5/rm32/.disp32            .             .           0/r32/eax   Trace-stream/disp32               # copy eax to *Trace-stream
    # clear-trace-stream()
    e8/call  clear-trace-stream/disp32
    # trace("C")
    # . . push args
    68/push  "C"/imm32
    # . . call
    e8/call  trace/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               4/imm32           # add to esp
    # trace("D")
    # . . push args
    68/push  "D"/imm32
    # . . call
    e8/call  trace/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               4/imm32           # add to esp
    # check-ints-equal(*_test-trace-stream->data, 43/C 0a/newline 44/D 0a/newline, msg)
    # . . push args
    68/push  "F - test-trace-appends"/imm32
    68/push  0x0a440a43/imm32/C-newline-D-newline
    # . . push *_test-trace-stream->data
    b8/copy-to-eax  _test-trace-stream/imm32
    ff          6/subop/push        1/mod/*+disp8   0/rm32/eax    .           .             .           .           0xc/disp8       .                 # push *(eax+12)
    # . . call
    e8/call  check-ints-equal/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               0xc/imm32         # add to esp
    # pop into *Trace-stream
    8f          0/subop/pop         0/mod/indirect  5/rm32/.disp32            .             .           .           Trace-stream/disp32               # pop into *Trace-stream
    # end
    c3/return

test-trace-empty-line:
    # push *Trace-stream
    ff          6/subop/push        0/mod/indirect  5/rm32/.disp32            .             .           .           Trace-stream/disp32               # push *Trace-stream
    # *Trace-stream = _test-trace-stream
    b8/copy-to-eax  _test-trace-stream/imm32
    89/copy                         0/mod/indirect  5/rm32/.disp32            .             .           0/r32/eax   Trace-stream/disp32               # copy eax to *Trace-stream
    # clear-trace-stream()
    e8/call  clear-trace-stream/disp32
    # trace("")
    # . . push args
    68/push  ""/imm32
    # . . call
    e8/call  trace/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               4/imm32           # add to esp
    # check-ints-equal(*_test-trace-stream->data, 0, msg)
    # . . push args
    68/push  "F - test-trace-empty-line"/imm32
    68/push  0/imm32
    # . . push *_test-trace-stream->data
    b8/copy-to-eax  _test-trace-stream/imm32
    ff          6/subop/push        1/mod/*+disp8   0/rm32/eax    .           .             .           .           0xc/disp8       .                 # push *(eax+12)
    # . . call
    e8/call  check-ints-equal/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               0xc/imm32         # add to esp
    # pop into *Trace-stream
    8f          0/subop/pop         0/mod/indirect  5/rm32/.disp32            .             .           .           Trace-stream/disp32               # pop into *Trace-stream
    # end
    c3/return

check-trace-contains:  # line: (addr string), msg: (addr string)
    # . prologue
    55/push-ebp
    89/copy                         3/mod/direct    5/rm32/ebp    .           .             .           4/r32/esp   .               .                 # copy esp to ebp
    # rewind-stream(*Trace-stream)
    # . . push args
    ff          6/subop/push        0/mod/indirect  5/rm32/.disp32            .             .           .           Trace-stream/disp32               # push *Trace-stream
    # . . call
    e8/call  rewind-stream/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               4/imm32           # add to esp
    # check-trace-scans-to(line, msg)
    # . . push args
    ff          6/subop/push        1/mod/*+disp8   5/rm32/ebp    .           .             .           .           0xc/disp8       .                 # push *(ebp+12)
    ff          6/subop/push        1/mod/*+disp8   5/rm32/ebp    .           .             .           .           8/disp8         .                 # push *(ebp+8)
    # . . call
    e8/call  check-trace-scans-to/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
$check-trace-contains:end:
    # . epilogue
    89/copy                         3/mod/direct    4/rm32/esp    .           .             .           5/r32/ebp   .               .                 # copy ebp to esp
    5d/pop-to-ebp
    c3/return

check-trace-scans-to:  # line: (addr string), msg: (addr string)
    # . prologue
    55/push-ebp
    89/copy                         3/mod/direct    5/rm32/ebp    .           .             .           4/r32/esp   .               .                 # copy esp to ebp
    # . save registers
    50/push-eax
    # eax = trace-scan(line)
    # . . push args
    ff          6/subop/push        1/mod/*+disp8   5/rm32/ebp    .           .             .           .           8/disp8         .                 # push *(ebp+8)
    # . . call
    e8/call  trace-scan/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               4/imm32           # add to esp
    # check-ints-equal(eax, 1, msg)
    # . . push args
    ff          6/subop/push        1/mod/*+disp8   5/rm32/ebp    .           .             .           .           0xc/disp8       .                 # push *(ebp+12)
    68/push  1/imm32
    50/push-eax
    # . . call
    e8/call check-ints-equal/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               0xc/imm32         # add to esp
$check-trace-scans-to:end:
    # . restore registers
    58/pop-to-eax
    # . epilogue
    89/copy                         3/mod/direct    4/rm32/esp    .           .             .           5/r32/ebp   .               .                 # copy ebp to esp
    5d/pop-to-ebp
    c3/return

# Start scanning from Trace-stream->read for 'line'. If found, update Trace-stream->read and return true.
trace-scan:  # line: (addr array byte) -> result/eax: boolean
    # pseudocode:
    #   push Trace-stream->read
    #   while true:
    #     if Trace-stream->read >= Trace-stream->write
    #       break
    #     if next-line-matches?(Trace-stream, line)
    #       skip-next-line(Trace-stream)
    #       dump saved copy of Trace-stream->read
    #       return true
    #     skip-next-line(Trace-stream)
    #   pop saved copy of Trace-stream->read
    #   return false
    #
    # . prologue
    55/push-ebp
    89/copy                         3/mod/direct    5/rm32/ebp    .           .             .           4/r32/esp   .               .                 # copy esp to ebp
    # . save registers
    51/push-ecx
    56/push-esi
    # esi = *Trace-stream
    8b/copy                         0/mod/indirect  5/rm32/.disp32            .             .           6/r32/esi   Trace-stream/disp32               # copy *Trace-stream to esi
    # ecx = Trace-stream->write
    8b/copy                         0/mod/indirect  6/rm32/esi    .           .             .           1/r32/ecx                   .                 # copy *esi to ecx
    # push Trace-stream->read
    ff          6/subop/push        1/mod/*+disp8   6/rm32/esi    .           .             .           .           4/disp8         .                 # push *(esi+4)
$trace-scan:loop:
    # if (Trace-stream->read >= Trace-stream->write) return false
    39/compare                      1/mod/*+disp8   6/rm32/esi    .           .             .           1/r32/ecx   4/disp8         .                 # compare ecx with *(esi+4)
    7d/jump-if->=  $trace-scan:false/disp8
    # eax = next-line-matches?(Trace-stream, line)
    # . . push args
    ff          6/subop/push        1/mod/*+disp8   5/rm32/ebp    .           .             .           .           8/disp8         .                 # push *(ebp+8)
    56/push-esi
    # . . call
    e8/call  next-line-matches?/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
    # if (eax == false) continue
    3d/compare-eax-and  0/imm32/false
    74/jump-if-=  $trace-scan:continue/disp8
$trace-scan:true:
    # skip-next-line(Trace-stream)
    # . . push args
    56/push-esi
    # . . call
    e8/call  skip-next-line/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               4/imm32           # add to esp
    # dump saved copy of Trace-stream->read
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               4/imm32           # add to esp
    # return true
    b8/copy-to-eax  1/imm32/true
    eb/jump  $trace-scan:end/disp8
$trace-scan:continue:
    # skip-next-line(Trace-stream)
    # . . push args
    56/push-esi
    # . . call
    e8/call  skip-next-line/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               4/imm32           # add to esp
    eb/jump  $trace-scan:loop/disp8
$trace-scan:false:
    # restore saved copy of Trace-stream->read
    8f          0/subop/pop         1/mod/*+disp8   6/rm32/esi    .           .             .           .           4/disp8         .                 # pop to *(esi+4)
    # return false
    b8/copy-to-eax  0/imm32/false
$trace-scan:end:
    # . restore registers
    59/pop-to-ecx
    # . epilogue
    89/copy                         3/mod/direct    4/rm32/esp    .           .             .           5/r32/ebp   .               .                 # copy ebp to esp
    5d/pop-to-ebp
    c3/return

test-trace-scan-first:
    # push *Trace-stream
    ff          6/subop/push        0/mod/indirect  5/rm32/.disp32            .             .           .           Trace-stream/disp32               # push *Trace-stream
    # setup
    # . *Trace-stream = _test-trace-stream
    b8/copy-to-eax  _test-trace-stream/imm32
    89/copy                         0/mod/indirect  5/rm32/.disp32            .             .           0/r32/eax   Trace-stream/disp32               # copy eax to *Trace-stream
    # . clear-trace-stream()
    e8/call  clear-trace-stream/disp32
    # . trace("Ab")
    # . . push args
    68/push  "Ab"/imm32
    # . . call
    e8/call  trace/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               4/imm32           # add to esp
    # eax = trace-scan("Ab")
    # . . push args
    68/push  "Ab"/imm32
    # . . call
    e8/call  trace-scan/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               4/imm32           # add to esp
    # check-ints-equal(eax, 1, msg)
    # . . push args
    68/push  "F - test-trace-scan-first"/imm32
    68/push  1/imm32
    50/push-eax
    # . . call
    e8/call check-ints-equal/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               0xc/imm32         # add to esp
    # pop into *Trace-stream
    8f          0/subop/pop         0/mod/indirect  5/rm32/.disp32            .             .           .           Trace-stream/disp32               # pop into *Trace-stream
    # . end
    c3/return

test-trace-scan-skips-lines-until-found:
    # push *Trace-stream
    ff          6/subop/push        0/mod/indirect  5/rm32/.disp32            .             .           .           Trace-stream/disp32               # push *Trace-stream
    # setup
    # . *Trace-stream = _test-trace-stream
    b8/copy-to-eax  _test-trace-stream/imm32
    89/copy                         0/mod/indirect  5/rm32/.disp32            .             .           0/r32/eax   Trace-stream/disp32               # copy eax to *Trace-stream
    # . clear-trace-stream()
    e8/call  clear-trace-stream/disp32
    # . trace("Ab")
    # . . push args
    68/push  "Ab"/imm32
    # . . call
    e8/call  trace/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               4/imm32           # add to esp
    # . trace("cd")
    # . . push args
    68/push  "cd"/imm32
    # . . call
    e8/call  trace/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               4/imm32           # add to esp
    # eax = trace-scan("cd")
    # . . push args
    68/push  "cd"/imm32
    # . . call
    e8/call  trace-scan/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               4/imm32           # add to esp
    # check-ints-equal(eax, 1, msg)
    # . . push args
    68/push  "F - test-trace-scan-skips-lines-until-found"/imm32
    68/push  1/imm32
    50/push-eax
    # . . call
    e8/call check-ints-equal/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               0xc/imm32         # add to esp
    # pop into *Trace-stream
    8f          0/subop/pop         0/mod/indirect  5/rm32/.disp32            .             .           .           Trace-stream/disp32               # pop into *Trace-stream
    # . end
    c3/return

test-trace-second-scan-starts-where-first-left-off:
    # push *Trace-stream
    ff          6/subop/push        0/mod/indirect  5/rm32/.disp32            .             .           .           Trace-stream/disp32               # push *Trace-stream
    # setup
    # . *Trace-stream = _test-trace-stream
    b8/copy-to-eax  _test-trace-stream/imm32
    89/copy                         0/mod/indirect  5/rm32/.disp32            .             .           0/r32/eax   Trace-stream/disp32               # copy eax to *Trace-stream
    # . clear-trace-stream()
    e8/call  clear-trace-stream/disp32
    # . trace("Ab")
    # . . push args
    68/push  "Ab"/imm32
    # . . call
    e8/call  trace/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               4/imm32           # add to esp
    # . eax = trace-scan("Ab")
    # . . push args
    68/push  "Ab"/imm32
    # . . call
    e8/call  trace-scan/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               4/imm32           # add to esp
    # second scan fails
    # . eax = trace-scan("Ab")
    # . . push args
    68/push  "Ab"/imm32
    # . . call
    e8/call  trace-scan/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               4/imm32           # add to esp
    # check-ints-equal(eax, 0, msg)
    # . . push args
    68/push  "F - test-trace-second-scan-starts-where-first-left-off"/imm32
    68/push  0/imm32
    50/push-eax
    # . . call
    e8/call check-ints-equal/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               0xc/imm32         # add to esp
    # pop into *Trace-stream
    8f          0/subop/pop         0/mod/indirect  5/rm32/.disp32            .             .           .           Trace-stream/disp32               # pop into *Trace-stream
    # . end
    c3/return

test-trace-scan-failure-leaves-read-index-untouched:
    # push *Trace-stream
    ff          6/subop/push        0/mod/indirect  5/rm32/.disp32            .             .           .           Trace-stream/disp32               # push *Trace-stream
    # setup
    # . *Trace-stream = _test-trace-stream
    b8/copy-to-eax  _test-trace-stream/imm32
    89/copy                         0/mod/indirect  5/rm32/.disp32            .             .           0/r32/eax   Trace-stream/disp32               # copy eax to *Trace-stream
    # . clear-trace-stream()
    e8/call  clear-trace-stream/disp32
    # . trace("Ab")
    # . . push args
    68/push  "Ab"/imm32
    # . . call
    e8/call  trace/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               4/imm32           # add to esp
    # . check-ints-equal(_test-trace-stream->read, 0, msg)
    # . . push args
    68/push  "F - test-trace-second-scan-starts-where-first-left-off/precondition-failure"/imm32
    68/push  0/imm32
    b8/copy-to-eax  _test-trace-stream/imm32
    ff          6/subop/push        1/mod/*+disp8   0/rm32/eax    .           .             .           .           4/disp8         .                 # push *(eax+4)
    # . . call
    e8/call check-ints-equal/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               0xc/imm32         # add to esp
    # perform a failing scan
    # . eax = trace-scan("Ax")
    # . . push args
    68/push  "Ax"/imm32
    # . . call
    e8/call  trace-scan/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               4/imm32           # add to esp
    # no change in read index
    # . check-ints-equal(_test-trace-stream->read, 0, msg)
    # . . push args
    68/push  "F - test-trace-second-scan-starts-where-first-left-off"/imm32
    68/push  0/imm32
    b8/copy-to-eax  _test-trace-stream/imm32
    ff          6/subop/push        1/mod/*+disp8   0/rm32/eax    .           .             .           .           4/disp8         .                 # push *(eax+4)
    # . . call
    e8/call check-ints-equal/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               0xc/imm32         # add to esp
    # pop into *Trace-stream
    8f          0/subop/pop         0/mod/indirect  5/rm32/.disp32            .             .           .           Trace-stream/disp32               # pop into *Trace-stream
    # . end
    c3/return

next-line-matches?:  # t: (addr stream byte), line: (addr array byte) -> result/eax: boolean
    # pseudocode:
    #   while true:
    #     if (currl >= maxl) break
    #     if (currt >= maxt) return false
    #     if (*currt != *currl) return false
    #     ++currt
    #     ++currl
    #   return *currt == '\n'
    #
    # . prologue
    55/push-ebp
    89/copy                         3/mod/direct    5/rm32/ebp    .           .             .           4/r32/esp   .               .                 # copy esp to ebp
    # . save registers
    51/push-ecx
    52/push-edx
    53/push-ebx
    56/push-esi
    57/push-edi
    # edx = line
    8b/copy                         1/mod/*+disp8   5/rm32/ebp    .           .                         2/r32/edx   0xc/disp8       .                 # copy *(ebp+12) to edx
    # var currl/esi: (addr byte) = line->data
    # . esi = line/edx->data
    8d/copy-address                 1/mod/*+disp8   2/rm32/edx    .           .             .           6/r32/esi   4/disp8         .                 # copy edx+4 to esi
    # var maxl/ecx: (addr byte) = &line->data[line->size]
    # . eax = line/edx->size
    8b/copy                         0/mod/indirect  2/rm32/edx    .           .                         0/r32/eax   .               .                 # copy *edx to eax
    # . maxl = &line->data[line->size]
    8d/copy-address                 0/mod/indirect  4/rm32/sib    6/base/esi  0/index/eax   .           1/r32/ecx   .               .                 # copy edx+eax to ecx
    # edi = t
    8b/copy                         1/mod/*+disp8   5/rm32/ebp    .           .                         7/r32/edi   8/disp8         .                 # copy *(ebp+8) to edi
    # var ebx: (addr byte) = t->data
    8d/copy-address                 1/mod/*+disp8   7/rm32/edi    .           .             .           3/r32/ebx   0xc/disp8       .                 # copy edi+12 to ebx
    # var maxt/edx: (addr byte) = &t->data[t->write]
    # . eax = t->write
    8b/copy                         0/mod/indirect  7/rm32/edi    .           .                         0/r32/eax   .               .                 # copy *edi to eax
    # . maxt = &t->data[t->write]
    8d/copy-address                 0/mod/indirect  4/rm32/sib    3/base/ebx  0/index/eax   .           2/r32/edx   .               .                 # copy ebx+eax to edx
    # var currt/edi: (addr byte) = &t->data[t->read]
    # . eax = t/edi->read
    8b/copy                         1/mod/*+disp8   7/rm32/edi    .           .                         0/r32/eax   4/disp8         .                 # copy *(edi+4) to eax
    # . currt = &t->data[t->read]
    8d/copy-address                 0/mod/indirect  4/rm32/sib    3/base/ebx  0/index/eax   .           7/r32/edi   .               .                 # copy ebx+eax to edi
$next-line-matches?:loop:
    # if (currl >= maxl) break
    39/compare                      3/mod/direct    6/rm32/esi    .           .             .           1/r32/ecx   .               .                 # compare esi and ecx
    73/jump-if-addr>=  $next-line-matches?:break/disp8
    # if (currt >= maxt) return false
    # . eax = false
    b8/copy-to-eax  0/imm32/false
    39/compare                      3/mod/direct    7/rm32/edi    .           .             .           2/r32/edx   .               .                 # compare edi and edx
    73/jump-if-addr>=  $next-line-matches?:end/disp8
    # if (*currt != *currl) return false
    31/xor                          3/mod/direct    0/rm32/eax    .           .             .           0/r32/eax   .               .                 # clear eax
    31/xor                          3/mod/direct    3/rm32/eax    .           .             .           3/r32/eax   .               .                 # clear ebx
    # . eax: byte = *currt
    8a/copy-byte                    0/mod/indirect  7/rm32/edi    .           .                         0/r32/eax   .               .                 # copy *edi to eax
    # . ebx: byte = *currl
    8a/copy-byte                    0/mod/indirect  6/rm32/esi    .           .                         3/r32/ebx   .               .                 # copy *esi to ebx
    # . eax >= ebx
    39/compare                      3/mod/direct    0/rm32/eax    .           .             .           3/r32/ebx   .               .                 # compare eax and ebx
    # . eax = false
    b8/copy-to-eax  0/imm32/false
    75/jump-if-!=  $next-line-matches?:end/disp8
    # ++currt
    47/increment-edi
    # ++currl
    46/increment-esi
    eb/jump  $next-line-matches?:loop/disp8
$next-line-matches?:break:
    # return *currt == '\n'
    31/xor                          3/mod/direct    0/rm32/eax    .           .             .           0/r32/eax   .               .                 # clear eax
    # . eax: byte = *currt
    8a/copy-byte                    0/mod/indirect  7/rm32/edi    .           .                         0/r32/eax   .               .                 # copy *edi to eax
    3d/compare-eax-and  0xa/imm32/newline
    # . eax = false
    b8/copy-to-eax  1/imm32/true
    74/jump-if-=  $next-line-matches?:end/disp8
    b8/copy-to-eax  0/imm32/true
$next-line-matches?:end:
    # . restore registers
    5f/pop-to-edi
    5e/pop-to-esi
    5b/pop-to-ebx
    5a/pop-to-edx
    59/pop-to-ecx
    # . epilogue
    89/copy                         3/mod/direct    4/rm32/esp    .           .             .           5/r32/ebp   .               .                 # copy ebp to esp
    5d/pop-to-ebp
    c3/return

test-next-line-matches?-no-match-1:
    # next line of "ABABA" does not match "blah blah"
    # . eax = next-line-matches?(_test-stream-line-ABABA, "blah blah")
    # . . push args
    68/push  "blah blah"/imm32
    68/push  _test-stream-line-ABABA/imm32
    # . . call
    e8/call  next-line-matches?/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
    # . check-ints-equal(eax, 0, msg)
    # . . push args
    68/push  "F - test-next-line-matches?-no-match-1"/imm32
    68/push  0/imm32
    50/push-eax
    # . . call
    e8/call  check-ints-equal/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               0xc/imm32         # add to esp
    c3/return

test-next-line-matches?-no-match-2:
    # next line of "ABABA" does not match ""
    # . eax = next-line-matches?(_test-stream-line-ABABA, "")
    # . . push args
    68/push  ""/imm32
    68/push  _test-stream-line-ABABA/imm32
    # . . call
    e8/call  next-line-matches?/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
    # . check-ints-equal(eax, 0, msg)
    # . . push args
    68/push  "F - test-next-line-matches?-no-match-2"/imm32
    68/push  0/imm32
    50/push-eax
    # . . call
    e8/call  check-ints-equal/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               0xc/imm32         # add to esp
    c3/return

test-next-line-matches?-no-match-3:
    # next line of "ABABA" does not match  "AA"
    # . eax = next-line-matches?(_test-stream-line-ABABA, "AA")
    # . . push args
    68/push  "AA"/imm32
    68/push  _test-stream-line-ABABA/imm32
    # . . call
    e8/call  next-line-matches?/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
    # . check-ints-equal(eax, 0, msg)
    # . . push args
    68/push  "F - test-next-line-matches?-no-match-3"/imm32
    68/push  0/imm32
    50/push-eax
    # . . call
    e8/call  check-ints-equal/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               0xc/imm32         # add to esp
    c3/return

test-next-line-matches?-match:
    # next line of "ABABA" matches "ABABA"
    # . eax = next-line-matches?(_test-stream-line-ABABA, "ABABA")
    # . . push args
    68/push  "ABABA"/imm32
    68/push  _test-stream-line-ABABA/imm32
    # . . call
    e8/call  next-line-matches?/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
    # . check-ints-equal(eax, 1, msg)
    # . . push args
    68/push  "F - test-next-line-matches?-match"/imm32
    68/push  1/imm32
    50/push-eax
    # . . call
    e8/call  check-ints-equal/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               0xc/imm32         # add to esp
    c3/return

# move t->read to _after_ next newline
skip-next-line:  # t: (addr stream byte)
    # pseudocode:
    #   max = &t->data[t->write]
    #   i = t->read
    #   curr = &t->data[t->read]
    #   while true
    #     if (curr >= max) break
    #     ++i
    #     if (*curr == '\n') break
    #     ++curr
    #   t->read = i
    #
    # . prologue
    55/push-ebp
    89/copy                         3/mod/direct    5/rm32/ebp    .           .             .           4/r32/esp   .               .                 # copy esp to ebp
    # . save registers
    50/push-eax
    51/push-ecx
    52/push-edx
    53/push-ebx
    # ecx = t
    8b/copy                         1/mod/*+disp8   5/rm32/ebp    .           .                         1/r32/ecx   8/disp8         .                 # copy *(ebp+8) to ecx
    # edx = t->data
    8d/copy-address                 1/mod/*+disp8   1/rm32/ecx    .           .             .           2/r32/edx   0xc/disp8       .                 # copy ecx+12 to edx
    # eax = t->write
    8b/copy                         0/mod/indirect  1/rm32/ecx    .           .             .           0/r32/eax   .               .                 # copy *ecx to eax
    # var max/ebx: (addr byte) = &t->data[t->write]
    8d/copy-address                 0/mod/indirect  4/rm32/sib    2/base/edx  0/index/eax   .           3/r32/ebx   .               .                 # copy edx+eax to ebx
    # eax = t->read
    8b/copy                         1/mod/*+disp8   1/rm32/ecx    .           .             .           0/r32/eax   4/disp8         .                 # copy *(ecx+4) to edx
    # var curr/ecx: (addr byte) = &t->data[t->read]
    8d/copy-address                 0/mod/indirect  4/rm32/sib    2/base/edx  0/index/eax   .           1/r32/ecx   .               .                 # copy edx+eax to ecx
    # var i/edx: int = t->read
    89/copy                         3/mod/direct    2/rm32/edx    .           .             .           0/r32/eax   .               .                 # copy eax to edx
$skip-next-line:loop:
    # if (curr >= max) break
    39/compare                      3/mod/direct    1/rm32/ecx    .           .             .           3/r32/ebx   .               .                 # compare ecx and ebx
    73/jump-if-addr>=  $skip-next-line:end/disp8
    # ++i
    42/increment-edx
    # if (*curr == '\n') break
    31/xor                          3/mod/direct    0/rm32/eax    .           .             .           0/r32/eax   .               .                 # clear eax
    8a/copy-byte                    0/mod/indirect  1/rm32/ecx    .           .             .           0/r32/eax   .               .                 # copy *ecx to eax
    3d/compare-eax-and  0a/imm32/newline
    74/jump-if-=  $skip-next-line:end/disp8
    # ++curr
    41/increment-ecx
    # loop
    eb/jump  $skip-next-line:loop/disp8
$skip-next-line:end:
    # ecx = t
    8b/copy                         1/mod/*+disp8   5/rm32/ebp    .           .                         1/r32/ecx   8/disp8         .                 # copy *(ebp+8) to ecx
    # t->read = i
    89/copy                         1/mod/*+disp8   1/rm32/ecx    .           .             .           2/r32/edx   4/disp8         .                 # copy edx to *(ecx+4)
    # . restore registers
    5b/pop-to-ebx
    5a/pop-to-edx
    59/pop-to-ecx
    58/pop-to-eax
    # . epilogue
    89/copy                         3/mod/direct    4/rm32/esp    .           .             .           5/r32/ebp   .               .                 # copy ebp to esp
    5d/pop-to-ebp
    c3/return

test-skip-next-line-empty:
    # skipping next line in empty stream leaves read pointer at 0
    # . skip-next-line(_test-stream-empty)
    # . . push args
    68/push  _test-stream-empty/imm32
    # . . call
    e8/call  skip-next-line/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               4/imm32           # add to esp
    # . check-ints-equal(_test-stream-empty->read, 0, msg)
    # . . push args
    68/push  "F - test-skip-next-line-empty"/imm32
    68/push  0/imm32
    b8/copy-to-eax  _test-stream-empty/imm32
    8b/copy                         1/mod/*+disp8   0/rm32/eax    .           .             .           0/r32/eax   4/disp8         .                 # copy *(eax+4) to eax
    50/push-eax
    # . . call
    e8/call  check-ints-equal/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               0xc/imm32         # add to esp
    c3/return

test-skip-next-line-filled:
    # skipping next line increments read pointer by length of line + 1 (for newline)
    # . skip-next-line(_test-stream-filled)
    # . . push args
    68/push  _test-stream-filled/imm32
    # . . call
    e8/call  skip-next-line/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               4/imm32           # add to esp
    # . check-ints-equal(_test-stream-filled->read, 5, msg)
    # . . push args
    68/push  "F - test-skip-next-line-filled"/imm32
    68/push  5/imm32
    b8/copy-to-eax  _test-stream-filled/imm32
    8b/copy                         1/mod/*+disp8   0/rm32/eax    .           .             .           0/r32/eax   4/disp8         .                 # copy *(eax+4) to eax
    50/push-eax
    # . . call
    e8/call  check-ints-equal/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               0xc/imm32         # add to esp
    c3/return

clear-trace-stream:
    # . prologue
    55/push-ebp
    89/copy                         3/mod/direct    5/rm32/ebp    .           .             .           4/r32/esp   .               .                 # copy esp to ebp
    # clear-stream(*Trace-stream)
    # . . push args
    ff          6/subop/push        0/mod/indirect  5/rm32/.disp32            .             .           .           Trace-stream/disp32               # push *Trace-stream
    # . . call
    e8/call  clear-stream/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               4/imm32           # add to esp
$clear-trace-stream:end:
    # . epilogue
    89/copy                         3/mod/direct    4/rm32/esp    .           .             .           5/r32/ebp   .               .                 # copy ebp to esp
    5d/pop-to-ebp
    c3/return

# - helpers

# 3-argument variant of _append
_append-3:  # out: (addr byte), outend: (addr byte), s: (addr array byte) -> num_bytes_appended/eax
    # . prologue
    55/push-ebp
    89/copy                         3/mod/direct    5/rm32/ebp    .           .             .           4/r32/esp   .               .                 # copy esp to ebp
    # . save registers
    51/push-ecx
    # eax = _append-4(out, outend, &s->data[0], &s->data[s->size])
    # . . push &s->data[s->size]
    8b/copy                         1/mod/*+disp8   5/rm32/ebp    .           .                         0/r32/eax   0x10/disp8      .                 # copy *(ebp+16) to eax
    8b/copy                         0/mod/indirect  0/rm32/eax    .           .             .           1/r32/ecx   .               .                 # copy *eax to ecx
    8d/copy-address                 1/mod/*+disp8   4/rm32/sib    0/base/eax  1/index/ecx   .           1/r32/ecx   4/disp8         .                 # copy eax+ecx+4 to ecx
    51/push-ecx
    # . . push &s->data[0]
    8d/copy-address                 1/mod/*+disp8   0/rm32/eax    .           .             .           1/r32/ecx   4/disp8         .                 # copy eax+4 to ecx
    51/push-ecx
    # . . push outend
    ff          6/subop/push        1/mod/*+disp8   5/rm32/ebp    .           .             .           .           0xc/disp8       .                 # push *(ebp+12)
    # . . push out
    ff          6/subop/push        1/mod/*+disp8   5/rm32/ebp    .           .             .           .           8/disp8         .                 # push *(ebp+8)
    # . . call
    e8/call  _append-4/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               0x10/imm32        # add to esp
$_append-3:end:
    # . restore registers
    59/pop-to-ecx
    # . epilogue
    89/copy                         3/mod/direct    4/rm32/esp    .           .             .           5/r32/ebp   .               .                 # copy ebp to esp
    5d/pop-to-ebp
    c3/return

# 4-argument variant of _append
_append-4:  # out: (addr byte), outend: (addr byte), in: (addr byte), inend: (addr byte) -> num_bytes_appended/eax: int
    # . prologue
    55/push-ebp
    89/copy                         3/mod/direct    5/rm32/ebp    .           .             .           4/r32/esp   .               .                 # copy esp to ebp
    # . save registers
    51/push-ecx
    52/push-edx
    53/push-ebx
    56/push-esi
    57/push-edi
    # num_bytes_appended = 0
    b8/copy-to-eax  0/imm32
    # edi = out
    8b/copy                         1/mod/*+disp8   5/rm32/ebp    .           .             .           7/r32/edi   8/disp8         .                 # copy *(ebp+8) to edi
    # edx = outend
    8b/copy                         1/mod/*+disp8   5/rm32/ebp    .           .             .           2/r32/edx   0xc/disp8       .                 # copy *(ebp+12) to edx
    # esi = in
    8b/copy                         1/mod/*+disp8   5/rm32/ebp    .           .             .           6/r32/esi   0x10/disp8      .                 # copy *(ebp+16) to esi
    # ecx = inend
    8b/copy                         1/mod/*+disp8   5/rm32/ebp    .           .             .           1/r32/ecx   0x14/disp8      .                 # copy *(ebp+20) to ecx
$_append-4:loop:
    # if (in >= inend) break
    39/compare                      3/mod/direct    6/rm32/esi    .           .             .           1/r32/ecx   .               .                 # compare esi with ecx
    73/jump-if-addr>=  $_append-4:end/disp8
    # if (out >= outend) abort  # just to catch test failures fast
    39/compare                      3/mod/direct    7/rm32/edi    .           .             .           2/r32/edx   .               .                 # compare edi with edx
    73/jump-if-addr>=  $_append-4:abort/disp8
    # *out = *in
    8a/copy-byte                    0/mod/indirect  6/rm32/esi    .           .             .           3/r32/BL    .               .                 # copy byte at *esi to BL
    88/copy-byte                    0/mod/indirect  7/rm32/edi    .           .             .           3/r32/BL    .               .                 # copy byte at BL to *edi
    # ++num_bytes_appended
    40/increment-eax
    # ++in
    46/increment-esi
    # ++out
    47/increment-edi
    eb/jump  $_append-4:loop/disp8
$_append-4:end:
    # . restore registers
    5f/pop-to-edi
    5e/pop-to-esi
    5b/pop-to-ebx
    5a/pop-to-edx
    59/pop-to-ecx
    # . epilogue
    89/copy                         3/mod/direct    4/rm32/esp    .           .             .           5/r32/ebp   .               .                 # copy ebp to esp
    5d/pop-to-ebp
    c3/return

$_append-4:abort:
    # . _write(2/stderr, error)
    # . . push args
    68/push  "stream overflow\n"/imm32
    68/push  2/imm32/stderr
    # . . call
    e8/call  _write/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
    # . syscall(exit, 1)
    bb/copy-to-ebx  1/imm32
    e8/call  syscall_exit/disp32
    # never gets here

== data

_test-stream-line-ABABA:  # (stream byte)
    # write
    8/imm32
    # read
    0/imm32
    # size
    8/imm32
    # data
    41 42 41 42 41 0a 00 00  # 8 bytes

_test-stream-empty:  # (stream byte)
    # write
    0/imm32
    # read
    0/imm32
    # size
    8/imm32
    # data
    00 00 00 00 00 00 00 00  # 8 bytes

_test-stream-filled:  # (stream byte)
    # write
    8/imm32
    # read
    0/imm32
    # size
    8/imm32
    # data
    41 41 41 41 0a 41 41 41  # 8 bytes

# . . vim:nowrap:textwidth=0