5437

Break a dependency from `print-int32` to `from-hex-char`.

1 files changed, 389 insertions, 0 deletions

diff --git a/subx/066print-int.subx b/subx/066print-int.subx
new file mode 100644
index 00000000..c5968837
--- /dev/null
+++ b/subx/066print-int.subx
@@ -0,0 +1,389 @@
+# Print the (hex) textual representation of numbers.
+
+== 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
+
+to-hex-char:  # in/EAX : nibble -> out/EAX : byte
+    # no error checking; accepts argument in EAX
+    # if (EAX <= 9) return EAX + '0'
+    3d/compare-EAX-with  0x9/imm32/9
+    7f/jump-if-greater  $to-hex-char:else/disp8
+    05/add-to-EAX  0x30/imm32/0
+    c3/return
+$to-hex-char:else:
+    # otherwise return EAX + 'a' - 10
+    05/add-to-EAX  0x57/imm32/a-10
+    c3/return
+
+append-byte-hex:  # f : (address stream), n : int -> <void>
+    # . prolog
+    55/push-EBP
+    89/copy                         3/mod/direct    5/rm32/EBP    .           .             .           4/r32/ESP   .               .                 # copy ESP to EBP
+    # . save registers
+    50/push-EAX
+    # AL = convert upper nibble to hex
+    8b/copy                         1/mod/*+disp8   5/rm32/EBP    .           .             .           0/r32/EAX   0xc/disp8       .                 # copy *(EBP+12) to EAX
+    c1/shift    5/subop/logic-right 3/mod/direct    0/rm32/EAX    .           .             .           .           .               4/imm8            # shift EAX right by 4 bits, while padding zeroes
+    25/and-EAX  0xf/imm32
+    # . AL = to-hex-char(AL)
+    e8/call  to-hex-char/disp32
+    # append-byte(f, AL)
+    # . . push args
+    50/push-EAX
+    ff          6/subop/push        1/mod/*+disp8   5/rm32/EBP    .           .             .           .           8/disp8         .                 # push *(EBP+8)
+    # . . call
+    e8/call  append-byte/disp32
+    # . . discard args
+    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add to ESP
+    # AL = convert lower nibble to hex
+    8b/copy                         1/mod/*+disp8   5/rm32/EBP    .           .             .           0/r32/EAX   0xc/disp8       .                 # copy *(EBP+12) to EAX
+    25/and-EAX  0xf/imm32
+    # . AL = to-hex-char(AL)
+    e8/call  to-hex-char/disp32
+    # append-byte(f, AL)
+    # . . push args
+    50/push-EAX
+    ff          6/subop/push        1/mod/*+disp8   5/rm32/EBP    .           .             .           .           8/disp8         .                 # push *(EBP+8)
+    # . . call
+    e8/call  append-byte/disp32
+    # . . discard args
+    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add to ESP
+$append-byte-hex:end:
+    # . restore registers
+    58/pop-to-EAX
+    # . epilog
+    89/copy                         3/mod/direct    4/rm32/ESP    .           .             .           5/r32/EBP   .               .                 # copy EBP to ESP
+    5d/pop-to-EBP
+    c3/return
+
+test-append-byte-hex:
+    # - check that append-byte-hex adds the hex textual representation
+    # setup
+    # . clear-stream(_test-stream)
+    # . . push args
+    68/push  _test-stream/imm32
+    # . . call
+    e8/call  clear-stream/disp32
+    # . . discard args
+    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               4/imm32           # add to ESP
+    # append-byte-hex(_test-stream, 0xa)  # exercises digit, non-digit as well as leading zero
+    # . . push args
+    68/push  0xa/imm32
+    68/push  _test-stream/imm32
+    # . . call
+    e8/call  append-byte-hex/disp32
+    # . . discard args
+    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add to ESP
+    # check-stream-equal(_test-stream, "0a", msg)
+    # . . push args
+    68/push  "F - test-append-byte-hex"/imm32
+    68/push  "0a"/imm32
+    68/push  _test-stream/imm32
+    # . . call
+    e8/call  check-stream-equal/disp32
+    # . . discard args
+    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               0xc/imm32         # add to ESP
+    # . end
+    c3/return
+
+# print the hex representation for the lowest byte of a number
+print-byte-buffered:  # f : (address buffered-file), n : int -> <void>
+    # . prolog
+    55/push-EBP
+    89/copy                         3/mod/direct    5/rm32/EBP    .           .             .           4/r32/ESP   .               .                 # copy ESP to EBP
+    # . save registers
+    50/push-EAX
+    # AL = convert upper nibble to hex
+    8b/copy                         1/mod/*+disp8   5/rm32/EBP    .           .             .           0/r32/EAX   0xc/disp8       .                 # copy *(EBP+12) to EAX
+    c1/shift    5/subop/logic-right 3/mod/direct    0/rm32/EAX    .           .             .           .           .               4/imm8            # shift EAX right by 4 bits, while padding zeroes
+    25/and-EAX  0xf/imm32
+    # . AL = to-hex-char(AL)
+    e8/call  to-hex-char/disp32
+    # write-byte-buffered(f, AL)
+    # . . push args
+    50/push-EAX
+    ff          6/subop/push        1/mod/*+disp8   5/rm32/EBP    .           .             .           .           8/disp8         .                 # push *(EBP+8)
+    # . . call
+    e8/call  write-byte-buffered/disp32
+    # . . discard args
+    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add to ESP
+    # AL = convert lower nibble to hex
+    8b/copy                         1/mod/*+disp8   5/rm32/EBP    .           .             .           0/r32/EAX   0xc/disp8       .                 # copy *(EBP+12) to EAX
+    25/and-EAX  0xf/imm32
+    # . AL = to-hex-char(AL)
+    e8/call  to-hex-char/disp32
+    # write-byte-buffered(f, AL)
+    # . . push args
+    50/push-EAX
+    ff          6/subop/push        1/mod/*+disp8   5/rm32/EBP    .           .             .           .           8/disp8         .                 # push *(EBP+8)
+    # . . call
+    e8/call  write-byte-buffered/disp32
+    # . . discard args
+    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add to ESP
+$print-byte-buffered:end:
+    # . restore registers
+    58/pop-to-EAX
+    # . epilog
+    89/copy                         3/mod/direct    4/rm32/ESP    .           .             .           5/r32/EBP   .               .                 # copy EBP to ESP
+    5d/pop-to-EBP
+    c3/return
+
+test-print-byte-buffered:
+    # - check that print-byte-buffered prints the hex textual representation
+    # setup
+    # . clear-stream(_test-stream)
+    # . . push args
+    68/push  _test-stream/imm32
+    # . . call
+    e8/call  clear-stream/disp32
+    # . . discard args
+    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               4/imm32           # add to ESP
+    # . clear-stream(_test-buffered-file+4)
+    # . . push args
+    b8/copy-to-EAX  _test-buffered-file/imm32
+    05/add-to-EAX  4/imm32
+    50/push-EAX
+    # . . call
+    e8/call  clear-stream/disp32
+    # . . discard args
+    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               4/imm32           # add to ESP
+    # print-byte-buffered(_test-buffered-file, 0xa)  # exercises digit, non-digit as well as leading zero
+    # . . push args
+    68/push  0xa/imm32
+    68/push  _test-buffered-file/imm32
+    # . . call
+    e8/call  print-byte-buffered/disp32
+    # . . discard args
+    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add to ESP
+    # flush(_test-buffered-file)
+    # . . push args
+    68/push  _test-buffered-file/imm32
+    # . . call
+    e8/call  flush/disp32
+    # . . discard args
+    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               4/imm32           # add to ESP
+    # check-stream-equal(_test-stream, "0a", msg)
+    # . . push args
+    68/push  "F - test-print-byte-buffered"/imm32
+    68/push  "0a"/imm32
+    68/push  _test-stream/imm32
+    # . . call
+    e8/call  check-stream-equal/disp32
+    # . . discard args
+    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               0xc/imm32         # add to ESP
+    # . end
+    c3/return
+
+print-int32:  # f : (address stream), n : int -> <void>
+    # pseudocode:
+    #  write(f, "0x")
+    #  ECX = 28
+    #  while true
+    #    if (ECX < 0) break
+    #    EAX = n >> ECX
+    #    EAX = EAX & 0xf
+    #    append-byte(f, AL)
+    #    ECX -= 4
+    #
+    # . prolog
+    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 = 28
+    b9/copy-to-ECX  0x1c/imm32
+$print-int32:print-hex-prefix:
+    # write(f, "0x")
+    # . . push args
+    68/push  "0x"/imm32
+    ff          6/subop/push        1/mod/*+disp8   5/rm32/EBP    .           .             .           .           8/disp8         .                 # push *(EBP+8)
+    # . . call
+    e8/call  write/disp32
+    # . . discard args
+    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add to ESP
+$print-int32:loop:
+    # if (ECX < 0) break
+    81          7/subop/compare     3/mod/direct    1/rm32/ECX    .           .             .           .           .               0/imm32           # compare ECX
+    7c/jump-if-lesser  $print-int32:end/disp8
+    # EAX = n >> ECX
+    8b/copy                         1/mod/*+disp8   5/rm32/EBP    .           .             .           0/r32/EAX   0xc/disp8       .                 # copy *(EBP+12) to EAX
+    d3/>>ECX    5/subop/pad-zeroes  3/mod/direct    0/rm32/EAX    .           .             .           .           .               .                 # shift EAX right by ECX bits, padding zeroes
+    # EAX = to-hex-char(AL)
+    25/and-EAX  0xf/imm32
+    e8/call  to-hex-char/disp32
+    # append-byte(f, AL)
+    # . . push args
+    50/push-EAX
+    ff          6/subop/push        1/mod/*+disp8   5/rm32/EBP    .           .             .           .           8/disp8         .                 # push *(EBP+8)
+    # . . call
+    e8/call  append-byte/disp32
+    # . . discard args
+    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add to ESP
+    # ECX -= 4
+    81          5/subop/subtract    3/mod/direct    1/rm32/ECX    .           .             .           .           .               4/imm32           # subtract from ECX
+    eb/jump  $print-int32:loop/disp8
+$print-int32:end:
+    # . restore registers
+    59/pop-to-ECX
+    58/pop-to-EAX
+    # . epilog
+    89/copy                         3/mod/direct    4/rm32/ESP    .           .             .           5/r32/EBP   .               .                 # copy EBP to ESP
+    5d/pop-to-EBP
+    c3/return
+
+test-print-int32:
+    # - check that print-int32 prints the hex textual representation
+    # setup
+    # . clear-stream(_test-stream)
+    # . . push args
+    68/push  _test-stream/imm32
+    # . . call
+    e8/call  clear-stream/disp32
+    # . . discard args
+    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               4/imm32           # add to ESP
+    # print-int32(_test-stream, 0x8899aa)
+    # . . push args
+    68/push  0x8899aa/imm32
+    68/push  _test-stream/imm32
+    # . . call
+    e8/call  print-int32/disp32
+    # . . discard args
+    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add to ESP
+    # check-stream-equal(_test-stream, "0x008899aa", msg)
+    # . . push args
+    68/push  "F - test-print-int32"/imm32
+    68/push  "0x008899aa"/imm32
+    68/push  _test-stream/imm32
+    # . . call
+    e8/call  check-stream-equal/disp32
+    # . . discard args
+    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               0xc/imm32         # add to ESP
+    # . end
+    c3/return
+
+print-int32-buffered:  # f : (address buffered-file), n : int -> <void>
+    # pseudocode:
+    #  write-buffered(f, "0x")
+    #  ECX = 28
+    #  while true
+    #    if (ECX < 0) break
+    #    EAX = n >> ECX
+    #    EAX = EAX & 0xf
+    #    write-byte-buffered(f, AL)
+    #    ECX -= 4
+    #
+    # . prolog
+    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 = 28
+    b9/copy-to-ECX  0x1c/imm32
+$print-int32-buffered:print-hex-prefix:
+    # write-buffered(f, "0x")
+    # . . push args
+    68/push  "0x"/imm32
+    ff          6/subop/push        1/mod/*+disp8   5/rm32/EBP    .           .             .           .           8/disp8         .                 # push *(EBP+8)
+    # . . call
+    e8/call  write-buffered/disp32
+    # . . discard args
+    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add to ESP
+$print-int32-buffered:loop:
+    # if (ECX < 0) break
+    81          7/subop/compare     3/mod/direct    1/rm32/ECX    .           .             .           .           .               0/imm32           # compare ECX
+    7c/jump-if-lesser  $print-int32-buffered:end/disp8
+    # EAX = n >> ECX
+    8b/copy                         1/mod/*+disp8   5/rm32/EBP    .           .             .           0/r32/EAX   0xc/disp8       .                 # copy *(EBP+12) to EAX
+    d3/>>ECX    5/subop/pad-zeroes  3/mod/direct    0/rm32/EAX    .           .             .           .           .               .                 # shift EAX right by ECX bits, padding zeroes
+    # EAX = to-hex-char(AL)
+    25/and-EAX  0xf/imm32
+    e8/call  to-hex-char/disp32
+    # write-byte-buffered(f, AL)
+    # . . push args
+    50/push-EAX
+    ff          6/subop/push        1/mod/*+disp8   5/rm32/EBP    .           .             .           .           8/disp8         .                 # push *(EBP+8)
+    # . . call
+    e8/call  write-byte-buffered/disp32
+    # . . discard args
+    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add to ESP
+    # ECX -= 4
+    81          5/subop/subtract    3/mod/direct    1/rm32/ECX    .           .             .           .           .               4/imm32           # subtract from ECX
+    eb/jump  $print-int32-buffered:loop/disp8
+$print-int32-buffered:end:
+    # . restore registers
+    59/pop-to-ECX
+    58/pop-to-EAX
+    # . epilog
+    89/copy                         3/mod/direct    4/rm32/ESP    .           .             .           5/r32/EBP   .               .                 # copy EBP to ESP
+    5d/pop-to-EBP
+    c3/return
+
+test-print-int32-buffered:
+    # - check that print-int32-buffered prints the hex textual representation
+    # setup
+    # . clear-stream(_test-stream)
+    # . . push args
+    68/push  _test-stream/imm32
+    # . . call
+    e8/call  clear-stream/disp32
+    # . . discard args
+    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               4/imm32           # add to ESP
+    # . clear-stream(_test-buffered-file+4)
+    # . . push args
+    b8/copy-to-EAX  _test-buffered-file/imm32
+    05/add-to-EAX  4/imm32
+    50/push-EAX
+    # . . call
+    e8/call  clear-stream/disp32
+    # . . discard args
+    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               4/imm32           # add to ESP
+    # print-int32-buffered(_test-buffered-file, 0x8899aa)
+    # . . push args
+    68/push  0x8899aa/imm32
+    68/push  _test-buffered-file/imm32
+    # . . call
+    e8/call  print-int32-buffered/disp32
+    # . . discard args
+    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add to ESP
+    # flush(_test-buffered-file)
+    # . . push args
+    68/push  _test-buffered-file/imm32
+    # . . call
+    e8/call  flush/disp32
+    # . . discard args
+    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               4/imm32           # add to ESP
+#?     # dump line {{{
+#?     # . write-stream(2/stderr, line)
+#?     # . . push args
+#?     68/push  _test-stream/imm32
+#?     68/push  2/imm32/stderr
+#?     # . . call
+#?     e8/call  write-stream/disp32
+#?     # . . discard args
+#?     81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add to ESP
+#?     # . write(2/stderr, "$\n")
+#?     # . . push args
+#?     68/push  "$\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
+#?     # }}}
+    # check-stream-equal(_test-stream, "0x008899aa", msg)
+    # . . push args
+    68/push  "F - test-print-int32-buffered"/imm32
+    68/push  "0x008899aa"/imm32
+    68/push  _test-stream/imm32
+    # . . call
+    e8/call  check-stream-equal/disp32
+    # . . discard args
+    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               0xc/imm32         # add to ESP
+    # . end
+    c3/return
+
+# . . vim:nowrap:textwidth=0