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-rw-r--r--linux/118parse-hex-int.subx938
1 files changed, 938 insertions, 0 deletions
diff --git a/linux/118parse-hex-int.subx b/linux/118parse-hex-int.subx
new file mode 100644
index 00000000..5d92b13a
--- /dev/null
+++ b/linux/118parse-hex-int.subx
@@ -0,0 +1,938 @@
+# some utilities for converting numbers from hex
+# lowercase letters only for now
+
+== 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
+
+is-hex-int?:  # in: (addr slice) -> result/eax: boolean
+    # . 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
+    # ecx = s
+    8b/copy                         1/mod/*+disp8   5/rm32/ebp    .           .             .           1/r32/ecx   8/disp8         .                 # copy *(ebp+8) to ecx
+    # edx = s->end
+    8b/copy                         1/mod/*+disp8   1/rm32/ecx    .           .             .           2/r32/edx   4/disp8         .                 # copy *(ecx+4) to edx
+    # var curr/ecx: (addr byte) = s->start
+    8b/copy                         0/mod/indirect  1/rm32/ecx    .           .             .           1/r32/ecx   .               .                 # copy *ecx to ecx
+    # if s is empty return false
+    b8/copy-to-eax  0/imm32/false
+    39/compare                      3/mod/direct    1/rm32/ecx    .           .             .           2/r32/edx   .               .                 # compare ecx with edx
+    73/jump-if-addr>=  $is-hex-int?:end/disp8
+    # skip past leading '-'
+    # . if (*curr == '-') ++curr
+    31/xor                          3/mod/direct    3/rm32/ebx    .           .             .           3/r32/ebx   .               .                 # clear ebx
+    8a/copy-byte                    0/mod/indirect  1/rm32/ecx    .           .             .           3/r32/BL    .               .                 # copy byte at *ecx to BL
+    81          7/subop/compare     3/mod/direct    3/rm32/ebx    .           .             .           .           .               0x2d/imm32/-      # compare ebx
+    75/jump-if-!=  $is-hex-int?:initial-0/disp8
+    # . ++curr
+    41/increment-ecx
+    # skip past leading '0x'
+$is-hex-int?:initial-0:
+    # . if (*curr != '0') jump to loop
+    31/xor                          3/mod/direct    3/rm32/ebx    .           .             .           3/r32/ebx   .               .                 # clear ebx
+    8a/copy-byte                    0/mod/indirect  1/rm32/ecx    .           .             .           3/r32/BL    .               .                 # copy byte at *ecx to BL
+    81          7/subop/compare     3/mod/direct    3/rm32/ebx    .           .             .           .           .               0x30/imm32/0      # compare ebx
+    75/jump-if-!=  $is-hex-int?:loop/disp8
+    # . ++curr
+    41/increment-ecx
+$is-hex-int?:initial-0x:
+    # . if (curr >= in->end) return true
+    39/compare                      3/mod/direct    1/rm32/ecx    .           .             .           2/r32/edx   .               .                 # compare ecx with edx
+    73/jump-if-addr>=  $is-hex-int?:true/disp8
+    # . if (*curr != 'x') jump to loop  # the previous '0' is still valid so doesn't need to be checked again
+    31/xor                          3/mod/direct    3/rm32/ebx    .           .             .           3/r32/ebx   .               .                 # clear ebx
+    8a/copy-byte                    0/mod/indirect  1/rm32/ecx    .           .             .           3/r32/BL    .               .                 # copy byte at *ecx to BL
+    81          7/subop/compare     3/mod/direct    3/rm32/ebx    .           .             .           .           .               0x78/imm32/x      # compare ebx
+    75/jump-if-!=  $is-hex-int?:loop/disp8
+    # . ++curr
+    41/increment-ecx
+$is-hex-int?:loop:
+    # if (curr >= in->end) return true
+    39/compare                      3/mod/direct    1/rm32/ecx    .           .             .           2/r32/edx   .               .                 # compare ecx with edx
+    73/jump-if-addr>=  $is-hex-int?:true/disp8
+    # var eax: boolean = is-hex-digit?(*curr)
+    # . . push args
+    8a/copy-byte                    0/mod/indirect  1/rm32/ecx    .           .             .           0/r32/AL    .               .                 # copy byte at *ecx to AL
+    50/push-eax
+    # . . call
+    e8/call  is-hex-digit?/disp32
+    # . . discard args
+    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               4/imm32           # add to esp
+    # if (eax == false) return false
+    3d/compare-eax-and  0/imm32/false
+    74/jump-if-=  $is-hex-int?:end/disp8
+    # ++curr
+    41/increment-ecx
+    # loop
+    eb/jump  $is-hex-int?:loop/disp8
+$is-hex-int?:true:
+    # return true
+    b8/copy-to-eax  1/imm32/true
+$is-hex-int?:end:
+    # . restore registers
+    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-is-hex-int:
+    # . prologue
+    55/push-ebp
+    89/copy                         3/mod/direct    5/rm32/ebp    .           .             .           4/r32/esp   .               .                 # copy esp to ebp
+    # (eax..ecx) = "34"
+    b8/copy-to-eax  "34"/imm32
+    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
+    05/add-to-eax  4/imm32
+    # var slice/ecx: slice = {eax, ecx}
+    51/push-ecx
+    50/push-eax
+    89/copy                         3/mod/direct    1/rm32/ecx    .           .             .           4/r32/esp   .               .                 # copy esp to ecx
+    # eax = is-hex-int?(slice)
+    # . . push args
+    51/push-ecx
+    # . . call
+    e8/call  is-hex-int?/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-is-hex-int"/imm32
+    68/push  1/imm32/true
+    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
+    # . epilogue
+    89/copy                         3/mod/direct    4/rm32/esp    .           .             .           5/r32/ebp   .               .                 # copy ebp to esp
+    5d/pop-to-ebp
+    c3/return
+
+test-is-hex-int-handles-letters:
+    # . prologue
+    55/push-ebp
+    89/copy                         3/mod/direct    5/rm32/ebp    .           .             .           4/r32/esp   .               .                 # copy esp to ebp
+    # (eax..ecx) = "34a"
+    b8/copy-to-eax  "34a"/imm32
+    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
+    05/add-to-eax  4/imm32
+    # var slice/ecx: slice = {eax, ecx}
+    51/push-ecx
+    50/push-eax
+    89/copy                         3/mod/direct    1/rm32/ecx    .           .             .           4/r32/esp   .               .                 # copy esp to ecx
+    # eax = is-hex-int?(slice)
+    # . . push args
+    51/push-ecx
+    # . . call
+    e8/call  is-hex-int?/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-is-hex-int-handles-letters"/imm32
+    68/push  1/imm32/true
+    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
+    # . epilogue
+    89/copy                         3/mod/direct    4/rm32/esp    .           .             .           5/r32/ebp   .               .                 # copy ebp to esp
+    5d/pop-to-ebp
+    c3/return
+
+test-is-hex-int-with-trailing-char:
+    # . prologue
+    55/push-ebp
+    89/copy                         3/mod/direct    5/rm32/ebp    .           .             .           4/r32/esp   .               .                 # copy esp to ebp
+    # (eax..ecx) = "34q"
+    b8/copy-to-eax  "34q"/imm32
+    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
+    05/add-to-eax  4/imm32
+    # var slice/ecx: slice = {eax, ecx}
+    51/push-ecx
+    50/push-eax
+    89/copy                         3/mod/direct    1/rm32/ecx    .           .             .           4/r32/esp   .               .                 # copy esp to ecx
+    # eax = is-hex-int?(slice)
+    # . . push args
+    51/push-ecx
+    # . . call
+    e8/call  is-hex-int?/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-is-hex-int-with-trailing-char"/imm32
+    68/push  0/imm32/false
+    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
+    # . epilogue
+    89/copy                         3/mod/direct    4/rm32/esp    .           .             .           5/r32/ebp   .               .                 # copy ebp to esp
+    5d/pop-to-ebp
+    c3/return
+
+test-is-hex-int-with-leading-char:
+    # . prologue
+    55/push-ebp
+    89/copy                         3/mod/direct    5/rm32/ebp    .           .             .           4/r32/esp   .               .                 # copy esp to ebp
+    # (eax..ecx) = "q34"
+    b8/copy-to-eax  "q34"/imm32
+    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
+    05/add-to-eax  4/imm32
+    # var slice/ecx: slice = {eax, ecx}
+    51/push-ecx
+    50/push-eax
+    89/copy                         3/mod/direct    1/rm32/ecx    .           .             .           4/r32/esp   .               .                 # copy esp to ecx
+    # eax = is-hex-int?(slice)
+    # . . push args
+    51/push-ecx
+    # . . call
+    e8/call  is-hex-int?/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-is-hex-int-with-leading-char"/imm32
+    68/push  0/imm32/false
+    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
+    # . epilogue
+    89/copy                         3/mod/direct    4/rm32/esp    .           .             .           5/r32/ebp   .               .                 # copy ebp to esp
+    5d/pop-to-ebp
+    c3/return
+
+test-is-hex-int-empty:
+    # . prologue
+    55/push-ebp
+    89/copy                         3/mod/direct    5/rm32/ebp    .           .             .           4/r32/esp   .               .                 # copy esp to ebp
+    # var slice/ecx: slice = ""
+    68/push  0/imm32
+    68/push  0/imm32
+    89/copy                         3/mod/direct    1/rm32/ecx    .           .             .           4/r32/esp   .               .                 # copy esp to ecx
+    # eax = is-hex-int?(slice)
+    # . . push args
+    51/push-ecx
+    # . . call
+    e8/call  is-hex-int?/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-is-hex-int-empty"/imm32
+    68/push  0/imm32/false
+    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
+    # . epilogue
+    89/copy                         3/mod/direct    4/rm32/esp    .           .             .           5/r32/ebp   .               .                 # copy ebp to esp
+    5d/pop-to-ebp
+    c3/return
+
+test-is-hex-int-handles-0x-prefix:
+    # . prologue
+    55/push-ebp
+    89/copy                         3/mod/direct    5/rm32/ebp    .           .             .           4/r32/esp   .               .                 # copy esp to ebp
+    # (eax..ecx) = "0x3a"
+    b8/copy-to-eax  "0x3a"/imm32
+    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
+    05/add-to-eax  4/imm32
+    # var slice/ecx: slice = {eax, ecx}
+    51/push-ecx
+    50/push-eax
+    89/copy                         3/mod/direct    1/rm32/ecx    .           .             .           4/r32/esp   .               .                 # copy esp to ecx
+    # eax = is-hex-int?(slice)
+    # . . push args
+    51/push-ecx
+    # . . call
+    e8/call  is-hex-int?/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-is-hex-int-handles-0x-prefix"/imm32
+    68/push  1/imm32/true
+    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
+    # . epilogue
+    89/copy                         3/mod/direct    4/rm32/esp    .           .             .           5/r32/ebp   .               .                 # copy ebp to esp
+    5d/pop-to-ebp
+    c3/return
+
+test-is-hex-int-handles-negative:
+    # . prologue
+    55/push-ebp
+    89/copy                         3/mod/direct    5/rm32/ebp    .           .             .           4/r32/esp   .               .                 # copy esp to ebp
+    # (eax..ecx) = "-34a"
+    b8/copy-to-eax  "-34a"/imm32
+    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
+    05/add-to-eax  4/imm32
+    # var slice/ecx: slice = {eax, ecx}
+    51/push-ecx
+    50/push-eax
+    89/copy                         3/mod/direct    1/rm32/ecx    .           .             .           4/r32/esp   .               .                 # copy esp to ecx
+    # eax = is-hex-int?(slice)
+    # . . push args
+    51/push-ecx
+    # . . call
+    e8/call  is-hex-int?/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-is-hex-int-handles-negative"/imm32
+    68/push  1/imm32/true
+    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
+    # . epilogue
+    89/copy                         3/mod/direct    4/rm32/esp    .           .             .           5/r32/ebp   .               .                 # copy ebp to esp
+    5d/pop-to-ebp
+    c3/return
+
+test-is-hex-int-handles-negative-0x-prefix:
+    # . prologue
+    55/push-ebp
+    89/copy                         3/mod/direct    5/rm32/ebp    .           .             .           4/r32/esp   .               .                 # copy esp to ebp
+    # (eax..ecx) = "-0x3a"
+    b8/copy-to-eax  "-0x3a"/imm32
+    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
+    05/add-to-eax  4/imm32
+    # var slice/ecx: slice = {eax, ecx}
+    51/push-ecx
+    50/push-eax
+    89/copy                         3/mod/direct    1/rm32/ecx    .           .             .           4/r32/esp   .               .                 # copy esp to ecx
+    # eax = is-hex-int?(slice)
+    # . . push args
+    51/push-ecx
+    # . . call
+    e8/call  is-hex-int?/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-is-hex-int-handles-negative-0x-prefix"/imm32
+    68/push  1/imm32/true
+    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
+    # . epilogue
+    89/copy                         3/mod/direct    4/rm32/esp    .           .             .           5/r32/ebp   .               .                 # copy ebp to esp
+    5d/pop-to-ebp
+    c3/return
+
+parse-hex-int:  # in: (addr array byte) -> result/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
+    # eax = in
+    8b/copy                         1/mod/*+disp8   5/rm32/ebp    .           .             .           0/r32/eax   8/disp8         .                 # copy *(ebp+8) to eax
+    # var curr/ecx: (addr byte) = &in->data
+    8d/copy-address                 1/mod/*+disp8   0/rm32/eax    .           .             .           1/r32/ecx   4/disp8         .                 # copy eax+4 to ecx
+    # var max/edx: (addr byte) = &in->data[in->size]
+    # . edx = in->size
+    8b/copy                         0/mod/indirect  0/rm32/eax    .           .             .           2/r32/edx   .               .                 # copy *eax to edx
+    # . edx = in->data + in->size
+    8d/copy-address                 1/mod/*+disp8   4/rm32/sib    0/base/eax  2/index/edx   .           2/r32/edx   4/disp8         .                 # copy eax+edx+4 to edx
+    # return parse-hex-int-helper(curr, max)
+    # . . push args
+    52/push-edx
+    51/push-ecx
+    # . . call
+    e8/call  parse-hex-int-helper/disp32
+    # . . discard args
+    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
+$parse-hex-int:end:
+    # . restore registers
+    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
+
+parse-hex-int-from-slice:  # in: (addr slice) -> result/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
+    # ecx = in
+    8b/copy                         1/mod/*+disp8   5/rm32/ebp    .           .             .           1/r32/ecx   8/disp8         .                 # copy *(ebp+8) to ecx
+    # var max/edx: (addr byte) = in->end
+    8b/copy                         1/mod/*+disp8   1/rm32/ecx    .           .             .           2/r32/edx   4/disp8         .                 # copy *(ecx+4) to edx
+    # var curr/ecx: (addr byte) = in->start
+    8b/copy                         0/mod/indirect  1/rm32/ecx    .           .             .           1/r32/ecx   .               .                 # copy *ecx to ecx
+    # return parse-hex-int-helper(curr, max)
+    # . . push args
+    52/push-edx
+    51/push-ecx
+    # . . call
+    e8/call  parse-hex-int-helper/disp32
+    # . . discard args
+    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
+$parse-hex-int-from-slice:end:
+    # . restore registers
+    5a/pop-to-edx
+    59/pop-to-ecx
+    # . epilogue
+    89/copy                         3/mod/direct    4/rm32/esp    .           .             .           5/r32/ebp   .               .                 # copy ebp to esp
+    5d/pop-to-ebp
+    c3/return
+
+parse-hex-int-helper:  # start: (addr byte), end: (addr byte) -> result/eax: int
+    # . prologue
+    55/push-ebp
+    89/copy                         3/mod/direct    5/rm32/ebp    .           .             .           4/r32/esp   .               .                 # copy esp to ebp
+    # . save registers
+    51/push-ecx
+    52/push-edx
+    53/push-ebx
+    56/push-esi
+    # var curr/ecx: (addr byte) = start
+    8b/copy                         1/mod/*+disp8   5/rm32/ebp    .           .             .           1/r32/ecx   8/disp8         .                 # copy *(ebp+8) to ecx
+    # edx = max
+    8b/copy                         1/mod/*+disp8   5/rm32/ebp    .           .             .           2/r32/edx   0xc/disp8       .                 # copy *(ebp+12) to edx
+    # var result/ebx: int = 0
+    31/xor                          3/mod/direct    3/rm32/ebx    .           .             .           3/r32/ebx   .               .                 # clear ebx
+    # var negate?/esi: boolean = false
+    31/xor                          3/mod/direct    6/rm32/esi    .           .             .           6/r32/esi   .               .                 # clear esi
+$parse-hex-int-helper:negative:
+    # if (*curr == '-') ++curr, negate = true
+    31/xor                          3/mod/direct    0/rm32/eax    .           .             .           0/r32/eax   .               .                 # clear eax
+    8a/copy-byte                    0/mod/indirect  1/rm32/ecx    .           .             .           0/r32/AL    .               .                 # copy byte at *ecx to AL
+    3d/compare-eax-and  0x2d/imm32/-
+    75/jump-if-!=  $parse-hex-int-helper:initial-0/disp8
+    # . ++curr
+    41/increment-ecx
+    # . negate = true
+    be/copy-to-esi  1/imm32/true
+$parse-hex-int-helper:initial-0:
+    # skip past leading '0x'
+    # . if (*curr != '0') jump to loop
+    8a/copy-byte                    0/mod/indirect  1/rm32/ecx    .           .             .           0/r32/AL    .               .                 # copy byte at *ecx to AL
+    3d/compare-eax-and  0x30/imm32/0
+    75/jump-if-!=  $parse-hex-int-helper:loop/disp8
+    # . ++curr
+    41/increment-ecx
+$parse-hex-int-helper:initial-0x:
+    # . if (curr >= in->end) return result
+    39/compare                      3/mod/direct    1/rm32/ecx    .           .             .           2/r32/edx   .               .                 # compare ecx with edx
+    73/jump-if-addr>=  $parse-hex-int-helper:end/disp8
+    # . if (*curr != 'x') jump to loop  # the previous '0' is still valid so doesn't need to be checked again
+    31/xor                          3/mod/direct    0/rm32/eax    .           .             .           0/r32/eax   .               .                 # clear eax
+    8a/copy-byte                    0/mod/indirect  1/rm32/ecx    .           .             .           0/r32/AL    .               .                 # copy byte at *ecx to AL
+    3d/compare-eax-and  0x78/imm32/x
+    75/jump-if-!=  $parse-hex-int-helper:loop/disp8
+    # . ++curr
+    41/increment-ecx
+$parse-hex-int-helper:loop:
+    # if (curr >= in->end) break
+    39/compare                      3/mod/direct    1/rm32/ecx    .           .             .           2/r32/edx   .               .                 # compare ecx with edx
+    73/jump-if-addr>=  $parse-hex-int-helper:negate/disp8
+    # var eax: int = from-hex-char(*curr)
+    # . . copy arg to eax
+    8a/copy-byte                    0/mod/indirect  1/rm32/ecx    .           .             .           0/r32/AL    .               .                 # copy byte at *ecx to AL
+    # . . call
+    e8/call  from-hex-char/disp32
+    # result = result * 16 + eax
+    c1/shift    4/subop/left        3/mod/direct    3/rm32/ebx    .           .             .           .           .               4/imm8            # shift ebx left by 4 bits
+    01/add                          3/mod/direct    3/rm32/ebx    .           .             .           0/r32/eax   .               .                 # add eax to ebx
+    # ++curr
+    41/increment-ecx
+    # loop
+    eb/jump  $parse-hex-int-helper:loop/disp8
+$parse-hex-int-helper:negate:
+    # if (negate?) result = -result
+    81          7/subop/compare     3/mod/direct    6/rm32/esi    .           .             .           .           .               0/imm32/false     # compare esi
+    74/jump-if-=  $parse-hex-int-helper:end/disp8
+    f7          3/subop/negate      3/mod/direct    3/rm32/ebx    .           .             .           .           .               .                 # negate ebx
+$parse-hex-int-helper:end:
+    # return result
+    89/copy                         3/mod/direct    0/rm32/eax    .           .             .           3/r32/ebx   .               .                 # copy ebx to eax
+    # . restore registers
+    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-parse-hex-int-from-slice-single-digit:
+    # . prologue
+    55/push-ebp
+    89/copy                         3/mod/direct    5/rm32/ebp    .           .             .           4/r32/esp   .               .                 # copy esp to ebp
+    # (eax..ecx) = "a"
+    b8/copy-to-eax  "a"/imm32
+    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
+    05/add-to-eax  4/imm32
+    # var slice/ecx: slice = {eax, ecx}
+    51/push-ecx
+    50/push-eax
+    89/copy                         3/mod/direct    1/rm32/ecx    .           .             .           4/r32/esp   .               .                 # copy esp to ecx
+    # eax = parse-hex-int-from-slice(slice)
+    # . . push args
+    51/push-ecx
+    # . . call
+    e8/call  parse-hex-int-from-slice/disp32
+    # . . discard args
+    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               4/imm32           # add to esp
+    # check-ints-equal(eax, 0xa, msg)
+    # . . push args
+    68/push  "F - test-parse-hex-int-from-slice-single-digit"/imm32
+    68/push  0xa/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
+    # . epilogue
+    89/copy                         3/mod/direct    4/rm32/esp    .           .             .           5/r32/ebp   .               .                 # copy ebp to esp
+    5d/pop-to-ebp
+    c3/return
+
+test-parse-hex-int-from-slice-multi-digit:
+    # . prologue
+    55/push-ebp
+    89/copy                         3/mod/direct    5/rm32/ebp    .           .             .           4/r32/esp   .               .                 # copy esp to ebp
+    # (eax..ecx) = "34a"
+    b8/copy-to-eax  "34a"/imm32
+    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
+    05/add-to-eax  4/imm32
+    # var slice/ecx: slice = {eax, ecx}
+    51/push-ecx
+    50/push-eax
+    89/copy                         3/mod/direct    1/rm32/ecx    .           .             .           4/r32/esp   .               .                 # copy esp to ecx
+    # eax = parse-hex-int-from-slice(slice)
+    # . . push args
+    51/push-ecx
+    # . . call
+    e8/call  parse-hex-int-from-slice/disp32
+    # . . discard args
+    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               4/imm32           # add to esp
+    # check-ints-equal(eax, 0x34a, msg)
+    # . . push args
+    68/push  "F - test-parse-hex-int-from-slice-multi-digit"/imm32
+    68/push  0x34a/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
+    # . epilogue
+    89/copy                         3/mod/direct    4/rm32/esp    .           .             .           5/r32/ebp   .               .                 # copy ebp to esp
+    5d/pop-to-ebp
+    c3/return
+
+test-parse-hex-int-from-slice-0x-prefix:
+    # . prologue
+    55/push-ebp
+    89/copy                         3/mod/direct    5/rm32/ebp    .           .             .           4/r32/esp   .               .                 # copy esp to ebp
+    # (eax..ecx) = "0x34"
+    b8/copy-to-eax  "0x34"/imm32
+    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
+    05/add-to-eax  4/imm32
+    # var slice/ecx: slice = {eax, ecx}
+    51/push-ecx
+    50/push-eax
+    89/copy                         3/mod/direct    1/rm32/ecx    .           .             .           4/r32/esp   .               .                 # copy esp to ecx
+    # eax = parse-hex-int-from-slice(slice)
+    # . . push args
+    51/push-ecx
+    # . . call
+    e8/call  parse-hex-int-from-slice/disp32
+    # . . discard args
+    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               4/imm32           # add to esp
+    # check-ints-equal(eax, 0x34, msg)
+    # . . push args
+    68/push  "F - test-parse-hex-int-from-slice-0x-prefix"/imm32
+    68/push  0x34/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
+    # . epilogue
+    89/copy                         3/mod/direct    4/rm32/esp    .           .             .           5/r32/ebp   .               .                 # copy ebp to esp
+    5d/pop-to-ebp
+    c3/return
+
+test-parse-hex-int-from-slice-zero:
+    # . prologue
+    55/push-ebp
+    89/copy                         3/mod/direct    5/rm32/ebp    .           .             .           4/r32/esp   .               .                 # copy esp to ebp
+    # (eax..ecx) = "0"
+    b8/copy-to-eax  "0"/imm32
+    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
+    05/add-to-eax  4/imm32
+    # var slice/ecx: slice = {eax, ecx}
+    51/push-ecx
+    50/push-eax
+    89/copy                         3/mod/direct    1/rm32/ecx    .           .             .           4/r32/esp   .               .                 # copy esp to ecx
+    # eax = parse-hex-int-from-slice(slice)
+    # . . push args
+    51/push-ecx
+    # . . call
+    e8/call  parse-hex-int-from-slice/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-parse-hex-int-from-slice-zero"/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
+    # . epilogue
+    89/copy                         3/mod/direct    4/rm32/esp    .           .             .           5/r32/ebp   .               .                 # copy ebp to esp
+    5d/pop-to-ebp
+    c3/return
+
+test-parse-hex-int-from-slice-0-prefix:
+    # . prologue
+    55/push-ebp
+    89/copy                         3/mod/direct    5/rm32/ebp    .           .             .           4/r32/esp   .               .                 # copy esp to ebp
+    # (eax..ecx) = "03"
+    b8/copy-to-eax  "03"/imm32
+    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
+    05/add-to-eax  4/imm32
+    # var slice/ecx: slice = {eax, ecx}
+    51/push-ecx
+    50/push-eax
+    89/copy                         3/mod/direct    1/rm32/ecx    .           .             .           4/r32/esp   .               .                 # copy esp to ecx
+    # eax = parse-hex-int-from-slice(slice)
+    # . . push args
+    51/push-ecx
+    # . . call
+    e8/call  parse-hex-int-from-slice/disp32
+    # . . discard args
+    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               4/imm32           # add to esp
+    # check-ints-equal(eax, 0x3, msg)
+    # . . push args
+    68/push  "F - test-parse-hex-int-from-slice-0-prefix"/imm32
+    68/push  0x3/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
+    # . epilogue
+    89/copy                         3/mod/direct    4/rm32/esp    .           .             .           5/r32/ebp   .               .                 # copy ebp to esp
+    5d/pop-to-ebp
+    c3/return
+
+test-parse-hex-int-from-slice-negative:
+    # . prologue
+    55/push-ebp
+    89/copy                         3/mod/direct    5/rm32/ebp    .           .             .           4/r32/esp   .               .                 # copy esp to ebp
+    # (eax..ecx) = "-03"
+    b8/copy-to-eax  "-03"/imm32
+    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
+    05/add-to-eax  4/imm32
+    # var slice/ecx: slice = {eax, ecx}
+    51/push-ecx
+    50/push-eax
+    89/copy                         3/mod/direct    1/rm32/ecx    .           .             .           4/r32/esp   .               .                 # copy esp to ecx
+    # eax = parse-hex-int-from-slice(slice)
+    # . . push args
+    51/push-ecx
+    # . . call
+    e8/call  parse-hex-int-from-slice/disp32
+    # . . discard args
+    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               4/imm32           # add to esp
+    # check-ints-equal(eax, -3, msg)
+    # . . push args
+    68/push  "F - test-parse-hex-int-from-slice-negative"/imm32
+    68/push  -3/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
+    # . epilogue
+    89/copy                         3/mod/direct    4/rm32/esp    .           .             .           5/r32/ebp   .               .                 # copy ebp to esp
+    5d/pop-to-ebp
+    c3/return
+
+is-hex-digit?:  # c: byte -> result/eax: boolean
+    # . prologue
+    55/push-ebp
+    89/copy                         3/mod/direct    5/rm32/ebp    .           .             .           4/r32/esp   .               .                 # copy esp to ebp
+    # . save registers
+    51/push-ecx
+    # ecx = c
+    8b/copy                         1/mod/*+disp8   5/rm32/ebp    .           .             .           1/r32/ecx   8/disp8         .                 # copy *(ebp+8) to ecx
+    # return false if c < '0'
+    81          7/subop/compare     3/mod/direct    1/rm32/ecx    .           .             .           .           .               0x30/imm32        # compare ecx
+    7c/jump-if-<  $is-hex-digit?:false/disp8
+    # return true if c <= '9'
+    81          7/subop/compare     3/mod/direct    1/rm32/ecx    .           .             .           .           .               0x39/imm32        # compare ecx
+    7e/jump-if-<=  $is-hex-digit?:true/disp8
+    # drop case
+    25/and-eax-with 0x5f/imm32
+    # return false if c > 'f'
+    81          7/subop/compare     3/mod/direct    1/rm32/ecx    .           .             .           .           .               0x66/imm32        # compare ecx
+    7f/jump-if->  $is-hex-digit?:false/disp8
+    # return true if c >= 'a'
+    81          7/subop/compare     3/mod/direct    1/rm32/ecx    .           .             .           .           .               0x61/imm32        # compare ecx
+    7d/jump-if->=  $is-hex-digit?:true/disp8
+    # otherwise return false
+$is-hex-digit?:false:
+    b8/copy-to-eax  0/imm32/false
+    eb/jump $is-hex-digit?:end/disp8
+$is-hex-digit?:true:
+    b8/copy-to-eax  1/imm32/true
+$is-hex-digit?: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-hex-below-0:
+    # eax = is-hex-digit?(0x2f)
+    # . . push args
+    68/push  0x2f/imm32
+    # . . call
+    e8/call  is-hex-digit?/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-hex-below-0"/imm32
+    68/push  0/imm32/false
+    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-hex-0-to-9:
+    # eax = is-hex-digit?(0x30)
+    # . . push args
+    68/push  0x30/imm32
+    # . . call
+    e8/call  is-hex-digit?/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-hex-at-0"/imm32
+    68/push  1/imm32/true
+    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
+    # eax = is-hex-digit?(0x39)
+    # . . push args
+    68/push  0x39/imm32
+    # . . call
+    e8/call  is-hex-digit?/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-hex-at-9"/imm32
+    68/push  1/imm32/true
+    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-hex-above-9-to-a:
+    # eax = is-hex-digit?(0x3a)
+    # . . push args
+    68/push  0x3a/imm32
+    # . . call
+    e8/call  is-hex-digit?/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-hex-above-9-to-a"/imm32
+    68/push  0/imm32/false
+    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-hex-a-to-f:
+    # eax = is-hex-digit?(0x61)
+    # . . push args
+    68/push  0x61/imm32
+    # . . call
+    e8/call  is-hex-digit?/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-hex-at-a"/imm32
+    68/push  1/imm32/true
+    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
+    # eax = is-hex-digit?(0x66)
+    # . . push args
+    68/push  0x66/imm32
+    # . . call
+    e8/call  is-hex-digit?/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-hex-at-f"/imm32
+    68/push  1/imm32/true
+    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-hex-above-f:
+    # eax = is-hex-digit?(0x67)
+    # . . push args
+    68/push  0x67/imm32
+    # . . call
+    e8/call  is-hex-digit?/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-hex-above-f"/imm32
+    68/push  0/imm32/false
+    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
+
+from-hex-char:  # in/eax: byte -> out/eax: nibble
+$from-hex-char:check0:
+    # if (eax < '0') goto abort
+    3d/compare-eax-with  0x30/imm32/0
+    7c/jump-if-<  $from-hex-char:abort/disp8
+$from-hex-char:check1:
+    # if (eax > 'f') goto abort
+    3d/compare-eax-with  0x66/imm32/f
+    7f/jump-if->  $from-hex-char:abort/disp8
+$from-hex-char:check2:
+    # if (eax > '9') goto next check
+    3d/compare-eax-with  0x39/imm32/9
+    7f/jump-if->  $from-hex-char:check3/disp8
+$from-hex-char:digit:
+    # return eax - '0'
+    2d/subtract-from-eax  0x30/imm32/0
+    c3/return
+$from-hex-char:check3:
+    # if (eax < 'a') goto abort
+    3d/compare-eax-with  0x61/imm32/a
+    7c/jump-if-<  $from-hex-char:abort/disp8
+$from-hex-char:letter:
+    # return eax - ('a'-10)
+    2d/subtract-from-eax  0x57/imm32/a-10
+    c3/return
+
+$from-hex-char:abort:
+    # . _write(2/stderr, error)
+    # . . push args
+    68/push  "invalid hex char: "/imm32
+    68/push  2/imm32/stderr
+    # . . call
+    e8/call  _write/disp32
+    # . . discard args
+    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
+    # . clear-stream($Stderr->buffer)
+    # . . save eax
+    50/push-eax
+    # . . push args
+    68/push  $Stderr->buffer/imm32
+    # . . call
+    e8/call  clear-stream/disp32
+    # . . discard args
+    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               4/imm32           # add to esp
+    # . . restore eax
+    58/pop-to-eax
+    # . write-int32-hex-buffered(Stderr, eax)
+    # . . push args
+    50/push-eax
+    68/push  Stderr/imm32
+    # . . call
+    e8/call  write-int32-hex-buffered/disp32
+    # . . discard args
+    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
+    # . flush(Stderr)
+    # . . push args
+    68/push  Stderr/imm32
+    # . . call
+    e8/call  flush/disp32
+    # . . discard args
+    81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               4/imm32           # add to esp
+    # . _write(2/stderr, "\n")
+    # . . push args
+    68/push  Newline/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
+
+# . . vim:nowrap:textwidth=0