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Some apps written in SubX and Mu, in 3 categories:

* `ex*`: small stand-alone examples that don't need any of the shared code at
  the top-level. They each have a simple pedagogical goal. Try these first.

* Code unique to phases of our build toolchain:
  * Core SubX: `hex`, `survey`, `pack`, `dquotes`, `assort`, `tests`
  * Syntax sugar for SubX: `sigils`, `calls`, `braces`
  * More ambitious translator for a memory-safe language (in progress): `mu`

* Miscellaneous test programs.

All SubX apps include binaries. At any commit, an example's binary should be
identical bit for bit with the result of translating the corresponding `.subx`
file. The binary should also be natively runnable on a Linux system running on
Intel x86 processors, either 32- or 64-bit. If either of these invariants is
broken, it's a bug.
generated by cgit-pink 1.4.1-2-gfad0 (git 2.36.2.497.gbbea4dcf42) at 2024-11-03 01:49:06 +0000
espace */ .highlight .py { color: #336699; font-weight: bold } /* Name.Property */ .highlight .nt { color: #bb0066; font-weight: bold } /* Name.Tag */ .highlight .nv { color: #336699 } /* Name.Variable */ .highlight .ow { color: #008800 } /* Operator.Word */ .highlight .w { color: #bbbbbb } /* Text.Whitespace */ .highlight .mb { color: #0000DD; font-weight: bold } /* Literal.Number.Bin */ .highlight .mf { color: #0000DD; font-weight: bold } /* Literal.Number.Float */ .highlight .mh { color: #0000DD; font-weight: bold } /* Literal.Number.Hex */ .highlight .mi { color: #0000DD; font-weight: bold } /* Literal.Number.Integer */ .highlight .mo { color: #0000DD; font-weight: bold } /* Literal.Number.Oct */ .highlight .sa { color: #dd2200; background-color: #fff0f0 } /* Literal.String.Affix */ .highlight .sb { color: #dd2200; background-color: #fff0f0 } /* Literal.String.Backtick */ .highlight .sc { color: #dd2200; background-color: #fff0f0 } /* Literal.String.Char */ .highlight .dl { color: #dd2200; background-color: #fff0f0 } /* Literal.String.Delimiter */ .highlight .sd { color: #dd2200; background-color: #fff0f0 } /* Literal.String.Doc */ .highlight .s2 { color: #dd2200; background-color: #fff0f0 } /* Literal.String.Double */ .highlight .se { color: #0044dd; background-color: #fff0f0 } /* Literal.String.Escape */ .highlight .sh { color: #dd2200; background-color: #fff0f0 } /* Literal.String.Heredoc */ .highlight .si { color: #3333bb; background-color: #fff0f0 } /* Literal.String.Interpol */ .highlight .sx { color: #22bb22; background-color: #f0fff0 } /* Literal.String.Other */ .highlight .sr { color: #008800; background-color: #fff0ff } /* Literal.String.Regex */ .highlight .s1 { color: #dd2200; background-color: #fff0f0 } /* Literal.String.Single */ .highlight .ss { color: #aa6600; background-color: #fff0f0 } /* Literal.String.Symbol */ .highlight .bp { color: #003388 } /* Name.Builtin.Pseudo */ .highlight .fm { color: #0066bb; font-weight: bold } /* Name.Function.Magic */ .highlight .vc { color: #336699 } /* Name.Variable.Class */ .highlight .vg { color: #dd7700 } /* Name.Variable.Global */ .highlight .vi { color: #3333bb } /* Name.Variable.Instance */ .highlight .vm { color: #336699 } /* Name.Variable.Magic */ .highlight .il { color: #0000DD; font-weight: bold } /* Literal.Number.Integer.Long */
# Comparing 'regular' length-prefixed strings.

== 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

Entry:  # run all tests
#?     e8/call test-compare-equal-strings/disp32
    e8/call  run-tests/disp32  # 'run-tests' is a function created automatically by SubX. It calls all functions that start with 'test-'.
    # syscall(exit, Num-test-failures)
    8b/copy                         0/mod/indirect  5/rm32/.disp32            .             .           3/r32/EBX   Num-test-failures/disp32          # copy *Num-test-failures to EBX
    b8/copy-to-EAX  1/imm32/exit
    cd/syscall  0x80/imm8

string-equal?:  # s : (address string), benchmark : (address string) -> EAX : boolean
    # pseudocode:
    #   lens = s->length
    #   if (lens != benchmark->length) return false
    #   i = 0
    #   currs = s->data
    #   currb = benchmark->data
    #   while i < s->length
    #     c1 = *currs
    #     c2 = *currb
    #     if (c1 != c2) return false
    #     ++i, ++currs, ++currb
    #   return true
    #
    # registers:
    #   i: ECX
    #   lens: EDX
    #   currs: ESI
    #   currb: EDI
    #   c1: EAX
    #   c2: EBX
    #
    # . prolog
    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
    # ESI = s
    8b/copy                         1/mod/*+disp8   5/rm32/EBP    .           .             .           6/r32/ESI   8/disp8         .                 # copy *(EBP+8) to ESI
    # EDI = benchmark
    8b/copy                         1/mod/*+disp8   5/rm32/EBP    .           .             .           7/r32/EDI   0xc/disp8       .                 # copy *(EBP+12) to EDI
    # lens/EDX = s->length
    8b/copy                         0/mod/indirect  6/rm32/ESI    .           .             .           2/r32/EDX   .               .                 # copy *ESI to EDX
$string-equal?:lengths:
    # if (lens != benchmark->length) return false
    39/compare                      0/mod/indirect  7/rm32/EDI    .           .             .           2/r32/EDX   .               .                 # compare *EDI and EDX
    75/jump-if-not-equal  $string-equal?:false/disp8
    # currs/ESI = s->data
    81          0/subop/add         3/mod/direct    6/rm32/ESI    .           .             .           .           .               4/imm32           # add to ESI
    # currb/EDI = benchmark->data
    81          0/subop/add         3/mod/direct    7/rm32/EDI    .           .             .           .           .               4/imm32           # add to EDI
    # i/ECX = c1/EAX = c2/EBX = 0
    31/xor                          3/mod/direct    1/rm32/ECX    .           .             .           1/r32/ECX   .               .                 # clear ECX
    31/xor                          3/mod/direct    0/rm32/EAX    .           .             .           0/r32/EAX   .               .                 # clear EAX
    31/xor                          3/mod/direct    3/rm32/EBX    .           .             .           3/r32/EBX   .               .                 # clear EBX
$string-equal?:loop:
    # if (i >= lens) return true
    39/compare                      3/mod/direct    1/rm32/ECX    .           .             .           2/r32/EDX   .               .                 # compare ECX with EDX
    7d/jump-if-greater-or-equal  $string-equal?:true/disp8
    # c1 = *currs
    8a/copy-byte                    0/mod/indirect  6/rm32/ESI    .           .             .           0/r32/AL    .               .                 # copy byte at *ESI to AL
    # c2 = *currb
    8a/copy-byte                    0/mod/indirect  7/rm32/EDI    .           .             .           3/r32/BL    .               .                 # copy byte at *EDI to BL
    # if (c1 != c2) return false
    39/compare                      3/mod/direct    0/rm32/EAX    .           .             .           3/r32/EBX   .               .                 # compare EAX and EBX
    75/jump-if-not-equal  $string-equal?:false/disp8
    # ++i
    41/increment-ECX
    # ++currs
    46/increment-ESI
    # ++currb
    47/increment-EDI
    eb/jump  $string-equal?:loop/disp8
$string-equal?:true:
    b8/copy-to-EAX  1/imm32
    eb/jump  $string-equal?:end/disp8
$string-equal?:false:
    b8/copy-to-EAX  0/imm32
$string-equal?:end:
    # . restore registers
    5f/pop-to-EDI
    5e/pop-to-ESI
    5b/pop-to-EBX
    5a/pop-to-EDX
    59/pop-to-ECX
    # . epilog
    89/copy                         3/mod/direct    4/rm32/ESP    .           .             .           5/r32/EBP   .               .                 # copy EBP to ESP
    5d/pop-to-EBP
    c3/return

# - tests

test-compare-empty-with-empty-string:
    # EAX = string-equal?("", "")
    # . . push args
    68/push  ""/imm32
    68/push  ""/imm32
    # . . call
    e8/call  string-equal?/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-compare-empty-with-empty-string"/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-compare-empty-with-non-empty-string:  # also checks length-mismatch code path
    # EAX = string-equal?("", "Abc")
    # . . push args
    68/push  "Abc"/imm32
    68/push  ""/imm32
    # . . call
    e8/call  string-equal?/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-compare-empty-with-non-empty-string"/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-compare-equal-strings:
    # EAX = string-equal?("Abc", "Abc")
    # . . push args
    68/push  "Abc"/imm32
    68/push  "Abc"/imm32
    # . . call
    e8/call  string-equal?/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-compare-equal-strings"/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-compare-inequal-strings-equal-lengths:
    # EAX = string-equal?("Abc", "Adc")
    # . . push args
    68/push  "Adc"/imm32
    68/push  "Abc"/imm32
    # . . call
    e8/call  string-equal?/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-compare-inequal-strings-equal-lengths"/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

# . . vim:nowrap:textwidth=0
generated by cgit-pink 1.4.1-2-gfad0 (git 2.36.2.497.gbbea4dcf42) at 2024-11-03 01:49:05 +0000