diff options
| author | Kartik Agaram <vc@akkartik.com> | 2018-10-05 19:49:47 -0700 |
|---|---|---|
| committer | Kartik Agaram <vc@akkartik.com> | 2018-10-05 19:49:47 -0700 |
| commit | 03d50cc83c7c2bebb2b019667b80c1c51f4a8def (patch) | |
| tree | 9c0447e91ac0da2aa0fe983f41c4d95d1787f512 /subx/examples/ex10.subx | |
| parent | 7163541bf2ced701d00b16b1cf1eac6a7d019a15 (diff) | |
| download | mu-03d50cc83c7c2bebb2b019667b80c1c51f4a8def.tar.gz | |
4667
Standardize on hyphens in all names. And we'll use colons for namespacing labels in functions.
Diffstat (limited to 'subx/examples/ex10.subx')
| -rw-r--r-- | subx/examples/ex10.subx | 23 |
1 files changed, 12 insertions, 11 deletions
diff --git a/subx/examples/ex10.subx b/subx/examples/ex10.subx index f2eadc5d..43b0e1d1 100644 --- a/subx/examples/ex10.subx +++ b/subx/examples/ex10.subx @@ -12,7 +12,7 @@ # 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 -# main: return argv_equal(argv[1], argv[2]) +# main: return argv-equal(argv[1], argv[2]) # At the start of a SubX program: # argc: *ESP # argv[0]: *(ESP+4) @@ -20,13 +20,13 @@ # ... # prolog 89/copy 3/mod/direct 5/rm32/EBP . . . 4/r32/ESP . . # copy ESP to EBP - # call argv_equal(argv[1], argv[2]) + # call argv-equal(argv[1], argv[2]) # push argv[2] ff 6/subop/push 1/mod/*+disp8 4/rm32/sib 5/base/EBP 4/index/none . . 0xc/disp8 . # push *(EBP+12) # push argv[1] ff 6/subop/push 1/mod/*+disp8 4/rm32/sib 5/base/EBP 4/index/none . . 0x8/disp8 . # push *(EBP+8) # call - e8/call argv_equal/disp32 + e8/call argv-equal/disp32 # exit(EAX) $exit: 89/copy 3/mod/direct 3/rm32/EBX . . . 0/r32/EAX . . # copy EAX to EBX @@ -35,12 +35,12 @@ $exit: # compare two null-terminated ascii strings # reason for the name: the only place we should have null-terminated ascii strings is from commandline args -argv_equal: # (s1, s2) : null-terminated ascii strings -> EAX : boolean +argv-equal: # (s1, s2) : null-terminated ascii strings -> EAX : boolean # initialize s1 (ECX) and s2 (EDX) 8b/copy 1/mod/*+disp8 4/rm32/sib 4/base/ESP 4/index/none . 1/r32/ECX 4/disp8 . # copy *(ESP+4) to ECX 8b/copy 1/mod/*+disp8 4/rm32/sib 4/base/ESP 4/index/none . 2/r32/EDX 8/disp8 . # copy *(ESP+8) to EDX # while (true) -$argv_loop: +$argv-equal:loop: # c1/EAX, c2/EBX = *s1, *s2 b8/copy 0/imm32 # clear EAX 8a/copy 0/mod/indirect 1/rm32/ECX . . . 0/r32/EAX . . # copy byte at *ECX to lower byte of EAX @@ -48,23 +48,24 @@ $argv_loop: 8a/copy 0/mod/indirect 2/rm32/EDX . . . 3/r32/EBX . . # copy byte at *EDX to lower byte of EBX # if (c1 == 0) break 3d/compare-EAX 0/imm32 - 74/jump-if-equal $argv_break/disp8 + 74/jump-if-equal $argv-equal:break/disp8 # if (c1 != c2) return false 39/compare 3/mod/direct 0/rm32/EAX . . . 3/r32/EBX . . # compare EAX with EBX - 75/jump-if-not-equal $argv_fail/disp8 + 75/jump-if-not-equal $argv-equal:false/disp8 # ++s1, ++s2 41/inc-ECX 42/inc-EDX # end while - eb/jump $argv_loop/disp8 -$argv_break: + eb/jump $argv-equal:loop/disp8 +$argv-equal:break: # if (c2 == 0) return true 81 7/subop/compare 3/mod/direct 3/rm32/EBX . . . . . 0/imm32 # compare EBX - 75/jump-if-not-equal $argv_fail/disp8 + 75/jump-if-not-equal $argv-equal:false/disp8 +$argv-equal:success: b8/copy . . . . . . . 1/imm32 # copy to EAX c3/return # return false -$argv_fail: +$argv-equal:false: b8/copy . . . . . . . 0/imm32 # copy to EAX c3/return |