From 3350c34a74844e21ea69077e01efff3bae64bdcd Mon Sep 17 00:00:00 2001 From: Kartik Agaram Date: Tue, 23 Mar 2021 17:31:08 -0700 Subject: . --- html/apps/ex10.subx.html | 132 ----------------------------------------------- 1 file changed, 132 deletions(-) delete mode 100644 html/apps/ex10.subx.html (limited to 'html/apps/ex10.subx.html') diff --git a/html/apps/ex10.subx.html b/html/apps/ex10.subx.html deleted file mode 100644 index 21f57033..00000000 --- a/html/apps/ex10.subx.html +++ /dev/null @@ -1,132 +0,0 @@ - - - - -Mu - apps/ex10.subx - - - - - - - - - - -https://github.com/akkartik/mu/blob/main/apps/ex10.subx -
- 1 # String comparison: return 1 iff the two args passed in at the commandline are equal.
- 2 #
- 3 # To run:
- 4 #   $ ./bootstrap translate init.linux apps/ex10.subx -o apps/ex10
- 5 #   $ ./bootstrap run apps/ex10 abc abd
- 6 # Expected result:
- 7 #   $ echo $?
- 8 #   0  # false
- 9 
-10 == code
-11 #   instruction                     effective address                                                   register    displacement    immediate
-12 # . op          subop               mod             rm32          base        index         scale       r32
-13 # . 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
-14 
-15 Entry:  # return argv-equal(argv[1], argv[2])
-16 #       At the start of a SubX program:
-17 #         argc: *esp
-18 #         argv[0]: *(esp+4)
-19 #         argv[1]: *(esp+8)
-20 #         ...
-21     # . prologue
-22     89/copy                         3/mod/direct    5/rm32/ebp    .           .             .           4/r32/esp   .               .                 # copy esp to ebp
-23     # argv-equal(argv[1], argv[2])
-24     # . . push argv[2]
-25     ff          6/subop/push        1/mod/*+disp8   5/rm32/ebp    .           .             .           .           0xc/disp8       .                 # push *(ebp+12)
-26     # . . push argv[1]
-27     ff          6/subop/push        1/mod/*+disp8   5/rm32/ebp    .           .             .           .           8/disp8         .                 # push *(ebp+8)
-28     # . . call
-29     e8/call argv-equal/disp32
-30     # exit(eax)
-31     89/copy                         3/mod/direct    3/rm32/ebx    .           .             .           0/r32/eax   .               .                 # copy eax to ebx
-32     e8/call  syscall_exit/disp32
-33 
-34 # compare two null-terminated ascii strings
-35 # reason for the name: the only place we should have null-terminated ascii strings is from commandline args
-36 argv-equal:  # (s1, s2): null-terminated ascii strings -> eax: boolean
-37     # initialize s1 (ecx) and s2 (edx)
-38     8b/copy                         1/mod/*+disp8   4/rm32/sib    4/base/esp  4/index/none  .           1/r32/ecx   4/disp8         .                 # copy *(esp+4) to ecx
-39     8b/copy                         1/mod/*+disp8   4/rm32/sib    4/base/esp  4/index/none  .           2/r32/edx   8/disp8         .                 # copy *(esp+8) to edx
-40 $argv-equal:loop:
-41     # c1/eax, c2/ebx = *s1, *s2
-42     b8/copy-to-eax  0/imm32
-43     8a/copy-byte                    0/mod/indirect  1/rm32/ecx    .           .             .           0/r32/AL    .               .                 # copy byte at *ecx to AL
-44     bb/copy-to-ebx  0/imm32
-45     8a/copy-byte                    0/mod/indirect  2/rm32/edx    .           .             .           3/r32/BL    .               .                 # copy byte at *edx to BL
-46     # if (c1 == 0) break
-47     3d/compare-eax-and  0/imm32/null
-48     74/jump-if-=  $argv-equal:break/disp8
-49     # if (c1 != c2) return false
-50     39/compare                      3/mod/direct    0/rm32/eax    .           .             .           3/r32/ebx   .               .                 # compare eax and ebx
-51     75/jump-if-!=  $argv-equal:false/disp8
-52     # ++s1, ++s2
-53     41/increment-ecx
-54     42/increment-edx
-55     # end while
-56     eb/jump  $argv-equal:loop/disp8
-57 $argv-equal:break:
-58     # if (c2 == 0) return true
-59     81          7/subop/compare     3/mod/direct    3/rm32/ebx    .           .             .           .           .               0/imm32/null      # compare ebx
-60     75/jump-if-!=  $argv-equal:false/disp8
-61 $argv-equal:success:
-62     b8/copy-to-eax  1/imm32
-63     c3/return
-64     # return false
-65 $argv-equal:false:
-66     b8/copy-to-eax  0/imm32
-67     c3/return
-68 
-69 # . . vim:nowrap:textwidth=0
-
- - - -- cgit 1.4.1-2-gfad0