diff options
Diffstat (limited to 'subx/apps')
-rwxr-xr-x | subx/apps/factorial | bin | 284 -> 410 bytes | |||
-rw-r--r-- | subx/apps/factorial.subx | 100 |
2 files changed, 85 insertions, 15 deletions
diff --git a/subx/apps/factorial b/subx/apps/factorial index 15fa68ec..07c92714 100755 --- a/subx/apps/factorial +++ b/subx/apps/factorial Binary files differdiff --git a/subx/apps/factorial.subx b/subx/apps/factorial.subx index f1cce6a4..dc89f7c0 100644 --- a/subx/apps/factorial.subx +++ b/subx/apps/factorial.subx @@ -6,6 +6,12 @@ # Expected result: # $ echo $? # 120 +# +# You can also run an automated test (that does the exact same thing): +# $ subx run apps/factorial test +# Expected output: +# . +# Every '.' indicates a passing test. Failing tests get a 'F'. == code # instruction effective address operand displacement immediate @@ -13,19 +19,34 @@ # 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: - e8/call run_tests/disp32 -#? # prepare to make a call -#? 55/push . . . . . . . . # push EBP -#? 89/copy 3/mod/direct 5/rm32/EBP . . . 4/r32/ESP . . # copy ESP to EBP -#? # factorial(5) -#? 68/push . . . . . . . 5/imm32 # push 5 -#? e8/call . . . . . . factorial/disp32 -#? # discard arg -#? 81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 4/imm32 # add 4 to ESP -#? # clean up after call -#? 89/copy 3/mod/direct 4/rm32/ESP . . . 5/r32/EBP . . # copy EBP to ESP -#? 5d/pop . . . . . . . . # pop to EBP - + # if (argc > 1) + 8b/copy 0/mod/indirect 4/rm32/sib 4/base/ESP 4/index/none . 0/r32/EAX . . # copy *ESP to EAX + 3d/compare . . . . . . . 1/imm32 # compare EAX with 1 + 7e/jump-if-lesser-or-equal $run_main/disp8 + # and if (argv[1] == "test") + 8b/copy 1/mod/*+disp8 4/rm32/sib 4/base/ESP 4/index/none . 0/r32/EAX 8/disp8 . # copy *(ESP+8) to EAX + # push args + 68/push Test_argv/imm32 + 50/push-EAX + # call + e8/call argv_equal/disp32 + # discard args + 81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 8/imm32 # add 8 to ESP + # check result + 3d/compare . . . . . . . 1/imm32 # compare EAX with 1 + 75/jump-if-not-equal $run_main/disp8 + # then + e8/call run_tests/disp32 + eb/jump $main_exit/disp8 + # else EAX <- factorial(5) +$run_main: + # push arg + 68/push . . . . . . . 5/imm32 # push 5 + # EAX <- call + e8/call . . . . . . factorial/disp32 + # discard arg + 81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 4/imm32 # add 4 to ESP +$main_exit: # exit(EAX) 89/copy 3/mod/direct 3/rm32/EBX . . . 0/r32/EAX . . # copy EAX to EBX b8/copy . . . . . . . 1/imm32 # copy 1 to EAX @@ -94,23 +115,72 @@ $test_factorial:else: ## helpers +# compare two null-terminated ascii strings +# reason for the name: the only place we should have null-terminated ascii strings is from commandline args +argv_equal: # (s1, s2) : null-terminated ascii strings -> EAX : boolean + # initialize s1 (ECX) and s2 (EDX) + 8b/copy 1/mod/*+disp8 4/rm32/sib 4/base/ESP 4/index/none . 1/r32/ECX 8/disp8 . # copy *(ESP+8) to ECX + 8b/copy 1/mod/*+disp8 4/rm32/sib 4/base/ESP 4/index/none . 2/r32/EDX 4/disp8 . # copy *(ESP+4) to EDX + # while (true) +$argv_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 + bb/copy 0/imm32 # clear EBX + 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 . . . . . . . 0/imm32 # compare EAX with 0 + 74/jump-if-equal $argv_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 + # ++s1, ++s2 + 41/inc-ECX + 42/inc-EDX + # end while + eb/jump $argv_loop/disp8 +$argv_break: + # if (c2 == 0) return true + 81 7/subop/compare 3/mod/direct 3/rm32/EBX . . . . . 0/imm32 # compare EBX with 0 + 75/jump-if-not-equal $argv_fail/disp8 + b8/copy . . . . . . . 1/imm32 # copy 1 to EAX + c3/return + # return false +$argv_fail: + b8/copy . . . . . . . 0/imm32 # copy 0 to EAX + c3/return + write_stderr: # s : (address array byte) -> <void> + # save registers + 50/push . . . . . . . . # push EAX + 51/push . . . . . . . . # push ECX + 52/push . . . . . . . . # push EDX + 53/push . . . . . . . . # push EBX # write(2/stderr, (data) s+4, (size) *s) # fd = 2 (stderr) bb/copy . . . . . . . 2/imm32 # copy 2 to EBX # x = s+4 - 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 . 1/r32/ECX 0x14/disp8 . # copy *(ESP+20) to ECX 81 0/subop/add 3/mod/direct 1/rm32/ECX . . . . . 4/imm32 # add 4 to ECX # size = *s - 8b/copy 1/mod/*+disp8 4/rm32/SIB 4/base/ESP 4/index/none . 2/r32/EDX 4/disp8 . # copy *(ESP+4) to EDX + 8b/copy 1/mod/*+disp8 4/rm32/SIB 4/base/ESP 4/index/none . 2/r32/EDX 0x14/disp8 . # copy *(ESP+20) to EDX 8b/copy 0/mod/indirect 2/rm32/EDX . . . 2/r32/EDX . . # copy *EDX to EDX # call write() b8/copy . . . . . . . 4/imm32/write # copy 1 to EAX cd/syscall 0x80/imm8 + # restore registers + 5b/pop . . . . . . . . # pop EBX + 5a/pop . . . . . . . . # pop EDX + 59/pop . . . . . . . . # pop ECX + 58/pop . . . . . . . . # pop EAX # end c3/return == data +Test_argv: # null-terminated + # data + 74/t 65/e 73/s 74/t 00/null + Test_passed: # size 01 00 00 00 |