diff options
Diffstat (limited to 'apps/factorial.subx')
| -rw-r--r-- | apps/factorial.subx | 100 |
1 files changed, 50 insertions, 50 deletions
diff --git a/apps/factorial.subx b/apps/factorial.subx index 74e4dd6d..b027696e 100644 --- a/apps/factorial.subx +++ b/apps/factorial.subx @@ -18,6 +18,55 @@ # . 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 +factorial: # n: int -> int/eax + # . prologue + 55/push-ebp + 89/copy 3/mod/direct 5/rm32/ebp . . . 4/r32/esp . . # copy esp to ebp + 53/push-ebx + # if (n <= 1) return 1 + b8/copy-to-eax 1/imm32 + 81 7/subop/compare 1/mod/*+disp8 5/rm32/ebp . . . . 8/disp8 1/imm32 # compare *(ebp+8) + 7e/jump-if-<= $factorial:end/disp8 + # var ebx: int = n-1 + 8b/copy 1/mod/*+disp8 5/rm32/ebp . . 3/r32/ebx 8/disp8 . # copy *(ebp+8) to ebx + 4b/decrement-ebx + # var eax: int = factorial(n-1) + # . . push args + 53/push-ebx + # . . call + e8/call factorial/disp32 + # . . discard args + 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 4/imm32 # add to esp + # return n * factorial(n-1) + f7 4/subop/multiply 1/mod/*+disp8 5/rm32/ebp . . 8/disp8 . # multiply *(ebp+8) into eax + # TODO: check for overflow +$factorial:end: + # . epilogue + 5b/pop-to-ebx + 89/copy 3/mod/direct 4/rm32/esp . . . 5/r32/ebp . . # copy ebp to esp + 5d/pop-to-ebp + c3/return + +test-factorial: + # factorial(5) + # . . push args + 68/push 5/imm32 + # . . call + e8/call factorial/disp32 + # . . discard args + 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 4/imm32 # add to esp + # check-ints-equal(eax, 120, msg) + # . . push args + 68/push "F - test-factorial"/imm32 + 68/push 0x78/imm32/expected-120 + 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 + # end + c3/return + Entry: # run tests if necessary, compute `factorial(5)` if not # . prologue 89/copy 3/mod/direct 5/rm32/ebp . . . 4/r32/esp . . # copy esp to ebp @@ -92,58 +141,9 @@ $run-main: e8/call write/disp32 # . . discard args 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 8/imm32 # add to esp - # syscall(exit, eax) + # 89/copy 3/mod/direct 3/rm32/ebx . . . 0/r32/eax . . # copy eax to ebx $main:end: e8/call syscall_exit/disp32 -factorial: # n: int -> int/eax - # . prologue - 55/push-ebp - 89/copy 3/mod/direct 5/rm32/ebp . . . 4/r32/esp . . # copy esp to ebp - 53/push-ebx - # if (n <= 1) return 1 - b8/copy-to-eax 1/imm32 - 81 7/subop/compare 1/mod/*+disp8 5/rm32/ebp . . . . 8/disp8 1/imm32 # compare *(ebp+8) - 7e/jump-if-<= $factorial:end/disp8 - # var ebx: int = n-1 - 8b/copy 1/mod/*+disp8 5/rm32/ebp . . 3/r32/ebx 8/disp8 . # copy *(ebp+8) to ebx - 4b/decrement-ebx - # var eax: int = factorial(n-1) - # . . push args - 53/push-ebx - # . . call - e8/call factorial/disp32 - # . . discard args - 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 4/imm32 # add to esp - # return n * factorial(n-1) - f7 4/subop/multiply 1/mod/*+disp8 5/rm32/ebp . . 8/disp8 . # multiply *(ebp+8) into eax - # TODO: check for overflow -$factorial:end: - # . epilogue - 5b/pop-to-ebx - 89/copy 3/mod/direct 4/rm32/esp . . . 5/r32/ebp . . # copy ebp to esp - 5d/pop-to-ebp - c3/return - -test-factorial: - # factorial(5) - # . . push args - 68/push 5/imm32 - # . . call - e8/call factorial/disp32 - # . . discard args - 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 4/imm32 # add to esp - # check-ints-equal(eax, 120, msg) - # . . push args - 68/push "F - test-factorial"/imm32 - 68/push 0x78/imm32/expected-120 - 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 - # end - c3/return - # . . vim:nowrap:textwidth=0 |