diff options
Diffstat (limited to 'apps/factorial3.subx')
| -rw-r--r-- | apps/factorial3.subx | 39 |
1 files changed, 19 insertions, 20 deletions
diff --git a/apps/factorial3.subx b/apps/factorial3.subx index eb07b5ca..b2624fe7 100644 --- a/apps/factorial3.subx +++ b/apps/factorial3.subx @@ -21,27 +21,25 @@ == code -factorial: # n: int -> int/eax +factorial: # n: int -> _/eax: int # . prologue 55/push-ebp 89/<- %ebp 4/r32/esp # save registers - 53/push-ebx + 51/push-ecx # if (n <= 1) return 1 b8/copy-to-eax 1/imm32 81 7/subop/compare *(ebp+8) 1/imm32 7e/jump-if-<= $factorial:end/disp8 - # var ebx: int = n-1 - 8b/-> *(ebp+8) 3/r32/ebx - 4b/decrement-ebx - # - (factorial %ebx) # => eax - # return n * factorial(n-1) + # n > 1; return n * factorial(n-1) + 8b/-> *(ebp+8) 1/r32/ecx + 49/decrement-ecx + (factorial %ecx) # => eax f7 4/subop/multiply-into-eax *(ebp+8) # TODO: check for overflow $factorial:end: # restore registers - 5b/pop-to-ebx + 59/pop-to-ecx # . epilogue 89/<- %esp 5/r32/ebp 5d/pop-to-ebp @@ -59,23 +57,24 @@ Entry: # run tests if necessary, compute `factorial(5)` if not # initialize heap (needed by tests elsewhere) (new-segment *Heap-size Heap) - # - if argc > 1 and argv[1] == "test", then return run_tests() - # if (argc <= 1) goto run-main + # if (argc <= 1) return factorial(5) 81 7/subop/compare *ebp 1/imm32 - 7e/jump-if-<= $run-main/disp8 - # if (!kernel-string-equal?(argv[1], "test")) goto run-main + 7f/jump-if-> $main:run-tests/disp8 + (factorial 5) # => eax + 89/<- %ebx 0/r32/eax + eb/jump $main:end/disp8 +$main:run-tests: + # otherwise if first arg is "test", then return run_tests() + # if (!kernel-string-equal?(argv[1], "test")) goto do-nothing (kernel-string-equal? *(ebp+8) "test") # => eax - # . if (eax == false) goto run-main 3d/compare-eax-and 0/imm32/false - 74/jump-if-= $run-main/disp8 + 74/jump-if-= $main:do-nothing/disp8 # (run-tests) - # syscall(exit, *Num-test-failures) + # exit(*Num-test-failures) 8b/-> *Num-test-failures 3/r32/ebx eb/jump $main:end/disp8 -$run-main: - # - otherwise - (factorial 5) # => eax - 89/<- %ebx 0/r32/eax +$main:do-nothing: + bb/copy-to-ebx 0/imm32 $main:end: e8/call syscall_exit/disp32 |