diff options
Diffstat (limited to 'apps/factorial4.subx')
| -rw-r--r-- | apps/factorial4.subx | 31 |
1 files changed, 15 insertions, 16 deletions
diff --git a/apps/factorial4.subx b/apps/factorial4.subx index 6228f9ab..e39c2178 100644 --- a/apps/factorial4.subx +++ b/apps/factorial4.subx @@ -22,7 +22,7 @@ == code -factorial: # n: int -> int/eax +factorial: # n: int -> _/eax: int # . prologue 55/push-ebp 89/<- %ebp 4/r32/esp @@ -33,16 +33,15 @@ factorial: # n: int -> int/eax { 7f/jump-if-> break/disp8 b8/copy-to-eax 1/imm32 + eb/jump $factorial:end/disp8 } - # if (n > 1) return n * factorial(n-1) - { - 7e/jump-if-<= break/disp8 - # var tmp/ecx: int = n-1 - 8b/-> *(ebp+8) 1/r32/ecx - 49/decrement-ecx - (factorial %ecx) # => eax - f7 4/subop/multiply-into-eax *(ebp+8) - } + # n > 1; return n * factorial(n-1) + 8b/-> *(ebp+8) 1/r32/ecx + 49/decrement-ecx + (factorial %ecx) # => eax + f7 4/subop/multiply-into-eax *(ebp+8) + # TODO: check for overflow +$factorial:end: # restore registers 59/pop-to-ecx # . epilogue @@ -70,20 +69,20 @@ Entry: # run tests if necessary, compute `factorial(5)` if not # ebx = factorial(5) (factorial 5) # => eax 89/<- %ebx 0/r32/eax + eb/jump $main:end/disp8 } - # otherwise if an arg exists and is "test", then return run_tests() + # otherwise if first arg is "test", then return run_tests() { - # if (argc <= 1) break - 81 7/subop/compare *ebp 1/imm32 - 7e/jump-if-<= break/disp8 # if (!kernel-string-equal?(argv[1], "test")) break (kernel-string-equal? *(ebp+8) "test") # => eax 3d/compare-eax-and 0/imm32/false 74/jump-if-= break/disp8 # (run-tests) - # ebx = *Num-test-failures + # exit(*Num-test-failures) 8b/-> *Num-test-failures 3/r32/ebx + eb/jump $main:end/disp8 } - + bb/copy-to-ebx 0/imm32 +$main:end: e8/call syscall_exit/disp32 |