diff options
| -rw-r--r-- | 305keyboard.subx | 6 | ||||
| -rw-r--r-- | 311decimal-int.subx | 12 | ||||
| -rw-r--r-- | apps/advent2020/1a.mu | 84 |
3 files changed, 97 insertions, 5 deletions
diff --git a/305keyboard.subx b/305keyboard.subx index 079814fa..32159e49 100644 --- a/305keyboard.subx +++ b/305keyboard.subx @@ -159,13 +159,9 @@ read-line-from-real-keyboard: # out: (addr stream byte) # . prologue 55/push-ebp 89/<- %ebp 4/r32/esp - # . save registers - 50/push-eax # - (read 0 *(ebp+8)) # => eax + (read-line-buffered Stdin *(ebp+8)) $read-line-from-real-keyboard:end: - # . restore registers - 58/pop-to-eax # . epilogue 89/<- %esp 5/r32/ebp 5d/pop-to-ebp diff --git a/311decimal-int.subx b/311decimal-int.subx index 62ec51d6..badae601 100644 --- a/311decimal-int.subx +++ b/311decimal-int.subx @@ -60,6 +60,18 @@ parse-decimal-int-from-stream: # in: (addr stream byte) -> result/eax: int # var end/edx: (addr byte) = &in->data[in->write] 8b/-> *eax 2/r32/edx 8d/copy-address *(eax+edx+0xc) 2/r32/edx + # trim a trailing newline + { + # speculatively trim + 4a/decrement-edx + # if it's a newline, break + 8a/byte-> *edx 0/r32/eax + 81 4/subop/and %eax 0xff/imm32 + 3d/compare-eax-and 0xa/imm32/newline + 74/jump-if-= break/disp8 + # not a newline, so restore it + 42/increment-edx + } # (parse-decimal-int-helper %ecx %edx) # => eax $parse-decimal-int-from-stream:end: diff --git a/apps/advent2020/1a.mu b/apps/advent2020/1a.mu new file mode 100644 index 00000000..45bb5bd2 --- /dev/null +++ b/apps/advent2020/1a.mu @@ -0,0 +1,84 @@ +fn main -> _/ebx: int { + # data structure + var numbers-storage: (array int 0x100) # 256 ints + var numbers/esi: (addr array int) <- address numbers-storage + var numbers-index/ecx: int <- copy 0 + # phase 1: parse each line from stdin and add it to numbers + { + var line-storage: (stream byte 0x100) # 256 bytes + var line/edx: (addr stream byte) <- address line-storage + { +#? print-string 0, "== iter\n" + # read line from stdin + clear-stream line + read-line-from-real-keyboard line + # if line is empty (not even a newline), quit + var done?/eax: boolean <- stream-empty? line + compare done?, 0 # false + break-if-!= +#? print-stream-to-real-screen line + # convert line to int and append it to numbers + var n/eax: int <- parse-decimal-int-from-stream line +#? print-int32-decimal 0, n +#? print-string 0, "\n" + var dest/ebx: (addr int) <- index numbers, numbers-index + copy-to *dest, n + numbers-index <- increment +#? print-string 0, "== " +#? print-int32-decimal 0, numbers-index +#? print-string 0, "\n" + loop + } + } + # phase 2: for each number in the array, check if 2020-it is in the rest of + # the array + var i/eax: int <- copy 0 + { + compare i, numbers-index + break-if->= + var src/ebx: (addr int) <- index numbers, i +#? print-int32-decimal 0, *src +#? print-string 0, "\n" + var target/ecx: int <- copy 0x7e4 # 2020 + target <- subtract *src + { + var found?/eax: boolean <- find-after numbers, i, target + compare found?, 0 # false + break-if-= + print-string 0, "found\n" + print-int32-decimal 0, *src + print-string 0, " " + print-int32-decimal 0, target + print-string 0, "\n" + target <- multiply *src + print-int32-decimal 0, target + print-string 0, "\n" + return 0 # success + } + i <- increment + loop + } + return 1 # not found +} + +fn find-after _numbers: (addr array int), start: int, _target: int -> _/eax: boolean { + var numbers/esi: (addr array int) <- copy _numbers + var target/edi: int <- copy _target + var len/ecx: int <- length numbers + var i/eax: int <- copy start + i <- increment + { + compare i, len + break-if->= + var src/edx: (addr int) <- index numbers, i + # if *src == target, return true + compare *src, target + { + break-if-!= + return 1 # true + } + i <- increment + loop + } + return 0 # false +} |