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author | Kartik K. Agaram <vc@akkartik.com> | 2021-03-03 22:09:50 -0800 |
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committer | Kartik K. Agaram <vc@akkartik.com> | 2021-03-03 22:21:03 -0800 |
commit | 71e4f3812982dba2efb471283d310224e8db363e (patch) | |
tree | ea111a1acb8b8845dbda39c0e1b4bac1d198143b /linux/advent2020/3b.mu | |
parent | c6b928be29ac8cdb4e4d6e1eaa20420ff03e5a4c (diff) | |
download | mu-71e4f3812982dba2efb471283d310224e8db363e.tar.gz |
7842 - new directory organization
Baremetal is now the default build target and therefore has its sources at the top-level. Baremetal programs build using the phase-2 Mu toolchain that requires a Linux kernel. This phase-2 codebase which used to be at the top-level is now under the linux/ directory. Finally, the phase-2 toolchain, while self-hosting, has a way to bootstrap from a C implementation, which is now stored in linux/bootstrap. The bootstrap C implementation uses some literate programming tools that are now in linux/bootstrap/tools. So the whole thing has gotten inverted. Each directory should build one artifact and include the main sources (along with standard library). Tools used for building it are relegated to sub-directories, even though those tools are often useful in their own right, and have had lots of interesting programs written using them. A couple of things have gotten dropped in this process: - I had old ways to run on just a Linux kernel, or with a Soso kernel. No more. - I had some old tooling for running a single test at the cursor. I haven't used that lately. Maybe I'll bring it back one day. The reorg isn't done yet. Still to do: - redo documentation everywhere. All the README files, all other markdown, particularly vocabulary.md. - clean up how-to-run comments at the start of programs everywhere - rethink what to do with the html/ directory. Do we even want to keep supporting it? In spite of these shortcomings, all the scripts at the top-level, linux/ and linux/bootstrap are working. The names of the scripts also feel reasonable. This is a good milestone to take stock at.
Diffstat (limited to 'linux/advent2020/3b.mu')
-rw-r--r-- | linux/advent2020/3b.mu | 137 |
1 files changed, 137 insertions, 0 deletions
diff --git a/linux/advent2020/3b.mu b/linux/advent2020/3b.mu new file mode 100644 index 00000000..fcc9261a --- /dev/null +++ b/linux/advent2020/3b.mu @@ -0,0 +1,137 @@ +# https://adventofcode.com/2020/day/3 +# +# To run (on Linux): +# $ git clone https://github.com/akkartik/mu +# $ cd mu +# $ ./translate_mu apps/advent2020/3a.mu +# $ ./a.elf < input +# +# You'll need to register to download the 'input' file for yourself. + +fn main -> _/ebx: int { + # represent trees in a 2D array of ints + # wasteful since each tree is just one bit + var trees-storage: (array int 0x2800) # 10k ints + var trees/esi: (addr array int) <- address trees-storage + var trees-length/ecx: int <- copy 0 + var num-rows: int + var width: int + # phase 1: parse each row of trees from stdin + { + var line-storage: (stream byte 0x40) # 64 bytes + var line/edx: (addr stream byte) <- address line-storage + { + # 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-!= + # wastefully recompute width on every line + # zero error-checking; we assume input lines are all equally long + copy-to width, 0 + # turn each byte into a tree and append it + $main:line-loop: { + var done?/eax: boolean <- stream-empty? line + compare done?, 0/false + break-if-!= +#? print-int32-decimal 0, num-rows +#? print-string 0, " " +#? print-int32-decimal 0, width +#? print-string 0, "\n" + var dest/ebx: (addr int) <- index trees, trees-length + var c/eax: byte <- read-byte line + # newline comes only at end of line + compare c, 0xa/newline + break-if-= + # '#' = tree + compare c, 0x23/hash + { + break-if-!= + copy-to *dest, 1 + } + # anything else = no tree + { + break-if-= + copy-to *dest, 0 + } + increment width + trees-length <- increment + loop + } + increment num-rows + loop + } + } + # phase 2: compute + var product/edi: int <- copy 1 + var result/eax: int <- num-trees-hit trees, width, num-rows, 1, 1 + print-int32-decimal 0, result + print-string 0, " x " + product <- multiply result + var result/eax: int <- num-trees-hit trees, width, num-rows, 3, 1 + print-int32-decimal 0, result + print-string 0, " x " + product <- multiply result + var result/eax: int <- num-trees-hit trees, width, num-rows, 5, 1 + print-int32-decimal 0, result + print-string 0, " x " + product <- multiply result + var result/eax: int <- num-trees-hit trees, width, num-rows, 7, 1 + print-int32-decimal 0, result + print-string 0, " x " + product <- multiply result + var result/eax: int <- num-trees-hit trees, width, num-rows, 1, 2 + print-int32-decimal 0, result + print-string 0, " = " + product <- multiply result + print-int32-hex 0, product + print-string 0, "\n" + return 0 +} + +fn num-trees-hit trees: (addr array int), width: int, num-rows: int, right: int, down: int -> _/eax: int { +#? print-string 0, "== " +#? print-int32-decimal 0, right +#? print-string 0, " " +#? print-int32-decimal 0, down +#? print-string 0, "\n" + var row/ecx: int <- copy 0 + var col/edx: int <- copy 0 + var num-trees-hit/edi: int <- copy 0 + { + compare row, num-rows + break-if->= +#? print-int32-decimal 0, col +#? print-string 0, "\n" + var curr/eax: int <- index2d trees, row, col, width + compare curr, 0 + { + break-if-= + num-trees-hit <- increment + } + col <- add right + row <- add down + loop + } + return num-trees-hit +} + +fn index2d _arr: (addr array int), _row: int, _col: int, width: int -> _/eax: int { + # handle repeating columns of trees + var dummy/eax: int <- copy 0 + var col/edx: int <- copy 0 + dummy, col <- integer-divide _col, width +#? print-string 0, " " +#? print-int32-decimal 0, col +#? print-string 0, "\n" + # compute index + var index/eax: int <- copy _row + index <- multiply width + index <- add col + # look up array + var arr/esi: (addr array int) <- copy _arr + var src/eax: (addr int) <- index arr, index + return *src +} |