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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/factorial3.subx | |
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/factorial3.subx')
-rw-r--r-- | linux/factorial3.subx | 80 |
1 files changed, 80 insertions, 0 deletions
diff --git a/linux/factorial3.subx b/linux/factorial3.subx new file mode 100644 index 00000000..82d59b5e --- /dev/null +++ b/linux/factorial3.subx @@ -0,0 +1,80 @@ +## compute the factorial of 5, and return the result in the exit code +# +# Uses syntax sugar for: +# rm32 operands +# function calls +# +# To run: +# $ ./translate_subx init.linux [01]*.subx apps/factorial.subx -o apps/factorial +# $ ./bootstrap run apps/factorial +# Expected result: +# $ echo $? +# 120 +# +# You can also run the automated test suite: +# $ ./bootstrap run apps/factorial test +# Expected output: +# ........ +# Every '.' indicates a passing test. Failing tests get a 'F'. +# +# Compare apps/factorial2.subx + +== code + +factorial: # n: int -> _/eax: int + # . prologue + 55/push-ebp + 89/<- %ebp 4/r32/esp + # save registers + 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-<= $factorial:end/disp8 + # n > 1; return n * factorial(n-1) + 8b/-> *(ebp+8) 1/r32/ecx + 49/decrement-ecx + (factorial %ecx) # => eax + f7 4/subop/multiply-into-eax *(ebp+8) + # TODO: check for overflow +$factorial:end: + # restore registers + 59/pop-to-ecx + # . epilogue + 89/<- %esp 5/r32/ebp + 5d/pop-to-ebp + c3/return + +test-factorial: + (factorial 5) + (check-ints-equal %eax 0x78 "F - test-factorial") + c3/return + +Entry: # run tests if necessary, compute `factorial(5)` if not + # . prologue + 89/<- %ebp 4/r32/esp + + # initialize heap (needed by tests elsewhere) + (new-segment *Heap-size Heap) + + # if (argc <= 1) return factorial(5) + 81 7/subop/compare *ebp 1/imm32 + 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 + 3d/compare-eax-and 0/imm32/false + 74/jump-if-= $main:do-nothing/disp8 + # + (run-tests) + # exit(*Num-test-failures) + 8b/-> *Num-test-failures 3/r32/ebx + eb/jump $main:end/disp8 +$main:do-nothing: + bb/copy-to-ebx 0/imm32 +$main:end: + e8/call syscall_exit/disp32 |