From c83dca9cb45a7e15b28a979d0ccfce5c202859ba Mon Sep 17 00:00:00 2001 From: Kartik Agaram Date: Sat, 19 Oct 2019 18:39:45 -0700 Subject: 5706 - example at different levels of syntax sugar MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Thanks Mateusz Czapliński for the feedback: https://lobste.rs/s/xtxlec/mu_minimal_hobbyist_computing_stack#c_1mzq94 --- html/apps/factorial4.subx.html | 146 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 146 insertions(+) create mode 100644 html/apps/factorial4.subx.html (limited to 'html/apps/factorial4.subx.html') diff --git a/html/apps/factorial4.subx.html b/html/apps/factorial4.subx.html new file mode 100644 index 00000000..d8cdec7d --- /dev/null +++ b/html/apps/factorial4.subx.html @@ -0,0 +1,146 @@ + + + + +Mu - apps/factorial4.subx + + + + + + + + + + +https://github.com/akkartik/mu/blob/master/apps/factorial4.subx +
+ 1 ## compute the factorial of 5, and return the result in the exit code
+ 2 #
+ 3 # To run:
+ 4 #   $ ./ntranslate init.linux 0*.subx apps/factorial.subx -o apps/factorial
+ 5 #   $ ./subx run apps/factorial
+ 6 # Expected result:
+ 7 #   $ echo $?
+ 8 #   120
+ 9 #
+10 # You can also run the automated test suite:
+11 #   $ ./subx run apps/factorial test
+12 # Expected output:
+13 #   ........
+14 # Every '.' indicates a passing test. Failing tests get a 'F'.
+15 
+16 == code
+17 
+18 Entry:  # run tests if necessary, compute `factorial(5)` if not
+19     # . prologue
+20     89/<- %ebp 4/r32/esp
+21 
+22     # initialize heap
+23     (new-segment 0x10000 Heap)
+24 
+25     # - if argc > 1, then return run_tests()
+26     {
+27       # if (argc <= 1) break
+28       81 7/subop/compare *ebp 1/imm32
+29       7e/jump-if-lesser-or-equal break/disp8
+30       # if (!kernel-string-equal?(argv[1], "test")) break
+31       (kernel-string-equal? *(ebp+8) "test")  # => eax
+32       3d/compare-eax-and 0/imm32
+33       74/jump-if-equal break/disp8
+34       #
+35       (run-tests)
+36       # eax = *Num-test-failures
+37       8b/-> *Num-test-failures 3/r32/ebx
+38     }
+39     # if (argc <= 1) factorial(5)
+40     {
+41       # if (argc > 1) break
+42       81 7/subop/compare *ebp 1/imm32
+43       7f/jump-if-greater break/disp8
+44       # eax = factorial(5)
+45       (factorial 5)
+46       # syscall(exit, eax)
+47       89/<- %ebx 0/r32/eax
+48     }
+49 
+50     b8/copy-to-eax 1/imm32/exit
+51     cd/syscall 0x80/imm8
+52 
+53 factorial:  # n : int -> int/eax
+54     # . prologue
+55     55/push-ebp
+56     89/<- %ebp 4/r32/esp
+57     # save registers
+58     53/push-ebx
+59     # if (n <= 1) return 1
+60     81 7/subop/compare *(ebp+8) 1/imm32
+61     {
+62       7f/jump-if-greater break/disp8
+63       b8/copy-to-eax 1/imm32
+64     }
+65     # if (n > 1) return n * factorial(n-1)
+66     {
+67       7e/jump-if-lesser-or-equal break/disp8
+68       8b/-> *(ebp+8) 3/r32/ebx
+69       4b/decrement-ebx
+70       (factorial %ebx)  # => eax
+71       f7 4/subop/multiply-into-eax *(ebp+8)
+72     }
+73     # restore registers
+74     5b/pop-to-ebx
+75     # . epilogue
+76     89/<- %esp 5/r32/ebp
+77     5d/pop-to-ebp
+78     c3/return
+79 
+80 test-factorial:
+81     (factorial 5)
+82     (check-ints-equal %eax 0x78 "F - test-factorial")
+83     c3/return
+
+ + + -- cgit 1.4.1-2-gfad0