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/factorial2.subx.html | 179 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 179 insertions(+) create mode 100644 html/apps/factorial2.subx.html (limited to 'html/apps/factorial2.subx.html') diff --git a/html/apps/factorial2.subx.html b/html/apps/factorial2.subx.html new file mode 100644 index 00000000..5dd07391 --- /dev/null +++ b/html/apps/factorial2.subx.html @@ -0,0 +1,179 @@ + + + + +Mu - apps/factorial2.subx + + + + + + + + + + +https://github.com/akkartik/mu/blob/master/apps/factorial2.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     # . Heap = new-segment(Heap-size)
+ 24     # . . push args
+ 25     68/push Heap/imm32
+ 26     68/push Heap-size/imm32
+ 27     # . . call
+ 28     e8/call new-segment/disp32
+ 29     # . . discard args
+ 30     81 0/subop/add %esp 8/imm32
+ 31 
+ 32     # - if argc > 1 and argv[1] == "test", then return run_tests()
+ 33     # if (argc <= 1) goto run-main
+ 34     81 7/subop/compare *ebp 1/imm32
+ 35     7e/jump-if-lesser-or-equal $run-main/disp8
+ 36     # if (!kernel-string-equal?(argv[1], "test")) goto run-main
+ 37     # . eax = kernel-string-equal?(argv[1], "test")
+ 38     # . . push args
+ 39     68/push "test"/imm32
+ 40     ff 6/subop/push *(ebp+8)
+ 41     # . . call
+ 42     e8/call kernel-string-equal?/disp32
+ 43     # . . discard args
+ 44     81 0/subop/add %esp 8/imm32
+ 45     # . if (eax == 0) goto run-main
+ 46     3d/compare-eax-and 0/imm32
+ 47     74/jump-if-equal $run-main/disp8
+ 48     # run-tests()
+ 49     e8/call run-tests/disp32
+ 50     # syscall(exit, *Num-test-failures)
+ 51     8b/-> *Num-test-failures 3/r32/ebx
+ 52     eb/jump $main:end/disp8
+ 53 $run-main:
+ 54     # - otherwise return factorial(5)
+ 55     # eax = factorial(5)
+ 56     # . . push args
+ 57     68/push 5/imm32
+ 58     # . . call
+ 59     e8/call factorial/disp32
+ 60     # . . discard args
+ 61     81 0/subop/add %esp 4/imm32
+ 62     # syscall(exit, eax)
+ 63     89/<- %ebx 0/r32/eax
+ 64 $main:end:
+ 65     b8/copy-to-eax 1/imm32/exit
+ 66     cd/syscall 0x80/imm8
+ 67 
+ 68 factorial:  # n : int -> int/eax
+ 69     # . prologue
+ 70     55/push-ebp
+ 71     89/<- %ebp 4/r32/esp
+ 72     53/push-ebx
+ 73     # if (n <= 1) return 1
+ 74     b8/copy-to-eax 1/imm32
+ 75     81 7/subop/compare *(ebp+8) 1/imm32
+ 76     7e/jump-if-<= $factorial:end/disp8
+ 77     # ebx = n-1
+ 78     8b/-> *(ebp+8) 3/r32/ebx
+ 79     4b/decrement-ebx
+ 80     # eax = factorial(n-1)
+ 81     # . . push args
+ 82     53/push-ebx
+ 83     # . . call
+ 84     e8/call factorial/disp32
+ 85     # . . discard args
+ 86     81 0/subop/add %esp 4/imm32
+ 87     # return n * factorial(n-1)
+ 88     f7 4/subop/multiply-into-eax *(ebp+8)
+ 89     # TODO: check for overflow
+ 90 $factorial:end:
+ 91     # . epilogue
+ 92     5b/pop-to-ebx
+ 93     89/<- %esp 5/r32/ebp
+ 94     5d/pop-to-ebp
+ 95     c3/return
+ 96 
+ 97 test-factorial:
+ 98     # factorial(5)
+ 99     # . . push args
+100     68/push 5/imm32
+101     # . . call
+102     e8/call factorial/disp32
+103     # . . discard args
+104     81 0/subop/add %esp 4/imm32
+105     # check-ints-equal(eax, 120, msg)
+106     # . . push args
+107     68/push "F - test-factorial"/imm32
+108     68/push 0x78/imm32/expected-120
+109     50/push-eax
+110     # . . call
+111     e8/call check-ints-equal/disp32
+112     # . . discard args
+113     81 0/subop/add %esp 0xc/imm32
+114     # end
+115     c3/return
+
+ + + -- cgit 1.4.1-2-gfad0