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-rwxr-xr-xsubx/apps/factorialbin476 -> 1215 bytes
-rw-r--r--subx/apps/factorial.subx204
2 files changed, 184 insertions, 20 deletions
diff --git a/subx/apps/factorial b/subx/apps/factorial
index e5c76c6e..c487af47 100755
--- a/subx/apps/factorial
+++ b/subx/apps/factorial
Binary files differdiff --git a/subx/apps/factorial.subx b/subx/apps/factorial.subx
index 88f4baa8..209206ca 100644
--- a/subx/apps/factorial.subx
+++ b/subx/apps/factorial.subx
@@ -7,11 +7,12 @@
 #   $ echo $?
 #   120
 #
-# You can also run an automated test (that does the exact same thing):
+# You can also run the automated test suite:
 #   $ subx run apps/factorial test
 # Expected output:
-#   .
+#   ........
 # Every '.' indicates a passing test. Failing tests get a 'F'.
+# When running tests the exit status doesn't mean anything. Yet.
 
 == code
 # instruction                     effective address                                                   operand     displacement    immediate
@@ -26,8 +27,8 @@
   # and if (argv[1] == "test")
   8b/copy                         1/mod/*+disp8   4/rm32/sib    4/base/ESP  4/index/none  .           0/r32/EAX   8/disp8         .                 # copy *(ESP+8) to EAX
     # push args
-  68/push  Test_argv/imm32
   50/push-EAX
+  68/push  "test"/imm32
     # call
   e8/call  argv_equal/disp32
     # discard args
@@ -141,33 +142,59 @@ $check_ints_equal:else:
   # end
   c3/return
 
-# compare two null-terminated ascii strings
+# compare a null-terminated ascii string with a more idiomatic length-prefixed byte array
 # reason for the name: the only place we should have null-terminated ascii strings is from commandline args
-argv_equal:  # (s1, s2) : null-terminated ascii strings -> EAX : boolean
-  # initialize s1 (ECX) and s2 (EDX)
-  8b/copy                         1/mod/*+disp8   4/rm32/sib    4/base/ESP  4/index/none  .           1/r32/ECX   8/disp8         .                 # copy *(ESP+8) to ECX
+argv_equal:  # s : null-terminated ascii string, benchmark : length-prefixed ascii string -> EAX : boolean
+  # pseudocode:
+  #   initialize n = b.length
+  #   initialize s1 = s
+  #   initialize s2 = b.data
+  #   i = 0
+  #   for (i = 0; i < n; ++n)
+  #     c1 = *s1
+  #     c2 = *s2
+  #     if c1 == 0
+  #       return false
+  #     if c1 != c2
+  #       return false
+  #   return *s1 == 0
+# {{{
+  # initialize s into EDI
+  8b/copy                         1/mod/*+disp8   4/rm32/sib    4/base/ESP  4/index/none  .           7/r32/EDI   8/disp8         .                 # copy *(ESP+8) to EDI
+  # initialize benchmark length n into EDX
   8b/copy                         1/mod/*+disp8   4/rm32/sib    4/base/ESP  4/index/none  .           2/r32/EDX   4/disp8         .                 # copy *(ESP+4) to EDX
-  # while (true)
+  8b/copy                         0/mod/indirect  2/rm32/EDX    .           .             .           2/r32/EDX   .               .                 # copy *EDX to EDX
+  # initialize benchmark data into ESI
+  8b/copy                         1/mod/*+disp8   4/rm32/sib    4/base/ESP  4/index/none  .           6/r32/ESI   4/disp8         .                 # copy *(ESP+4) to ESI
+  81          0/subop/add         3/mod/direct    6/rm32/ESI    .           .             .           .           .               4/imm32           # add 4 to ESI
+  # initialize loop counter i into ECX
+  b9/copy                         .               .             .           .             .           .           .               0/imm32/exit      # copy 1 to ECX
+  # while (i/ECX < n/EDX)
 $argv_loop:
-    # c1/EAX, c2/EBX = *s1, *s2
+  39/compare                      3/mod/direct    1/rm32/ECX    .           .             .           2/r32/EDX   .               .                 # compare ECX with EDX
+  74/jump-if-equal  $argv_break/disp8
+    # c1/EAX, c2/EBX = *s, *benchmark
   b8/copy  0/imm32  # clear EAX
-  8a/copy                         0/mod/indirect  1/rm32/ECX    .           .             .           0/r32/EAX   .               .                 # copy byte at *ECX to lower byte of EAX
+  8a/copy                         0/mod/indirect  7/rm32/EDI    .           .             .           0/r32/EAX   .               .                 # copy byte at *EDI to lower byte of EAX
   bb/copy  0/imm32  # clear EBX
-  8a/copy                         0/mod/indirect  2/rm32/EDX    .           .             .           3/r32/EBX   .               .                 # copy byte at *EDX to lower byte of EBX
-    # if (c1 == 0) break
+  8a/copy                         0/mod/indirect  6/rm32/ESI    .           .             .           3/r32/EBX   .               .                 # copy byte at *ESI to lower byte of EBX
+    # if (c1 == 0) return false
   3d/compare                      .               .             .           .             .           .           .               0/imm32           # compare EAX with 0
-  74/jump-if-equal  $argv_break/disp8
+  74/jump-if-equal  $argv_fail/disp8
     # if (c1 != c2) return false
   39/compare                      3/mod/direct    0/rm32/EAX    .           .             .           3/r32/EBX   .               .                 # compare EAX with EBX
   75/jump-if-not-equal  $argv_fail/disp8
-    # ++s1, ++s2
+    # ++s1, ++s2, ++i
   41/inc-ECX
-  42/inc-EDX
+  46/inc-ESI
+  47/inc-EDI
   # end while
   eb/jump  $argv_loop/disp8
 $argv_break:
-  # if (c2 == 0) return true
-  81          7/subop/compare     3/mod/direct    3/rm32/EBX    .           .             .           .           .               0/imm32           # compare EBX with 0
+  # if (*s/EDI == 0) return true
+  b8/copy  0/imm32  # clear EAX
+  8a/copy                         0/mod/indirect  7/rm32/EDI    .           .             .           0/r32/EAX   .               .                 # copy byte at *EDI to lower byte of EAX
+  81          7/subop/compare     3/mod/direct    0/rm32/EAX    .           .             .           .           .               0/imm32           # compare EAX with 0
   75/jump-if-not-equal  $argv_fail/disp8
   b8/copy                         .               .             .           .             .           .           .               1/imm32           # copy 1 to EAX
   c3/return
@@ -175,6 +202,141 @@ $argv_break:
 $argv_fail:
   b8/copy                         .               .             .           .             .           .           .               0/imm32           # copy 0 to EAX
   c3/return
+# }}}
+# tests for argv_equal {{{
+test_compare_null_argv_with_empty_array:
+  # EAX = argv_equal(Null_argv, "")
+    # push args
+  68/push  Null_argv/imm32
+  68/push  ""/imm32
+    # call
+  e8/call  argv_equal/disp32
+    # discard args
+  81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add 8 to ESP
+  # call check_ints_equal(EAX, 1)
+  50/push-EAX
+  68/push  1/imm32/true
+  68/push  "F - test_compare_null_argv_with_empty_array"/imm32
+    # call
+  e8/call  check_ints_equal/disp32
+    # discard args
+  81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               0xc/imm32         # add 12 to ESP
+  c3/return
+
+test_compare_null_argv_with_non_empty_array:
+  # EAX = argv_equal(Null_argv, "Abc")
+    # push args
+  68/push  Null_argv/imm32
+  68/push  "Abc"/imm32
+    # call
+  e8/call  argv_equal/disp32
+    # discard args
+  81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add 8 to ESP
+  # call check_ints_equal(EAX, 0)
+  50/push-EAX
+  68/push  0/imm32/false
+  68/push  "F - test_compare_null_argv_with_non_empty_array"/imm32
+    # call
+  e8/call  check_ints_equal/disp32
+    # discard args
+  81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               0xc/imm32         # add 12 to ESP
+  c3/return
+
+test_compare_argv_with_equal_array:
+  # EAX = argv_equal(Abc_argv, "Abc")
+    # push args
+  68/push  Abc_argv/imm32
+  68/push  "Abc"/imm32
+    # call
+  e8/call  argv_equal/disp32
+    # discard args
+  81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add 8 to ESP
+  # call check_ints_equal(EAX, 1)
+  50/push-EAX
+  68/push  1/imm32/true
+  68/push  "F - test_compare_argv_with_equal_array"/imm32
+    # call
+  e8/call  check_ints_equal/disp32
+    # discard args
+  81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               0xc/imm32         # add 12 to ESP
+  c3/return
+
+test_compare_argv_with_inequal_array:
+  # EAX = argv_equal(Abc_argv, "Adc")
+    # push args
+  68/push  Abc_argv/imm32
+  68/push  "Adc"/imm32
+    # call
+  e8/call  argv_equal/disp32
+    # discard args
+  81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add 8 to ESP
+  # call check_ints_equal(EAX, 0)
+  50/push-EAX
+  68/push  0/imm32/false
+  68/push  "F - test_compare_argv_with_equal_array"/imm32
+    # call
+  e8/call  check_ints_equal/disp32
+    # discard args
+  81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               0xc/imm32         # add 12 to ESP
+  c3/return
+
+test_compare_argv_with_empty_array:
+  # EAX = argv_equal(Abc_argv, "")
+    # push args
+  68/push  Abc_argv/imm32
+  68/push  ""/imm32
+    # call
+  e8/call  argv_equal/disp32
+    # discard args
+  81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add 8 to ESP
+  # call check_ints_equal(EAX, 0)
+  50/push-EAX
+  68/push  0/imm32/false
+  68/push  "F - test_compare_argv_with_equal_array"/imm32
+    # call
+  e8/call  check_ints_equal/disp32
+    # discard args
+  81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               0xc/imm32         # add 12 to ESP
+  c3/return
+
+test_compare_argv_with_shorter_array:
+  # EAX = argv_equal(Abc_argv, "Ab")
+    # push args
+  68/push  Abc_argv/imm32
+  68/push  "Ab"/imm32
+    # call
+  e8/call  argv_equal/disp32
+    # discard args
+  81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add 8 to ESP
+  # call check_ints_equal(EAX, 0)
+  50/push-EAX
+  68/push  0/imm32/false
+  68/push  "F - test_compare_argv_with_shorter_array"/imm32
+    # call
+  e8/call  check_ints_equal/disp32
+    # discard args
+  81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               0xc/imm32         # add 12 to ESP
+  c3/return
+
+test_compare_argv_with_longer_array:
+  # EAX = argv_equal(Abc_argv, "Abcd")
+    # push args
+  68/push  Abc_argv/imm32
+  68/push  "Abcd"/imm32
+    # call
+  e8/call  argv_equal/disp32
+    # discard args
+  81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add 8 to ESP
+  # call check_ints_equal(EAX, 0)
+  50/push-EAX
+  68/push  0/imm32/false
+  68/push  "F - test_compare_argv_with_longer_array"/imm32
+    # call
+  e8/call  check_ints_equal/disp32
+    # discard args
+  81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               0xc/imm32         # add 12 to ESP
+  c3/return
+# }}}
 
 write_stderr:  # s : (address array byte) -> <void>
   # save registers
@@ -209,8 +371,10 @@ Newline:
   # data
   0a/newline
 
-Test_argv:  # null-terminated
-  # data
-  74/t 65/e 73/s 74/t 00/null
+# for argv_equal tests
+Null_argv:
+  00/null
+Abc_argv:
+  41/A 62/b 63/c 00/null
 
 # vim:ft=subx:nowrap:so=0