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# Rudimentary test harness
== code
# instruction effective address register displacement immediate
# . op subop mod rm32 base index scale r32
# . 1-3 bytes 3 bits 2 bits 3 bits 3 bits 3 bits 2 bits 2 bits 0/1/2/4 bytes 0/1/2/4 bytes
#? Entry: # manual test
#? # check-ints-equal(34, 34)
#? # . . push args
#? 68/push "error in check-ints-equal"/imm32
#? 68/push 34/imm32
#? 68/push 34/imm32
#? # . . call
#? e8/call check-ints-equal/disp32
#? # . . discard args
#? 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 0xc/imm32 # add to esp
#? # syscall_exit(0)
#? bb/copy-to-ebx 0/imm32
#? e8/call syscall_exit/disp32
# print msg to stderr if a != b, otherwise print "."
check-ints-equal: # a: int, b: int, msg: (addr array byte)
# . prologue
55/push-ebp
89/copy 3/mod/direct 5/rm32/ebp . . . 4/r32/esp . . # copy esp to ebp
# . save registers
50/push-eax
51/push-ecx
53/push-ebx
# load first 2 args into eax and ebx
8b/copy 1/mod/*+disp8 5/rm32/ebp . . . 0/r32/eax 8/disp8 . # copy *(ebp+8) to eax
8b/copy 1/mod/*+disp8 5/rm32/ebp . . . 3/r32/ebx 0xc/disp8 . # copy *(ebp+12) to ebx
# if (eax == ebx) success
39/compare 3/mod/direct 0/rm32/eax . . . 3/r32/ebx . . # compare eax and ebx
75/jump-if-unequal $check-ints-equal:else/disp8
# . _write(2/stderr, '.')
# . . push args
68/push "."/imm32
68/push 2/imm32/stderr
# . . call
e8/call _write/disp32
# . . discard args
81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 8/imm32 # add to esp
# . return
eb/jump $check-ints-equal:end/disp8
# otherwise print error message
$check-ints-equal:else:
# . _write(2/stderr, msg)
# . . push args
8b/copy 1/mod/*+disp8 5/rm32/ebp . . . 1/r32/ecx 0x10/disp8 . # copy *(ebp+16) to ecx
51/push-ecx
68/push 2/imm32/stderr
# . . call
e8/call _write/disp32
# . . discard args
81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 8/imm32 # add to esp
# . _write(2/stderr, Newline)
# . . push args
68/push Newline/imm32
68/push 2/imm32/stderr
# . . call
e8/call _write/disp32
# . . discard args
81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 8/imm32 # add to esp
# increment Num-test-failures
ff 0/subop/increment 0/mod/indirect 5/rm32/.disp32 . . . Num-test-failures/disp32 # increment *Num-test-failures
$check-ints-equal:end:
# . restore registers
5b/pop-to-ebx
59/pop-to-ecx
58/pop-to-eax
# . epilogue
89/copy 3/mod/direct 4/rm32/esp . . . 5/r32/ebp . . # copy ebp to esp
5d/pop-to-ebp
c3/return
== data
# length-prefixed string containing just a single newline
# convenient to have when printing messages and so on
Newline: # (array byte)
# size: int
1/imm32
# data
0a/newline
# every test failure increments this counter
Num-test-failures: # int
0/imm32
# length-prefixed string containing just a single space
Space: # (array byte)
# size: int
1/imm32
# data
20/space
# length-prefixed string containing just a single slash
Slash: # (array byte)
# size: int
1/imm32
# data
2f/slash
# . . vim:nowrap:textwidth=0
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