diff options
| author | Kartik Agaram <vc@akkartik.com> | 2019-05-02 23:44:43 -0700 |
|---|---|---|
| committer | Kartik Agaram <vc@akkartik.com> | 2019-05-02 23:48:52 -0700 |
| commit | d134a83b7454911285101dee8d14b9a41671d850 (patch) | |
| tree | 8a2a01164bf73f001fac05d8979996477c011ebf /subx/066print-byte.subx | |
| parent | f2cd405d04cd904bf1ed4d5ddf4916234c0509f5 (diff) | |
| download | mu-d134a83b7454911285101dee8d14b9a41671d850.tar.gz | |
new primitives: append-byte, append-byte-hex
These are variants of write-byte-buffered and print-byte-buffered respectively that operate on in-memory `stream`s rather than `buffered-file`s. They don't operate on files, so we'll avoid using the prefix 'write-'.
Diffstat (limited to 'subx/066print-byte.subx')
| -rw-r--r-- | subx/066print-byte.subx | 71 |
1 files changed, 71 insertions, 0 deletions
diff --git a/subx/066print-byte.subx b/subx/066print-byte.subx index b8b1dd24..80a29a0c 100644 --- a/subx/066print-byte.subx +++ b/subx/066print-byte.subx @@ -5,6 +5,77 @@ # . 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 +append-byte-hex: # f : (address stream), n : int -> <void> + # . prolog + 55/push-EBP + 89/copy 3/mod/direct 5/rm32/EBP . . . 4/r32/ESP . . # copy ESP to EBP + # . save registers + 50/push-EAX + # AL = convert upper nibble to hex + 8b/copy 1/mod/*+disp8 5/rm32/EBP . . . 0/r32/EAX 0xc/disp8 . # copy *(EBP+12) to EAX + c1/shift 5/subop/logic-right 3/mod/direct 0/rm32/EAX . . . . . 4/imm8 # shift EAX right by 4 bits, while padding zeroes + 25/and-EAX 0xf/imm32 + # . AL = to-hex-char(AL) + e8/call to-hex-char/disp32 + # append-byte(f, AL) + # . . push args + 50/push-EAX + ff 6/subop/push 1/mod/*+disp8 5/rm32/EBP . . . . 8/disp8 . # push *(EBP+8) + # . . call + e8/call append-byte/disp32 + # . . discard args + 81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 8/imm32 # add to ESP + # AL = convert lower nibble to hex + 8b/copy 1/mod/*+disp8 5/rm32/EBP . . . 0/r32/EAX 0xc/disp8 . # copy *(EBP+12) to EAX + 25/and-EAX 0xf/imm32 + # . AL = to-hex-char(AL) + e8/call to-hex-char/disp32 + # append-byte(f, AL) + # . . push args + 50/push-EAX + ff 6/subop/push 1/mod/*+disp8 5/rm32/EBP . . . . 8/disp8 . # push *(EBP+8) + # . . call + e8/call append-byte/disp32 + # . . discard args + 81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 8/imm32 # add to ESP +$append-byte-hex:end: + # . restore registers + 58/pop-to-EAX + # . epilog + 89/copy 3/mod/direct 4/rm32/ESP . . . 5/r32/EBP . . # copy EBP to ESP + 5d/pop-to-EBP + c3/return + +test-append-byte-hex: + # - check that append-byte-hex adds the hex textual representation + # setup + # . clear-stream(_test-stream) + # . . push args + 68/push _test-stream/imm32 + # . . call + e8/call clear-stream/disp32 + # . . discard args + 81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 4/imm32 # add to ESP + # append-byte-hex(_test-stream, 0xa) # exercises digit, non-digit as well as leading zero + # . . push args + 68/push 0xa/imm32 + 68/push _test-stream/imm32 + # . . call + e8/call append-byte-hex/disp32 + # . . discard args + 81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 8/imm32 # add to ESP + # check-stream-equal(_test-stream, "0a", msg) + # . . push args + 68/push "F - test-append-byte-hex"/imm32 + 68/push "0a"/imm32 + 68/push _test-stream/imm32 + # . . call + e8/call check-stream-equal/disp32 + # . . discard args + 81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 0xc/imm32 # add to ESP + # . end + c3/return + print-byte-buffered: # f : (address buffered-file), n : int -> <void> # . prolog 55/push-EBP |