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author | Kartik Agaram <vc@akkartik.com> | 2019-07-27 16:01:55 -0700 |
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committer | Kartik Agaram <vc@akkartik.com> | 2019-07-27 17:47:59 -0700 |
commit | 6e1eeeebfb453fa7c871869c19375ce60fbd7413 (patch) | |
tree | 539c4a3fdf1756ae79770d5c4aaf6366f1d1525e /subx/065write-buffered.subx | |
parent | 8846a7f85cc04b77b2fe8a67b6d317723437b00c (diff) | |
download | mu-6e1eeeebfb453fa7c871869c19375ce60fbd7413.tar.gz |
5485 - promote SubX to top-level
Diffstat (limited to 'subx/065write-buffered.subx')
-rw-r--r-- | subx/065write-buffered.subx | 228 |
1 files changed, 0 insertions, 228 deletions
diff --git a/subx/065write-buffered.subx b/subx/065write-buffered.subx deleted file mode 100644 index 88b14b2d..00000000 --- a/subx/065write-buffered.subx +++ /dev/null @@ -1,228 +0,0 @@ -# write-buffered: like 'write', but for a buffered-file - -== 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 - -write-buffered: # f : (address buffered-file), msg : (address array byte) -> <void> - # pseudocode: - # in = msg->data - # inend = &msg->data[msg->length] - # while (in < inend) - # if f->write >= f->length - # flush(f) - # clear-stream(f) - # c = *in - # f->data[f->write] = c - # ++f->write - # ++in - # - # registers: - # in: ESI - # inend: ECX - # f: EDI - # f->length: EDX - # f->write: EBX (cached; need to keep in sync) - # c: EAX - # - # . prolog - 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 - 52/push-EDX - 53/push-EBX - 56/push-ESI - 57/push-EDI - # EAX = msg - 8b/copy 1/mod/*+disp8 5/rm32/EBP . . 0/r32/EAX 0xc/disp8 . # copy *(EBP+12) to EAX - # in/ESI = msg->data - 8d/copy-address 1/mod/*+disp8 0/rm32/EAX . . . 6/r32/ESI 4/disp8 . # copy EAX+4 to ESI - # inend/ECX = &msg->data[msg->length] - 8b/copy 0/mod/indirect 0/rm32/EAX . . . 1/r32/ECX . . # copy *EAX to ECX - 8d/copy-address 0/mod/indirect 4/rm32/sib 6/base/ESI 1/index/ECX . 1/r32/ECX . . # copy ESI+ECX to ECX - # EDI = f - 8b/copy 1/mod/*+disp8 5/rm32/EBP . . 7/r32/EDI 8/disp8 . # copy *(EBP+8) to EDI - # EDX = f->length - 8b/copy 1/mod/*+disp8 7/rm32/EDI . . . 2/r32/EDX 0xc/disp8 . # copy *(EDI+12) to EDX - # EBX = f->write - 8b/copy 1/mod/*+disp8 7/rm32/EDI . . . 3/r32/EBX 4/disp8 . # copy *(EDI+4) to EBX -$write-buffered:loop: - # if (in >= inend) break - 39/compare 3/mod/direct 6/rm32/ESI . . . 1/r32/ECX . . # compare ESI with ECX - 73/jump-if-greater-or-equal-unsigned $write-buffered:loop-end/disp8 - # if (f->write >= f->length) flush and clear f's stream - 39/compare 3/mod/direct 3/rm32/EBX . . . 2/r32/EDX . . # compare EBX with EDX - 7c/jump-if-lesser $write-buffered:to-stream/disp8 - # . persist f->write - 89/copy 1/mod/*+disp8 7/rm32/EDI . . . 3/r32/EBX 4/disp8 . # copy EBX to *(EDI+4) - # . flush(f) - # . . push args - 57/push-EDI - # . . call - e8/call flush/disp32 - # . . discard args - 81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 4/imm32 # add to ESP - # . clear-stream(stream = f+4) - # . . push args - 8d/copy-address 1/mod/*+disp8 7/rm32/EDI . . . 0/r32/EAX 4/disp8 . # copy EDI+4 to EAX - 50/push-EAX - # . . call - e8/call clear-stream/disp32 - # . . discard args - 81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 4/imm32 # add to ESP - # . f->write must now be 0; update its cache at EBX - 31/xor 3/mod/direct 3/rm32/EBX . . . 3/r32/EBX . . # clear EBX -$write-buffered:to-stream: - # write to stream - # f->data[f->write] = *in - # . AL = *in - 31/xor 3/mod/direct 0/rm32/EAX . . . 0/r32/EAX . . # clear EAX - 8a/copy-byte 0/mod/indirect 6/rm32/ESI . . . 0/r32/AL . . # copy byte at *ESI to AL - # . f->data[f->write] = AL - 88/copy-byte 1/mod/*+disp8 4/rm32/sib 7/base/EDI 3/index/EBX . 0/r32/AL 0x10/disp8 . # copy AL to *(EDI+EBX+16) - # ++f->write - 43/increment-EBX - # ++in - 46/increment-ESI - eb/jump $write-buffered:loop/disp8 -$write-buffered:loop-end: - # persist necessary variables from registers - 89/copy 1/mod/*+disp8 7/rm32/EDI . . . 3/r32/EBX 4/disp8 . # copy EBX to *(EDI+4) -$write-buffered:end: - # . restore registers - 5f/pop-to-EDI - 5e/pop-to-ESI - 5b/pop-to-EBX - 5a/pop-to-EDX - 59/pop-to-ECX - 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-write-buffered: - # - check that write-buffered writes to the file - # 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 - # . clear-stream(_test-buffered-file+4) - # . . push args - b8/copy-to-EAX _test-buffered-file/imm32 - 05/add-to-EAX 4/imm32 - 50/push-EAX - # . . call - e8/call clear-stream/disp32 - # . . discard args - 81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 4/imm32 # add to ESP - # write-buffered(_test-buffered-file, "Abc") - # . . push args - 68/push "Abc"/imm32 - 68/push _test-buffered-file/imm32 - # . . call - e8/call write-buffered/disp32 - # . . discard args - 81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 8/imm32 # add to ESP - # flush(_test-buffered-file) - # . . push args - 68/push _test-buffered-file/imm32 - # . . call - e8/call flush/disp32 - # . . discard args - 81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 4/imm32 # add to ESP - # check-stream-equal(_test-stream, "Abc", msg) - # . . push args - 68/push "F - test-write-buffered-single"/imm32 - 68/push "Abc"/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 - -test-write-buffered-with-intermediate-flush: - # - check that write-buffered flushes in the middle if its buffer fills up - # 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 - # . clear-stream(_test-buffered-file+4) - # . . push args - b8/copy-to-EAX _test-buffered-file/imm32 - 05/add-to-EAX 4/imm32 - 50/push-EAX - # . . call - e8/call clear-stream/disp32 - # . . discard args - 81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 4/imm32 # add to ESP - # _test-stream can hold 8 bytes, but _test-buffered-file can hold only 6. - # Try to write 7 bytes. - # . write-buffered(_test-buffered-file, "Abcdefg") - # . . push args - 68/push "Abcdefg"/imm32 - 68/push _test-buffered-file/imm32 - # . . call - e8/call write-buffered/disp32 - # . . discard args - 81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 8/imm32 # add to ESP - # don't flush - # 6 bytes should still have gotten to _test-stream - # . check-ints-equal(*_test-stream->write, 6, msg) - # . . push args - 68/push "F - test-write-buffered-with-intermediate-flush: flushed data"/imm32 - 68/push 6/imm32 - # . . push *_test-stream->write - b8/copy-to-EAX _test-stream/imm32 - ff 6/subop/push 0/mod/indirect 0/rm32/EAX . . . . . . # push *EAX - # . . call - e8/call check-ints-equal/disp32 - # . . discard args - 81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 0xc/imm32 # add to ESP - # and 1 byte should still be in _test-buffered-file - # . check-ints-equal(*_test-buffered-file->write, 1, msg) - # . . push args - 68/push "F - test-write-buffered-with-intermediate-flush: unflushed bytes"/imm32 - 68/push 1/imm32 - # . . push *_test-buffered-file->write - b8/copy-to-EAX _test-buffered-file/imm32 - ff 6/subop/push 1/mod/*+disp8 0/rm32/EAX . . . . 4/disp8 . # push *(EAX+4) - # . . call - e8/call check-ints-equal/disp32 - # . . discard args - 81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 0xc/imm32 # add to ESP - # . end - c3/return - -== data - -# The buffered file for standard error. -Stderr: - # file descriptor or (address stream) - 2/imm32 # standard error - # current write index - 0/imm32 - # current read index - 0/imm32 - # length - 8/imm32 - # data - 00 00 00 00 00 00 00 00 # 8 bytes - -# TODO: 8 bytes is too small. We'll need to grow the buffer for efficiency. But -# I don't want to type in 1024 bytes here. - -# . . vim:nowrap:textwidth=0 |