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Diffstat (limited to 'apps/crenshaw2-1.subx')
| -rw-r--r-- | apps/crenshaw2-1.subx | 585 |
1 files changed, 585 insertions, 0 deletions
diff --git a/apps/crenshaw2-1.subx b/apps/crenshaw2-1.subx new file mode 100644 index 00000000..0c3f180b --- /dev/null +++ b/apps/crenshaw2-1.subx @@ -0,0 +1,585 @@ +# Port of https://github.com/akkartik/crenshaw/blob/master/tutor2.1.pas +# which corresponds to the section "single digits" in https://compilers.iecc.com/crenshaw/tutor2.txt +# except that we support hex digits. +# +# To run (from the subx/ directory): +# $ ./subx translate *.subx apps/crenshaw2-1.subx -o apps/crenshaw2-1 +# $ echo '3' |./subx run apps/crenshaw2-1 +# Expected output: +# # syscall(exit, 3) +# bb/copy-to-EBX 3/imm32 +# b8/copy-to-EAX 1/imm32/exit +# cd/syscall 0x80/imm8 +# +# To run the generated output: +# $ echo '3' |./subx run apps/crenshaw2-1 > z1.subx +# $ ./subx translate z1.subx -o z1 +# $ ./subx run z1 +# $ echo $? +# 3 +# +# Stdin must contain just a single hex digit. Other input will print an error: +# $ echo 'xyz' |./subx run apps/crenshaw2-1 +# Error: integer expected +# +# Names in this file sometimes follow Crenshaw's original rather than my usual +# naming conventions. + +== 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: # run tests if necessary, call 'compile' if not + # initialize heap + # . Heap = new-segment(64KB) + # . . push args + 68/push Heap/imm32 + 68/push 0x10000/imm32/64KB + # . . call + e8/call new-segment/disp32 + # . . discard args + 81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 8/imm32 # add to ESP + + # . prolog + 89/copy 3/mod/direct 5/rm32/EBP . . . 4/r32/ESP . . # copy ESP to EBP + # - if argc > 1 and argv[1] == "test", then return run_tests() + # . argc > 1 + 81 7/subop/compare 1/mod/*+disp8 5/rm32/EBP . . . . 0/disp8 1/imm32 # compare *EBP + 7e/jump-if-lesser-or-equal $run-main/disp8 + # . argv[1] == "test" + # . . push args + 68/push "test"/imm32 + ff 6/subop/push 1/mod/*+disp8 5/rm32/EBP . . . . 8/disp8 . # push *(EBP+8) + # . . call + e8/call kernel-string-equal?/disp32 + # . . discard args + 81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 8/imm32 # add to ESP + # . check result + 3d/compare-EAX-and 1/imm32 + 75/jump-if-not-equal $run-main/disp8 + # . run-tests() + e8/call run-tests/disp32 + 8b/copy 0/mod/indirect 5/rm32/.disp32 . . 3/r32/EBX Num-test-failures/disp32 # copy *Num-test-failures to EBX + eb/jump $main:end/disp8 +$run-main: + # - otherwise read a program from stdin and emit its translation to stdout + # var ed/EAX : exit-descriptor + 81 5/subop/subtract 3/mod/direct 4/rm32/ESP . . . . . 8/imm32 # subtract from ESP + 89/copy 3/mod/direct 0/rm32/EAX . . . 4/r32/ESP . . # copy ESP to EAX + # configure ed to really exit() + # . ed->target = 0 + c7 0/subop/copy 0/mod/direct 0/rm32/EAX . . . . . 0/imm32 # copy to *EAX + # return compile(Stdin, 1/stdout, 2/stderr, ed) + # . . push args + 50/push-EAX/ed + 68/push 2/imm32/stderr + 68/push 1/imm32/stdout + 68/push Stdin/imm32 + # . . call + e8/call compile/disp32 + # . . discard args + 81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 0x10/imm32 # add to ESP + # . syscall(exit, 0) + bb/copy-to-EBX 0/imm32 +$main:end: + b8/copy-to-EAX 1/imm32/exit + cd/syscall 0x80/imm8 + +# the main entry point +compile: # in : (address buffered-file), out : fd or (address stream), err : fd or (address stream), ed : (address exit-descriptor) -> <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 + 51/push-ECX + # prime the pump + # . Look = get-char(in) + # . . push args + ff 6/subop/push 1/mod/*+disp8 5/rm32/EBP . . . . 8/disp8 . # push *(EBP+8) + # . . call + e8/call get-char/disp32 + # . . discard args + 81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 4/imm32 # add to ESP + # var num/ECX : (address stream) on the stack + # Numbers can be 32 bits or 8 hex bytes long. One of them will be in 'Look', so we need space for 7 bytes. + # Sizing the stream just right buys us overflow-handling for free inside 'get-num'. + # Add 12 bytes for 'read', 'write' and 'length' fields, for a total of 19 bytes, or 0x13 in hex. + # The stack pointer is no longer aligned, so dump_stack() can be misleading past this point. + 81 5/subop/subtract 3/mod/direct 4/rm32/ESP . . . . . 0x13/imm32 # subtract from ESP + 89/copy 3/mod/direct 1/rm32/ECX . . . 4/r32/ESP . . # copy ESP to ECX + # initialize the stream + # . num->length = 7 + c7 0/subop/copy 1/mod/*+disp8 1/rm32/ECX . . . . 8/disp8 7/imm32 # copy to *(ECX+8) + # . clear-stream(num) + # . . push args + 51/push-ECX + # . . call + e8/call clear-stream/disp32 + # . . discard args + 81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 4/imm32 # add to ESP + # read a digit from 'in' into 'num' + # . get-num(in, num, err, ed) + # . . push args + ff 6/subop/push 1/mod/*+disp8 5/rm32/EBP . . . . 0x14/disp8 . # push *(EBP+20) + ff 6/subop/push 1/mod/*+disp8 5/rm32/EBP . . . . 0x10/disp8 . # push *(EBP+16) + 51/push-ECX/num + ff 6/subop/push 1/mod/*+disp8 5/rm32/EBP . . . . 8/disp8 . # push *(EBP+8) + # . . call + e8/call get-num/disp32 + # . . discard args + 81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 0x10/imm32 # add to ESP + # render 'num' into the following template on 'out': + # bb/copy-to-EBX _num_ + # b8/copy-to-EAX 1/imm32/exit + # cd/syscall 0x80/imm8 + # + # . write(out, "bb/copy-to-EBX ") + # . . push args + 68/push "bb/copy-to-EBX "/imm32 + ff 6/subop/push 1/mod/*+disp8 5/rm32/EBP . . . . 0xc/disp8 . # push *(EBP+12) + # . . call + e8/call write/disp32 + # . . discard args + 81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 8/imm32 # add to ESP + # . write-stream(out, num) + # . . push args + 51/push-ECX/num + ff 6/subop/push 1/mod/*+disp8 5/rm32/EBP . . . . 0xc/disp8 . # push *(EBP+12) + # . . call + e8/call write-stream/disp32 + # . . discard args + 81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 8/imm32 # add to ESP + # . write(out, Newline) + # . . push args + 68/push Newline/imm32 + ff 6/subop/push 1/mod/*+disp8 5/rm32/EBP . . . . 0xc/disp8 . # push *(EBP+12) + # . . call + e8/call write/disp32 + # . . discard args + 81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 8/imm32 # add to ESP + # . write(out, "b8/copy-to-EAX 1/imm32/exit\n") + # . . push args + 68/push "b8/copy-to-EAX 1/imm32/exit\n"/imm32 + ff 6/subop/push 1/mod/*+disp8 5/rm32/EBP . . . . 0xc/disp8 . # push *(EBP+12) + # . . call + e8/call write/disp32 + # . . discard args + 81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 8/imm32 # add to ESP + # . write(out, "cd/syscall 0x80/imm8\n") + # . . push args + 68/push "cd/syscall 0x80/imm8\n"/imm32 + ff 6/subop/push 1/mod/*+disp8 5/rm32/EBP . . . . 0xc/disp8 . # push *(EBP+12) + # . . call + e8/call write/disp32 + # . . discard args + 81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 8/imm32 # add to ESP +$compile:end: + # . restore registers + 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 + +# Read a single digit into 'out'. Abort if there are none, or if there is no space in 'out'. +# Input comes from the global variable 'Look', and we leave the next byte from +# 'in' into it on exit. +get-num: # in : (address buffered-file), out : (address stream), err : fd or (address stream), ed : (address exit-descriptor) -> <void> + # pseudocode: + # if (!is-digit?(Look)) expected(ed, err, "integer") + # if out->write >= out->length + # write(err, "Error: too many digits in number\n") + # stop(ed, 1) + # out->data[out->write] = LSB(Look) + # ++out->write + # Look = get-char(in) + # + # registers: + # in: ESI + # out: EDI + # out->write: ECX (cached copy; need to keep in sync) + # out->length: EDX + # temporaries: EAX, EBX + # We can't allocate Look to a register because it gets written implicitly in + # get-char in each iteration of the loop. (Thereby demonstrating that it's + # not the right interface for us. But we'll keep it just to follow Crenshaw.) + # + # . prolog + 55/push-EBP + 89/copy 3/mod/direct 5/rm32/EBP . . . 4/r32/ESP . . # copy ESP to EBP + # - if (is-digit?(Look)) expected(ed, err, "integer") + # . EAX = is-digit?(Look) + # . . push args + ff 6/subop/push 0/mod/indirect 5/rm32/.disp32 . . . Look/disp32 . # push *Look + # . . call + e8/call is-digit?/disp32 + # . . discard args + 81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 4/imm32 # add to ESP + # . if (EAX == 0) + 3d/compare-EAX-and 0/imm32 + 75/jump-if-not-equal $get-num:main/disp8 + # . expected(ed, err, "integer") + # . . push args + 68/push "integer"/imm32 + ff 6/subop/push 1/mod/*+disp8 5/rm32/EBP . . . . 0x10/disp8 . # push *(EBP+16) + ff 6/subop/push 1/mod/*+disp8 5/rm32/EBP . . . . 0x14/disp8 . # push *(EBP+20) + # . . call + e8/call expected/disp32 # never returns + # . . discard args + 81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 0xc/imm32 # add to ESP +$get-num:main: + # - otherwise read a digit + # . save registers + 50/push-EAX + 51/push-ECX + 52/push-EDX + 53/push-EBX + 56/push-ESI + 57/push-EDI + # read necessary variables to registers + # ESI = in + 8b/copy 1/mod/*+disp8 5/rm32/EBP . . . 6/r32/ESI 8/disp8 . # copy *(EBP+8) to ESI + # EDI = out + 8b/copy 1/mod/*+disp8 5/rm32/EBP . . . 7/r32/EDI 0xc/disp8 . # copy *(EBP+12) to EDI + # ECX = out->write + 8b/copy 0/mod/indirect 7/rm32/EDI . . . 1/r32/ECX . . # copy *EDI to ECX + # EDX = out->length + 8b/copy 1/mod/*+disp8 7/rm32/EDI . . . 2/r32/EDX 8/disp8 . # copy *(EDI+8) to EDX + # if (out->write >= out->length) error + 39/compare 3/mod/direct 2/rm32/EDX . . . 1/r32/ECX . . # compare EDX with ECX + 7d/jump-if-lesser $get-num:stage2/disp8 + # . error(ed, err, msg) # TODO: show full number + # . . push args + 68/push "get-num: too many digits in number"/imm32 + ff 6/subop/push 1/mod/*+disp8 5/rm32/EBP . . . . 0x10/disp8 . # push *(EBP+16) + ff 6/subop/push 1/mod/*+disp8 5/rm32/EBP . . . . 0x14/disp8 . # push *(EBP+20) + # . . call + e8/call error/disp32 # never returns + # . . discard args + 81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 0xc/imm32 # add to ESP +$get-num:stage2: + # out->data[out->write] = LSB(Look) + 8d/copy-address 1/mod/*+disp8 4/rm32/sib 7/base/EDI 1/index/ECX . 3/r32/EBX 0xc/disp8 . # copy EDI+ECX+12 to EBX + 8b/copy 0/mod/indirect 5/rm32/.disp32 . . 0/r32/EAX Look/disp32 . # copy *Look to EAX + 88/copy-byte 0/mod/indirect 3/rm32/EBX . . . 0/r32/AL . . # copy byte at AL to *EBX + # ++out->write + 41/increment-ECX + # Look = get-char(in) + # . . push args + 56/push-ESI + # . . call + e8/call get-char/disp32 + # . . discard args + 81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 4/imm32 # add to ESP +$get-num:loop-end: + # persist necessary variables from registers + 89/copy 0/mod/indirect 7/rm32/EDI . . . 1/r32/ECX . . # copy ECX to *EDI +$get-num: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-get-num-reads-single-digit: + # - check that get-num returns first character if it's a digit + # This test uses exit-descriptors. Use EBP for setting up local variables. + 55/push-EBP + 89/copy 3/mod/direct 5/rm32/EBP . . . 4/r32/ESP . . # copy ESP to EBP + # clear all streams + # . 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 + # . clear-stream(_test-output-stream) + # . . push args + 68/push _test-output-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-error-stream) + # . . push args + 68/push _test-error-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 + # initialize 'in' + # . write(_test-stream, "3") + # . . push args + 68/push "3"/imm32 + 68/push _test-stream/imm32 + # . . call + e8/call write/disp32 + # . . discard args + 81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 8/imm32 # add to ESP + # initialize exit-descriptor 'ed' for the call to 'get-num' below + # . var ed/EAX : exit-descriptor + 81 5/subop/subtract 3/mod/direct 4/rm32/ESP . . . . . 8/imm32 # subtract from ESP + 89/copy 3/mod/direct 0/rm32/EAX . . . 4/r32/ESP . . # copy ESP to EAX + # . tailor-exit-descriptor(ed, 16) + # . . push args + 68/push 0x10/imm32/nbytes-of-args-for-get-num + 50/push-EAX/ed + # . . call + e8/call tailor-exit-descriptor/disp32 + # . . discard args + 81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 8/imm32 # add to ESP + # prime the pump + # . get-char(_test-buffered-file) + # . . push args + 68/push _test-buffered-file/imm32 + # . . call + e8/call get-char/disp32 + # . . discard args + 81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 4/imm32 # add to ESP + # get-num(in, out, err, ed) + # . . push args + 50/push-EAX/ed + 68/push _test-error-stream/imm32 + 68/push _test-output-stream/imm32 + 68/push _test-buffered-file/imm32 + # . . call + e8/call get-num/disp32 + # registers except ESP may be clobbered at this point + # . . discard args + 81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 0x10/imm32 # add to ESP + # check-ints-equal(*_test-output-stream->data, '3', msg) + # . . push args + 68/push "F - test-get-num-reads-single-digit"/imm32 + 68/push 0x33/imm32 + b8/copy-to-EAX _test-output-stream/imm32 + ff 6/subop/push 1/mod/*+disp8 0/rm32/EAX . . . . 0xc/disp8 . # push *(EAX+12) + # . . call + e8/call check-ints-equal/disp32 + # . . discard args + 81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 0xc/imm32 # add to ESP + # . reclaim locals + 81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 8/imm32 # add to ESP + 5d/pop-to-EBP + c3/return + +test-get-num-aborts-on-non-digit-in-Look: + # - check that get-num returns first character if it's a digit + # This test uses exit-descriptors. Use EBP for setting up local variables. + 55/push-EBP + 89/copy 3/mod/direct 5/rm32/EBP . . . 4/r32/ESP . . # copy ESP to EBP + # clear all streams + # . 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 + # . clear-stream(_test-output-stream) + # . . push args + 68/push _test-output-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-error-stream) + # . . push args + 68/push _test-error-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 + # initialize 'in' + # . write(_test-stream, "3") + # . . push args + 68/push "3"/imm32 + 68/push _test-stream/imm32 + # . . call + e8/call write/disp32 + # . . discard args + 81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 8/imm32 # add to ESP + # initialize exit-descriptor 'ed' for the call to 'get-num' below + # . var ed/EAX : (address exit-descriptor) + 81 5/subop/subtract 3/mod/direct 4/rm32/ESP . . . . . 8/imm32 # subtract from ESP + 89/copy 3/mod/direct 0/rm32/EAX . . . 4/r32/ESP . . # copy ESP to EAX + # . tailor-exit-descriptor(ed, 16) + # . . push args + 68/push 0x10/imm32/nbytes-of-args-for-get-num + 50/push-EAX/ed + # . . call + e8/call tailor-exit-descriptor/disp32 + # . . discard args + 81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 8/imm32 # add to ESP + # *don't* prime the pump + # get-num(in, out, err, ed) + # . . push args + 50/push-EAX/ed + 68/push _test-error-stream/imm32 + 68/push _test-output-stream/imm32 + 68/push _test-buffered-file/imm32 + # . . call + e8/call get-num/disp32 + # registers except ESP may be clobbered at this point + # . . discard args + 81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 0x10/imm32 # add to ESP + # check that get-num tried to call exit(1) + # . check-ints-equal(ed->value, 2, msg) # i.e. stop was called with value 1 + # . . push args + 68/push "F - test-get-num-aborts-on-non-digit-in-Look"/imm32 + 68/push 2/imm32 + # . . push ed->value + 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 + # . reclaim locals + 81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 8/imm32 # add to ESP + 5d/pop-to-EBP + c3/return + +## helpers + +# write(f, "Error: "+s+" expected\n") then stop(ed, 1) +expected: # ed : (address exit-descriptor), f : fd or (address stream), s : (address array byte) -> <void> + # . prolog + 55/push-EBP + 89/copy 3/mod/direct 5/rm32/EBP . . . 4/r32/ESP . . # copy ESP to EBP + # write(f, "Error: ") + # . . push args + 68/push "Error: "/imm32 + ff 6/subop/push 1/mod/*+disp8 5/rm32/EBP . . . . 0xc/disp8 . # push *(EBP+12) + # . . call + e8/call write/disp32 + # . . discard args + 81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 8/imm32 # add to ESP + # write(f, s) + # . . push args + ff 6/subop/push 1/mod/*+disp8 5/rm32/EBP . . . . 0x10/disp8 . # push *(EBP+16) + ff 6/subop/push 1/mod/*+disp8 5/rm32/EBP . . . . 0xc/disp8 . # push *(EBP+12) + # . . call + e8/call write/disp32 + # . . discard args + 81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 8/imm32 # add to ESP + # write(f, " expected") + # . . push args + 68/push " expected\n"/imm32 + ff 6/subop/push 1/mod/*+disp8 5/rm32/EBP . . . . 0xc/disp8 . # push *(EBP+12) + # . . call + e8/call write/disp32 + # . . discard args + 81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 8/imm32 # add to ESP + # stop(ed, 1) + # . . push args + 68/push 1/imm32 + ff 6/subop/push 1/mod/*+disp8 5/rm32/EBP . . . . 8/disp8 . # push *(EBP+8) + # . . call + e8/call stop/disp32 + # should never get past this point +$expected:dead-end: + # . epilog + 89/copy 3/mod/direct 4/rm32/ESP . . . 5/r32/EBP . . # copy EBP to ESP + 5d/pop-to-EBP + c3/return + +# read a byte from 'f', and save it in 'Look' +get-char: # f : (address buffered-file) -> <void> + # . prolog + 55/push-EBP + 89/copy 3/mod/direct 5/rm32/EBP . . . 4/r32/ESP . . # copy ESP to EBP + # . save registers + 50/push-EAX + # EAX = read-byte-buffered(f) + # . . push args + ff 6/subop/push 1/mod/*+disp8 5/rm32/EBP . . . . 8/disp8 . # push *(EBP+8) + # . . call + e8/call read-byte-buffered/disp32 + # . . discard args + 81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 4/imm32 # add to ESP + # save EAX to Look + 89/copy 0/mod/indirect 5/rm32/.disp32 . . 0/r32/EAX Look/disp32 . # copy EAX to *Look +$get-char: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 + +is-digit?: # c : int -> EAX : boolean + # . prolog + 55/push-EBP + 89/copy 3/mod/direct 5/rm32/EBP . . . 4/r32/ESP . . # copy ESP to EBP + # EAX = false + b8/copy-to-EAX 0/imm32 + # if (c < '0') return false + 81 7/subop/compare 1/mod/*+disp8 5/rm32/EBP . . . . 8/disp8 0x30/imm32 # compare *(EBP+8) + 7c/jump-if-lesser $is-digit?:end/disp8 + # if (c > '9') return false + 81 7/subop/compare 1/mod/*+disp8 5/rm32/EBP . . . . 8/disp8 0x39/imm32 # compare *(EBP+8) + 7f/jump-if-greater $is-digit?:end/disp8 + # otherwise return true + b8/copy-to-EAX 1/imm32 +$is-digit?:end: + # . epilog + 89/copy 3/mod/direct 4/rm32/ESP . . . 5/r32/EBP . . # copy EBP to ESP + 5d/pop-to-EBP + c3/return + +== data + +Look: # (char with some extra padding) + 0/imm32 + +_test-output-stream: + # current write index + 0/imm32 + # current read index + 0/imm32 + # length + 8/imm32 + # data + 00 00 00 00 00 00 00 00 # 8 bytes + +_test-error-stream: + # current write index + 0/imm32 + # current read index + 0/imm32 + # length + 0x40/imm32 + # data (4 lines x 16 bytes/line) + 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 + 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 + 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 + 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 + +# . . vim:nowrap:textwidth=0 |