mu - Soul of a tiny new machine. More thorough tests → More comprehensible and rewrite-friendly software → More resilient society.

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Commits per author per week (path 'html/apps/ex7.mu.html')

Author	W22 2024	W23 2024	W24 2024	W25 2024	Total
Total	0	0	0	0	0

<!DOCTYPE html> <html> <head> <meta charset="UTF-8"> <title>Mu - 106stream.subx</title> <meta name="Generator" content="Vim/8.2"> <meta name="plugin-version" content="vim8.1_v2"> <meta name="syntax" content="none"> <meta name="settings" content="number_lines,use_css,no_foldcolumn,expand_tabs,line_ids,prevent_copy=,use_input_for_pc=fallback"> <meta name="colorscheme" content="minimal-light"> <style>  </style> <script>  </script> </head> <body onload='JumpToLine();'> <a href='https://github.com/akkartik/mu/blob/main/106stream.subx'>https://github.com/akkartik/mu/blob/main/106stream.subx</a> <pre id='vimCodeElement'> 1 # streams: data structure for operating on arrays in a stateful manner 2 # 3 # A stream looks like this: 4 # write: int # index at which writes go 5 # read: int # index that we've read until 6 # data: (array byte) # prefixed by size as usual 7 # 8 # some primitives for operating on streams: 9 # - clear-stream (clears everything but the data size) 10 # - rewind-stream (resets read pointer) 11 # 12 # We need to do this in machine code because streams need to be opaque types, 13 # and we don't yet support opaque types in Mu. 14 15 == code 16 # instruction effective address register displacement immediate 17 # . op subop mod rm32 base index scale r32 18 # . 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 19 20 clear-stream: # f: (addr stream byte) 21 # . prologue 22 55/push-ebp 23 89/copy 3/mod/direct 5/rm32/ebp . . . 4/r32/esp . . # copy esp to ebp 24 # . save registers 25 50/push-eax 26 51/push-ecx 27 # eax = f 28 8b/copy 1/mod/*+disp8 5/rm32/ebp . . 0/r32/eax 8/disp8 . # copy *(ebp+8) to eax 29 # var count/ecx: int = f->size 30 8b/copy 1/mod/*+disp8 0/rm32/eax . . . 1/r32/ecx 8/disp8 . # copy *(eax+8) to ecx 31 # var max/ecx: (addr byte) = &f->data[f->size] 32 8d/copy-address 1/mod/*+disp8 4/rm32/sib 0/base/eax 1/index/ecx . 1/r32/ecx 0xc/disp8 . # copy eax+ecx+12 to ecx 33 # f->write = 0 34 c7 0/subop/copy 0/mod/direct 0/rm32/eax . . . . . 0/imm32 # copy to *eax 35 # f->read = 0 36 c7 0/subop/copy 1/mod/*+disp8 0/rm32/eax . . . . 4/disp8 0/imm32 # copy to *(eax+4) 37 # - clear all stream data 38 # - this isn't strictly necessary, and it can slow things down *a lot*, but better safe than sorry. 39 # var curr/eax: (addr byte) = f->data 40 81 0/subop/add 3/mod/direct 0/rm32/eax . . . . . 0xc/imm32 # add to eax 41 $clear-stream:loop: 42 # if (curr >= max) break 43 39/compare 3/mod/direct 0/rm32/eax . . . 1/r32/ecx . . # compare eax with ecx 44 73/jump-if-addr>= $clear-stream:end/disp8 45 # *curr = 0 46 c6 0/subop/copy-byte 0/mod/direct 0/rm32/eax . . . . . 0/imm8 # copy byte to *eax 47 # ++curr 48 40/increment-eax 49 eb/jump $clear-stream:loop/disp8 50 $clear-stream:end: 51 # . restore registers 52 59/pop-to-ecx 53 58/pop-to-eax 54 # . epilogue 55 89/copy 3/mod/direct 4/rm32/esp . . . 5/r32/ebp . . # copy ebp to esp 56 5d/pop-to-ebp 57 c3/return 58 59 rewind-stream: # f: (addr stream byte) 60 # . prologue 61 55/push-ebp 62 89/copy 3/mod/direct 5/rm32/ebp . . . 4/r32/esp . . # copy esp to ebp 63 # . save registers 64 50/push-eax 65 # eax = f 66 8b/copy 1/mod/*+disp8 5/rm32/ebp . . 0/r32/eax 8/disp8 . # copy *(ebp+8) to eax 67 # f->read = 0 68 c7 0/subop/copy 1/mod/*+disp8 0/rm32/eax . . . . 4/disp8 0/imm32 # copy to *(eax+4) 69 $rewind-stream:end: 70 # . restore registers 71 58/pop-to-eax 72 # . epilogue 73 89/copy 3/mod/direct 4/rm32/esp . . . 5/r32/ebp . . # copy ebp to esp 74 5d/pop-to-ebp 75 c3/return 76 77 # . . vim:nowrap:textwidth=0 </pre> </body> </html>


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