Mu - linux/132slurp.subx

From 3350c34a74844e21ea69077e01efff3bae64bdcd Mon Sep 17 00:00:00 2001 From: Kartik Agaram Date: Tue, 23 Mar 2021 17:31:08 -0700 Subject: . --- html/linux/132slurp.subx.html | 221 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 221 insertions(+) create mode 100644 html/linux/132slurp.subx.html (limited to 'html/linux/132slurp.subx.html') diff --git a/html/linux/132slurp.subx.html b/html/linux/132slurp.subx.html new file mode 100644 index 00000000..3bcdb688 --- /dev/null +++ b/html/linux/132slurp.subx.html @@ -0,0 +1,221 @@ + + + + +Mu - linux/132slurp.subx + + + + + + + + + + +https://github.com/akkartik/mu/blob/main/linux/132slurp.subx +
+  1 == code
+  2 #   instruction                     effective address                                                   register    displacement    immediate
+  3 # . op          subop               mod             rm32          base        index         scale       r32
+  4 # . 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
+  5 
+  6 # read all bytes from 'f' and store them into 's'
+  7 # abort if 's' is too small
+  8 slurp:  # f: (addr buffered-file), s: (addr stream byte)
+  9     # pseudocode:
+ 10     #   while true
+ 11     #     if (s->write >= s->size) abort
+ 12     #     if (f->read >= f->write) populate stream from file
+ 13     #     if (f->write == 0) break
+ 14     #     AL = f->data[f->read]
+ 15     #     s->data[s->write] = AL
+ 16     #     ++f->read
+ 17     #     ++s->write
+ 18     # . prologue
+ 19     55/push-ebp
+ 20     89/copy                         3/mod/direct    5/rm32/ebp    .           .             .           4/r32/esp   .               .                 # copy esp to ebp
+ 21     # . save registers
+ 22     50/push-eax
+ 23     51/push-ecx
+ 24     52/push-edx
+ 25     56/push-esi
+ 26     57/push-edi
+ 27     # esi = f
+ 28     8b/copy                         1/mod/*+disp8   5/rm32/ebp    .           .             .           6/r32/esi   8/disp8         .                 # copy *(ebp+8) to esi
+ 29     # ecx = f->read
+ 30     8b/copy                         1/mod/*+disp8   6/rm32/esi    .           .             .           1/r32/ecx   8/disp8         .                 # copy *(esi+8) to ecx
+ 31     # edi = s
+ 32     8b/copy                         1/mod/*+disp8   5/rm32/ebp    .           .             .           7/r32/edi   0xc/disp8       .                 # copy *(ebp+12) to edi
+ 33     # edx = s->write
+ 34     8b/copy                         0/mod/indirect  7/rm32/edi    .           .             .           2/r32/edx   .               .                 # copy *edi to edx
+ 35 $slurp:loop:
+ 36     # if (s->write >= s->size) abort
+ 37     3b/compare                      1/mod/*+disp8   7/rm32/edi    .           .             .           2/r32/edx   8/disp8         .                 # compare edx with *(edi+8)
+ 38     7d/jump-if->=  $slurp:abort/disp8
+ 39     # if (f->read >= f->write) populate stream from file
+ 40     3b/compare                      1/mod/*+disp8   6/rm32/esi    .           .             .           1/r32/ecx   4/disp8         .                 # compare ecx with *(esi+4)
+ 41     7c/jump-if-<  $slurp:from-stream/disp8
+ 42     # . clear-stream(stream = f+4)
+ 43     # . . push args
+ 44     8d/copy-address                 1/mod/*+disp8   6/rm32/esi    .           .             .           0/r32/eax   4/disp8         .                 # copy esi+4 to eax
+ 45     50/push-eax
+ 46     # . . call
+ 47     e8/call  clear-stream/disp32
+ 48     # . . discard args
+ 49     81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               4/imm32           # add to esp
+ 50     # . f->read must now be 0; update its cache at ecx
+ 51     31/xor                          3/mod/direct    1/rm32/ecx    .           .             .           1/r32/ecx   .               .                 # clear ecx
+ 52     # . eax = read(f->fd, stream = f+4)
+ 53     # . . push args
+ 54     50/push-eax
+ 55     ff          6/subop/push        0/mod/indirect  6/rm32/esi    .           .             .           .           .               .                 # push *esi
+ 56     # . . call
+ 57     e8/call  read/disp32
+ 58     # . . discard args
+ 59     81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
+ 60     # if (f->write == 0) break
+ 61     # since f->read was initially 0, eax is the same as f->write
+ 62     # . if (eax == 0) return true
+ 63     3d/compare-eax-and  0/imm32
+ 64     74/jump-if-=  $slurp:end/disp8
+ 65 $slurp:from-stream:
+ 66     # var c/eax: byte = f->data[f->read]
+ 67     31/xor                          3/mod/direct    0/rm32/eax    .           .             .           0/r32/eax   .               .                 # clear eax
+ 68     8a/copy-byte                    1/mod/*+disp8   4/rm32/sib    6/base/esi  1/index/ecx   .           0/r32/AL    0x10/disp8      .                 # copy byte at *(esi+ecx+16) to AL
+ 69     # s->data[s->write] = c
+ 70     88/copy-byte                    1/mod/*+disp8   4/rm32/sib    7/base/edi  2/index/edx   .           0/r32/AL    0xc/disp8       .                 # copy AL to *(edi+edx+12)
+ 71     # ++f->read
+ 72     41/increment-ecx
+ 73     # ++s->write
+ 74     42/increment-edx
+ 75     eb/jump  $slurp:loop/disp8
+ 76 $slurp:end:
+ 77     # save f->read
+ 78     89/copy                         1/mod/*+disp8   6/rm32/esi    .           .             .           1/r32/ecx   8/disp8         .                 # copy ecx to *(esi+8)
+ 79     # save s->write
+ 80     89/copy                         0/mod/indirect  7/rm32/edi    .           .             .           2/r32/edx   .               .                 # copy edx to *edi
+ 81     # . restore registers
+ 82     5f/pop-to-edi
+ 83     5e/pop-to-esi
+ 84     5a/pop-to-edx
+ 85     59/pop-to-ecx
+ 86     58/pop-to-eax
+ 87     # . epilogue
+ 88     89/copy                         3/mod/direct    4/rm32/esp    .           .             .           5/r32/ebp   .               .                 # copy ebp to esp
+ 89     5d/pop-to-ebp
+ 90     c3/return
+ 91 
+ 92 $slurp:abort:
+ 93     # . _write(2/stderr, error)
+ 94     # . . push args
+ 95     68/push  "slurp: destination too small\n"/imm32
+ 96     68/push  2/imm32/stderr
+ 97     # . . call
+ 98     e8/call  _write/disp32
+ 99     # . . discard args
+100     81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
+101     # . syscall(exit, 1)
+102     bb/copy-to-ebx  1/imm32
+103     e8/call  syscall_exit/disp32
+104     # never gets here
+105 
+106 test-slurp:
+107     # setup
+108     # . clear-stream(_test-stream)
+109     # . . push args
+110     68/push  _test-stream/imm32
+111     # . . call
+112     e8/call  clear-stream/disp32
+113     # . . discard args
+114     81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               4/imm32           # add to esp
+115     # . clear-stream($_test-buffered-file->buffer)
+116     # . . push args
+117     68/push  $_test-buffered-file->buffer/imm32
+118     # . . call
+119     e8/call  clear-stream/disp32
+120     # . . discard args
+121     81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               4/imm32           # add to esp
+122     # . clear-stream(_test-tmp-stream)
+123     # . . push args
+124     68/push  _test-tmp-stream/imm32
+125     # . . call
+126     e8/call  clear-stream/disp32
+127     # . . discard args
+128     81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               4/imm32           # add to esp
+129     # write(_test-stream, "ab\ncd")
+130     # . . push args
+131     68/push  "ab\ncd"/imm32
+132     68/push  _test-stream/imm32
+133     # . . call
+134     e8/call  write/disp32
+135     # . . discard args
+136     81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
+137     # read a line from _test-stream (buffered by _test-buffered-file) into _test-tmp-stream
+138     # . eax = slurp(_test-buffered-file, _test-tmp-stream)
+139     # . . push args
+140     68/push  _test-tmp-stream/imm32
+141     68/push  _test-buffered-file/imm32
+142     # . . call
+143     e8/call  slurp/disp32
+144     # . . discard args
+145     81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               8/imm32           # add to esp
+146     # check-stream-equal(_test-tmp-stream, "ab\ncd", msg)
+147     # . . push args
+148     68/push  "F - test-slurp"/imm32
+149     68/push  "ab\ncd"/imm32
+150     68/push  _test-tmp-stream/imm32
+151     # . . call
+152     e8/call  check-stream-equal/disp32
+153     # . . discard args
+154     81          0/subop/add         3/mod/direct    4/rm32/esp    .           .             .           .           .               0xc/imm32         # add to esp
+155     # end
+156     c3/return
+157 
+158 # . . vim:nowrap:textwidth=0
+
+ + + -- cgit 1.4.1-2-gfad0