| blob | 58c6c26d2b8e157b8fb5f9add6ba7cc4c73d23a3 |
1 # Helper to dynamically allocate memory on the heap.
2 #
3 # We'd like to be able to write tests for functions that allocate memory,
4 # making assertions on the precise addresses used. To achieve this we'll pass
5 # in an *allocation descriptor* to allocate from.
6 #
7 # Allocation descriptors are also useful outside of tests. Assembly and machine
8 # code are of necessity unsafe languages, and one of the most insidious kinds
9 # of bugs unsafe languages expose us to are dangling pointers to memory that
10 # has been freed and potentially even reused for something totally different.
11 # To reduce the odds of such "use after free" errors, SubX programs tend to not
12 # reclaim and reuse dynamically allocated memory. (Running out of memory is far
13 # easier to debug.) Long-running programs that want to reuse memory are mostly
14 # on their own to be careful. However, they do get one bit of help: they can
15 # carve out chunks of memory and then allocate from them manually using this
16 # very same 'allocate' helper. They just need a new allocation descriptor for
17 # their book-keeping.
19 == data
21 # Allocations are returned in a handle, which consists of an alloc-id and a payload.
22 # The alloc-id helps detect use-after-free errors.
23 Handle-size: # (addr int)
24 8/imm32
26 # A default allocation descriptor for programs to use.
27 Heap: # allocation-descriptor
28 # curr
29 0/imm32
30 # limit
31 0/imm32
33 # a reasonable default
34 Heap-size: # int
35 0x800000/imm32/8MB
37 Next-alloc-id: # int
38 0x100/imm32 # save a few alloc ids for fake handles
40 == code
41 # instruction effective address register displacement immediate
42 # . op subop mod rm32 base index scale r32
43 # . 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
45 #? # Let's start initializing the default allocation descriptor.
46 #?
47 #? Entry:
48 #? # initialize heap
49 #? # . Heap = new-segment(Heap-size)
50 #? # . . push args
51 #? 68/push Heap/imm32
52 #? ff 6/subop/push 0/mod/indirect 5/rm32/.disp32 . . . Heap-size/disp32 # push *Heap-size
53 #? # . . call
54 #? e8/call new-segment/disp32
55 #? # . . discard args
56 #? 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 8/imm32 # add to esp
58 e8/call run-tests/disp32 # 'run-tests' is a function created automatically by SubX. It calls all functions that start with 'test-'.
59 $array-equal-main:end:
60 # syscall_exit(Num-test-failures)
61 8b/copy 0/mod/indirect 5/rm32/.disp32 . . 3/r32/ebx Num-test-failures/disp32 # copy *Num-test-failures to ebx
62 e8/call syscall_exit/disp32
64 # Allocate and clear 'n' bytes of memory from an allocation-descriptor 'ad'.
65 # Abort if there isn't enough memory in 'ad'.
66 allocate: # ad: (addr allocation-descriptor), n: int, out: (addr handle _)
67 # . prologue
68 55/push-ebp
69 89/copy 3/mod/direct 5/rm32/ebp . . . 4/r32/esp . . # copy esp to ebp
70 # . save registers
71 50/push-eax
72 # allocate-raw(ad, n, out)
73 # . . push args
74 ff 6/subop/push 1/mod/*+disp8 5/rm32/ebp . . . . 0x10/disp8 . # push *(ebp+16)
75 ff 6/subop/push 1/mod/*+disp8 5/rm32/ebp . . . . 0xc/disp8 . # push *(ebp+12)
76 ff 6/subop/push 1/mod/*+disp8 5/rm32/ebp . . . . 8/disp8 . # push *(ebp+8)
77 # . . call
78 e8/call allocate-raw/disp32
79 # . . discard args
80 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 0xc/imm32 # add to esp
81 # eax = out->payload + 4
82 8b/copy 1/mod/*+disp8 5/rm32/ebp . . . 0/r32/eax 0x10/disp8 . # copy *(ebp+16) to eax
83 8b/copy 1/mod/*+disp8 0/rm32/eax . . . 0/r32/eax 4/disp8 . # copy *(eax+4) to eax
84 05/add-to-eax 4/imm32
85 # zero-out(eax, n)
86 # . . push args
87 ff 6/subop/push 1/mod/*+disp8 5/rm32/ebp . . . . 0xc/disp8 . # push *(ebp+12)
88 50/push-eax
89 # . . call
90 e8/call zero-out/disp32
91 # . . discard args
92 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 8/imm32 # add to esp
93 $allocate:end:
94 # . restore registers
95 58/pop-to-eax
96 # . epilogue
97 89/copy 3/mod/direct 4/rm32/esp . . . 5/r32/ebp . . # copy ebp to esp
98 5d/pop-to-ebp
99 c3/return
101 # Claim the next 'n' bytes of memory starting at ad->curr and update ad->curr.
102 # Abort if there isn't enough memory in 'ad'.
103 allocate-raw: # ad: (addr allocation-descriptor), n: int, out: (addr handle _)
104 # . prologue
105 55/push-ebp
106 89/copy 3/mod/direct 5/rm32/ebp . . . 4/r32/esp . . # copy esp to ebp
107 # . save registers
108 50/push-eax
109 51/push-ecx
110 52/push-edx
111 53/push-ebx
112 56/push-esi
113 57/push-edi
114 # ecx = ad
115 8b/copy 1/mod/*+disp8 5/rm32/ebp . . . 1/r32/ecx 8/disp8 . # copy *(ebp+8) to ecx
116 # edx = out
117 8b/copy 1/mod/*+disp8 5/rm32/ebp . . . 2/r32/edx 0x10/disp8 . # copy *(ebp+16) to edx
118 # ebx = n
119 8b/copy 1/mod/*+disp8 5/rm32/ebp . . . 3/r32/ebx 0xc/disp8 . # copy *(ebp+12) to ebx
120 # out->alloc-id = Next-alloc-id
121 8b/copy 0/mod/indirect 5/rm32/.disp32 . . 0/r32/eax Next-alloc-id/disp32 # copy *Next-alloc-id to eax
122 89/copy 0/mod/indirect 2/rm32/edx . . . 0/r32/eax . . # copy eax to *edx
123 # out->payload = ad->curr
124 8b/copy 0/mod/indirect 1/rm32/ecx . . . 0/r32/eax . . # copy *ecx to eax
125 $allocate-raw:save-payload-in-eax:
126 89/copy 1/mod/*+disp8 2/rm32/edx . . . 0/r32/eax 4/disp8 . # copy eax to *(edx+4)
127 # *out->payload = Next-alloc-id
128 8b/copy 1/mod/*+disp8 2/rm32/edx . . . 7/r32/edi 4/disp8 . # copy *(edx+4) to edi
129 8b/copy 0/mod/indirect 5/rm32/.disp32 . . 6/r32/esi Next-alloc-id/disp32 # copy *Next-alloc-id to esi
130 89/copy 0/mod/indirect 7/rm32/edi . . . 6/r32/esi . . # copy esi to *edi
131 $allocate-raw:increment-next-alloc-id:
132 # increment *Next-alloc-id
133 ff 0/subop/increment 0/mod/indirect 5/rm32/.disp32 . . . Next-alloc-id/disp32 # increment *Next-alloc-id
134 # check if there's enough space
135 # TODO: move this check up before any state updates when we support error recovery
136 8d/copy-address 1/mod/*+disp8 4/rm32/sib 0/base/eax 3/index/ebx . 0/r32/eax 4/disp8 . # copy eax+ebx+4 to eax
137 3b/compare 1/mod/*+disp8 1/rm32/ecx . . . 0/r32/eax 4/disp8 . # compare eax with *(ecx+4)
138 73/jump-if->=-signed $allocate-raw:abort/disp8
139 $allocate-raw:commit:
140 # ad->curr += n+4
141 89/copy 0/mod/indirect 1/rm32/ecx . . . 0/r32/eax . . # copy eax to *ecx
142 $allocate-raw:end:
143 # . restore registers
144 5f/pop-to-edi
145 5e/pop-to-esi
146 5b/pop-to-ebx
147 5a/pop-to-edx
148 59/pop-to-ecx
149 58/pop-to-eax
150 # . epilogue
151 89/copy 3/mod/direct 4/rm32/esp . . . 5/r32/ebp . . # copy ebp to esp
152 5d/pop-to-ebp
153 c3/return
155 $allocate-raw:abort:
156 # . _write(2/stderr, error)
157 # . . push args
158 68/push "allocate: failed\n"/imm32
159 68/push 2/imm32/stderr
160 # . . call
161 e8/call _write/disp32
162 # . . discard args
163 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 8/imm32 # add to esp
164 # . syscall_exit(1)
165 bb/copy-to-ebx 1/imm32
166 e8/call syscall_exit/disp32
167 # never gets here
169 test-allocate-raw-success:
170 # . prologue
171 55/push-ebp
172 89/copy 3/mod/direct 5/rm32/ebp . . . 4/r32/esp . . # copy esp to ebp
173 # var ad/ecx: allocation-descriptor
174 68/push 0/imm32/limit
175 68/push 0/imm32/curr
176 89/copy 3/mod/direct 1/rm32/ecx . . . 4/r32/esp . . # copy esp to ecx
177 # ad = new-segment(512)
178 # . . push args
179 51/push-ecx
180 68/push 0x200/imm32
181 # . . call
182 e8/call new-segment/disp32
183 # . . discard args
184 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 8/imm32 # add to esp
185 # var expected-payload/ebx = ad->curr
186 8b/copy 0/mod/indirect 1/rm32/ecx . . . 3/r32/ebx . . # copy *ecx to ebx
187 # var h/edx: handle = {0, 0}
188 68/push 0/imm32
189 68/push 0/imm32
190 89/copy 3/mod/direct 2/rm32/edx . . . 4/r32/esp . . # copy esp to edx
191 # *Next-alloc-id = 0x34
192 c7 0/subop/copy 0/mod/indirect 5/rm32/.disp32 . . . Next-alloc-id/disp32 0x34/imm32 # copy to *Next-alloc-id
193 # allocate-raw(ad, 3, h)
194 # . . push args
195 52/push-edx
196 68/push 3/imm32
197 51/push-ecx
198 # . . call
199 e8/call allocate-raw/disp32
200 # . . discard args
201 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 0xc/imm32 # add to esp
202 # check-ints-equal(h->alloc-id, 0x34, msg)
203 # . . push args
204 68/push "F - test-allocate-raw-success: sets alloc-id in handle"/imm32
205 68/push 0x34/imm32
206 ff 6/subop/push 0/mod/indirect 2/rm32/edx . . . . . . # push *edx
207 # . . call
208 e8/call check-ints-equal/disp32
209 # . . discard args
210 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 0xc/imm32 # add to esp
211 # check-ints-equal(h->payload, expected-payload, msg)
212 # . . push args
213 68/push "F - test-allocate-raw-success: sets payload in handle"/imm32
214 53/push-ebx
215 ff 6/subop/push 1/mod/*+disp8 2/rm32/edx . . . . 4/disp8 . # push *(edx+4)
216 # . . call
217 e8/call check-ints-equal/disp32
218 # . . discard args
219 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 0xc/imm32 # add to esp
220 # check-ints-equal(h->payload->alloc-id, 0x34, msg)
221 # . . push args
222 68/push "F - test-allocate-raw-success: sets alloc-id in payload"/imm32
223 68/push 0x34/imm32
224 ff 6/subop/push 0/mod/indirect 3/rm32/ebx . . . . . . # push *ebx
225 # . . call
226 e8/call check-ints-equal/disp32
227 # . . discard args
228 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 0xc/imm32 # add to esp
229 # check-ints-equal(*Next-alloc-id, 0x35, msg)
230 # . . push args
231 68/push "F - test-allocate-raw-success: increments Next-alloc-id"/imm32
232 68/push 0x35/imm32
233 ff 6/subop/push 0/mod/indirect 5/rm32/.disp32 . . . Next-alloc-id/disp32 # push *Next-alloc-id
234 # . . call
235 e8/call check-ints-equal/disp32
236 # . . discard args
237 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 0xc/imm32 # add to esp
238 # check-ints-equal(ad->curr - expected-payload, 3 + 4 for alloc-id, msg)
239 # . . push args
240 68/push "F - test-allocate-raw-success: updates allocation descriptor"/imm32
241 68/push 7/imm32
242 8b/copy 0/mod/indirect 1/rm32/ecx . . . 0/r32/eax . . # copy *ecx to eax
243 29/subtract 3/mod/direct 0/rm32/eax . . . 3/r32/ebx . . # subtract ebx from eax
244 50/push-eax
245 # . . call
246 e8/call check-ints-equal/disp32
247 # . . discard args
248 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 0xc/imm32 # add to esp
249 # clean up
250 c7 0/subop/copy 0/mod/indirect 5/rm32/.disp32 . . . Next-alloc-id/disp32 0x100/imm32 # copy to *Next-alloc-id
251 # . reclaim locals
252 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 0x10/imm32 # add to esp
253 # . epilogue
254 89/copy 3/mod/direct 4/rm32/esp . . . 5/r32/ebp . . # copy ebp to esp
255 5d/pop-to-ebp
256 c3/return
258 lookup: # h: (handle _T) -> result/eax: (addr _T)
259 # . prologue
260 55/push-ebp
261 89/copy 3/mod/direct 5/rm32/ebp . . . 4/r32/esp . . # copy esp to ebp
262 # . save registers
263 51/push-ecx
264 # eax = 0
265 31/xor 3/mod/direct 0/rm32/eax . . . 0/r32/eax . . # clear eax
266 # ecx = handle->alloc_id
267 8b/copy 1/mod/*+disp8 5/rm32/ebp . . . 1/r32/ecx 8/disp8 . # copy *(ebp+8) to ecx
268 # if (ecx == 0) return 0
269 81 7/subop/compare 3/mod/direct 1/rm32/ecx . . . . . 0/imm32 # compare ecx
270 74/jump-if-= $lookup:end/disp8
271 # eax = handle->address (payload)
272 8b/copy 1/mod/*+disp8 5/rm32/ebp . . . 0/r32/eax 0xc/disp8 . # copy *(ebp+12) to eax
273 # if (ecx != *eax) abort
274 39/compare 0/mod/indirect 0/rm32/eax . . . 1/r32/ecx . . # compare *eax and ecx
275 75/jump-if-!= $lookup:abort/disp8
276 # add 4 to eax
277 05/add-to-eax 4/imm32
278 $lookup:end:
279 # . restore registers
280 59/pop-to-ecx
281 # . epilogue
282 89/copy 3/mod/direct 4/rm32/esp . . . 5/r32/ebp . . # copy ebp to esp
283 5d/pop-to-ebp
284 c3/return
286 $lookup:abort:
287 # . _write(2/stderr, msg)
288 # . . push args
289 68/push "lookup failed\n"/imm32
290 68/push 2/imm32/stderr
291 # . . call
292 e8/call _write/disp32
293 # . . discard args
294 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 8/imm32 # add to esp
295 # . syscall_exit(1)
296 bb/copy-to-ebx 1/imm32/exit-status
297 e8/call syscall_exit/disp32
299 test-lookup-success:
300 # . prologue
301 55/push-ebp
302 89/copy 3/mod/direct 5/rm32/ebp . . . 4/r32/esp . . # copy esp to ebp
303 # var ad/ebx: allocation-descriptor
304 68/push 0/imm32/limit
305 68/push 0/imm32/curr
306 89/copy 3/mod/direct 3/rm32/ebx . . . 4/r32/esp . . # copy esp to ebx
307 # ad = new-segment(512)
308 # . . push args
309 53/push-ebx
310 68/push 0x200/imm32
311 # . . call
312 e8/call new-segment/disp32
313 # . . discard args
314 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 8/imm32 # add to esp
315 # var handle/ecx: handle
316 68/push 0/imm32/address
317 68/push 0/imm32/alloc-id
318 89/copy 3/mod/direct 1/rm32/ecx . . . 4/r32/esp . . # copy esp to ecx
319 # var old-top/edx = ad->curr
320 8b/copy 0/mod/indirect 3/rm32/ebx . . . 2/r32/edx . . # copy *ebx to edx
321 # allocate-raw(ad, 2, handle)
322 # . . push args
323 51/push-ecx
324 68/push 2/imm32/size
325 53/push-ebx
326 # . . call
327 e8/call allocate-raw/disp32
328 # . . discard args
329 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 0xc/imm32 # add to esp
330 # eax = lookup(handle)
331 # . . push args
332 ff 6/subop/push 1/mod/*+disp8 1/rm32/ecx . . . . 4/disp8 . # push *(ecx+4)
333 ff 6/subop/push 0/mod/indirect 1/rm32/ecx . . . . . . # push *ecx
334 # . . call
335 e8/call lookup/disp32
336 # . . discard args
337 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 8/imm32 # add to esp
338 # eax contains old top of heap, except skipping the alloc-id in the payload
339 # . check-ints-equal(eax, old-top+4, msg)
340 # . . push args
341 68/push "F - test-lookup-success"/imm32
342 81 0/subop/add 3/mod/direct 2/rm32/edx . . . . . 4/imm32 # add to edx
343 52/push-edx
344 50/push-eax
345 # . . call
346 e8/call check-ints-equal/disp32
347 # . . discard args
348 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 0xc/imm32 # add to esp
349 # clean up
350 c7 0/subop/copy 0/mod/indirect 5/rm32/.disp32 . . . Next-alloc-id/disp32 0x100/imm32 # copy to *Next-alloc-id
351 # . reclaim locals
352 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 0x10/imm32 # add to esp
353 # . epilogue
354 89/copy 3/mod/direct 4/rm32/esp . . . 5/r32/ebp . . # copy ebp to esp
355 5d/pop-to-ebp
356 c3/return
358 test-lookup-null-returns-null:
359 # . prologue
360 55/push-ebp
361 89/copy 3/mod/direct 5/rm32/ebp . . . 4/r32/esp . . # copy esp to ebp
362 # var handle/ecx: handle
363 68/push 0/imm32/address
364 68/push 0/imm32/alloc-id
365 89/copy 3/mod/direct 1/rm32/ecx . . . 4/r32/esp . . # copy esp to ecx
366 # eax = lookup(handle)
367 # . . push args
368 ff 6/subop/push 1/mod/*+disp8 1/rm32/ecx . . . . 4/disp8 . # push *(ecx+4)
369 ff 6/subop/push 0/mod/indirect 1/rm32/ecx . . . . . . # push *ecx
370 # . . call
371 e8/call lookup/disp32
372 # . . discard args
373 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 8/imm32 # add to esp
374 # check-ints-equal(eax, 0, msg)
375 # . . push args
376 68/push "F - test-lookup-null-returns-null"/imm32
377 68/push 0/imm32
378 50/push-eax
379 # . . call
380 e8/call check-ints-equal/disp32
381 # . . discard args
382 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 0xc/imm32 # add to esp
383 # . reclaim locals
384 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 8/imm32 # add to esp
385 # . epilogue
386 89/copy 3/mod/direct 4/rm32/esp . . . 5/r32/ebp . . # copy ebp to esp
387 5d/pop-to-ebp
388 c3/return
390 _pending-test-lookup-failure:
391 # . prologue
392 55/push-ebp
393 89/copy 3/mod/direct 5/rm32/ebp . . . 4/r32/esp . . # copy esp to ebp
394 # var heap/esi: allocation-descriptor
395 68/push 0/imm32/limit
396 68/push 0/imm32/curr
397 89/copy 3/mod/direct 6/rm32/esi . . . 4/r32/esp . . # copy esp to esi
398 # heap = new-segment(512)
399 # . . push args
400 56/push-esi
401 68/push 0x200/imm32
402 # . . call
403 e8/call new-segment/disp32
404 # . . discard args
405 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 8/imm32 # add to esp
406 # var h1/ecx: handle
407 68/push 0/imm32/address
408 68/push 0/imm32/alloc-id
409 89/copy 3/mod/direct 1/rm32/ecx . . . 4/r32/esp . . # copy esp to ecx
410 # var old_top/ebx = heap->curr
411 8b/copy 0/mod/indirect 6/rm32/esi . . . 3/r32/ebx . . # copy *esi to ebx
412 # first allocation, to h1
413 # . allocate(heap, 2, h1)
414 # . . push args
415 51/push-ecx
416 68/push 2/imm32/size
417 56/push-esi
418 # . . call
419 e8/call allocate/disp32
420 # . . discard args
421 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 0xc/imm32 # add to esp
422 # reset heap->curr to mimic reclamation
423 89/copy 0/mod/indirect 6/rm32/esi . . . 3/r32/ebx . . # copy ebx to *esi
424 # second allocation that returns the same address as the first
425 # var h2/edx: handle
426 68/push 0/imm32/address
427 68/push 0/imm32/alloc-id
428 89/copy 3/mod/direct 2/rm32/edx . . . 4/r32/esp . . # copy esp to edx
429 # . allocate(heap, 2, h2)
430 # . . push args
431 52/push-edx
432 68/push 2/imm32/size
433 56/push-esi
434 # . . call
435 e8/call allocate/disp32
436 # . . discard args
437 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 0xc/imm32 # add to esp
438 # check-ints-equal(h1->address, h2->address, msg)
439 # . . push args
440 68/push "F - test-lookup-failure"/imm32
441 ff 6/subop/push 1/mod/*+disp8 2/rm32/ecx . . . . 4/disp8 . # push *(edx+4)
442 ff 6/subop/push 1/mod/*+disp8 1/rm32/ecx . . . . 4/disp8 . # push *(ecx+4)
443 # . . call
444 e8/call check-ints-equal/disp32
445 # . . discard args
446 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 0xc/imm32 # add to esp
447 # lookup(h1) should crash
448 # . . push args
449 ff 6/subop/push 1/mod/*+disp8 1/rm32/ecx . . . . 4/disp8 . # push *(ecx+4)
450 ff 6/subop/push 0/mod/indirect 1/rm32/ecx . . . . . . # push *ecx
451 # . . call
452 e8/call lookup/disp32
453 # should never get past this point
454 # . . discard args
455 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 8/imm32 # add to esp
456 # clean up
457 c7 0/subop/copy 0/mod/indirect 5/rm32/.disp32 . . . Next-alloc-id/disp32 0x100/imm32 # copy to *Next-alloc-id
458 # . reclaim locals
459 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 8/imm32 # add to esp
460 # . epilogue
461 89/copy 3/mod/direct 4/rm32/esp . . . 5/r32/ebp . . # copy ebp to esp
462 5d/pop-to-ebp
463 c3/return
465 # when comparing handles, just treat them as pure values
466 handle-equal?: # a: (handle _T), b: (handle _T) -> result/eax: boolean
467 # . prologue
468 55/push-ebp
469 89/copy 3/mod/direct 5/rm32/ebp . . . 4/r32/esp . . # copy esp to ebp
470 # . save registers
471 51/push-ecx
472 # eax = false
473 b8/copy-to-eax 0/imm32/false
474 $handle-equal?:compare-alloc-id:
475 # ecx = a->alloc_id
476 8b/copy 1/mod/*+disp8 5/rm32/ebp . . . 1/r32/ecx 8/disp8 . # copy *(ebp+8) to ecx
477 # if (ecx != b->alloc_id) return false
478 39/compare 1/mod/*+disp8 5/rm32/ebp . . . 1/r32/ecx 0x10/disp8 . # compare ecx and *(ebp+16)
479 75/jump-if-!= $handle-equal?:end/disp8
480 $handle-equal?:compare-address:
481 # ecx = handle->address
482 8b/copy 1/mod/*+disp8 5/rm32/ebp . . . 1/r32/ecx 0xc/disp8 . # copy *(ebp+12) to ecx
483 # if (ecx != b->address) return false
484 39/compare 1/mod/*+disp8 5/rm32/ebp . . . 1/r32/ecx 0x14/disp8 . # compare ecx and *(ebp+20)
485 75/jump-if-!= $handle-equal?:end/disp8
486 $handle-equal?:return-true:
487 # return true
488 b8/copy-to-eax 1/imm32/true
489 $handle-equal?:end:
490 # . restore registers
491 59/pop-to-ecx
492 # . epilogue
493 89/copy 3/mod/direct 4/rm32/esp . . . 5/r32/ebp . . # copy ebp to esp
494 5d/pop-to-ebp
495 c3/return
497 copy-handle: # src: (handle _T), dest: (addr handle _T)
498 # . prologue
499 55/push-ebp
500 89/copy 3/mod/direct 5/rm32/ebp . . . 4/r32/esp . . # copy esp to ebp
501 # . save registers
502 50/push-eax
503 51/push-ecx
504 # ecx = dest
505 8b/copy 1/mod/*+disp8 5/rm32/ebp . . . 1/r32/ecx 0x10/disp8 . # copy *(ebp+16) to ecx
506 # *dest = src
507 8b/copy 1/mod/*+disp8 5/rm32/ebp . . . 0/r32/eax 8/disp8 . # copy *(ebp+8) to eax
508 89/copy 0/mod/indirect 1/rm32/ecx . . . 0/r32/eax . . # copy eax to *ecx
509 8b/copy 1/mod/*+disp8 5/rm32/ebp . . . 0/r32/eax 0xc/disp8 . # copy *(ebp+12) to eax
510 89/copy 1/mod/*+disp8 1/rm32/ecx . . . 0/r32/eax 4/disp8 . # copy eax to *(ecx+4)
511 $copy-handle:end:
512 # . restore registers
513 59/pop-to-ecx
514 58/pop-to-eax
515 # . epilogue
516 89/copy 3/mod/direct 4/rm32/esp . . . 5/r32/ebp . . # copy ebp to esp
517 5d/pop-to-ebp
518 c3/return
520 # helper: create a nested allocation descriptor (useful for tests)
521 allocate-region: # ad: (addr allocation-descriptor), n: int, out: (addr handle allocation-descriptor)
522 # . prologue
523 55/push-ebp
524 89/copy 3/mod/direct 5/rm32/ebp . . . 4/r32/esp . . # copy esp to ebp
525 # . save registers
526 50/push-eax
527 51/push-ecx
528 # allocate(ad, n, out)
529 # . . push args
530 ff 6/subop/push 1/mod/*+disp8 5/rm32/ebp . . . . 0x10/disp8 . # push *(ebp+16)
531 ff 6/subop/push 1/mod/*+disp8 5/rm32/ebp . . . . 0xc/disp8 . # push *(ebp+12)
532 ff 6/subop/push 1/mod/*+disp8 5/rm32/ebp . . . . 8/disp8 . # push *(ebp+8)
533 # . . call
534 e8/call allocate/disp32
535 # . . discard args
536 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 0xc/imm32 # add to esp
537 # eax = out->payload
538 8b/copy 1/mod/*+disp8 5/rm32/ebp . . . 0/r32/eax 0x10/disp8 . # copy *(ebp+16) to eax
539 8b/copy 1/mod/*+disp8 0/rm32/eax . . . 0/r32/eax 4/disp8 . # copy *(eax+4) to eax
540 # skip payload->allocid
541 05/add-to-eax 4/imm32
542 # if (eax == 0) abort
543 3d/compare-eax-and 0/imm32
544 74/jump-if-= $allocate-region:abort/disp8
545 # earmark 8 bytes at the start for a new allocation descriptor
546 # . *eax = eax + 8
547 89/copy 3/mod/direct 1/rm32/ecx . . . 0/r32/eax . . # copy eax to ecx
548 81 0/subop/add 3/mod/direct 1/rm32/ecx . . . . . 8/imm32 # add to ecx
549 89/copy 0/mod/indirect 0/rm32/eax . . . 1/r32/ecx . . # copy ecx to *eax
550 # . *(eax+4) = eax + n
551 89/copy 3/mod/direct 1/rm32/ecx . . . 0/r32/eax . . # copy eax to ecx
552 03/add 1/mod/*+disp8 5/rm32/ebp . . . 1/r32/ecx 0xc/disp8 . # add *(ebp+12) to ecx
553 89/copy 1/mod/*+disp8 0/rm32/eax . . . 1/r32/ecx 4/disp8 . # copy ecx to *(eax+4)
554 # . restore registers
555 59/pop-to-ecx
556 58/pop-to-eax
557 # . epilogue
558 89/copy 3/mod/direct 4/rm32/esp . . . 5/r32/ebp . . # copy ebp to esp
559 5d/pop-to-ebp
560 c3/return
562 # We could create a more general '$abort' jump target, but then we'd need to do
563 # a conditional jump followed by loading the error message and an unconditional
564 # jump. Or we'd need to unconditionally load the error message before a
565 # conditional jump, even if it's unused the vast majority of the time. This way
566 # we bloat a potentially cold segment in RAM so we can abort with a single
567 # instruction.
568 $allocate-region:abort:
569 # . _write(2/stderr, error)
570 # . . push args
571 68/push "allocate-region: failed to allocate\n"/imm32
572 68/push 2/imm32/stderr
573 # . . call
574 e8/call _write/disp32
575 # . . discard args
576 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 8/imm32 # add to esp
577 # . syscall_exit(1)
578 bb/copy-to-ebx 1/imm32
579 e8/call syscall_exit/disp32
580 # never gets here
582 # Claim the next 'n+4' bytes of memory and initialize the first 4 to n.
583 # Abort if there isn't enough memory in 'ad'.
584 allocate-array: # ad: (addr allocation-descriptor), n: int, out: (addr handle _)
585 # . prologue
586 55/push-ebp
587 89/copy 3/mod/direct 5/rm32/ebp . . . 4/r32/esp . . # copy esp to ebp
588 # . save registers
589 50/push-eax
590 51/push-ecx
591 52/push-edx
592 # ecx = n
593 8b/copy 1/mod/*+disp8 5/rm32/ebp . . . 1/r32/ecx 0xc/disp8 . # copy *(ebp+12) to ecx
594 # var size/edx: int = n+4
595 8d/copy-address 1/mod/*+disp8 1/rm32/ecx . . . 2/r32/edx 4/disp8 . # copy ecx+4 to edx
596 # allocate(ad, size, out)
597 # . . push args
598 ff 6/subop/push 1/mod/*+disp8 5/rm32/ebp . . . . 0x10/disp8 . # push *(ebp+16)
599 52/push-edx
600 ff 6/subop/push 1/mod/*+disp8 5/rm32/ebp . . . . 8/disp8 . # push *(ebp+8)
601 # . . call
602 e8/call allocate/disp32
603 # . . discard args
604 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 0xc/imm32 # add to esp
605 # *out->payload = n
606 8b/copy 1/mod/*+disp8 5/rm32/ebp . . . 0/r32/eax 0x10/disp8 . # copy *(ebp+16) to eax
607 8b/copy 1/mod/*+disp8 0/rm32/eax . . . 0/r32/eax 4/disp8 . # copy *(eax+4) to eax
608 # . skip payload->allocid
609 05/add-to-eax 4/imm32
610 # .
611 89/copy 0/mod/indirect 0/rm32/eax . . . 1/r32/ecx . . # copy ecx to *eax
612 $allocate-array:end:
613 # . restore registers
614 5a/pop-to-edx
615 59/pop-to-ecx
616 58/pop-to-eax
617 # . epilogue
618 89/copy 3/mod/direct 4/rm32/esp . . . 5/r32/ebp . . # copy ebp to esp
619 5d/pop-to-ebp
620 c3/return
622 test-allocate-array:
623 # . prologue
624 55/push-ebp
625 89/copy 3/mod/direct 5/rm32/ebp . . . 4/r32/esp . . # copy esp to ebp
626 # var ad/ecx: allocation-descriptor
627 68/push 0/imm32/limit
628 68/push 0/imm32/curr
629 89/copy 3/mod/direct 1/rm32/ecx . . . 4/r32/esp . . # copy esp to ecx
630 # ad = new-segment(512)
631 # . . push args
632 51/push-ecx
633 68/push 0x200/imm32
634 # . . call
635 e8/call new-segment/disp32
636 # . . discard args
637 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 8/imm32 # add to esp
638 # var expected-payload/ebx = ad->curr
639 8b/copy 0/mod/indirect 1/rm32/ecx . . . 3/r32/ebx . . # copy *ecx to ebx
640 # var h/edx: handle = {0, 0}
641 68/push 0/imm32
642 68/push 0/imm32
643 89/copy 3/mod/direct 2/rm32/edx . . . 4/r32/esp . . # copy esp to edx
644 # *Next-alloc-id = 0x34
645 c7 0/subop/copy 0/mod/indirect 5/rm32/.disp32 . . . Next-alloc-id/disp32 0x34/imm32 # copy to *Next-alloc-id
646 # allocate-array(ad, 3, h)
647 # . . push args
648 52/push-edx
649 68/push 3/imm32
650 51/push-ecx
651 # . . call
652 e8/call allocate-array/disp32
653 # . . discard args
654 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 0xc/imm32 # add to esp
655 # check-ints-equal(h->alloc-id, 0x34, msg)
656 # . . push args
657 68/push "F - test-allocate-array: sets alloc-id in handle"/imm32
658 68/push 0x34/imm32
659 ff 6/subop/push 0/mod/indirect 2/rm32/edx . . . . . . # push *edx
660 # . . call
661 e8/call check-ints-equal/disp32
662 # . . discard args
663 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 0xc/imm32 # add to esp
664 # check-ints-equal(h->payload, expected-payload, msg)
665 # . . push args
666 68/push "F - test-allocate-array: sets payload in handle"/imm32
667 53/push-ebx
668 ff 6/subop/push 1/mod/*+disp8 2/rm32/edx . . . . 4/disp8 . # push *(edx+4)
669 # . . call
670 e8/call check-ints-equal/disp32
671 # . . discard args
672 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 0xc/imm32 # add to esp
673 # check-ints-equal(h->payload->alloc-id, 0x34, msg)
674 # . . push args
675 68/push "F - test-allocate-array: sets alloc-id in payload"/imm32
676 68/push 0x34/imm32
677 ff 6/subop/push 0/mod/indirect 3/rm32/ebx . . . . . . # push *ebx
678 # . . call
679 e8/call check-ints-equal/disp32
680 # . . discard args
681 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 0xc/imm32 # add to esp
682 # check-ints-equal(h->payload->size, 3, msg)
683 # . . push args
684 68/push "F - test-allocate-array: sets array size in payload"/imm32
685 68/push 3/imm32
686 ff 6/subop/push 1/mod/*+disp8 3/rm32/ebx . . . . 4/disp8 . # push *(ebx+4)
687 # . . call
688 e8/call check-ints-equal/disp32
689 # . . discard args
690 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 0xc/imm32 # add to esp
691 # check-ints-equal(*Next-alloc-id, 0x35, msg)
692 # . . push args
693 68/push "F - test-allocate-array: increments Next-alloc-id"/imm32
694 68/push 0x35/imm32
695 ff 6/subop/push 0/mod/indirect 5/rm32/.disp32 . . . Next-alloc-id/disp32 # push *Next-alloc-id
696 # . . call
697 e8/call check-ints-equal/disp32
698 # . . discard args
699 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 0xc/imm32 # add to esp
700 # check-ints-equal(ad->curr - expected-payload, 3 + 4 for alloc-id + 4 for array size, msg)
701 # . . push args
702 68/push "F - test-allocate-array: updates allocation descriptor"/imm32
703 68/push 0xb/imm32
704 8b/copy 0/mod/indirect 1/rm32/ecx . . . 0/r32/eax . . # copy *ecx to eax
705 29/subtract 3/mod/direct 0/rm32/eax . . . 3/r32/ebx . . # subtract ebx from eax
706 50/push-eax
707 # . . call
708 e8/call check-ints-equal/disp32
709 # . . discard args
710 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 0xc/imm32 # add to esp
711 # clean up
712 c7 0/subop/copy 0/mod/indirect 5/rm32/.disp32 . . . Next-alloc-id/disp32 1/imm32 # copy to *Next-alloc-id
713 # . reclaim locals
714 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 0x10/imm32 # add to esp
715 # . epilogue
716 89/copy 3/mod/direct 4/rm32/esp . . . 5/r32/ebp . . # copy ebp to esp
717 5d/pop-to-ebp
718 c3/return
720 copy-array: # ad: (addr allocation-descriptor), src: (addr array _T), out: (addr handle array _T)
721 # . prologue
722 55/push-ebp
723 89/copy 3/mod/direct 5/rm32/ebp . . . 4/r32/esp . . # copy esp to ebp
724 # . save registers
725 50/push-eax
726 51/push-ecx
727 52/push-edx
728 56/push-esi
729 # esi = src
730 8b/copy 1/mod/*+disp8 5/rm32/ebp . . . 6/r32/esi 0xc/disp8 . # copy *(ebp+12) to esi
731 # var size/ecx: int = src->size+4
732 8b/copy 0/mod/indirect 6/rm32/esi . . . 1/r32/ecx . . # copy *esi to ecx
733 81 0/subop/add 3/mod/direct 1/rm32/ecx . . . . . 4/imm32 # add to ecx
734 # allocate(ad, size, out)
735 # . . push args
736 ff 6/subop/push 1/mod/*+disp8 5/rm32/ebp . . . . 0x10/disp8 . # push *(ebp+16)
737 51/push-ecx
738 ff 6/subop/push 1/mod/*+disp8 5/rm32/ebp . . . . 8/disp8 . # push *(ebp+8)
739 # . . call
740 e8/call allocate/disp32
741 # . . discard args
742 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 0xc/imm32 # add to esp
743 # var payload/eax: (addr byte) = out->payload
744 8b/copy 1/mod/*+disp8 5/rm32/ebp . . . 0/r32/eax 0x10/disp8 . # copy *(ebp+16) to eax
745 8b/copy 1/mod/*+disp8 0/rm32/eax . . . 0/r32/eax 4/disp8 . # copy *(eax+4) to eax
746 # . skip payload->allocid
747 05/add-to-eax 4/imm32
748 # var max/ecx: (addr byte) = payload + size
749 01/add 3/mod/direct 1/rm32/ecx . . . 0/r32/eax . . # add eax to ecx
750 # _append-4(payload, max, src, &src->data[src->size])
751 # . . push &src->data[src->size]
752 8b/copy 0/mod/indirect 6/rm32/esi . . . 2/r32/edx . . # copy *esi to edx
753 8d/copy-address 1/mod/*+disp8 4/rm32/sib 6/base/esi 2/index/edx . 2/r32/edx 4/disp8 . # copy esi+edx+4 to edx
754 52/push-edx
755 # . . push src
756 56/push-esi
757 # . . push max
758 51/push-ecx
759 # . . push payload
760 50/push-eax
761 # . . call
762 e8/call _append-4/disp32
763 # . . discard args
764 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 0x10/imm32 # add to esp
765 $copy-array:end:
766 # . restore registers
767 5e/pop-to-esi
768 5a/pop-to-edx
769 59/pop-to-ecx
770 58/pop-to-eax
771 # . epilogue
772 89/copy 3/mod/direct 4/rm32/esp . . . 5/r32/ebp . . # copy ebp to esp
773 5d/pop-to-ebp
774 c3/return
776 test-copy-array:
777 # . prologue
778 55/push-ebp
779 89/copy 3/mod/direct 5/rm32/ebp . . . 4/r32/esp . . # copy esp to ebp
780 # var src/esi: (addr array int) = [3, 4, 5]
781 68/push 5/imm32
782 68/push 4/imm32
783 68/push 3/imm32
784 68/push 0xc/imm32/size
785 89/copy 3/mod/direct 6/rm32/esi . . . 4/r32/esp . . # copy esp to esi
786 # var ad/ecx: allocation-descriptor
787 68/push 0/imm32/limit
788 68/push 0/imm32/curr
789 89/copy 3/mod/direct 1/rm32/ecx . . . 4/r32/esp . . # copy esp to ecx
790 # ad = new-segment(512)
791 # . . push args
792 51/push-ecx
793 68/push 0x200/imm32
794 # . . call
795 e8/call new-segment/disp32
796 # . . discard args
797 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 8/imm32 # add to esp
798 # var expected-payload/ebx = ad->curr
799 8b/copy 0/mod/indirect 1/rm32/ecx . . . 3/r32/ebx . . # copy *ecx to ebx
800 # var h/edx: handle = {0, 0}
801 68/push 0/imm32
802 68/push 0/imm32
803 89/copy 3/mod/direct 2/rm32/edx . . . 4/r32/esp . . # copy esp to edx
804 # *Next-alloc-id = 0x34
805 c7 0/subop/copy 0/mod/indirect 5/rm32/.disp32 . . . Next-alloc-id/disp32 0x34/imm32 # copy to *Next-alloc-id
806 # copy-array(ad, src, h)
807 # . . push args
808 52/push-edx
809 56/push-esi
810 51/push-ecx
811 # . . call
812 e8/call copy-array/disp32
813 # . . discard args
814 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 0xc/imm32 # add to esp
815 # check-ints-equal(h->alloc-id, 0x34, msg)
816 # . . push args
817 68/push "F - test-copy-array: sets alloc-id in handle"/imm32
818 68/push 0x34/imm32
819 ff 6/subop/push 0/mod/indirect 2/rm32/edx . . . . . . # push *edx
820 # . . call
821 e8/call check-ints-equal/disp32
822 # . . discard args
823 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 0xc/imm32 # add to esp
824 # check-ints-equal(h->payload, expected-payload, msg)
825 # . . push args
826 68/push "F - test-copy-array: sets payload in handle"/imm32
827 53/push-ebx
828 ff 6/subop/push 1/mod/*+disp8 2/rm32/edx . . . . 4/disp8 . # push *(edx+4)
829 # . . call
830 e8/call check-ints-equal/disp32
831 # . . discard args
832 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 0xc/imm32 # add to esp
833 # check-ints-equal(h->payload->alloc-id, 0x34, msg)
834 # . . push args
835 68/push "F - test-copy-array: sets alloc-id in payload"/imm32
836 68/push 0x34/imm32
837 ff 6/subop/push 0/mod/indirect 2/rm32/edx . . . . . . # push *edx
838 # . . call
839 e8/call check-ints-equal/disp32
840 # . . discard args
841 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 0xc/imm32 # add to esp
842 # var payload/eax: (addr int) = lookup(h)
843 # . . push args
844 ff 6/subop/push 1/mod/*+disp8 2/rm32/edx . . . . 4/disp8 . # push *(edx+4)
845 ff 6/subop/push 0/mod/indirect 2/rm32/edx . . . . . . # push *edx
846 # . . call
847 e8/call lookup/disp32
848 # . . discard args
849 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 8/imm32 # add to esp
850 # check-ints-equal(payload->size, 0xc, msg)
851 # . . push args
852 68/push "F - test-copy-array: sets array size in payload"/imm32
853 68/push 0xc/imm32
854 ff 6/subop/push 0/mod/indirect 0/rm32/eax . . . . . . # push *eax
855 # . . call
856 e8/call check-ints-equal/disp32
857 # . . discard args
858 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 0xc/imm32 # add to esp
859 # check-ints-equal(*Next-alloc-id, 0x35, msg)
860 # . . push args
861 68/push "F - test-copy-array: increments Next-alloc-id"/imm32
862 68/push 0x35/imm32
863 ff 6/subop/push 0/mod/indirect 5/rm32/.disp32 . . . Next-alloc-id/disp32 # push *Next-alloc-id
864 # . . call
865 e8/call check-ints-equal/disp32
866 # . . discard args
867 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 0xc/imm32 # add to esp
868 # check-ints-equal(ad->curr - expected-payload, 12 + 4 for alloc-id + 4 for size, msg)
869 # . . push args
870 68/push "F - test-copy-array: updates allocation descriptor"/imm32
871 68/push 0x14/imm32
872 8b/copy 0/mod/indirect 1/rm32/ecx . . . 0/r32/eax . . # copy *ecx to eax
873 29/subtract 3/mod/direct 0/rm32/eax . . . 3/r32/ebx . . # subtract ebx from eax
874 50/push-eax
875 # . . call
876 e8/call check-ints-equal/disp32
877 # . . discard args
878 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 0xc/imm32 # add to esp
879 # clean up
880 c7 0/subop/copy 0/mod/indirect 5/rm32/.disp32 . . . Next-alloc-id/disp32 1/imm32 # copy to *Next-alloc-id
881 # . reclaim locals
882 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 0x20/imm32 # add to esp
883 # . epilogue
884 89/copy 3/mod/direct 4/rm32/esp . . . 5/r32/ebp . . # copy ebp to esp
885 5d/pop-to-ebp
886 c3/return
888 # Fill a region of memory with zeroes.
889 zero-out: # start: (addr byte), size: int
890 # pseudocode:
891 # curr/esi = start
892 # i/ecx = 0
893 # while true
894 # if (i >= size) break
895 # *curr = 0
896 # ++curr
897 # ++i
898 #
899 # . prologue
900 55/push-ebp
901 89/copy 3/mod/direct 5/rm32/ebp . . . 4/r32/esp . . # copy esp to ebp
902 # . save registers
903 50/push-eax
904 51/push-ecx
905 52/push-edx
906 56/push-esi
907 # curr/esi = start
908 8b/copy 1/mod/*+disp8 5/rm32/ebp . . . 6/r32/esi 8/disp8 . # copy *(ebp+8) to esi
909 # var i/ecx: int = 0
910 31/xor 3/mod/direct 1/rm32/ecx . . . 1/r32/ecx . . # clear ecx
911 # edx = size
912 8b/copy 1/mod/*+disp8 5/rm32/ebp . . . 2/r32/edx 0xc/disp8 . # copy *(ebp+12) to edx
913 $zero-out:loop:
914 # if (i >= size) break
915 39/compare 3/mod/direct 1/rm32/ecx . . . 2/r32/edx . . # compare ecx with edx
916 7d/jump-if->= $zero-out:end/disp8
917 # *curr = 0
918 c6 0/subop/copy-byte 0/mod/direct 6/rm32/esi . . . . . 0/imm8 # copy byte to *esi
919 # ++curr
920 46/increment-esi
921 # ++i
922 41/increment-ecx
923 eb/jump $zero-out:loop/disp8
924 $zero-out:end:
925 # . restore registers
926 5e/pop-to-esi
927 5a/pop-to-edx
928 59/pop-to-ecx
929 58/pop-to-eax
930 # . epilogue
931 89/copy 3/mod/direct 4/rm32/esp . . . 5/r32/ebp . . # copy ebp to esp
932 5d/pop-to-ebp
933 c3/return
935 test-zero-out:
936 # . prologue
937 55/push-ebp
938 89/copy 3/mod/direct 5/rm32/ebp . . . 4/r32/esp . . # copy esp to ebp
939 # region/ecx = 34, 35, 36, 37
940 68/push 0x37363534/imm32
941 89/copy 3/mod/direct 1/rm32/ecx . . . 4/r32/esp . . # copy esp to ecx
942 # zero-out(ecx, 3)
943 # . . push args
944 68/push 3/imm32/size
945 51/push-ecx
946 # . . call
947 e8/call zero-out/disp32
948 # . . discard args
949 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 8/imm32 # add to esp
950 # first 3 bytes cleared, fourth left alone
951 # . check-ints-equal(*ecx, 0x37000000, msg)
952 # . . push args
953 68/push "F - test-zero-out"/imm32
954 68/push 0x37000000/imm32
955 ff 6/subop/push 0/mod/indirect 1/rm32/ecx . . . . . . # push *ecx
956 # . . call
957 e8/call check-ints-equal/disp32
958 # . . discard args
959 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 0xc/imm32 # add to esp
960 # . reclaim locals
961 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 4/imm32 # add to esp
962 # . epilogue
963 89/copy 3/mod/direct 4/rm32/esp . . . 5/r32/ebp . . # copy ebp to esp
964 5d/pop-to-ebp
965 c3/return
967 # . . vim:nowrap:textwidth=0