1 ;;;; the machine specific support routines needed by the file assembler
3 ;;;; This software is part of the SBCL system. See the README file for
6 ;;;; This software is derived from the CMU CL system, which was
7 ;;;; written at Carnegie Mellon University and released into the
8 ;;;; public domain. The software is in the public domain and is
9 ;;;; provided with absolutely no warranty. See the COPYING and CREDITS
10 ;;;; files for more information.
16 ;;; For RETURN-MULTIPLE, we have to move the results from the end of
17 ;;; the frame for the function that is returning to the end of the
18 ;;; frame for the function being returned to.
20 #+sb-assembling ;; We don't want a vop for this one.
21 (define-assembly-routine
22 (return-multiple (:return-style :none))
23 (;; These four are really arguments.
24 (:temp eax unsigned-reg eax-offset)
25 (:temp ebx unsigned-reg ebx-offset)
26 (:temp ecx unsigned-reg ecx-offset)
27 (:temp esi unsigned-reg esi-offset)
29 ;; These we need as temporaries.
30 (:temp edx unsigned-reg edx-offset)
31 (:temp edi unsigned-reg edi-offset))
33 ;; Pick off the cases where everything fits in register args.
34 (inst jecxz ZERO-VALUES)
35 (inst cmp ecx (fixnumize 1))
36 (inst jmp :e ONE-VALUE)
37 (inst cmp ecx (fixnumize 2))
38 (inst jmp :e TWO-VALUES)
39 (inst cmp ecx (fixnumize 3))
40 (inst jmp :e THREE-VALUES)
42 ;; Save the count, because the loop is going to destroy it.
45 ;; Blit the values down the stack. Note: there might be overlap, so
46 ;; we have to be careful not to clobber values before we've read
47 ;; them. Because the stack builds down, we are coping to a larger
48 ;; address. Therefore, we need to iterate from larger addresses to
49 ;; smaller addresses. pfw-this says copy ecx words from esi to edi
51 (inst shr ecx 2) ; fixnum to raw word count
52 (inst std) ; count down
54 (inst lea edi (make-ea :dword :base ebx :disp (- n-word-bytes)))
62 ;; Set the stack top to the last result.
63 (inst lea esp-tn (make-ea :dword :base edi :disp n-word-bytes))
65 ;; Load the register args.
74 ;; Handle the register arg cases.
77 (inst mov edx nil-value)
83 ONE-VALUE ; Note: we can get this, because the return-multiple vop
84 ; doesn't check for this case when size > speed.
93 (inst mov esi nil-value)
94 (inst lea esp-tn (make-ea :dword :base ebx :disp (* -2 n-word-bytes)))
102 (inst lea esp-tn (make-ea :dword :base ebx :disp (* -3 n-word-bytes)))
106 ;;;; TAIL-CALL-VARIABLE
108 ;;; For tail-call-variable, we have to copy the arguments from the end
109 ;;; of our stack frame (were args are produced) to the start of our
110 ;;; stack frame (were args are expected).
112 ;;; We take the function to call in EAX and a pointer to the arguments in
113 ;;; ESI. EBP says the same over the jump, and the old frame pointer is
114 ;;; still saved in the first stack slot. The return-pc is saved in
115 ;;; the second stack slot, so we have to push it to make it look like
116 ;;; we actually called. We also have to compute ECX from the difference
117 ;;; between ESI and the stack top.
118 #+sb-assembling ;; No vop for this one either.
119 (define-assembly-routine
121 (:return-style :none))
123 ((:temp eax unsigned-reg eax-offset)
124 (:temp ebx unsigned-reg ebx-offset)
125 (:temp ecx unsigned-reg ecx-offset)
126 (:temp edx unsigned-reg edx-offset)
127 (:temp edi unsigned-reg edi-offset)
128 (:temp esi unsigned-reg esi-offset))
130 ;; Calculate NARGS (as a fixnum)
132 (inst sub ecx esp-tn)
134 ;; Check for all the args fitting the registers.
135 (inst cmp ecx (fixnumize 3))
136 (inst jmp :le REGISTER-ARGS)
138 ;; Save the OLD-FP and RETURN-PC because the blit is going to trash
139 ;; those stack locations. Save the ECX, because the loop is going to
141 (pushw ebp-tn (frame-word-offset ocfp-save-offset))
142 (loadw ebx ebp-tn (frame-word-offset return-pc-save-offset))
145 ;; Do the blit. Because we are coping from smaller addresses to
146 ;; larger addresses, we have to start at the largest pair and work
148 (inst shr ecx 2) ; fixnum to raw words
149 (inst std) ; count down
150 (inst lea edi (make-ea :dword :base ebp-tn :disp (frame-byte-offset 0)))
151 (inst sub esi (fixnumize 1))
156 ;; Load the register arguments carefully.
157 (loadw edx ebp-tn (frame-word-offset ocfp-save-offset))
159 ;; Restore OLD-FP and ECX.
162 (popw ebp-tn (frame-word-offset ocfp-save-offset))
164 ;; Blow off the stack above the arguments.
165 (inst lea esp-tn (make-ea :dword :base edi :disp n-word-bytes))
167 ;; remaining register args
169 (loadw edx ebp-tn (frame-word-offset 0))
170 (loadw esi ebp-tn (frame-word-offset 2))
172 ;; Push the (saved) return-pc so it looks like we just called.
175 ;; And jump into the function.
176 (inst jmp (make-ea-for-object-slot eax closure-fun-slot fun-pointer-lowtag))
178 ;; All the arguments fit in registers, so load them.
184 ;; Clear most of the stack.
186 (make-ea :dword :base ebp-tn :disp (* -3 n-word-bytes)))
188 ;; Push the return-pc so it looks like we just called.
189 (pushw ebp-tn (frame-word-offset return-pc-save-offset))
192 (inst jmp (make-ea-for-object-slot eax closure-fun-slot fun-pointer-lowtag)))
194 (define-assembly-routine (throw
195 (:return-style :none))
196 ((:arg target (descriptor-reg any-reg) edx-offset)
197 (:arg start any-reg ebx-offset)
198 (:arg count any-reg ecx-offset)
199 (:temp catch any-reg eax-offset))
201 (declare (ignore start count))
203 (load-tl-symbol-value catch *current-catch-block*)
207 (let ((error (generate-error-code nil 'unseen-throw-tag-error target)))
208 (inst or catch catch) ; check for NULL pointer
211 (inst cmp target (make-ea-for-object-slot catch catch-block-tag-slot 0))
214 (loadw catch catch catch-block-previous-catch-slot)
219 ;; Here EAX points to catch block containing symbol pointed to by EDX.
220 (inst jmp (make-fixup 'unwind :assembly-routine)))
222 ;;;; non-local exit noise
225 (define-assembly-routine (unwind
226 (:return-style :none)
227 (:translate %continue-unwind)
228 (:policy :fast-safe))
229 ((:arg block (any-reg descriptor-reg) eax-offset)
230 (:arg start (any-reg descriptor-reg) ebx-offset)
231 (:arg count (any-reg descriptor-reg) ecx-offset)
232 (:temp uwp unsigned-reg esi-offset))
233 (declare (ignore start count))
235 (let ((error (generate-error-code nil 'invalid-unwind-error)))
236 (inst or block block) ; check for NULL pointer
239 (load-tl-symbol-value uwp *current-unwind-protect-block*)
241 ;; Does *CURRENT-UNWIND-PROTECT-BLOCK* match the value stored in
242 ;; argument's CURRENT-UWP-SLOT?
244 (make-ea-for-object-slot block unwind-block-current-uwp-slot 0))
245 ;; If a match, return to context in arg block.
246 (inst jmp :e DO-EXIT)
248 ;; Not a match - return to *CURRENT-UNWIND-PROTECT-BLOCK* context.
249 ;; Important! Must save (and return) the arg 'block' for later use!!
252 ;; Set next unwind protect context.
253 (loadw uwp uwp unwind-block-current-uwp-slot)
254 ;; we're about to reload ebp anyway, so let's borrow it here as a
255 ;; temporary. Hope this works
256 (store-tl-symbol-value uwp *current-unwind-protect-block* ebp-tn)
260 (loadw ebp-tn block unwind-block-current-cont-slot)
262 ;; Uwp-entry expects some things in known locations so that they can
263 ;; be saved on the stack: the block in edx-tn, start in ebx-tn, and
266 (inst jmp (make-ea-for-object-slot block unwind-block-entry-pc-slot 0)))
269 ;;;; Win32 non-local exit noise
272 (define-assembly-routine (unwind
273 (:return-style :none)
274 (:policy :fast-safe))
275 ((:arg block (any-reg descriptor-reg) eax-offset)
276 (:arg start (any-reg descriptor-reg) ebx-offset)
277 (:arg count (any-reg descriptor-reg) ecx-offset))
278 (declare (ignore start count))
280 (let ((error (generate-error-code nil 'invalid-unwind-error)))
281 (inst or block block) ; check for NULL pointer
284 ;; Save all our registers, as we're about to clobber them.
287 ;; Find the SEH frame surrounding our target.
288 (loadw ecx-tn block unwind-block-next-seh-frame-slot)
290 ;; This section copied from VOP CALL-OUT.
291 ;; Setup the NPX for C; all the FP registers need to be
292 ;; empty; pop them all.
296 ;; I'm unlikely to ever forget this again.
299 ;; Set up a bogus stack frame for RtlUnwind to pick its return
300 ;; address from. (Yes, this is how RtlUnwind works.)
301 (inst push (make-fixup 'win32-unwind-tail :assembly-routine))
303 (inst mov ebp-tn esp-tn)
305 ;; Actually call out for the unwind.
310 (inst call (make-fixup "RtlUnwind@16" :foreign)))
312 ;; We want no VOP for this one and for it to only happen on Win32
313 ;; targets. Hence the following disaster.
314 #!+#.(cl:if (cl:member sb-assembling cl:*features*) win32 '(or))
315 (define-assembly-routine
316 (win32-unwind-tail (:return-style :none))
317 ((:temp block unsigned-reg eax-offset))
319 ;; The unwind returns here. Had to use a VOP for this because
320 ;; PUSH won't accept a label as an argument.
322 ;; Clean up the bogus stack frame we pushed for the unwind.
324 (inst pop esi-tn) ;; Random scratch register.
326 ;; This section based on VOP CALL-OUT.
327 ;; Restore the NPX for lisp; ensure no regs are empty
334 ;; By now we've unwound all the UWP frames required, so we
335 ;; just jump to our target block.
336 (loadw ebp-tn block unwind-block-current-cont-slot)
338 ;; Nlx-entry expects the arg start in ebx-tn and the arg count
339 ;; in ecx-tn. Fortunately, that's where they are already.
340 (inst jmp (make-ea-for-object-slot block unwind-block-entry-pc-slot 0)))
343 ;;;; Win32 UWP block SEH interface.
345 ;; We want no VOP for this one and for it to only happen on Win32
346 ;; targets. Hence the following disaster.
347 #!+#.(cl:if (cl:member sb-assembling cl:*features*) win32 '(or))
348 (define-assembly-routine
349 (uwp-seh-handler (:return-style :none))
350 ((:temp block unsigned-reg eax-offset))
352 ;; We get called for any exception which happens within our
353 ;; dynamic contour that isn't handled below us, and for
356 ;; For the exceptions we just return ExceptionContinueSearch.
358 ;; Find the exception record.
359 (inst mov eax-tn (make-ea :dword :base esp-tn :disp 4))
361 ;; Check unwind flags.
362 (inst test (make-ea :byte :base eax-tn :disp 4) 6) ; EH_UNWINDING | EH_EXIT_UNWIND
364 ;; To see if we're unwinding or not.
365 (inst jmp :nz UNWINDING)
367 ;; We're not unwinding, so we're not interested.
368 (inst mov eax-tn 1) ;; exception-continue-search
371 ;; For the unwinds we establish a basic environment as per
372 ;; call_into_lisp, but without the extra SEH frame (the theory
373 ;; being that we're already in a Lisp SEH context), and invoke
374 ;; our UWP block to unwind itself.
376 ;; FIXME: Do we need to establish an SEH frame anyway? And do
377 ;; we need to do the same stack frame hackery for the debugger
378 ;; as we do for the main exception handler?
380 ;; When the UWP block calls %continue-unwind, we come back to
381 ;; the next assembly routine, below, which reinitializes for C
382 ;; and returns to the Win32 unwind machinery.
384 ;; If the UWP block sees fit to do a non-local exit, things
385 ;; Just Work, thanks to the Win32 API being sanely designed
386 ;; and our complying with it.
388 ;; We also must update *current-unwind-protect-block* before
389 ;; calling the cleanup function.
393 ;; Save all registers (overkill)
396 ;; Establish our stack frame.
397 (inst mov ebp-tn esp-tn)
399 ;; This section based on VOP CALL-OUT.
400 ;; Restore the NPX for lisp; ensure no regs are empty
404 ;; Find our unwind-block by way of our SEH frame.
405 (inst mov block (make-ea :dword :base ebp-tn :disp #x28))
406 (inst lea block (make-ea :dword :base block
407 :disp (- (* unwind-block-next-seh-frame-slot
410 ;; Update *CURRENT-UNWIND-PROTECT-BLOCK*.
411 (loadw ebx-tn block unwind-block-current-uwp-slot)
412 (store-tl-symbol-value ebx-tn *current-unwind-protect-block* ecx-tn)
414 ;; Uwp-entry expects some things in known locations so that they can
415 ;; be saved on the stack: the block in edx-tn, start in ebx-tn, and
416 ;; count in ecx-tn. We don't actually have any of that here, but we
417 ;; do need to have access to our own stack frame, so we hijack the
418 ;; known locations to cover our own state.
420 (inst xor ebx-tn ebx-tn)
421 (inst xor ecx-tn ecx-tn)
422 (inst mov ebx-tn ebp-tn)
423 (loadw ebp-tn block unwind-block-current-cont-slot)
424 (inst jmp (make-ea-for-object-slot block unwind-block-entry-pc-slot 0)))
427 (define-assembly-routine (continue-unwind
428 (:return-style :none)
429 (:translate %continue-unwind)
430 (:policy :fast-safe))
431 ((:arg block (any-reg descriptor-reg) eax-offset)
432 (:arg start (any-reg descriptor-reg) ebx-offset)
433 (:arg count (any-reg descriptor-reg) ecx-offset))
434 (declare (ignore block count))
435 ;; The args here are mostly ignored because we're using the
436 ;; win32 unwind mechanism and keep all that elsewhere. The
437 ;; exception is START, which we use to pass the saved EBP for
438 ;; our exception handler.
440 ;; "All" we have to do here is reload our EBP, reestablish a C
441 ;; environment, and return ExceptionContinueSearch. The OS
444 ;; Restore our frame pointer.
445 (inst mov esp-tn start)
447 ;; This section copied from VOP CALL-OUT.
448 ;; Setup the NPX for C; all the FP registers need to be
449 ;; empty; pop them all.
453 ;; I'm unlikely to ever forget this again.
456 ;; Restore our saved registers
460 (inst mov eax-tn 1) ;; exception-continue-search