aboutsummaryrefslogtreecommitdiffstats
path: root/erts/emulator/hipe/hipe_x86_glue.S
blob: 152c515fa7e022dceb6eafbd3736f41568fe525a (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
/*
 * %CopyrightBegin%

 *
 * Copyright Ericsson AB 2001-2011. All Rights Reserved.
 *
 * The contents of this file are subject to the Erlang Public License,
 * Version 1.1, (the "License"); you may not use this file except in
 * compliance with the License. You should have received a copy of the
 * Erlang Public License along with this software. If not, it can be
 * retrieved online at http://www.erlang.org/.
 *
 * Software distributed under the License is distributed on an "AS IS"
 * basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
 * the License for the specific language governing rights and limitations
 * under the License.
 *
 * %CopyrightEnd%
 */

#define ASM
#include "hipe_x86_asm.h"
#include "hipe_literals.h"
#include "hipe_mode_switch.h"

/*
 * Enter Erlang from C.
 * Create a new frame on the C stack.
 * Save C callee-save registers in the frame.
 * Retrieve the process pointer from the C parameters.
 * SWITCH_C_TO_ERLANG.
 *
 * Our C frame includes:
 * - 4*4 == 16 bytes for saving %edi, %esi, %ebx, and %ebp
 * - 6*4 == 24 bytes of parameter area for recursive calls
 *   to C BIFs: actual parameters are moved to it, not pushed
 * - 8 bytes to pad the frame to a multiple of 16 bytes,
 *   minus 4 bytes for the return address pushed by the caller.
 *   OSX requires 16-byte alignment of %esp at calls (for SSE2).
 */
#define ENTER_FROM_C		\
	/* create stack frame and save C callee-save registers in it */ \
	subl	$44, %esp;	\
	movl	%edi, 28(%esp);	\
	movl	%esi, 32(%esp);	\
	movl	%ebx, 36(%esp);	\
	movl	%ebp, 40(%esp);	\
	/* get the process pointer */	\
	movl	48(%esp), P;	\
	/* switch to native stack */	\
	SWITCH_C_TO_ERLANG

	TEXT

/*
 * int x86_call_to_native(Process *p);
 * Emulated code recursively calls native code.
 */
	.align	4
	GLOBAL(CSYM(x86_call_to_native))
	GLOBAL(ASYM(nbif_return))
CSYM(x86_call_to_native):
	ENTER_FROM_C
	/* get argument registers */
	LOAD_ARG_REGS
	/* call the target */
	NSP_CALL(*P_NCALLEE(P))
/*
 * We export this return address so that hipe_mode_switch() can discover
 * when native code tailcalls emulated code.
 *
 * This is where native code returns to emulated code.
 */
ASYM(nbif_return):
	movl	%eax, P_ARG0(P)			# save retval
	movl	$HIPE_MODE_SWITCH_RES_RETURN, %eax
/* FALLTHROUGH to .flush_exit
 *
 * Return to the calling C function with result token in %eax.
 *
 * .nosave_exit saves no state
 * .flush_exit saves cached P state
 * .suspend_exit also saves RA
 */
.suspend_exit:
	/* save RA, no-op on x86 */
.flush_exit:
	/* flush cached P state */
	SAVE_CACHED_STATE
.nosave_exit:
	/* switch to C stack */
	SWITCH_ERLANG_TO_C_QUICK
	/* restore C callee-save registers, drop frame, return */
	movl	28(%esp), %edi
	movl	32(%esp), %esi	# kills HP, if HP_IN_ESI is true
	movl	36(%esp), %ebx
	movl	40(%esp), %ebp	# kills P
	addl	$44, %esp
	ret

/*
 * Native code calls emulated code via a linker-generated
 * stub (hipe_x86_loader.erl) which should look as follows:
 *
 * stub for f/N:
 *	movl	$<f's BEAM code address>, P_BEAM_IP(P)
 *	movb	$<N>, P_ARITY(P)
 *	jmp	nbif_callemu
 *
 * XXX: Different stubs for different number of register parameters?
 */
	.align	4
	GLOBAL(ASYM(nbif_callemu))
ASYM(nbif_callemu):
	STORE_ARG_REGS
	movl	$HIPE_MODE_SWITCH_RES_CALL, %eax
	jmp	.suspend_exit

/*
 * nbif_apply
 */
	.align	4
	GLOBAL(ASYM(nbif_apply))
ASYM(nbif_apply):
	STORE_ARG_REGS
	movl	$HIPE_MODE_SWITCH_RES_APPLY, %eax
	jmp	.suspend_exit

/*
 * Native code calls an emulated-mode closure via a stub defined below.
 *
 * The closure is appended as the last actual parameter, and parameters
 * beyond the first few passed in registers are pushed onto the stack in
 * left-to-right order.
 * Hence, the location of the closure parameter only depends on the number
 * of parameters in registers, not the total number of parameters.
 */
#if X86_NR_ARG_REGS == 5
	.align	4
	GLOBAL(ASYM(nbif_ccallemu5))
ASYM(nbif_ccallemu5):
	movl	ARG4, P_ARG4(P)
	movl	4(NSP), ARG4
	/*FALLTHROUGH*/
#endif

#if X86_NR_ARG_REGS >= 4
	.align	4
	GLOBAL(ASYM(nbif_ccallemu4))
ASYM(nbif_ccallemu4):
	movl	ARG3, P_ARG3(P)
#if X86_NR_ARG_REGS > 4
	movl	ARG4, ARG3
#else
	movl	4(NSP), ARG3
#endif
	/*FALLTHROUGH*/
#endif

#if X86_NR_ARG_REGS >= 3
	.align	4
	GLOBAL(ASYM(nbif_ccallemu3))
ASYM(nbif_ccallemu3):
	movl	ARG2, P_ARG2(P)
#if X86_NR_ARG_REGS > 3
	movl	ARG3, ARG2
#else
	movl	4(NSP), ARG2
#endif
	/*FALLTHROUGH*/
#endif

#if X86_NR_ARG_REGS >= 2
	.align	4
	GLOBAL(ASYM(nbif_ccallemu2))
ASYM(nbif_ccallemu2):
	movl	ARG1, P_ARG1(P)
#if X86_NR_ARG_REGS > 2
	movl	ARG2, ARG1
#else
	movl	4(NSP), ARG1
#endif
	/*FALLTHROUGH*/
#endif

#if X86_NR_ARG_REGS >= 1
	.align	4
	GLOBAL(ASYM(nbif_ccallemu1))
ASYM(nbif_ccallemu1):
	movl	ARG0, P_ARG0(P)
#if X86_NR_ARG_REGS > 1
	movl	ARG1, ARG0
#else
	movl	4(NSP), ARG0
#endif
	/*FALLTHROUGH*/
#endif

	.align	4
	GLOBAL(ASYM(nbif_ccallemu0))
ASYM(nbif_ccallemu0):
	/* We use %eax not ARG0 here because ARG0 is not
	   defined when NR_ARG_REGS == 0. */
#if X86_NR_ARG_REGS == 0
	movl	4(NSP), %eax
#endif
	movl	%eax, P_CLOSURE(P)
	movl	$HIPE_MODE_SWITCH_RES_CALL_CLOSURE, %eax
	jmp	.suspend_exit

/*
 * This is where native code suspends.
 */
	.align	4
	GLOBAL(ASYM(nbif_suspend_0))
ASYM(nbif_suspend_0):
	movl	$HIPE_MODE_SWITCH_RES_SUSPEND, %eax
	jmp	.suspend_exit

/*
 * Suspend from a receive (waiting for a message)
 */
	.align	4
	GLOBAL(ASYM(nbif_suspend_msg))
ASYM(nbif_suspend_msg):
	movl	$HIPE_MODE_SWITCH_RES_WAIT, %eax
	jmp	.suspend_exit

/*
 * Suspend from a receive with a timeout (waiting for a message)
 *	if (!(p->flags & F_TIMO)) { suspend }
 *	else { return 0; }
 */
	.align	4
	GLOBAL(ASYM(nbif_suspend_msg_timeout))
ASYM(nbif_suspend_msg_timeout):
	movl	P_FLAGS(P), %eax
	/* this relies on F_TIMO (1<<2) fitting in a byte */
	testb	$F_TIMO, %al			# F_TIMO set?
	jz	.no_timeout			# if not set, suspend
	/* timeout has occurred */
	xorl	%eax, %eax			# return 0 to signal timeout
	NSP_RET0
.no_timeout:
	movl	$HIPE_MODE_SWITCH_RES_WAIT_TIMEOUT, %eax
	jmp	.suspend_exit

/*
 * int x86_return_to_native(Process *p);
 * Emulated code returns to its native code caller.
 */
	.align	4
	GLOBAL(CSYM(x86_return_to_native))
CSYM(x86_return_to_native):
	ENTER_FROM_C
	/* get return value */
	movl	P_ARG0(P), %eax
	/*
	 * Return using the stacked return address.
	 * The parameters were popped at the original native-to-emulated
	 * call (hipe_call_from_native_is_recursive), so a plain ret suffices.
	 */
	NSP_RET0

/*
 * int x86_tailcall_to_native(Process *p);
 * Emulated code tailcalls native code.
 */
	.align	4
	GLOBAL(CSYM(x86_tailcall_to_native))
CSYM(x86_tailcall_to_native):
	ENTER_FROM_C
	/* get argument registers */
	LOAD_ARG_REGS
	/* jump to the target label */
	jmp	*P_NCALLEE(P)

/*
 * int x86_throw_to_native(Process *p);
 * Emulated code throws an exception to its native code caller.
 */
	.align	4
	GLOBAL(CSYM(x86_throw_to_native))
CSYM(x86_throw_to_native):
	ENTER_FROM_C
	/* invoke the handler */
	jmp	*P_NCALLEE(P)		# set by hipe_find_handler()

/*
 * This is the default exception handler for native code.
 */
	.align	4
	GLOBAL(ASYM(nbif_fail))
ASYM(nbif_fail):
	movl	$HIPE_MODE_SWITCH_RES_THROW, %eax
	jmp	.flush_exit
	
	GLOBAL(nbif_0_gc_after_bif)
	GLOBAL(nbif_1_gc_after_bif)
	GLOBAL(nbif_2_gc_after_bif)
	GLOBAL(nbif_3_gc_after_bif)
	.align	4
nbif_0_gc_after_bif:
	xorl	%edx, %edx
	jmp	.gc_after_bif
	.align	4
nbif_1_gc_after_bif:
	movl	$1, %edx
	jmp	.gc_after_bif
	.align	4
nbif_2_gc_after_bif:
	movl	$2, %edx
	jmp	.gc_after_bif
	.align	4
nbif_3_gc_after_bif:
	movl	$3, %edx
	/*FALLTHROUGH*/
	.align	4
.gc_after_bif:
	movl	%edx, P_NARITY(P)
	subl	$(32-4), %esp
	movl	P, (%esp)
	movl	%eax, 4(%esp)
	movl	$0, 8(%esp)		# Pass NULL in regs
	movl	$0, 12(%esp)		# Pass 0 in arity
	call	CSYM(erts_gc_after_bif_call)
	addl	$(32-4), %esp
	movl	$0, P_NARITY(P)
	ret

/*
 * We end up here when a BIF called from native signals an
 * exceptional condition.
 * The stack/heap registers were just read from P.
 */
	GLOBAL(nbif_0_simple_exception)
	GLOBAL(nbif_1_simple_exception)
	GLOBAL(nbif_2_simple_exception)
	GLOBAL(nbif_3_simple_exception)
	.align	4
nbif_0_simple_exception:
	xorl	%eax, %eax
	jmp	.nbif_simple_exception
	.align	4
nbif_1_simple_exception:
	movl	$1, %eax
	jmp	.nbif_simple_exception
	.align	4
nbif_2_simple_exception:
	movl	$2, %eax
	jmp	.nbif_simple_exception
	.align	4
nbif_3_simple_exception:
	movl	$3, %eax
	/*FALLTHROUGH*/
	.align	4
.nbif_simple_exception:
	cmpl	$FREASON_TRAP, P_FREASON(P)
	je	.handle_trap
	/*
	 * Find and invoke catch handler (it must exist).
	 * The stack/heap registers were just read from P.
	 * - %eax should contain the current call's arity
	 */
	movl	%eax, P_NARITY(P)
	/* find and prepare to invoke the handler */
	SWITCH_ERLANG_TO_C_QUICK	# The cached state is clean and need not be saved.
	movl	P, (%esp)
	call	CSYM(hipe_handle_exception)	# Note: hipe_handle_exception() conses
	SWITCH_C_TO_ERLANG		# %esp updated by hipe_find_handler()
	/* now invoke the handler */
	jmp	*P_NCALLEE(P)		# set by hipe_find_handler()

	/*
	 * A BIF failed with freason TRAP:
	 * - the BIF's arity is in %eax
	 * - the native heap/stack/reds registers are saved in P
	 */
.handle_trap:
	movl	%eax, P_NARITY(P)
	movl	$HIPE_MODE_SWITCH_RES_TRAP, %eax
	jmp	.nosave_exit

/*
 * nbif_stack_trap_ra: trap return address for maintaining
 * the gray/white stack boundary
 */
	GLOBAL(ASYM(nbif_stack_trap_ra))
	.align	4
ASYM(nbif_stack_trap_ra):		# a return address, not a function
	# This only handles a single return value.
	# If we have more, we need to save them in the PCB.
	movl	%eax, TEMP_RV		# save retval
	SWITCH_ERLANG_TO_C_QUICK
	movl	P, (%esp)
	call	CSYM(hipe_handle_stack_trap)	# must not cons; preserves TEMP_RV
	movl	%eax, %edx		# original RA
	SWITCH_C_TO_ERLANG_QUICK
	movl	TEMP_RV, %eax		# restore retval
	jmp	*%edx			# resume at original RA

/*
 * nbif_inc_stack_0
 */
	.align	4
	GLOBAL(ASYM(nbif_inc_stack_0))
ASYM(nbif_inc_stack_0):
	SWITCH_ERLANG_TO_C_QUICK
	STORE_CALLER_SAVE
	movl	P, (%esp)
	# hipe_inc_nstack reads and writes NSP and NSP_LIMIT,
	# but does not access HP or FCALLS (or the non-x86 NRA).
	call	CSYM(hipe_inc_nstack)
	LOAD_CALLER_SAVE
	SWITCH_C_TO_ERLANG_QUICK
	NSP_RET0

#if defined(__linux__) && defined(__ELF__)
.section .note.GNU-stack,"",%progbits
#endif