2 * tramp-arm.c: JIT trampoline code for ARM
5 * Paolo Molaro (lupus@ximian.com)
7 * (C) 2001-2003 Ximian, Inc.
8 * Copyright 2003-2011 Novell Inc
9 * Copyright 2011 Xamarin Inc
15 #include <mono/metadata/appdomain.h>
16 #include <mono/metadata/marshal.h>
17 #include <mono/metadata/tabledefs.h>
18 #include <mono/arch/arm/arm-codegen.h>
23 #define ALIGN_TO(val,align) ((((guint64)val) + ((align) - 1)) & ~((align) - 1))
25 static guint8* nullified_class_init_trampoline;
28 mono_arch_patch_callsite (guint8 *method_start, guint8 *code_ptr, guint8 *addr)
30 guint32 *code = (guint32*)code_ptr;
32 /* This is the 'bl' or the 'mov pc' instruction */
36 * Note that methods are called also with the bl opcode.
38 if ((((*code) >> 25) & 7) == 5) {
39 /*g_print ("direct patching\n");*/
40 arm_patch ((guint8*)code, addr);
41 mono_arch_flush_icache ((guint8*)code, 4);
45 if ((((*code) >> 20) & 0xFF) == 0x12) {
46 /*g_print ("patching bx\n");*/
47 arm_patch ((guint8*)code, addr);
48 mono_arch_flush_icache ((guint8*)(code - 2), 4);
52 g_assert_not_reached ();
56 mono_arch_patch_plt_entry (guint8 *code, gpointer *got, mgreg_t *regs, guint8 *addr)
60 /* Patch the jump table entry used by the plt entry */
61 if (*(guint32*)code == 0xe59fc000) {
62 /* ARM_LDR_IMM (code, ARMREG_IP, ARMREG_PC, 0); */
63 guint32 offset = ((guint32*)code)[2];
65 jump_entry = code + offset + 12;
66 } else if (*(guint16*)(code - 4) == 0xf8df) {
68 * Thumb PLT entry, begins with ldr.w ip, [pc, #8], code points to entry + 4, see
69 * mono_arm_get_thumb_plt_entry ().
74 offset = *(guint32*)(code + 12);
75 jump_entry = code + offset + 8;
77 g_assert_not_reached ();
80 *(guint8**)jump_entry = addr;
84 mono_arch_nullify_class_init_trampoline (guint8 *code, mgreg_t *regs)
86 mono_arch_patch_callsite (NULL, code, nullified_class_init_trampoline);
90 mono_arch_nullify_plt_entry (guint8 *code, mgreg_t *regs)
92 if (mono_aot_only && !nullified_class_init_trampoline)
93 nullified_class_init_trampoline = mono_aot_get_trampoline ("nullified_class_init_trampoline");
95 mono_arch_patch_plt_entry (code, NULL, regs, nullified_class_init_trampoline);
100 #define arm_is_imm12(v) ((int)(v) > -4096 && (int)(v) < 4096)
103 * Return the instruction to jump from code to target, 0 if not
104 * reachable with a single instruction
107 branch_for_target_reachable (guint8 *branch, guint8 *target)
109 gint diff = target - branch - 8;
110 g_assert ((diff & 3) == 0);
112 if (diff <= 33554431)
113 return (ARMCOND_AL << ARMCOND_SHIFT) | (ARM_BR_TAG) | (diff >> 2);
115 /* diff between 0 and -33554432 */
116 if (diff >= -33554432)
117 return (ARMCOND_AL << ARMCOND_SHIFT) | (ARM_BR_TAG) | ((diff >> 2) & ~0xff000000);
122 static inline guint8*
123 emit_bx (guint8* code, int reg)
125 if (mono_arm_thumb_supported ())
128 ARM_MOV_REG_REG (code, ARMREG_PC, reg);
132 /* Stack size for trampoline function
134 #define STACK ALIGN_TO (sizeof (MonoLMF), 8)
136 /* Method-specific trampoline code fragment size */
137 #define METHOD_TRAMPOLINE_SIZE 64
139 /* Jump-specific trampoline code fragment size */
140 #define JUMP_TRAMPOLINE_SIZE 64
143 mono_arch_create_generic_trampoline (MonoTrampolineType tramp_type, MonoTrampInfo **info, gboolean aot)
145 guint8 *buf, *code = NULL;
146 guint8 *load_get_lmf_addr, *load_trampoline;
148 int cfa_offset, lmf_offset, regsave_size, lr_offset;
149 GSList *unwind_ops = NULL;
150 MonoJumpInfo *ji = NULL;
153 /* Now we'll create in 'buf' the ARM trampoline code. This
154 is the trampoline code common to all methods */
157 code = buf = mono_global_codeman_reserve (buf_len);
160 * At this point lr points to the specific arg and sp points to the saved
161 * regs on the stack (all but PC and SP). The original LR value has been
162 * saved as sp + LR_OFFSET by the push in the specific trampoline
165 /* The offset of lmf inside the stack frame */
166 lmf_offset = STACK - sizeof (MonoLMF);
167 /* The size of the area already allocated by the push in the specific trampoline */
168 regsave_size = 14 * sizeof (mgreg_t);
169 /* The offset where lr was saved inside the regsave area */
170 lr_offset = 13 * sizeof (mgreg_t);
172 // FIXME: Finish the unwind info, the current info allows us to unwind
173 // when the trampoline is not in the epilog
175 // CFA = SP + (num registers pushed) * 4
176 cfa_offset = 14 * sizeof (mgreg_t);
177 mono_add_unwind_op_def_cfa (unwind_ops, code, buf, ARMREG_SP, cfa_offset);
178 // PC saved at sp+LR_OFFSET
179 mono_add_unwind_op_offset (unwind_ops, code, buf, ARMREG_LR, -4);
181 if (aot && tramp_type != MONO_TRAMPOLINE_GENERIC_CLASS_INIT) {
183 * For page trampolines the data is in r1, so just move it, otherwise use the got slot as below.
184 * The trampoline contains a pc-relative offset to the got slot
185 * preceeding the got slot where the value is stored. The offset can be
189 ARM_MOV_REG_REG (code, ARMREG_V2, ARMREG_R1);
191 ARM_LDR_IMM (code, ARMREG_V2, ARMREG_LR, 0);
192 ARM_ADD_REG_IMM (code, ARMREG_V2, ARMREG_V2, 4, 0);
193 ARM_LDR_REG_REG (code, ARMREG_V2, ARMREG_V2, ARMREG_LR);
196 if (tramp_type != MONO_TRAMPOLINE_GENERIC_CLASS_INIT)
197 ARM_LDR_IMM (code, ARMREG_V2, ARMREG_LR, 0);
199 ARM_MOV_REG_REG (code, ARMREG_V2, MONO_ARCH_VTABLE_REG);
201 ARM_LDR_IMM (code, ARMREG_V3, ARMREG_SP, lr_offset);
203 /* ok, now we can continue with the MonoLMF setup, mostly untouched
204 * from emit_prolog in mini-arm.c
205 * This is a synthetized call to mono_get_lmf_addr ()
208 ji = mono_patch_info_list_prepend (ji, code - buf, MONO_PATCH_INFO_JIT_ICALL_ADDR, "mono_get_lmf_addr");
209 ARM_LDR_IMM (code, ARMREG_R0, ARMREG_PC, 0);
211 *(gpointer*)code = NULL;
213 ARM_LDR_REG_REG (code, ARMREG_R0, ARMREG_PC, ARMREG_R0);
215 load_get_lmf_addr = code;
218 ARM_MOV_REG_REG (code, ARMREG_LR, ARMREG_PC);
219 code = emit_bx (code, ARMREG_R0);
221 /* we build the MonoLMF structure on the stack - see mini-arm.h
222 * The pointer to the struct is put in r1.
223 * the iregs array is already allocated on the stack by push.
225 ARM_SUB_REG_IMM8 (code, ARMREG_SP, ARMREG_SP, STACK - regsave_size);
226 cfa_offset += STACK - regsave_size;
227 mono_add_unwind_op_def_cfa_offset (unwind_ops, code, buf, cfa_offset);
229 ARM_ADD_REG_IMM8 (code, ARMREG_V1, ARMREG_SP, STACK - sizeof (MonoLMF));
232 * The stack now looks like:
234 * v1 -> <rest of LMF>
238 /* r0 is the result from mono_get_lmf_addr () */
239 ARM_STR_IMM (code, ARMREG_R0, ARMREG_V1, G_STRUCT_OFFSET (MonoLMF, lmf_addr));
240 /* new_lmf->previous_lmf = *lmf_addr */
241 ARM_LDR_IMM (code, ARMREG_R2, ARMREG_R0, G_STRUCT_OFFSET (MonoLMF, previous_lmf));
242 ARM_STR_IMM (code, ARMREG_R2, ARMREG_V1, G_STRUCT_OFFSET (MonoLMF, previous_lmf));
243 /* *(lmf_addr) = r1 */
244 ARM_STR_IMM (code, ARMREG_V1, ARMREG_R0, G_STRUCT_OFFSET (MonoLMF, previous_lmf));
245 /* save method info (it's in v2) */
246 if ((tramp_type == MONO_TRAMPOLINE_JIT) || (tramp_type == MONO_TRAMPOLINE_JUMP))
247 ARM_STR_IMM (code, ARMREG_V2, ARMREG_V1, G_STRUCT_OFFSET (MonoLMF, method));
249 ARM_MOV_REG_IMM8 (code, ARMREG_R2, 0);
250 ARM_STR_IMM (code, ARMREG_R2, ARMREG_V1, G_STRUCT_OFFSET (MonoLMF, method));
253 ARM_ADD_REG_IMM8 (code, ARMREG_R2, ARMREG_SP, cfa_offset);
254 ARM_STR_IMM (code, ARMREG_R2, ARMREG_V1, G_STRUCT_OFFSET (MonoLMF, sp));
256 ARM_LDR_IMM (code, ARMREG_R2, ARMREG_V1, (G_STRUCT_OFFSET (MonoLMF, iregs) + ARMREG_FP*4));
257 ARM_STR_IMM (code, ARMREG_R2, ARMREG_V1, G_STRUCT_OFFSET (MonoLMF, fp));
258 /* save the IP (caller ip) */
259 if (tramp_type == MONO_TRAMPOLINE_JUMP) {
260 ARM_MOV_REG_IMM8 (code, ARMREG_R2, 0);
262 ARM_LDR_IMM (code, ARMREG_R2, ARMREG_V1, (G_STRUCT_OFFSET (MonoLMF, iregs) + 13*4));
264 ARM_STR_IMM (code, ARMREG_R2, ARMREG_V1, G_STRUCT_OFFSET (MonoLMF, ip));
267 * Now we're ready to call xxx_trampoline ().
269 /* Arg 1: the saved registers */
270 ARM_ADD_REG_IMM8 (code, ARMREG_R0, ARMREG_V1, G_STRUCT_OFFSET (MonoLMF, iregs));
272 /* Arg 2: code (next address to the instruction that called us) */
273 if (tramp_type == MONO_TRAMPOLINE_JUMP) {
274 ARM_MOV_REG_IMM8 (code, ARMREG_R1, 0);
276 ARM_MOV_REG_REG (code, ARMREG_R1, ARMREG_V3);
279 /* Arg 3: the specific argument, stored in v2
281 ARM_MOV_REG_REG (code, ARMREG_R2, ARMREG_V2);
284 char *icall_name = g_strdup_printf ("trampoline_func_%d", tramp_type);
285 ji = mono_patch_info_list_prepend (ji, code - buf, MONO_PATCH_INFO_JIT_ICALL_ADDR, icall_name);
286 ARM_LDR_IMM (code, ARMREG_IP, ARMREG_PC, 0);
288 *(gpointer*)code = NULL;
290 ARM_LDR_REG_REG (code, ARMREG_IP, ARMREG_PC, ARMREG_IP);
292 load_trampoline = code;
296 ARM_MOV_REG_REG (code, ARMREG_LR, ARMREG_PC);
297 code = emit_bx (code, ARMREG_IP);
299 /* OK, code address is now on r0. Move it to the place on the stack
300 * where IP was saved (it is now no more useful to us and it can be
301 * clobbered). This way we can just restore all the regs in one inst
304 ARM_STR_IMM (code, ARMREG_R0, ARMREG_V1, G_STRUCT_OFFSET (MonoLMF, iregs) + (ARMREG_R12 * sizeof (mgreg_t)));
306 /* Check for thread interruption */
307 /* This is not perf critical code so no need to check the interrupt flag */
309 * Have to call the _force_ variant, since there could be a protected wrapper on the top of the stack.
312 ji = mono_patch_info_list_prepend (ji, code - buf, MONO_PATCH_INFO_JIT_ICALL_ADDR, "mono_thread_force_interruption_checkpoint");
313 ARM_LDR_IMM (code, ARMREG_IP, ARMREG_PC, 0);
315 *(gpointer*)code = NULL;
317 ARM_LDR_REG_REG (code, ARMREG_IP, ARMREG_PC, ARMREG_IP);
319 ARM_LDR_IMM (code, ARMREG_IP, ARMREG_PC, 0);
321 *(gpointer*)code = mono_thread_force_interruption_checkpoint;
324 ARM_MOV_REG_REG (code, ARMREG_LR, ARMREG_PC);
325 code = emit_bx (code, ARMREG_IP);
328 * Now we restore the MonoLMF (see emit_epilogue in mini-arm.c)
329 * and the rest of the registers, so the method called will see
330 * the same state as before we executed.
332 /* ip = previous_lmf */
333 ARM_LDR_IMM (code, ARMREG_IP, ARMREG_V1, G_STRUCT_OFFSET (MonoLMF, previous_lmf));
335 ARM_LDR_IMM (code, ARMREG_LR, ARMREG_V1, G_STRUCT_OFFSET (MonoLMF, lmf_addr));
336 /* *(lmf_addr) = previous_lmf */
337 ARM_STR_IMM (code, ARMREG_IP, ARMREG_LR, G_STRUCT_OFFSET (MonoLMF, previous_lmf));
339 /* Non-standard function epilogue. Instead of doing a proper
340 * return, we just jump to the compiled code.
342 /* Restore the registers and jump to the code:
343 * Note that IP has been conveniently set to the method addr.
345 ARM_ADD_REG_IMM8 (code, ARMREG_SP, ARMREG_SP, STACK - regsave_size);
346 ARM_POP_NWB (code, 0x5fff);
347 if (tramp_type == MONO_TRAMPOLINE_RGCTX_LAZY_FETCH)
348 ARM_MOV_REG_REG (code, ARMREG_R0, ARMREG_IP);
349 ARM_ADD_REG_IMM8 (code, ARMREG_SP, ARMREG_SP, regsave_size);
350 if ((tramp_type == MONO_TRAMPOLINE_CLASS_INIT) || (tramp_type == MONO_TRAMPOLINE_GENERIC_CLASS_INIT) || (tramp_type == MONO_TRAMPOLINE_RGCTX_LAZY_FETCH))
351 code = emit_bx (code, ARMREG_LR);
353 code = emit_bx (code, ARMREG_IP);
355 constants = (gpointer*)code;
356 constants [0] = mono_get_lmf_addr;
357 constants [1] = (gpointer)mono_get_trampoline_func (tramp_type);
360 /* backpatch by emitting the missing instructions skipped above */
361 ARM_LDR_IMM (load_get_lmf_addr, ARMREG_R0, ARMREG_PC, (code - load_get_lmf_addr - 8));
362 ARM_LDR_IMM (load_trampoline, ARMREG_IP, ARMREG_PC, (code + 4 - load_trampoline - 8));
367 /* Flush instruction cache, since we've generated code */
368 mono_arch_flush_icache (buf, code - buf);
371 g_assert ((code - buf) <= buf_len);
373 if (tramp_type == MONO_TRAMPOLINE_CLASS_INIT)
374 /* Initialize the nullified class init trampoline used in the AOT case */
375 nullified_class_init_trampoline = mono_arch_get_nullified_class_init_trampoline (NULL);
378 *info = mono_tramp_info_create (mono_get_generic_trampoline_name (tramp_type), buf, code - buf, ji, unwind_ops);
384 mono_arch_get_nullified_class_init_trampoline (MonoTrampInfo **info)
388 code = buf = mono_global_codeman_reserve (16);
390 code = emit_bx (code, ARMREG_LR);
392 mono_arch_flush_icache (buf, code - buf);
395 *info = mono_tramp_info_create (g_strdup_printf ("nullified_class_init_trampoline"), buf, code - buf, NULL, NULL);
400 #define SPEC_TRAMP_SIZE 24
403 mono_arch_create_specific_trampoline (gpointer arg1, MonoTrampolineType tramp_type, MonoDomain *domain, guint32 *code_len)
405 guint8 *code, *buf, *tramp;
407 guint32 short_branch, size = SPEC_TRAMP_SIZE;
409 tramp = mono_get_trampoline_code (tramp_type);
411 mono_domain_lock (domain);
412 code = buf = mono_domain_code_reserve_align (domain, size, 4);
413 if ((short_branch = branch_for_target_reachable (code + 4, tramp))) {
415 mono_domain_code_commit (domain, code, SPEC_TRAMP_SIZE, size);
417 mono_domain_unlock (domain);
419 /* we could reduce this to 12 bytes if tramp is within reach:
423 * The called code can access method using the lr register
424 * A 20 byte sequence could be:
426 * ARM_MOV_REG_REG (lr, pc)
427 * ARM_LDR_IMM (pc, pc, 0)
431 /* We save all the registers, except PC and SP */
432 ARM_PUSH (code, 0x5fff);
434 constants = (gpointer*)code;
435 constants [0] = GUINT_TO_POINTER (short_branch | (1 << 24));
436 constants [1] = arg1;
439 ARM_LDR_IMM (code, ARMREG_R1, ARMREG_PC, 8); /* temp reg */
440 ARM_MOV_REG_REG (code, ARMREG_LR, ARMREG_PC);
441 code = emit_bx (code, ARMREG_R1);
443 constants = (gpointer*)code;
444 constants [0] = arg1;
445 constants [1] = tramp;
449 /* Flush instruction cache, since we've generated code */
450 mono_arch_flush_icache (buf, code - buf);
452 g_assert ((code - buf) <= size);
455 *code_len = code - buf;
461 * mono_arch_get_unbox_trampoline:
463 * @addr: pointer to native code for @m
465 * when value type methods are called through the vtable we need to unbox the
466 * this argument. This method returns a pointer to a trampoline which does
467 * unboxing before calling the method
470 mono_arch_get_unbox_trampoline (MonoMethod *m, gpointer addr)
472 guint8 *code, *start;
473 MonoDomain *domain = mono_domain_get ();
475 start = code = mono_domain_code_reserve (domain, 16);
477 ARM_LDR_IMM (code, ARMREG_IP, ARMREG_PC, 4);
478 ARM_ADD_REG_IMM8 (code, ARMREG_R0, ARMREG_R0, sizeof (MonoObject));
479 code = emit_bx (code, ARMREG_IP);
480 *(guint32*)code = (guint32)addr;
482 mono_arch_flush_icache (start, code - start);
483 g_assert ((code - start) <= 16);
484 /*g_print ("unbox trampoline at %d for %s:%s\n", this_pos, m->klass->name, m->name);
485 g_print ("unbox code is at %p for method at %p\n", start, addr);*/
491 mono_arch_get_static_rgctx_trampoline (MonoMethod *m, MonoMethodRuntimeGenericContext *mrgctx, gpointer addr)
493 guint8 *code, *start;
496 MonoDomain *domain = mono_domain_get ();
500 start = code = mono_domain_code_reserve (domain, buf_len);
502 ARM_LDR_IMM (code, MONO_ARCH_RGCTX_REG, ARMREG_PC, 0);
503 ARM_LDR_IMM (code, ARMREG_PC, ARMREG_PC, 0);
504 *(guint32*)code = (guint32)mrgctx;
506 *(guint32*)code = (guint32)addr;
509 g_assert ((code - start) <= buf_len);
511 mono_arch_flush_icache (start, code - start);
517 mono_arch_create_rgctx_lazy_fetch_trampoline (guint32 slot, MonoTrampInfo **info, gboolean aot)
523 guint8 **rgctx_null_jumps;
527 MonoJumpInfo *ji = NULL;
528 GSList *unwind_ops = NULL;
530 mrgctx = MONO_RGCTX_SLOT_IS_MRGCTX (slot);
531 index = MONO_RGCTX_SLOT_INDEX (slot);
533 index += MONO_SIZEOF_METHOD_RUNTIME_GENERIC_CONTEXT / sizeof (gpointer);
534 for (depth = 0; ; ++depth) {
535 int size = mono_class_rgctx_get_array_size (depth, mrgctx);
537 if (index < size - 1)
542 tramp_size = 64 + 16 * depth;
544 code = buf = mono_global_codeman_reserve (tramp_size);
546 mono_add_unwind_op_def_cfa (unwind_ops, code, buf, ARMREG_SP, 0);
548 rgctx_null_jumps = g_malloc (sizeof (guint8*) * (depth + 2));
551 /* The vtable/mrgctx is in R0 */
552 g_assert (MONO_ARCH_VTABLE_REG == ARMREG_R0);
556 ARM_MOV_REG_REG (code, ARMREG_R1, ARMREG_R0);
558 /* load rgctx ptr from vtable */
559 g_assert (arm_is_imm12 (G_STRUCT_OFFSET (MonoVTable, runtime_generic_context)));
560 ARM_LDR_IMM (code, ARMREG_R1, ARMREG_R0, G_STRUCT_OFFSET (MonoVTable, runtime_generic_context));
561 /* is the rgctx ptr null? */
562 ARM_CMP_REG_IMM (code, ARMREG_R1, 0, 0);
563 /* if yes, jump to actual trampoline */
564 rgctx_null_jumps [njumps ++] = code;
565 ARM_B_COND (code, ARMCOND_EQ, 0);
568 for (i = 0; i < depth; ++i) {
569 /* load ptr to next array */
570 if (mrgctx && i == 0) {
571 g_assert (arm_is_imm12 (MONO_SIZEOF_METHOD_RUNTIME_GENERIC_CONTEXT));
572 ARM_LDR_IMM (code, ARMREG_R1, ARMREG_R1, MONO_SIZEOF_METHOD_RUNTIME_GENERIC_CONTEXT);
574 ARM_LDR_IMM (code, ARMREG_R1, ARMREG_R1, 0);
576 /* is the ptr null? */
577 ARM_CMP_REG_IMM (code, ARMREG_R1, 0, 0);
578 /* if yes, jump to actual trampoline */
579 rgctx_null_jumps [njumps ++] = code;
580 ARM_B_COND (code, ARMCOND_EQ, 0);
584 code = mono_arm_emit_load_imm (code, ARMREG_R2, sizeof (gpointer) * (index + 1));
585 ARM_LDR_REG_REG (code, ARMREG_R1, ARMREG_R1, ARMREG_R2);
586 /* is the slot null? */
587 ARM_CMP_REG_IMM (code, ARMREG_R1, 0, 0);
588 /* if yes, jump to actual trampoline */
589 rgctx_null_jumps [njumps ++] = code;
590 ARM_B_COND (code, ARMCOND_EQ, 0);
591 /* otherwise return, result is in R1 */
592 ARM_MOV_REG_REG (code, ARMREG_R0, ARMREG_R1);
593 code = emit_bx (code, ARMREG_LR);
595 g_assert (njumps <= depth + 2);
596 for (i = 0; i < njumps; ++i)
597 arm_patch (rgctx_null_jumps [i], code);
599 g_free (rgctx_null_jumps);
603 /* The vtable/mrgctx is still in R0 */
606 ji = mono_patch_info_list_prepend (ji, code - buf, MONO_PATCH_INFO_JIT_ICALL_ADDR, g_strdup_printf ("specific_trampoline_lazy_fetch_%u", slot));
607 ARM_LDR_IMM (code, ARMREG_R1, ARMREG_PC, 0);
609 *(gpointer*)code = NULL;
611 ARM_LDR_REG_REG (code, ARMREG_PC, ARMREG_PC, ARMREG_R1);
613 tramp = mono_arch_create_specific_trampoline (GUINT_TO_POINTER (slot), MONO_TRAMPOLINE_RGCTX_LAZY_FETCH, mono_get_root_domain (), &code_len);
615 /* Jump to the actual trampoline */
616 ARM_LDR_IMM (code, ARMREG_R1, ARMREG_PC, 0); /* temp reg */
617 code = emit_bx (code, ARMREG_R1);
618 *(gpointer*)code = tramp;
622 mono_arch_flush_icache (buf, code - buf);
624 g_assert (code - buf <= tramp_size);
627 *info = mono_tramp_info_create (mono_get_rgctx_fetch_trampoline_name (slot), buf, code - buf, ji, unwind_ops);
633 mono_arch_create_general_rgctx_lazy_fetch_trampoline (MonoTrampInfo **info, gboolean aot)
637 MonoJumpInfo *ji = NULL;
638 GSList *unwind_ops = NULL;
644 code = buf = mono_global_codeman_reserve (tramp_size);
646 mono_add_unwind_op_def_cfa (unwind_ops, code, buf, ARMREG_SP, 0);
648 // FIXME: Currently, we always go to the slow path.
649 /* Load trampoline addr */
650 ARM_LDR_IMM (code, ARMREG_R1, MONO_ARCH_RGCTX_REG, 4);
651 /* The vtable/mrgctx is in R0 */
652 g_assert (MONO_ARCH_VTABLE_REG == ARMREG_R0);
653 code = emit_bx (code, ARMREG_R1);
655 mono_arch_flush_icache (buf, code - buf);
657 g_assert (code - buf <= tramp_size);
660 *info = mono_tramp_info_create ("rgctx_fetch_trampoline_general", buf, code - buf, ji, unwind_ops);
665 #define arm_is_imm8(v) ((v) > -256 && (v) < 256)
668 mono_arch_create_generic_class_init_trampoline (MonoTrampInfo **info, gboolean aot)
672 static int byte_offset = -1;
673 static guint8 bitmask;
676 guint32 code_len, imm8;
678 GSList *unwind_ops = NULL;
679 MonoJumpInfo *ji = NULL;
683 code = buf = mono_global_codeman_reserve (tramp_size);
686 mono_marshal_find_bitfield_offset (MonoVTable, initialized, &byte_offset, &bitmask);
688 g_assert (arm_is_imm8 (byte_offset));
689 ARM_LDRSB_IMM (code, ARMREG_IP, MONO_ARCH_VTABLE_REG, byte_offset);
690 imm8 = mono_arm_is_rotated_imm8 (bitmask, &rot_amount);
691 g_assert (imm8 >= 0);
692 ARM_AND_REG_IMM (code, ARMREG_IP, ARMREG_IP, imm8, rot_amount);
693 ARM_CMP_REG_IMM (code, ARMREG_IP, 0, 0);
695 ARM_B_COND (code, ARMCOND_EQ, 0);
697 /* Initialized case */
698 ARM_MOV_REG_REG (code, ARMREG_PC, ARMREG_LR);
700 /* Uninitialized case */
701 arm_patch (jump, code);
704 ji = mono_patch_info_list_prepend (ji, code - buf, MONO_PATCH_INFO_JIT_ICALL_ADDR, "specific_trampoline_generic_class_init");
705 ARM_LDR_IMM (code, ARMREG_R1, ARMREG_PC, 0);
707 *(gpointer*)code = NULL;
709 ARM_LDR_REG_REG (code, ARMREG_PC, ARMREG_PC, ARMREG_R1);
711 tramp = mono_arch_create_specific_trampoline (NULL, MONO_TRAMPOLINE_GENERIC_CLASS_INIT, mono_get_root_domain (), &code_len);
713 /* Jump to the actual trampoline */
714 ARM_LDR_IMM (code, ARMREG_R1, ARMREG_PC, 0); /* temp reg */
715 code = emit_bx (code, ARMREG_R1);
716 *(gpointer*)code = tramp;
720 mono_arch_flush_icache (buf, code - buf);
722 g_assert (code - buf <= tramp_size);
725 *info = mono_tramp_info_create (g_strdup_printf ("generic_class_init_trampoline"), buf, code - buf, ji, unwind_ops);
733 mono_arch_create_generic_trampoline (MonoTrampolineType tramp_type, MonoTrampInfo **info, gboolean aot)
735 g_assert_not_reached ();
740 mono_arch_create_specific_trampoline (gpointer arg1, MonoTrampolineType tramp_type, MonoDomain *domain, guint32 *code_len)
742 g_assert_not_reached ();
747 mono_arch_get_unbox_trampoline (MonoMethod *m, gpointer addr)
749 g_assert_not_reached ();
754 mono_arch_get_static_rgctx_trampoline (MonoMethod *m, MonoMethodRuntimeGenericContext *mrgctx, gpointer addr)
756 g_assert_not_reached ();
761 mono_arch_create_rgctx_lazy_fetch_trampoline (guint32 slot, MonoTrampInfo **info, gboolean aot)
763 g_assert_not_reached ();
768 mono_arch_create_generic_class_init_trampoline (MonoTrampInfo **info, gboolean aot)
770 g_assert_not_reached ();
774 #endif /* DISABLE_JIT */
777 mono_arch_get_call_target (guint8 *code)
779 guint32 ins = ((guint32*)(gpointer)code) [-1];
782 /* Should be a 'bl' or a 'b' */
783 if (((ins >> 25) & 0x7) == 0x5) {
785 /* Should be a 'bl' */
786 if ((((ins >> 25) & 0x7) == 0x5) && (((ins >> 24) & 0x1) == 0x1)) {
788 gint32 disp = ((gint32)ins) & 0xffffff;
789 guint8 *target = code - 4 + 8 + (disp * 4);
798 mono_arch_get_plt_info_offset (guint8 *plt_entry, mgreg_t *regs, guint8 *code)
800 /* The offset is stored as the 4th word of the plt entry */
801 return ((guint32*)plt_entry) [3];
805 * Return the address of the PLT entry called by the thumb code CODE.
808 mono_arm_get_thumb_plt_entry (guint8 *code)
810 int s, j1, j2, imm10, imm11, i1, i2, imm32;
815 /* code should be right after a BL */
816 code = (guint8*)((mgreg_t)code & ~1);
817 base = (guint8*)((mgreg_t)code & ~3);
819 t1 = ((guint16*)bl) [0];
820 t2 = ((guint16*)bl) [1];
822 g_assert ((t1 >> 11) == 0x1e);
824 s = (t1 >> 10) & 0x1;
825 imm10 = (t1 >> 0) & 0x3ff;
826 j1 = (t2 >> 13) & 0x1;
827 j2 = (t2 >> 11) & 0x1;
830 i1 = (s ^ j1) ? 0 : 1;
831 i2 = (s ^ j2) ? 0 : 1;
833 imm32 = (imm11 << 1) | (imm10 << 12) | (i2 << 22) | (i1 << 23);
837 target = code + imm32;
839 /* target now points to the thumb plt entry */
840 /* ldr.w r12, [pc, #8] */
841 g_assert (((guint16*)target) [0] == 0xf8df);
842 g_assert (((guint16*)target) [1] == 0xc008);
845 * The PLT info offset is at offset 16, but mono_arch_get_plt_entry_offset () returns
846 * the 3rd word, so compensate by returning a different value.
856 * mono_arch_get_gsharedvt_arg_trampoline:
858 * See tramp-x86.c for documentation.
861 mono_arch_get_gsharedvt_arg_trampoline (MonoDomain *domain, gpointer arg, gpointer addr)
863 guint8 *code, *start;
869 start = code = mono_domain_code_reserve (domain, buf_len);
871 /* Similar to the specialized trampoline code */
872 ARM_PUSH (code, (1 << ARMREG_R0) | (1 << ARMREG_R1) | (1 << ARMREG_R2) | (1 << ARMREG_R3) | (1 << ARMREG_LR));
873 ARM_LDR_IMM (code, ARMREG_IP, ARMREG_PC, 8);
874 /* arg is passed in LR */
875 ARM_LDR_IMM (code, ARMREG_LR, ARMREG_PC, 0);
876 code = emit_bx (code, ARMREG_IP);
877 constants = (gpointer*)code;
879 constants [1] = addr;
882 g_assert ((code - start) <= buf_len);
884 nacl_domain_code_validate (domain, &start, buf_len, &code);
885 mono_arch_flush_icache (start, code - start);
892 #if defined(MONOTOUCH) || defined(MONO_EXTENSIONS)
894 #include "../../../mono-extensions/mono/mini/tramp-arm-gsharedvt.c"
899 mono_arm_start_gsharedvt_call (GSharedVtCallInfo *info, gpointer *caller, gpointer *callee, gpointer *caller_regs, gpointer *callee_regs, gpointer mrgctx_reg)
901 g_assert_not_reached ();
906 mono_arch_get_gsharedvt_trampoline (MonoTrampInfo **info, gboolean aot)
913 #endif /* !MONOTOUCH */