2 * tramp-arm.c: JIT trampoline code for ARM
5 * Paolo Molaro (lupus@ximian.com)
7 * (C) 2001 Ximian, Inc.
13 #include <mono/metadata/appdomain.h>
14 #include <mono/metadata/marshal.h>
15 #include <mono/metadata/tabledefs.h>
16 #include <mono/arch/arm/arm-codegen.h>
17 #include <mono/arch/arm/arm-vfp-codegen.h>
22 #define ALIGN_TO(val,align) ((((guint64)val) + ((align) - 1)) & ~((align) - 1))
24 static guint8* nullified_class_init_trampoline;
27 mono_arch_patch_callsite (guint8 *method_start, guint8 *code_ptr, guint8 *addr)
29 guint32 *code = (guint32*)code_ptr;
31 /* This is the 'bl' or the 'mov pc' instruction */
35 * Note that methods are called also with the bl opcode.
37 if ((((*code) >> 25) & 7) == 5) {
38 /*g_print ("direct patching\n");*/
39 arm_patch ((guint8*)code, addr);
40 mono_arch_flush_icache ((guint8*)code, 4);
44 if ((((*code) >> 20) & 0xFF) == 0x12) {
45 /*g_print ("patching bx\n");*/
46 arm_patch ((guint8*)code, addr);
47 mono_arch_flush_icache ((guint8*)(code - 2), 4);
51 g_assert_not_reached ();
55 mono_arch_patch_plt_entry (guint8 *code, gpointer *got, mgreg_t *regs, guint8 *addr)
59 /* Patch the jump table entry used by the plt entry */
60 if (*(guint32*)code == 0xe59fc000) {
61 /* ARM_LDR_IMM (code, ARMREG_IP, ARMREG_PC, 0); */
62 guint32 offset = ((guint32*)code)[2];
64 jump_entry = code + offset + 12;
65 } else if (*(guint16*)(code - 4) == 0xf8df) {
67 * Thumb PLT entry, begins with ldr.w ip, [pc, #8], code points to entry + 4, see
68 * mono_arm_get_thumb_plt_entry ().
73 offset = *(guint32*)(code + 12);
74 jump_entry = code + offset + 8;
76 g_assert_not_reached ();
79 *(guint8**)jump_entry = addr;
83 mono_arch_nullify_class_init_trampoline (guint8 *code, mgreg_t *regs)
85 mono_arch_patch_callsite (NULL, code, nullified_class_init_trampoline);
89 mono_arch_nullify_plt_entry (guint8 *code, mgreg_t *regs)
91 if (mono_aot_only && !nullified_class_init_trampoline)
92 nullified_class_init_trampoline = mono_aot_get_trampoline ("nullified_class_init_trampoline");
94 mono_arch_patch_plt_entry (code, NULL, regs, nullified_class_init_trampoline);
99 #define arm_is_imm12(v) ((int)(v) > -4096 && (int)(v) < 4096)
102 * Return the instruction to jump from code to target, 0 if not
103 * reachable with a single instruction
106 branch_for_target_reachable (guint8 *branch, guint8 *target)
108 gint diff = target - branch - 8;
109 g_assert ((diff & 3) == 0);
111 if (diff <= 33554431)
112 return (ARMCOND_AL << ARMCOND_SHIFT) | (ARM_BR_TAG) | (diff >> 2);
114 /* diff between 0 and -33554432 */
115 if (diff >= -33554432)
116 return (ARMCOND_AL << ARMCOND_SHIFT) | (ARM_BR_TAG) | ((diff >> 2) & ~0xff000000);
121 static inline guint8*
122 emit_bx (guint8* code, int reg)
124 if (mono_arm_thumb_supported ())
127 ARM_MOV_REG_REG (code, ARMREG_PC, reg);
131 #define N_VFP_ARGREGS 16
133 /* Stack size for trampoline function
135 #define STACK ((ALIGN_TO (sizeof (MonoLMF), 8)) + (N_VFP_ARGREGS * 8))
137 /* Method-specific trampoline code fragment size */
138 #define METHOD_TRAMPOLINE_SIZE 64
140 /* Jump-specific trampoline code fragment size */
141 #define JUMP_TRAMPOLINE_SIZE 64
144 mono_arch_create_generic_trampoline (MonoTrampolineType tramp_type, MonoTrampInfo **info, gboolean aot)
146 guint8 *buf, *code = NULL;
147 guint8 *load_get_lmf_addr, *load_trampoline;
149 int cfa_offset, lmf_offset, regsave_size, lr_offset;
150 GSList *unwind_ops = NULL;
151 MonoJumpInfo *ji = NULL;
154 /* Now we'll create in 'buf' the ARM trampoline code. This
155 is the trampoline code common to all methods */
158 code = buf = mono_global_codeman_reserve (buf_len);
161 * At this point lr points to the specific arg and sp points to the saved
162 * regs on the stack (all but PC and SP). The original LR value has been
163 * saved as sp + LR_OFFSET by the push in the specific trampoline
166 /* The offset of lmf inside the stack frame */
167 lmf_offset = STACK - sizeof (MonoLMF);
168 /* The size of the area already allocated by the push in the specific trampoline */
169 regsave_size = 14 * sizeof (mgreg_t);
170 /* The offset where lr was saved inside the regsave area */
171 lr_offset = 13 * sizeof (mgreg_t);
173 // FIXME: Finish the unwind info, the current info allows us to unwind
174 // when the trampoline is not in the epilog
176 // CFA = SP + (num registers pushed) * 4
177 cfa_offset = 14 * sizeof (mgreg_t);
178 mono_add_unwind_op_def_cfa (unwind_ops, code, buf, ARMREG_SP, cfa_offset);
179 // PC saved at sp+LR_OFFSET
180 mono_add_unwind_op_offset (unwind_ops, code, buf, ARMREG_LR, -4);
182 if (aot && tramp_type != MONO_TRAMPOLINE_GENERIC_CLASS_INIT) {
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
188 ARM_LDR_IMM (code, ARMREG_V2, ARMREG_LR, 0);
189 ARM_ADD_REG_IMM (code, ARMREG_V2, ARMREG_V2, 4, 0);
190 ARM_LDR_REG_REG (code, ARMREG_V2, ARMREG_V2, ARMREG_LR);
192 if (tramp_type != MONO_TRAMPOLINE_GENERIC_CLASS_INIT)
193 ARM_LDR_IMM (code, ARMREG_V2, ARMREG_LR, 0);
195 ARM_MOV_REG_REG (code, ARMREG_V2, MONO_ARCH_VTABLE_REG);
197 ARM_LDR_IMM (code, ARMREG_V3, ARMREG_SP, lr_offset);
199 /* ok, now we can continue with the MonoLMF setup, mostly untouched
200 * from emit_prolog in mini-arm.c
201 * This is a synthetized call to mono_get_lmf_addr ()
204 ji = mono_patch_info_list_prepend (ji, code - buf, MONO_PATCH_INFO_JIT_ICALL_ADDR, "mono_get_lmf_addr");
205 ARM_LDR_IMM (code, ARMREG_R0, ARMREG_PC, 0);
207 *(gpointer*)code = NULL;
209 ARM_LDR_REG_REG (code, ARMREG_R0, ARMREG_PC, ARMREG_R0);
211 load_get_lmf_addr = code;
214 ARM_MOV_REG_REG (code, ARMREG_LR, ARMREG_PC);
215 code = emit_bx (code, ARMREG_R0);
217 /* we build the MonoLMF structure on the stack - see mini-arm.h
218 * The pointer to the struct is put in r1.
219 * the iregs array is already allocated on the stack by push.
221 code = mono_arm_emit_load_imm (code, ARMREG_R2, STACK - regsave_size);
222 ARM_SUB_REG_REG (code, ARMREG_SP, ARMREG_SP, ARMREG_R2);
223 cfa_offset += STACK - regsave_size;
224 mono_add_unwind_op_def_cfa_offset (unwind_ops, code, buf, cfa_offset);
226 code = mono_arm_emit_load_imm (code, ARMREG_R2, lmf_offset);
227 ARM_ADD_REG_REG (code, ARMREG_V1, ARMREG_SP, ARMREG_R2);
230 * The stack now looks like:
232 * v1 -> <rest of LMF>
236 /* r0 is the result from mono_get_lmf_addr () */
237 ARM_STR_IMM (code, ARMREG_R0, ARMREG_V1, G_STRUCT_OFFSET (MonoLMF, lmf_addr));
238 /* new_lmf->previous_lmf = *lmf_addr */
239 ARM_LDR_IMM (code, ARMREG_R2, ARMREG_R0, G_STRUCT_OFFSET (MonoLMF, previous_lmf));
240 ARM_STR_IMM (code, ARMREG_R2, ARMREG_V1, G_STRUCT_OFFSET (MonoLMF, previous_lmf));
241 /* *(lmf_addr) = r1 */
242 ARM_STR_IMM (code, ARMREG_V1, ARMREG_R0, G_STRUCT_OFFSET (MonoLMF, previous_lmf));
243 /* save method info (it's in v2) */
244 if ((tramp_type == MONO_TRAMPOLINE_JIT) || (tramp_type == MONO_TRAMPOLINE_JUMP))
245 ARM_STR_IMM (code, ARMREG_V2, ARMREG_V1, G_STRUCT_OFFSET (MonoLMF, method));
247 ARM_MOV_REG_IMM8 (code, ARMREG_R2, 0);
248 ARM_STR_IMM (code, ARMREG_R2, ARMREG_V1, G_STRUCT_OFFSET (MonoLMF, method));
251 code = mono_arm_emit_load_imm (code, ARMREG_R2, cfa_offset);
252 ARM_ADD_REG_REG (code, ARMREG_R2, ARMREG_SP, ARMREG_R2);
253 ARM_STR_IMM (code, ARMREG_R2, ARMREG_V1, G_STRUCT_OFFSET (MonoLMF, sp));
255 ARM_LDR_IMM (code, ARMREG_R2, ARMREG_V1, (G_STRUCT_OFFSET (MonoLMF, iregs) + ARMREG_FP*4));
256 ARM_STR_IMM (code, ARMREG_R2, ARMREG_V1, G_STRUCT_OFFSET (MonoLMF, fp));
257 /* save the IP (caller ip) */
258 if (tramp_type == MONO_TRAMPOLINE_JUMP) {
259 ARM_MOV_REG_IMM8 (code, ARMREG_R2, 0);
261 ARM_LDR_IMM (code, ARMREG_R2, ARMREG_V1, (G_STRUCT_OFFSET (MonoLMF, iregs) + 13*4));
263 ARM_STR_IMM (code, ARMREG_R2, ARMREG_V1, G_STRUCT_OFFSET (MonoLMF, ip));
265 /* Save VFP regs used to hold arguments */
266 if (mono_arm_hardfp_abi_supported ())
267 VSTMIA (code, ARMREG_SP, FALSE, 0, N_VFP_ARGREGS);
270 * Now we're ready to call xxx_trampoline ().
272 /* Arg 1: the saved registers */
273 ARM_ADD_REG_IMM8 (code, ARMREG_R0, ARMREG_V1, G_STRUCT_OFFSET (MonoLMF, iregs));
275 /* Arg 2: code (next address to the instruction that called us) */
276 if (tramp_type == MONO_TRAMPOLINE_JUMP) {
277 ARM_MOV_REG_IMM8 (code, ARMREG_R1, 0);
279 ARM_MOV_REG_REG (code, ARMREG_R1, ARMREG_V3);
282 /* Arg 3: the specific argument, stored in v2
284 ARM_MOV_REG_REG (code, ARMREG_R2, ARMREG_V2);
287 char *icall_name = g_strdup_printf ("trampoline_func_%d", tramp_type);
288 ji = mono_patch_info_list_prepend (ji, code - buf, MONO_PATCH_INFO_JIT_ICALL_ADDR, icall_name);
289 ARM_LDR_IMM (code, ARMREG_IP, ARMREG_PC, 0);
291 *(gpointer*)code = NULL;
293 ARM_LDR_REG_REG (code, ARMREG_IP, ARMREG_PC, ARMREG_IP);
295 load_trampoline = code;
299 ARM_MOV_REG_REG (code, ARMREG_LR, ARMREG_PC);
300 code = emit_bx (code, ARMREG_IP);
302 /* OK, code address is now on r0. Move it to the place on the stack
303 * where IP was saved (it is now no more useful to us and it can be
304 * clobbered). This way we can just restore all the regs in one inst
307 ARM_STR_IMM (code, ARMREG_R0, ARMREG_V1, G_STRUCT_OFFSET (MonoLMF, iregs) + (ARMREG_R12 * sizeof (mgreg_t)));
309 /* Check for thread interruption */
310 /* This is not perf critical code so no need to check the interrupt flag */
312 * Have to call the _force_ variant, since there could be a protected wrapper on the top of the stack.
315 ji = mono_patch_info_list_prepend (ji, code - buf, MONO_PATCH_INFO_JIT_ICALL_ADDR, "mono_thread_force_interruption_checkpoint");
316 ARM_LDR_IMM (code, ARMREG_IP, ARMREG_PC, 0);
318 *(gpointer*)code = NULL;
320 ARM_LDR_REG_REG (code, ARMREG_IP, ARMREG_PC, ARMREG_IP);
322 ARM_LDR_IMM (code, ARMREG_IP, ARMREG_PC, 0);
324 *(gpointer*)code = mono_thread_force_interruption_checkpoint;
327 ARM_MOV_REG_REG (code, ARMREG_LR, ARMREG_PC);
328 code = emit_bx (code, ARMREG_IP);
331 * Now we restore the MonoLMF (see emit_epilogue in mini-arm.c)
332 * and the rest of the registers, so the method called will see
333 * the same state as before we executed.
335 /* ip = previous_lmf */
336 ARM_LDR_IMM (code, ARMREG_IP, ARMREG_V1, G_STRUCT_OFFSET (MonoLMF, previous_lmf));
338 ARM_LDR_IMM (code, ARMREG_LR, ARMREG_V1, G_STRUCT_OFFSET (MonoLMF, lmf_addr));
339 /* *(lmf_addr) = previous_lmf */
340 ARM_STR_IMM (code, ARMREG_IP, ARMREG_LR, G_STRUCT_OFFSET (MonoLMF, previous_lmf));
342 /* Restore VFP regs used to hold arguments */
343 if (mono_arm_hardfp_abi_supported ())
344 VLDMIA (code, ARMREG_SP, FALSE, 0, N_VFP_ARGREGS);
346 /* Non-standard function epilogue. Instead of doing a proper
347 * return, we just jump to the compiled code.
349 /* Restore the registers and jump to the code:
350 * Note that IP has been conveniently set to the method addr.
352 ARM_ADD_REG_IMM8 (code, ARMREG_SP, ARMREG_SP, STACK - regsave_size);
353 ARM_POP_NWB (code, 0x5fff);
354 if (tramp_type == MONO_TRAMPOLINE_RGCTX_LAZY_FETCH)
355 ARM_MOV_REG_REG (code, ARMREG_R0, ARMREG_IP);
356 ARM_ADD_REG_IMM8 (code, ARMREG_SP, ARMREG_SP, regsave_size);
357 if ((tramp_type == MONO_TRAMPOLINE_CLASS_INIT) || (tramp_type == MONO_TRAMPOLINE_GENERIC_CLASS_INIT) || (tramp_type == MONO_TRAMPOLINE_RGCTX_LAZY_FETCH))
358 code = emit_bx (code, ARMREG_LR);
360 code = emit_bx (code, ARMREG_IP);
362 constants = (gpointer*)code;
363 constants [0] = mono_get_lmf_addr;
364 constants [1] = (gpointer)mono_get_trampoline_func (tramp_type);
367 /* backpatch by emitting the missing instructions skipped above */
368 ARM_LDR_IMM (load_get_lmf_addr, ARMREG_R0, ARMREG_PC, (code - load_get_lmf_addr - 8));
369 ARM_LDR_IMM (load_trampoline, ARMREG_IP, ARMREG_PC, (code + 4 - load_trampoline - 8));
374 /* Flush instruction cache, since we've generated code */
375 mono_arch_flush_icache (buf, code - buf);
378 g_assert ((code - buf) <= buf_len);
380 if (tramp_type == MONO_TRAMPOLINE_CLASS_INIT)
381 /* Initialize the nullified class init trampoline used in the AOT case */
382 nullified_class_init_trampoline = mono_arch_get_nullified_class_init_trampoline (NULL);
385 *info = mono_tramp_info_create (mono_get_generic_trampoline_name (tramp_type), buf, code - buf, ji, unwind_ops);
391 mono_arch_get_nullified_class_init_trampoline (MonoTrampInfo **info)
395 code = buf = mono_global_codeman_reserve (16);
397 code = emit_bx (code, ARMREG_LR);
399 mono_arch_flush_icache (buf, code - buf);
402 *info = mono_tramp_info_create (g_strdup_printf ("nullified_class_init_trampoline"), buf, code - buf, NULL, NULL);
407 #define SPEC_TRAMP_SIZE 24
410 mono_arch_create_specific_trampoline (gpointer arg1, MonoTrampolineType tramp_type, MonoDomain *domain, guint32 *code_len)
412 guint8 *code, *buf, *tramp;
414 guint32 short_branch, size = SPEC_TRAMP_SIZE;
416 tramp = mono_get_trampoline_code (tramp_type);
418 mono_domain_lock (domain);
419 code = buf = mono_domain_code_reserve_align (domain, size, 4);
420 if ((short_branch = branch_for_target_reachable (code + 4, tramp))) {
422 mono_domain_code_commit (domain, code, SPEC_TRAMP_SIZE, size);
424 mono_domain_unlock (domain);
426 /* we could reduce this to 12 bytes if tramp is within reach:
430 * The called code can access method using the lr register
431 * A 20 byte sequence could be:
433 * ARM_MOV_REG_REG (lr, pc)
434 * ARM_LDR_IMM (pc, pc, 0)
438 /* We save all the registers, except PC and SP */
439 ARM_PUSH (code, 0x5fff);
441 constants = (gpointer*)code;
442 constants [0] = GUINT_TO_POINTER (short_branch | (1 << 24));
443 constants [1] = arg1;
446 ARM_LDR_IMM (code, ARMREG_R1, ARMREG_PC, 8); /* temp reg */
447 ARM_MOV_REG_REG (code, ARMREG_LR, ARMREG_PC);
448 code = emit_bx (code, ARMREG_R1);
450 constants = (gpointer*)code;
451 constants [0] = arg1;
452 constants [1] = tramp;
456 /* Flush instruction cache, since we've generated code */
457 mono_arch_flush_icache (buf, code - buf);
459 g_assert ((code - buf) <= size);
462 *code_len = code - buf;
468 * mono_arch_get_unbox_trampoline:
470 * @addr: pointer to native code for @m
472 * when value type methods are called through the vtable we need to unbox the
473 * this argument. This method returns a pointer to a trampoline which does
474 * unboxing before calling the method
477 mono_arch_get_unbox_trampoline (MonoMethod *m, gpointer addr)
479 guint8 *code, *start;
480 MonoDomain *domain = mono_domain_get ();
482 start = code = mono_domain_code_reserve (domain, 16);
484 ARM_LDR_IMM (code, ARMREG_IP, ARMREG_PC, 4);
485 ARM_ADD_REG_IMM8 (code, ARMREG_R0, ARMREG_R0, sizeof (MonoObject));
486 code = emit_bx (code, ARMREG_IP);
487 *(guint32*)code = (guint32)addr;
489 mono_arch_flush_icache (start, code - start);
490 g_assert ((code - start) <= 16);
491 /*g_print ("unbox trampoline at %d for %s:%s\n", this_pos, m->klass->name, m->name);
492 g_print ("unbox code is at %p for method at %p\n", start, addr);*/
498 mono_arch_get_static_rgctx_trampoline (MonoMethod *m, MonoMethodRuntimeGenericContext *mrgctx, gpointer addr)
500 guint8 *code, *start;
503 MonoDomain *domain = mono_domain_get ();
507 start = code = mono_domain_code_reserve (domain, buf_len);
509 ARM_LDR_IMM (code, MONO_ARCH_RGCTX_REG, ARMREG_PC, 0);
510 ARM_LDR_IMM (code, ARMREG_PC, ARMREG_PC, 0);
511 *(guint32*)code = (guint32)mrgctx;
513 *(guint32*)code = (guint32)addr;
516 g_assert ((code - start) <= buf_len);
518 mono_arch_flush_icache (start, code - start);
524 mono_arch_create_rgctx_lazy_fetch_trampoline (guint32 slot, MonoTrampInfo **info, gboolean aot)
530 guint8 **rgctx_null_jumps;
534 MonoJumpInfo *ji = NULL;
535 GSList *unwind_ops = NULL;
537 mrgctx = MONO_RGCTX_SLOT_IS_MRGCTX (slot);
538 index = MONO_RGCTX_SLOT_INDEX (slot);
540 index += MONO_SIZEOF_METHOD_RUNTIME_GENERIC_CONTEXT / sizeof (gpointer);
541 for (depth = 0; ; ++depth) {
542 int size = mono_class_rgctx_get_array_size (depth, mrgctx);
544 if (index < size - 1)
549 tramp_size = 64 + 16 * depth;
551 code = buf = mono_global_codeman_reserve (tramp_size);
553 mono_add_unwind_op_def_cfa (unwind_ops, code, buf, ARMREG_SP, 0);
555 rgctx_null_jumps = g_malloc (sizeof (guint8*) * (depth + 2));
558 /* The vtable/mrgctx is in R0 */
559 g_assert (MONO_ARCH_VTABLE_REG == ARMREG_R0);
563 ARM_MOV_REG_REG (code, ARMREG_R1, ARMREG_R0);
565 /* load rgctx ptr from vtable */
566 g_assert (arm_is_imm12 (G_STRUCT_OFFSET (MonoVTable, runtime_generic_context)));
567 ARM_LDR_IMM (code, ARMREG_R1, ARMREG_R0, G_STRUCT_OFFSET (MonoVTable, runtime_generic_context));
568 /* is the rgctx ptr null? */
569 ARM_CMP_REG_IMM (code, ARMREG_R1, 0, 0);
570 /* if yes, jump to actual trampoline */
571 rgctx_null_jumps [njumps ++] = code;
572 ARM_B_COND (code, ARMCOND_EQ, 0);
575 for (i = 0; i < depth; ++i) {
576 /* load ptr to next array */
577 if (mrgctx && i == 0) {
578 g_assert (arm_is_imm12 (MONO_SIZEOF_METHOD_RUNTIME_GENERIC_CONTEXT));
579 ARM_LDR_IMM (code, ARMREG_R1, ARMREG_R1, MONO_SIZEOF_METHOD_RUNTIME_GENERIC_CONTEXT);
581 ARM_LDR_IMM (code, ARMREG_R1, ARMREG_R1, 0);
583 /* is the ptr null? */
584 ARM_CMP_REG_IMM (code, ARMREG_R1, 0, 0);
585 /* if yes, jump to actual trampoline */
586 rgctx_null_jumps [njumps ++] = code;
587 ARM_B_COND (code, ARMCOND_EQ, 0);
591 code = mono_arm_emit_load_imm (code, ARMREG_R2, sizeof (gpointer) * (index + 1));
592 ARM_LDR_REG_REG (code, ARMREG_R1, ARMREG_R1, ARMREG_R2);
593 /* is the slot null? */
594 ARM_CMP_REG_IMM (code, ARMREG_R1, 0, 0);
595 /* if yes, jump to actual trampoline */
596 rgctx_null_jumps [njumps ++] = code;
597 ARM_B_COND (code, ARMCOND_EQ, 0);
598 /* otherwise return, result is in R1 */
599 ARM_MOV_REG_REG (code, ARMREG_R0, ARMREG_R1);
600 code = emit_bx (code, ARMREG_LR);
602 g_assert (njumps <= depth + 2);
603 for (i = 0; i < njumps; ++i)
604 arm_patch (rgctx_null_jumps [i], code);
606 g_free (rgctx_null_jumps);
610 /* The vtable/mrgctx is still in R0 */
613 ji = mono_patch_info_list_prepend (ji, code - buf, MONO_PATCH_INFO_JIT_ICALL_ADDR, g_strdup_printf ("specific_trampoline_lazy_fetch_%u", slot));
614 ARM_LDR_IMM (code, ARMREG_R1, ARMREG_PC, 0);
616 *(gpointer*)code = NULL;
618 ARM_LDR_REG_REG (code, ARMREG_PC, ARMREG_PC, ARMREG_R1);
620 tramp = mono_arch_create_specific_trampoline (GUINT_TO_POINTER (slot), MONO_TRAMPOLINE_RGCTX_LAZY_FETCH, mono_get_root_domain (), &code_len);
622 /* Jump to the actual trampoline */
623 ARM_LDR_IMM (code, ARMREG_R1, ARMREG_PC, 0); /* temp reg */
624 code = emit_bx (code, ARMREG_R1);
625 *(gpointer*)code = tramp;
629 mono_arch_flush_icache (buf, code - buf);
631 g_assert (code - buf <= tramp_size);
634 *info = mono_tramp_info_create (mono_get_rgctx_fetch_trampoline_name (slot), buf, code - buf, ji, unwind_ops);
639 #define arm_is_imm8(v) ((v) > -256 && (v) < 256)
642 mono_arch_create_generic_class_init_trampoline (MonoTrampInfo **info, gboolean aot)
646 static int byte_offset = -1;
647 static guint8 bitmask;
650 guint32 code_len, imm8;
652 GSList *unwind_ops = NULL;
653 MonoJumpInfo *ji = NULL;
657 code = buf = mono_global_codeman_reserve (tramp_size);
660 mono_marshal_find_bitfield_offset (MonoVTable, initialized, &byte_offset, &bitmask);
662 g_assert (arm_is_imm8 (byte_offset));
663 ARM_LDRSB_IMM (code, ARMREG_IP, MONO_ARCH_VTABLE_REG, byte_offset);
664 imm8 = mono_arm_is_rotated_imm8 (bitmask, &rot_amount);
665 g_assert (imm8 >= 0);
666 ARM_AND_REG_IMM (code, ARMREG_IP, ARMREG_IP, imm8, rot_amount);
667 ARM_CMP_REG_IMM (code, ARMREG_IP, 0, 0);
669 ARM_B_COND (code, ARMCOND_EQ, 0);
671 /* Initialized case */
672 ARM_MOV_REG_REG (code, ARMREG_PC, ARMREG_LR);
674 /* Uninitialized case */
675 arm_patch (jump, code);
678 ji = mono_patch_info_list_prepend (ji, code - buf, MONO_PATCH_INFO_JIT_ICALL_ADDR, "specific_trampoline_generic_class_init");
679 ARM_LDR_IMM (code, ARMREG_R1, ARMREG_PC, 0);
681 *(gpointer*)code = NULL;
683 ARM_LDR_REG_REG (code, ARMREG_PC, ARMREG_PC, ARMREG_R1);
685 tramp = mono_arch_create_specific_trampoline (NULL, MONO_TRAMPOLINE_GENERIC_CLASS_INIT, mono_get_root_domain (), &code_len);
687 /* Jump to the actual trampoline */
688 ARM_LDR_IMM (code, ARMREG_R1, ARMREG_PC, 0); /* temp reg */
689 code = emit_bx (code, ARMREG_R1);
690 *(gpointer*)code = tramp;
694 mono_arch_flush_icache (buf, code - buf);
696 g_assert (code - buf <= tramp_size);
699 *info = mono_tramp_info_create (g_strdup_printf ("generic_class_init_trampoline"), buf, code - buf, ji, unwind_ops);
707 mono_arch_create_generic_trampoline (MonoTrampolineType tramp_type, MonoTrampInfo **info, gboolean aot)
709 g_assert_not_reached ();
714 mono_arch_create_specific_trampoline (gpointer arg1, MonoTrampolineType tramp_type, MonoDomain *domain, guint32 *code_len)
716 g_assert_not_reached ();
721 mono_arch_get_unbox_trampoline (MonoMethod *m, gpointer addr)
723 g_assert_not_reached ();
728 mono_arch_get_static_rgctx_trampoline (MonoMethod *m, MonoMethodRuntimeGenericContext *mrgctx, gpointer addr)
730 g_assert_not_reached ();
735 mono_arch_create_rgctx_lazy_fetch_trampoline (guint32 slot, MonoTrampInfo **info, gboolean aot)
737 g_assert_not_reached ();
742 mono_arch_create_generic_class_init_trampoline (MonoTrampInfo **info, gboolean aot)
744 g_assert_not_reached ();
748 #endif /* DISABLE_JIT */
751 mono_arch_get_call_target (guint8 *code)
753 guint32 ins = ((guint32*)(gpointer)code) [-1];
755 /* Should be a 'bl' */
756 if ((((ins >> 25) & 0x7) == 0x5) && (((ins >> 24) & 0x1) == 0x1)) {
757 gint32 disp = ((gint32)ins) & 0xffffff;
758 guint8 *target = code - 4 + 8 + (disp * 4);
767 mono_arch_get_plt_info_offset (guint8 *plt_entry, mgreg_t *regs, guint8 *code)
769 /* The offset is stored as the 4th word of the plt entry */
770 return ((guint32*)plt_entry) [3];
774 * Return the address of the PLT entry called by the thumb code CODE.
777 mono_arm_get_thumb_plt_entry (guint8 *code)
779 int s, j1, j2, imm10, imm11, i1, i2, imm32;
784 /* code should be right after a BL */
785 code = (guint8*)((mgreg_t)code & ~1);
786 base = (guint8*)((mgreg_t)code & ~3);
788 t1 = ((guint16*)bl) [0];
789 t2 = ((guint16*)bl) [1];
791 g_assert ((t1 >> 11) == 0x1e);
793 s = (t1 >> 10) & 0x1;
794 imm10 = (t1 >> 0) & 0x3ff;
795 j1 = (t2 >> 13) & 0x1;
796 j2 = (t2 >> 11) & 0x1;
799 i1 = (s ^ j1) ? 0 : 1;
800 i2 = (s ^ j2) ? 0 : 1;
802 imm32 = (imm11 << 1) | (imm10 << 12) | (i2 << 22) | (i1 << 23);
806 target = code + imm32;
808 /* target now points to the thumb plt entry */
809 /* ldr.w r12, [pc, #8] */
810 g_assert (((guint16*)target) [0] == 0xf8df);
811 g_assert (((guint16*)target) [1] == 0xc008);
814 * The PLT info offset is at offset 16, but mono_arch_get_plt_entry_offset () returns
815 * the 3rd word, so compensate by returning a different value.