/** * \file * JIT trampoline code for PowerPC * * Authors: * Dietmar Maurer (dietmar@ximian.com) * Paolo Molaro (lupus@ximian.com) * Carlos Valiente * Andreas Faerber * * (C) 2001 Ximian, Inc. * (C) 2007-2008 Andreas Faerber */ #include #include #include #include #include #include #include #include "mini.h" #include "mini-ppc.h" #if 0 /* Same as mono_create_ftnptr, but doesn't require a domain */ static gpointer mono_ppc_create_ftnptr (guint8 *code) { #ifdef PPC_USES_FUNCTION_DESCRIPTOR MonoPPCFunctionDescriptor *ftnptr = mono_global_codeman_reserve (sizeof (MonoPPCFunctionDescriptor)); ftnptr->code = code; ftnptr->toc = NULL; ftnptr->env = NULL; return ftnptr; #else return code; #endif } #endif /* * Return the instruction to jump from code to target, 0 if not * reachable with a single instruction */ static guint32 branch_for_target_reachable (guint8 *branch, guint8 *target) { gint diff = target - branch; g_assert ((diff & 3) == 0); if (diff >= 0) { if (diff <= 33554431) return (18 << 26) | (diff); } else { /* diff between 0 and -33554432 */ if (diff >= -33554432) return (18 << 26) | (diff & ~0xfc000000); } return 0; } /* * get_unbox_trampoline: * @m: method pointer * @addr: pointer to native code for @m * * when value type methods are called through the vtable we need to unbox the * this argument. This method returns a pointer to a trampoline which does * unboxing before calling the method */ gpointer mono_arch_get_unbox_trampoline (MonoMethod *m, gpointer addr) { guint8 *code, *start; int this_pos = 3; guint32 short_branch; MonoDomain *domain = mono_domain_get (); int size = MONO_PPC_32_64_CASE (20, 32) + PPC_FTNPTR_SIZE; addr = mono_get_addr_from_ftnptr (addr); mono_domain_lock (domain); start = code = mono_domain_code_reserve (domain, size); code = mono_ppc_create_pre_code_ftnptr (code); short_branch = branch_for_target_reachable (code + 4, addr); if (short_branch) mono_domain_code_commit (domain, code, size, 8); mono_domain_unlock (domain); if (short_branch) { ppc_addi (code, this_pos, this_pos, sizeof (MonoObject)); ppc_emit32 (code, short_branch); } else { ppc_load_ptr (code, ppc_r0, addr); ppc_mtctr (code, ppc_r0); ppc_addi (code, this_pos, this_pos, sizeof (MonoObject)); ppc_bcctr (code, 20, 0); } mono_arch_flush_icache (start, code - start); g_assert ((code - start) <= size); /*g_print ("unbox trampoline at %d for %s:%s\n", this_pos, m->klass->name, m->name); g_print ("unbox code is at %p for method at %p\n", start, addr);*/ mono_tramp_info_register (mono_tramp_info_create (NULL, start, code - start, NULL, NULL), domain); return start; } /* * mono_arch_get_static_rgctx_trampoline: * * Create a trampoline which sets RGCTX_REG to ARG, then jumps to ADDR. */ gpointer mono_arch_get_static_rgctx_trampoline (gpointer arg, gpointer addr) { guint8 *code, *start, *p; guint8 imm_buf [128]; guint32 short_branch; MonoDomain *domain = mono_domain_get (); int imm_size; int size = MONO_PPC_32_64_CASE (24, (PPC_LOAD_SEQUENCE_LENGTH * 2) + 8) + PPC_FTNPTR_SIZE; addr = mono_get_addr_from_ftnptr (addr); /* Compute size of code needed to emit the arg */ p = imm_buf; ppc_load_ptr (p, MONO_ARCH_RGCTX_REG, arg); imm_size = p - imm_buf; mono_domain_lock (domain); start = code = mono_domain_code_reserve (domain, size); code = mono_ppc_create_pre_code_ftnptr (code); short_branch = branch_for_target_reachable (code + imm_size, addr); if (short_branch) mono_domain_code_commit (domain, code, size, imm_size + 4); mono_domain_unlock (domain); if (short_branch) { ppc_load_ptr (code, MONO_ARCH_RGCTX_REG, arg); ppc_emit32 (code, short_branch); } else { ppc_load_ptr (code, ppc_r0, addr); ppc_mtctr (code, ppc_r0); ppc_load_ptr (code, MONO_ARCH_RGCTX_REG, arg); ppc_bcctr (code, 20, 0); } mono_arch_flush_icache (start, code - start); g_assert ((code - start) <= size); mono_tramp_info_register (mono_tramp_info_create (NULL, start, code - start, NULL, NULL), domain); return start; } void mono_arch_patch_callsite (guint8 *method_start, guint8 *code_ptr, guint8 *addr) { guint32 *code = (guint32*)code_ptr; addr = mono_get_addr_from_ftnptr (addr); /* This is the 'blrl' instruction */ --code; /* * Note that methods are called also with the bl opcode. */ if (((*code) >> 26) == 18) { /*g_print ("direct patching\n");*/ ppc_patch ((guint8*)code, addr); mono_arch_flush_icache ((guint8*)code, 4); return; } /* Sanity check */ g_assert (mono_ppc_is_direct_call_sequence (code)); ppc_patch ((guint8*)code, addr); } void mono_arch_patch_plt_entry (guint8 *code, gpointer *got, mgreg_t *regs, guint8 *addr) { guint32 ins1, ins2, offset; /* Patch the jump table entry used by the plt entry */ /* Should be a lis+ori */ ins1 = ((guint32*)code)[0]; g_assert (ins1 >> 26 == 15); ins2 = ((guint32*)code)[1]; g_assert (ins2 >> 26 == 24); offset = ((ins1 & 0xffff) << 16) | (ins2 & 0xffff); /* Either got or regs is set */ if (!got) got = (gpointer*)(gsize) regs [30]; *(guint8**)((guint8*)got + offset) = addr; } /* Stack size for trampoline function * PPC_MINIMAL_STACK_SIZE + 16 (args + alignment to ppc_magic_trampoline) * + MonoLMF + 14 fp regs + 13 gregs + alignment */ #define STACK (((PPC_MINIMAL_STACK_SIZE + 4 * sizeof (mgreg_t) + sizeof (MonoLMF) + 14 * sizeof (double) + 31 * sizeof (mgreg_t)) + (MONO_ARCH_FRAME_ALIGNMENT - 1)) & ~(MONO_ARCH_FRAME_ALIGNMENT - 1)) /* Method-specific trampoline code fragment size */ #define METHOD_TRAMPOLINE_SIZE 64 /* Jump-specific trampoline code fragment size */ #define JUMP_TRAMPOLINE_SIZE 64 #ifdef PPC_USES_FUNCTION_DESCRIPTOR #define PPC_TOC_REG ppc_r2 #else #define PPC_TOC_REG -1 #endif /* * Stack frame description when the generic trampoline is called. * caller frame * -------------------- * MonoLMF * ------------------- * Saved FP registers 0-13 * ------------------- * Saved general registers 0-30 * ------------------- * param area for 3 args to ppc_magic_trampoline * ------------------- * linkage area * ------------------- */ guchar* mono_arch_create_generic_trampoline (MonoTrampolineType tramp_type, MonoTrampInfo **info, gboolean aot) { char *tramp_name; guint8 *buf, *code = NULL; int i, offset; gconstpointer tramp_handler; int size = MONO_PPC_32_64_CASE (600, 800); GSList *unwind_ops = NULL; MonoJumpInfo *ji = NULL; /* Now we'll create in 'buf' the PowerPC trampoline code. This is the trampoline code common to all methods */ code = buf = mono_global_codeman_reserve (size); ppc_str_update (code, ppc_r1, -STACK, ppc_r1); /* start building the MonoLMF on the stack */ offset = STACK - sizeof (double) * MONO_SAVED_FREGS; for (i = 14; i < 32; i++) { ppc_stfd (code, i, offset, ppc_r1); offset += sizeof (double); } /* * now the integer registers. */ offset = STACK - sizeof (MonoLMF) + G_STRUCT_OFFSET (MonoLMF, iregs); ppc_str_multiple (code, ppc_r13, offset, ppc_r1); /* Now save the rest of the registers below the MonoLMF struct, first 14 * fp regs and then the 31 gregs. */ offset = STACK - sizeof (MonoLMF) - (14 * sizeof (double)); for (i = 0; i < 14; i++) { ppc_stfd (code, i, offset, ppc_r1); offset += sizeof (double); } #define GREGS_OFFSET (STACK - sizeof (MonoLMF) - (14 * sizeof (double)) - (31 * sizeof (mgreg_t))) offset = GREGS_OFFSET; for (i = 0; i < 31; i++) { ppc_str (code, i, offset, ppc_r1); offset += sizeof (mgreg_t); } /* we got here through a jump to the ctr reg, we must save the lr * in the parent frame (we do it here to reduce the size of the * method-specific trampoline) */ ppc_mflr (code, ppc_r0); ppc_str (code, ppc_r0, STACK + PPC_RET_ADDR_OFFSET, ppc_r1); /* ok, now we can continue with the MonoLMF setup, mostly untouched * from emit_prolog in mini-ppc.c */ if (aot) { code = mono_arch_emit_load_aotconst (buf, code, &ji, MONO_PATCH_INFO_JIT_ICALL_ADDR, "mono_get_lmf_addr"); #ifdef PPC_USES_FUNCTION_DESCRIPTOR ppc_ldptr (code, ppc_r2, sizeof (gpointer), ppc_r12); ppc_ldptr (code, ppc_r12, 0, ppc_r12); #endif ppc_mtlr (code, ppc_r12); ppc_blrl (code); } else { ppc_load_func (code, PPC_CALL_REG, mono_get_lmf_addr); ppc_mtlr (code, PPC_CALL_REG); ppc_blrl (code); } /* we build the MonoLMF structure on the stack - see mini-ppc.h * The pointer to the struct is put in ppc_r12. */ ppc_addi (code, ppc_r12, ppc_sp, STACK - sizeof (MonoLMF)); ppc_stptr (code, ppc_r3, G_STRUCT_OFFSET(MonoLMF, lmf_addr), ppc_r12); /* new_lmf->previous_lmf = *lmf_addr */ ppc_ldptr (code, ppc_r0, G_STRUCT_OFFSET(MonoLMF, previous_lmf), ppc_r3); ppc_stptr (code, ppc_r0, G_STRUCT_OFFSET(MonoLMF, previous_lmf), ppc_r12); /* *(lmf_addr) = r12 */ ppc_stptr (code, ppc_r12, G_STRUCT_OFFSET(MonoLMF, previous_lmf), ppc_r3); /* save method info (it's stored on the stack, so get it first). */ if ((tramp_type == MONO_TRAMPOLINE_JIT) || (tramp_type == MONO_TRAMPOLINE_JUMP)) { ppc_ldr (code, ppc_r0, GREGS_OFFSET, ppc_r1); ppc_stptr (code, ppc_r0, G_STRUCT_OFFSET(MonoLMF, method), ppc_r12); } else { ppc_load (code, ppc_r0, 0); ppc_stptr (code, ppc_r0, G_STRUCT_OFFSET(MonoLMF, method), ppc_r12); } /* store the frame pointer of the calling method */ ppc_addi (code, ppc_r0, ppc_sp, STACK); ppc_stptr (code, ppc_r0, G_STRUCT_OFFSET(MonoLMF, ebp), ppc_r12); /* save the IP (caller ip) */ if (tramp_type == MONO_TRAMPOLINE_JUMP) { ppc_li (code, ppc_r0, 0); } else { ppc_ldr (code, ppc_r0, STACK + PPC_RET_ADDR_OFFSET, ppc_r1); } ppc_stptr (code, ppc_r0, G_STRUCT_OFFSET(MonoLMF, eip), ppc_r12); /* * Now we're ready to call trampoline (mgreg_t *regs, guint8 *code, gpointer value, guint8 *tramp) * Note that the last argument is unused. */ /* Arg 1: a pointer to the registers */ ppc_addi (code, ppc_r3, ppc_r1, GREGS_OFFSET); /* Arg 2: code (next address to the instruction that called us) */ if (tramp_type == MONO_TRAMPOLINE_JUMP) ppc_li (code, ppc_r4, 0); else ppc_ldr (code, ppc_r4, STACK + PPC_RET_ADDR_OFFSET, ppc_r1); /* Arg 3: trampoline argument */ ppc_ldr (code, ppc_r5, GREGS_OFFSET, ppc_r1); if (aot) { code = mono_arch_emit_load_aotconst (buf, code, &ji, MONO_PATCH_INFO_JIT_ICALL_ADDR, g_strdup_printf ("trampoline_func_%d", tramp_type)); #ifdef PPC_USES_FUNCTION_DESCRIPTOR ppc_ldptr (code, ppc_r2, sizeof (gpointer), ppc_r12); ppc_ldptr (code, ppc_r12, 0, ppc_r12); #endif ppc_mtlr (code, ppc_r12); ppc_blrl (code); } else { tramp_handler = mono_get_trampoline_func (tramp_type); ppc_load_func (code, PPC_CALL_REG, tramp_handler); ppc_mtlr (code, PPC_CALL_REG); ppc_blrl (code); } /* OK, code address is now on r3. Move it to the counter reg * so it will be ready for the final jump: this is safe since we * won't do any more calls. */ if (!MONO_TRAMPOLINE_TYPE_MUST_RETURN (tramp_type)) { #ifdef PPC_USES_FUNCTION_DESCRIPTOR ppc_ldptr (code, ppc_r2, sizeof (gpointer), ppc_r3); ppc_ldptr (code, ppc_r3, 0, ppc_r3); #endif ppc_mtctr (code, ppc_r3); } /* * Now we restore the MonoLMF (see emit_epilogue in mini-ppc.c) * and the rest of the registers, so the method called will see * the same state as before we executed. * The pointer to MonoLMF is in ppc_r12. */ ppc_addi (code, ppc_r12, ppc_r1, STACK - sizeof (MonoLMF)); /* r5 = previous_lmf */ ppc_ldptr (code, ppc_r5, G_STRUCT_OFFSET(MonoLMF, previous_lmf), ppc_r12); /* r6 = lmf_addr */ ppc_ldptr (code, ppc_r6, G_STRUCT_OFFSET(MonoLMF, lmf_addr), ppc_r12); /* *(lmf_addr) = previous_lmf */ ppc_stptr (code, ppc_r5, G_STRUCT_OFFSET(MonoLMF, previous_lmf), ppc_r6); /* restore iregs */ ppc_ldr_multiple (code, ppc_r13, G_STRUCT_OFFSET(MonoLMF, iregs), ppc_r12); /* restore fregs */ for (i = 14; i < 32; i++) ppc_lfd (code, i, G_STRUCT_OFFSET(MonoLMF, fregs) + ((i-14) * sizeof (gdouble)), ppc_r12); /* restore the volatile registers, we skip r1, of course */ offset = STACK - sizeof (MonoLMF) - (14 * sizeof (double)); for (i = 0; i < 14; i++) { ppc_lfd (code, i, offset, ppc_r1); offset += sizeof (double); } offset = STACK - sizeof (MonoLMF) - (14 * sizeof (double)) - (31 * sizeof (mgreg_t)); ppc_ldr (code, ppc_r0, offset, ppc_r1); offset += 2 * sizeof (mgreg_t); for (i = 2; i < 13; i++) { if (i != PPC_TOC_REG && (i != 3 || tramp_type != MONO_TRAMPOLINE_RGCTX_LAZY_FETCH)) ppc_ldr (code, i, offset, ppc_r1); offset += sizeof (mgreg_t); } /* Non-standard function epilogue. Instead of doing a proper * return, we just jump to the compiled code. */ /* Restore stack pointer and LR and jump to the code */ ppc_ldr (code, ppc_r1, 0, ppc_r1); ppc_ldr (code, ppc_r12, PPC_RET_ADDR_OFFSET, ppc_r1); ppc_mtlr (code, ppc_r12); if (MONO_TRAMPOLINE_TYPE_MUST_RETURN (tramp_type)) ppc_blr (code); else ppc_bcctr (code, 20, 0); /* Flush instruction cache, since we've generated code */ mono_arch_flush_icache (buf, code - buf); /* Sanity check */ g_assert ((code - buf) <= size); g_assert (info); tramp_name = mono_get_generic_trampoline_name (tramp_type); *info = mono_tramp_info_create (tramp_name, buf, code - buf, ji, unwind_ops); g_free (tramp_name); return buf; } #define TRAMPOLINE_SIZE (MONO_PPC_32_64_CASE (24, (5+5+1+1)*4)) gpointer mono_arch_create_specific_trampoline (gpointer arg1, MonoTrampolineType tramp_type, MonoDomain *domain, guint32 *code_len) { guint8 *code, *buf, *tramp; guint32 short_branch; tramp = mono_get_trampoline_code (tramp_type); mono_domain_lock (domain); code = buf = mono_domain_code_reserve_align (domain, TRAMPOLINE_SIZE, 4); short_branch = branch_for_target_reachable (code + MONO_PPC_32_64_CASE (8, 5*4), tramp); #ifdef __mono_ppc64__ /* FIXME: make shorter if possible */ #else if (short_branch) mono_domain_code_commit (domain, code, TRAMPOLINE_SIZE, 12); #endif mono_domain_unlock (domain); if (short_branch) { ppc_load_sequence (code, ppc_r0, (mgreg_t)(gsize) arg1); ppc_emit32 (code, short_branch); } else { /* Prepare the jump to the generic trampoline code.*/ ppc_load_ptr (code, ppc_r0, tramp); ppc_mtctr (code, ppc_r0); /* And finally put 'arg1' in r0 and fly! */ ppc_load_ptr (code, ppc_r0, arg1); ppc_bcctr (code, 20, 0); } /* Flush instruction cache, since we've generated code */ mono_arch_flush_icache (buf, code - buf); g_assert ((code - buf) <= TRAMPOLINE_SIZE); if (code_len) *code_len = code - buf; return buf; } static guint8* emit_trampoline_jump (guint8 *code, guint8 *tramp) { guint32 short_branch = branch_for_target_reachable (code, tramp); /* FIXME: we can save a few bytes here by committing if the short branch is possible */ if (short_branch) { ppc_emit32 (code, short_branch); } else { ppc_load_ptr (code, ppc_r0, tramp); ppc_mtctr (code, ppc_r0); ppc_bcctr (code, 20, 0); } return code; } gpointer mono_arch_create_rgctx_lazy_fetch_trampoline (guint32 slot, MonoTrampInfo **info, gboolean aot) { guint8 *tramp; guint8 *code, *buf; guint8 **rgctx_null_jumps; int tramp_size; int depth, index; int i; gboolean mrgctx; MonoJumpInfo *ji = NULL; GSList *unwind_ops = NULL; mrgctx = MONO_RGCTX_SLOT_IS_MRGCTX (slot); index = MONO_RGCTX_SLOT_INDEX (slot); if (mrgctx) index += MONO_SIZEOF_METHOD_RUNTIME_GENERIC_CONTEXT / sizeof (gpointer); for (depth = 0; ; ++depth) { int size = mono_class_rgctx_get_array_size (depth, mrgctx); if (index < size - 1) break; index -= size - 1; } tramp_size = MONO_PPC_32_64_CASE (40, 52) + 12 * depth; if (mrgctx) tramp_size += 4; else tramp_size += 12; if (aot) tramp_size += 32; code = buf = mono_global_codeman_reserve (tramp_size); rgctx_null_jumps = g_malloc (sizeof (guint8*) * (depth + 2)); if (mrgctx) { /* get mrgctx ptr */ ppc_mr (code, ppc_r4, PPC_FIRST_ARG_REG); } else { /* load rgctx ptr from vtable */ ppc_ldptr (code, ppc_r4, MONO_STRUCT_OFFSET (MonoVTable, runtime_generic_context), PPC_FIRST_ARG_REG); /* is the rgctx ptr null? */ ppc_compare_reg_imm (code, 0, ppc_r4, 0); /* if yes, jump to actual trampoline */ rgctx_null_jumps [0] = code; ppc_bc (code, PPC_BR_TRUE, PPC_BR_EQ, 0); } for (i = 0; i < depth; ++i) { /* load ptr to next array */ if (mrgctx && i == 0) ppc_ldptr (code, ppc_r4, MONO_SIZEOF_METHOD_RUNTIME_GENERIC_CONTEXT, ppc_r4); else ppc_ldptr (code, ppc_r4, 0, ppc_r4); /* is the ptr null? */ ppc_compare_reg_imm (code, 0, ppc_r4, 0); /* if yes, jump to actual trampoline */ rgctx_null_jumps [i + 1] = code; ppc_bc (code, PPC_BR_TRUE, PPC_BR_EQ, 0); } /* fetch slot */ ppc_ldptr (code, ppc_r4, sizeof (gpointer) * (index + 1), ppc_r4); /* is the slot null? */ ppc_compare_reg_imm (code, 0, ppc_r4, 0); /* if yes, jump to actual trampoline */ rgctx_null_jumps [depth + 1] = code; ppc_bc (code, PPC_BR_TRUE, PPC_BR_EQ, 0); /* otherwise return r4 */ /* FIXME: if we use r3 as the work register we can avoid this copy */ ppc_mr (code, ppc_r3, ppc_r4); ppc_blr (code); for (i = mrgctx ? 1 : 0; i <= depth + 1; ++i) ppc_patch (rgctx_null_jumps [i], code); g_free (rgctx_null_jumps); /* move the rgctx pointer to the VTABLE register */ ppc_mr (code, MONO_ARCH_VTABLE_REG, ppc_r3); if (aot) { code = mono_arch_emit_load_aotconst (buf, code, &ji, MONO_PATCH_INFO_JIT_ICALL_ADDR, g_strdup_printf ("specific_trampoline_lazy_fetch_%u", slot)); /* Branch to the trampoline */ #ifdef PPC_USES_FUNCTION_DESCRIPTOR ppc_ldptr (code, ppc_r12, 0, ppc_r12); #endif ppc_mtctr (code, ppc_r12); ppc_bcctr (code, PPC_BR_ALWAYS, 0); } else { tramp = mono_arch_create_specific_trampoline (GUINT_TO_POINTER (slot), MONO_TRAMPOLINE_RGCTX_LAZY_FETCH, mono_get_root_domain (), NULL); /* jump to the actual trampoline */ code = emit_trampoline_jump (code, tramp); } mono_arch_flush_icache (buf, code - buf); g_assert (code - buf <= tramp_size); char *name = mono_get_rgctx_fetch_trampoline_name (slot); *info = mono_tramp_info_create (name, buf, code - buf, ji, unwind_ops); g_free (name); return buf; } guint8* mono_arch_get_call_target (guint8 *code) { /* Should be a bl */ guint32 ins = ((guint32*)(gpointer)code) [-1]; if ((ins >> 26 == 18) && ((ins & 1) == 1) && ((ins & 2) == 0)) { gint32 disp = (((gint32)ins) >> 2) & 0xffffff; guint8 *target = code - 4 + (disp * 4); return target; } else { return NULL; } } guint32 mono_arch_get_plt_info_offset (guint8 *plt_entry, mgreg_t *regs, guint8 *code) { #ifdef PPC_USES_FUNCTION_DESCRIPTOR return ((guint32*)plt_entry) [8]; #else return ((guint32*)plt_entry) [6]; #endif }