/* Copyright (c) 2009, 2010, 2011, 2012 ARM Ltd. Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the ``Software''), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions: The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software. THE SOFTWARE IS PROVIDED ``AS IS'', WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */ #if defined(__aarch64__) || defined(__arm64__)|| defined (_M_ARM64) #include #include #include #include #include #include #include "internal.h" #ifdef _WIN32 #define WIN32_LEAN_AND_MEAN #include /* FlushInstructionCache */ #endif #include /* Force FFI_TYPE_LONGDOUBLE to be different than FFI_TYPE_DOUBLE; all further uses in this file will refer to the 128-bit type. */ #if FFI_TYPE_DOUBLE != FFI_TYPE_LONGDOUBLE # if FFI_TYPE_LONGDOUBLE != 4 # error FFI_TYPE_LONGDOUBLE out of date # endif #else # undef FFI_TYPE_LONGDOUBLE # define FFI_TYPE_LONGDOUBLE 4 #endif union _d { UINT64 d; UINT32 s[2]; }; struct _v { union _d d[2] __attribute__((aligned(16))); }; struct call_context { struct _v v[N_V_ARG_REG]; UINT64 x[N_X_ARG_REG]; }; #if FFI_EXEC_TRAMPOLINE_TABLE #ifdef __MACH__ #ifdef HAVE_PTRAUTH #include #endif #include #endif #else #if defined (__clang__) && defined (__APPLE__) extern void sys_icache_invalidate (void *start, size_t len); #endif static inline void ffi_clear_cache (void *start, void *end) { #if defined (__clang__) && defined (__APPLE__) sys_icache_invalidate (start, (char *)end - (char *)start); #elif defined (__GNUC__) __builtin___clear_cache (start, end); #elif defined (_WIN32) FlushInstructionCache(GetCurrentProcess(), start, (char*)end - (char*)start); #else #error "Missing builtin to flush instruction cache" #endif } #endif /* A subroutine of is_vfp_type. Given a structure type, return the type code of the first non-structure element. Recurse for structure elements. Return -1 if the structure is in fact empty, i.e. no nested elements. */ static int is_hfa0 (const ffi_type *ty) { ffi_type **elements = ty->elements; int i, ret = -1; if (elements != NULL) for (i = 0; elements[i]; ++i) { ret = elements[i]->type; if (ret == FFI_TYPE_STRUCT || ret == FFI_TYPE_COMPLEX) { ret = is_hfa0 (elements[i]); if (ret < 0) continue; } break; } return ret; } /* A subroutine of is_vfp_type. Given a structure type, return true if all of the non-structure elements are the same as CANDIDATE. */ static int is_hfa1 (const ffi_type *ty, int candidate) { ffi_type **elements = ty->elements; int i; if (elements != NULL) for (i = 0; elements[i]; ++i) { int t = elements[i]->type; if (t == FFI_TYPE_STRUCT || t == FFI_TYPE_COMPLEX) { if (!is_hfa1 (elements[i], candidate)) return 0; } else if (t != candidate) return 0; } return 1; } /* Determine if TY may be allocated to the FP registers. This is both an fp scalar type as well as an homogenous floating point aggregate (HFA). That is, a structure consisting of 1 to 4 members of all the same type, where that type is an fp scalar. Returns non-zero iff TY is an HFA. The result is the AARCH64_RET_* constant for the type. */ static int is_vfp_type (const ffi_type *ty) { ffi_type **elements; int candidate, i; size_t size, ele_count; /* Quickest tests first. */ candidate = ty->type; switch (candidate) { default: return 0; case FFI_TYPE_FLOAT: case FFI_TYPE_DOUBLE: case FFI_TYPE_LONGDOUBLE: ele_count = 1; goto done; case FFI_TYPE_COMPLEX: candidate = ty->elements[0]->type; switch (candidate) { case FFI_TYPE_FLOAT: case FFI_TYPE_DOUBLE: case FFI_TYPE_LONGDOUBLE: ele_count = 2; goto done; } return 0; case FFI_TYPE_STRUCT: break; } /* No HFA types are smaller than 4 bytes, or larger than 64 bytes. */ size = ty->size; if (size < 4 || size > 64) return 0; /* Find the type of the first non-structure member. */ elements = ty->elements; candidate = elements[0]->type; if (candidate == FFI_TYPE_STRUCT || candidate == FFI_TYPE_COMPLEX) { for (i = 0; ; ++i) { candidate = is_hfa0 (elements[i]); if (candidate >= 0) break; } } /* If the first member is not a floating point type, it's not an HFA. Also quickly re-check the size of the structure. */ switch (candidate) { case FFI_TYPE_FLOAT: ele_count = size / sizeof(float); if (size != ele_count * sizeof(float)) return 0; break; case FFI_TYPE_DOUBLE: ele_count = size / sizeof(double); if (size != ele_count * sizeof(double)) return 0; break; case FFI_TYPE_LONGDOUBLE: ele_count = size / sizeof(long double); if (size != ele_count * sizeof(long double)) return 0; break; default: return 0; } if (ele_count > 4) return 0; /* Finally, make sure that all scalar elements are the same type. */ for (i = 0; elements[i]; ++i) { int t = elements[i]->type; if (t == FFI_TYPE_STRUCT || t == FFI_TYPE_COMPLEX) { if (!is_hfa1 (elements[i], candidate)) return 0; } else if (t != candidate) return 0; } /* All tests succeeded. Encode the result. */ done: return candidate * 4 + (4 - (int)ele_count); } /* Representation of the procedure call argument marshalling state. The terse state variable names match the names used in the AARCH64 PCS. */ struct arg_state { unsigned ngrn; /* Next general-purpose register number. */ unsigned nsrn; /* Next vector register number. */ size_t nsaa; /* Next stack offset. */ #if defined (__APPLE__) unsigned allocating_variadic; #endif }; /* Initialize a procedure call argument marshalling state. */ static void arg_init (struct arg_state *state) { state->ngrn = 0; state->nsrn = 0; state->nsaa = 0; #if defined (__APPLE__) state->allocating_variadic = 0; #endif } /* Allocate an aligned slot on the stack and return a pointer to it. */ static void * allocate_to_stack (struct arg_state *state, void *stack, size_t alignment, size_t size) { size_t nsaa = state->nsaa; /* Round up the NSAA to the larger of 8 or the natural alignment of the argument's type. */ #if defined (__APPLE__) if (state->allocating_variadic && alignment < 8) alignment = 8; #else if (alignment < 8) alignment = 8; #endif nsaa = FFI_ALIGN (nsaa, alignment); state->nsaa = nsaa + size; return (char *)stack + nsaa; } static ffi_arg extend_integer_type (void *source, int type) { switch (type) { case FFI_TYPE_UINT8: return *(UINT8 *) source; case FFI_TYPE_SINT8: return *(SINT8 *) source; case FFI_TYPE_UINT16: return *(UINT16 *) source; case FFI_TYPE_SINT16: return *(SINT16 *) source; case FFI_TYPE_UINT32: return *(UINT32 *) source; case FFI_TYPE_INT: case FFI_TYPE_SINT32: return *(SINT32 *) source; case FFI_TYPE_UINT64: case FFI_TYPE_SINT64: return *(UINT64 *) source; break; case FFI_TYPE_POINTER: return *(uintptr_t *) source; default: abort(); } } #if defined(_MSC_VER) void extend_hfa_type (void *dest, void *src, int h); #else static void extend_hfa_type (void *dest, void *src, int h) { ssize_t f = h - AARCH64_RET_S4; void *x0; asm volatile ( "adr %0, 0f\n" " add %0, %0, %1\n" " br %0\n" "0: ldp s16, s17, [%3]\n" /* S4 */ " ldp s18, s19, [%3, #8]\n" " b 4f\n" " ldp s16, s17, [%3]\n" /* S3 */ " ldr s18, [%3, #8]\n" " b 3f\n" " ldp s16, s17, [%3]\n" /* S2 */ " b 2f\n" " nop\n" " ldr s16, [%3]\n" /* S1 */ " b 1f\n" " nop\n" " ldp d16, d17, [%3]\n" /* D4 */ " ldp d18, d19, [%3, #16]\n" " b 4f\n" " ldp d16, d17, [%3]\n" /* D3 */ " ldr d18, [%3, #16]\n" " b 3f\n" " ldp d16, d17, [%3]\n" /* D2 */ " b 2f\n" " nop\n" " ldr d16, [%3]\n" /* D1 */ " b 1f\n" " nop\n" " ldp q16, q17, [%3]\n" /* Q4 */ " ldp q18, q19, [%3, #32]\n" " b 4f\n" " ldp q16, q17, [%3]\n" /* Q3 */ " ldr q18, [%3, #32]\n" " b 3f\n" " ldp q16, q17, [%3]\n" /* Q2 */ " b 2f\n" " nop\n" " ldr q16, [%3]\n" /* Q1 */ " b 1f\n" "4: str q19, [%2, #48]\n" "3: str q18, [%2, #32]\n" "2: str q17, [%2, #16]\n" "1: str q16, [%2]" : "=&r"(x0) : "r"(f * 12), "r"(dest), "r"(src) : "memory", "v16", "v17", "v18", "v19"); } #endif #if defined(_MSC_VER) void* compress_hfa_type (void *dest, void *src, int h); #else static void * compress_hfa_type (void *dest, void *reg, int h) { switch (h) { case AARCH64_RET_S1: if (dest == reg) { #ifdef __AARCH64EB__ dest += 12; #endif } else *(float *)dest = *(float *)reg; break; case AARCH64_RET_S2: asm ("ldp q16, q17, [%1]\n\t" "st2 { v16.s, v17.s }[0], [%0]" : : "r"(dest), "r"(reg) : "memory", "v16", "v17"); break; case AARCH64_RET_S3: asm ("ldp q16, q17, [%1]\n\t" "ldr q18, [%1, #32]\n\t" "st3 { v16.s, v17.s, v18.s }[0], [%0]" : : "r"(dest), "r"(reg) : "memory", "v16", "v17", "v18"); break; case AARCH64_RET_S4: asm ("ldp q16, q17, [%1]\n\t" "ldp q18, q19, [%1, #32]\n\t" "st4 { v16.s, v17.s, v18.s, v19.s }[0], [%0]" : : "r"(dest), "r"(reg) : "memory", "v16", "v17", "v18", "v19"); break; case AARCH64_RET_D1: if (dest == reg) { #ifdef __AARCH64EB__ dest += 8; #endif } else *(double *)dest = *(double *)reg; break; case AARCH64_RET_D2: asm ("ldp q16, q17, [%1]\n\t" "st2 { v16.d, v17.d }[0], [%0]" : : "r"(dest), "r"(reg) : "memory", "v16", "v17"); break; case AARCH64_RET_D3: asm ("ldp q16, q17, [%1]\n\t" "ldr q18, [%1, #32]\n\t" "st3 { v16.d, v17.d, v18.d }[0], [%0]" : : "r"(dest), "r"(reg) : "memory", "v16", "v17", "v18"); break; case AARCH64_RET_D4: asm ("ldp q16, q17, [%1]\n\t" "ldp q18, q19, [%1, #32]\n\t" "st4 { v16.d, v17.d, v18.d, v19.d }[0], [%0]" : : "r"(dest), "r"(reg) : "memory", "v16", "v17", "v18", "v19"); break; default: if (dest != reg) return memcpy (dest, reg, 16 * (4 - (h & 3))); break; } return dest; } #endif /* Either allocate an appropriate register for the argument type, or if none are available, allocate a stack slot and return a pointer to the allocated space. */ static void * allocate_int_to_reg_or_stack (struct call_context *context, struct arg_state *state, void *stack, size_t size) { if (state->ngrn < N_X_ARG_REG) return &context->x[state->ngrn++]; state->ngrn = N_X_ARG_REG; return allocate_to_stack (state, stack, size, size); } ffi_status FFI_HIDDEN ffi_prep_cif_machdep (ffi_cif *cif) { ffi_type *rtype = cif->rtype; size_t bytes = cif->bytes; int flags, i, n; switch (rtype->type) { case FFI_TYPE_VOID: flags = AARCH64_RET_VOID; break; case FFI_TYPE_UINT8: flags = AARCH64_RET_UINT8; break; case FFI_TYPE_UINT16: flags = AARCH64_RET_UINT16; break; case FFI_TYPE_UINT32: flags = AARCH64_RET_UINT32; break; case FFI_TYPE_SINT8: flags = AARCH64_RET_SINT8; break; case FFI_TYPE_SINT16: flags = AARCH64_RET_SINT16; break; case FFI_TYPE_INT: case FFI_TYPE_SINT32: flags = AARCH64_RET_SINT32; break; case FFI_TYPE_SINT64: case FFI_TYPE_UINT64: flags = AARCH64_RET_INT64; break; case FFI_TYPE_POINTER: flags = (sizeof(void *) == 4 ? AARCH64_RET_UINT32 : AARCH64_RET_INT64); break; case FFI_TYPE_FLOAT: case FFI_TYPE_DOUBLE: case FFI_TYPE_LONGDOUBLE: case FFI_TYPE_STRUCT: case FFI_TYPE_COMPLEX: flags = is_vfp_type (rtype); if (flags == 0) { size_t s = rtype->size; if (s > 16) { flags = AARCH64_RET_VOID | AARCH64_RET_IN_MEM; bytes += 8; } else if (s == 16) flags = AARCH64_RET_INT128; else if (s == 8) flags = AARCH64_RET_INT64; else flags = AARCH64_RET_INT128 | AARCH64_RET_NEED_COPY; } break; default: abort(); } for (i = 0, n = cif->nargs; i < n; i++) if (is_vfp_type (cif->arg_types[i])) { flags |= AARCH64_FLAG_ARG_V; break; } /* Round the stack up to a multiple of the stack alignment requirement. */ cif->bytes = (unsigned) FFI_ALIGN(bytes, 16); cif->flags = flags; #if defined (__APPLE__) cif->aarch64_nfixedargs = 0; #endif return FFI_OK; } #if defined (__APPLE__) /* Perform Apple-specific cif processing for variadic calls */ ffi_status FFI_HIDDEN ffi_prep_cif_machdep_var(ffi_cif *cif, unsigned int nfixedargs, unsigned int ntotalargs) { ffi_status status = ffi_prep_cif_machdep (cif); cif->aarch64_nfixedargs = nfixedargs; return status; } #else ffi_status FFI_HIDDEN ffi_prep_cif_machdep_var(ffi_cif *cif, unsigned int nfixedargs, unsigned int ntotalargs) { ffi_status status = ffi_prep_cif_machdep (cif); cif->flags |= AARCH64_FLAG_VARARG; return status; } #endif /* __APPLE__ */ extern void ffi_call_SYSV (struct call_context *context, void *frame, void (*fn)(void), void *rvalue, int flags, void *closure) FFI_HIDDEN; /* Call a function with the provided arguments and capture the return value. */ static void ffi_call_int (ffi_cif *cif, void (*fn)(void), void *orig_rvalue, void **avalue, void *closure) { struct call_context *context; void *stack, *frame, *rvalue; struct arg_state state; size_t stack_bytes, rtype_size, rsize; int i, nargs, flags, isvariadic = 0; ffi_type *rtype; flags = cif->flags; rtype = cif->rtype; rtype_size = rtype->size; stack_bytes = cif->bytes; if (flags & AARCH64_FLAG_VARARG) { isvariadic = 1; flags &= ~AARCH64_FLAG_VARARG; } /* If the target function returns a structure via hidden pointer, then we cannot allow a null rvalue. Otherwise, mash a null rvalue to void return type. */ rsize = 0; if (flags & AARCH64_RET_IN_MEM) { if (orig_rvalue == NULL) rsize = rtype_size; } else if (orig_rvalue == NULL) flags &= AARCH64_FLAG_ARG_V; else if (flags & AARCH64_RET_NEED_COPY) rsize = 16; /* Allocate consectutive stack for everything we'll need. The frame uses 40 bytes for: lr, fp, rvalue, flags, sp */ context = alloca (sizeof(struct call_context) + stack_bytes + 40 + rsize); stack = context + 1; frame = (void*)((uintptr_t)stack + (uintptr_t)stack_bytes); rvalue = (rsize ? (void*)((uintptr_t)frame + 40) : orig_rvalue); arg_init (&state); for (i = 0, nargs = cif->nargs; i < nargs; i++) { ffi_type *ty = cif->arg_types[i]; size_t s = ty->size; void *a = avalue[i]; int h, t; t = ty->type; switch (t) { case FFI_TYPE_VOID: FFI_ASSERT (0); break; /* If the argument is a basic type the argument is allocated to an appropriate register, or if none are available, to the stack. */ case FFI_TYPE_INT: case FFI_TYPE_UINT8: case FFI_TYPE_SINT8: case FFI_TYPE_UINT16: case FFI_TYPE_SINT16: case FFI_TYPE_UINT32: case FFI_TYPE_SINT32: case FFI_TYPE_UINT64: case FFI_TYPE_SINT64: case FFI_TYPE_POINTER: do_pointer: { ffi_arg ext = extend_integer_type (a, t); if (state.ngrn < N_X_ARG_REG) context->x[state.ngrn++] = ext; else { void *d = allocate_to_stack (&state, stack, ty->alignment, s); state.ngrn = N_X_ARG_REG; /* Note that the default abi extends each argument to a full 64-bit slot, while the iOS abi allocates only enough space. */ #ifdef __APPLE__ memcpy(d, a, s); #else *(ffi_arg *)d = ext; #endif } } break; case FFI_TYPE_FLOAT: case FFI_TYPE_DOUBLE: case FFI_TYPE_LONGDOUBLE: case FFI_TYPE_STRUCT: case FFI_TYPE_COMPLEX: { void *dest; h = is_vfp_type (ty); if (h) { int elems = 4 - (h & 3); if (cif->abi == FFI_WIN64 && isvariadic) { if (state.ngrn + elems <= N_X_ARG_REG) { dest = &context->x[state.ngrn]; state.ngrn += elems; extend_hfa_type(dest, a, h); break; } state.nsrn = N_X_ARG_REG; dest = allocate_to_stack(&state, stack, ty->alignment, s); } else { if (state.nsrn + elems <= N_V_ARG_REG) { dest = &context->v[state.nsrn]; state.nsrn += elems; extend_hfa_type (dest, a, h); break; } state.nsrn = N_V_ARG_REG; dest = allocate_to_stack (&state, stack, ty->alignment, s); } } else if (s > 16) { /* If the argument is a composite type that is larger than 16 bytes, then the argument has been copied to memory, and the argument is replaced by a pointer to the copy. */ a = &avalue[i]; t = FFI_TYPE_POINTER; s = sizeof (void *); goto do_pointer; } else { size_t n = (s + 7) / 8; if (state.ngrn + n <= N_X_ARG_REG) { /* If the argument is a composite type and the size in double-words is not more than the number of available X registers, then the argument is copied into consecutive X registers. */ dest = &context->x[state.ngrn]; state.ngrn += (unsigned int)n; } else { /* Otherwise, there are insufficient X registers. Further X register allocations are prevented, the NSAA is adjusted and the argument is copied to memory at the adjusted NSAA. */ state.ngrn = N_X_ARG_REG; dest = allocate_to_stack (&state, stack, ty->alignment, s); } } memcpy (dest, a, s); } break; default: abort(); } #if defined (__APPLE__) if (i + 1 == cif->aarch64_nfixedargs) { state.ngrn = N_X_ARG_REG; state.nsrn = N_V_ARG_REG; state.allocating_variadic = 1; } #endif } ffi_call_SYSV (context, frame, fn, rvalue, flags, closure); if (flags & AARCH64_RET_NEED_COPY) memcpy (orig_rvalue, rvalue, rtype_size); } void ffi_call (ffi_cif *cif, void (*fn) (void), void *rvalue, void **avalue) { ffi_call_int (cif, fn, rvalue, avalue, NULL); } #if FFI_CLOSURES #ifdef FFI_GO_CLOSURES void ffi_call_go (ffi_cif *cif, void (*fn) (void), void *rvalue, void **avalue, void *closure) { ffi_call_int (cif, fn, rvalue, avalue, closure); } #endif /* FFI_GO_CLOSURES */ /* Build a trampoline. */ extern void ffi_closure_SYSV (void) FFI_HIDDEN; extern void ffi_closure_SYSV_V (void) FFI_HIDDEN; #if defined(FFI_EXEC_STATIC_TRAMP) extern void ffi_closure_SYSV_alt (void) FFI_HIDDEN; extern void ffi_closure_SYSV_V_alt (void) FFI_HIDDEN; #endif ffi_status ffi_prep_closure_loc (ffi_closure *closure, ffi_cif* cif, void (*fun)(ffi_cif*,void*,void**,void*), void *user_data, void *codeloc) { if (cif->abi != FFI_SYSV && cif->abi != FFI_WIN64) return FFI_BAD_ABI; void (*start)(void); if (cif->flags & AARCH64_FLAG_ARG_V) start = ffi_closure_SYSV_V; else start = ffi_closure_SYSV; #if FFI_EXEC_TRAMPOLINE_TABLE #ifdef __MACH__ #ifdef HAVE_PTRAUTH codeloc = ptrauth_auth_data(codeloc, ptrauth_key_function_pointer, 0); #endif void **config = (void **)((uint8_t *)codeloc - PAGE_MAX_SIZE); config[0] = closure; config[1] = start; #endif #else static const unsigned char trampoline[16] = { 0x90, 0x00, 0x00, 0x58, /* ldr x16, tramp+16 */ 0xf1, 0xff, 0xff, 0x10, /* adr x17, tramp+0 */ 0x00, 0x02, 0x1f, 0xd6 /* br x16 */ }; char *tramp = closure->tramp; #if defined(FFI_EXEC_STATIC_TRAMP) if (ffi_tramp_is_present(closure)) { /* Initialize the static trampoline's parameters. */ if (start == ffi_closure_SYSV_V) start = ffi_closure_SYSV_V_alt; else start = ffi_closure_SYSV_alt; ffi_tramp_set_parms (closure->ftramp, start, closure); goto out; } #endif /* Initialize the dynamic trampoline. */ memcpy (tramp, trampoline, sizeof(trampoline)); *(UINT64 *)(tramp + 16) = (uintptr_t)start; ffi_clear_cache(tramp, tramp + FFI_TRAMPOLINE_SIZE); /* Also flush the cache for code mapping. */ #ifdef _WIN32 // Not using dlmalloc.c for Windows ARM64 builds // so calling ffi_data_to_code_pointer() isn't necessary unsigned char *tramp_code = tramp; #else unsigned char *tramp_code = ffi_data_to_code_pointer (tramp); #endif ffi_clear_cache (tramp_code, tramp_code + FFI_TRAMPOLINE_SIZE); out: #endif closure->cif = cif; closure->fun = fun; closure->user_data = user_data; return FFI_OK; } #ifdef FFI_GO_CLOSURES extern void ffi_go_closure_SYSV (void) FFI_HIDDEN; extern void ffi_go_closure_SYSV_V (void) FFI_HIDDEN; ffi_status ffi_prep_go_closure (ffi_go_closure *closure, ffi_cif* cif, void (*fun)(ffi_cif*,void*,void**,void*)) { void (*start)(void); if (cif->abi != FFI_SYSV && cif->abi != FFI_WIN64) return FFI_BAD_ABI; if (cif->flags & AARCH64_FLAG_ARG_V) start = ffi_go_closure_SYSV_V; else start = ffi_go_closure_SYSV; closure->tramp = start; closure->cif = cif; closure->fun = fun; return FFI_OK; } #endif /* FFI_GO_CLOSURES */ /* Primary handler to setup and invoke a function within a closure. A closure when invoked enters via the assembler wrapper ffi_closure_SYSV(). The wrapper allocates a call context on the stack, saves the interesting registers (from the perspective of the calling convention) into the context then passes control to ffi_closure_SYSV_inner() passing the saved context and a pointer to the stack at the point ffi_closure_SYSV() was invoked. On the return path the assembler wrapper will reload call context registers. ffi_closure_SYSV_inner() marshalls the call context into ffi value descriptors, invokes the wrapped function, then marshalls the return value back into the call context. */ int FFI_HIDDEN ffi_closure_SYSV_inner (ffi_cif *cif, void (*fun)(ffi_cif*,void*,void**,void*), void *user_data, struct call_context *context, void *stack, void *rvalue, void *struct_rvalue) { void **avalue = (void**) alloca (cif->nargs * sizeof (void*)); int i, h, nargs, flags, isvariadic = 0; struct arg_state state; arg_init (&state); flags = cif->flags; if (flags & AARCH64_FLAG_VARARG) { isvariadic = 1; flags &= ~AARCH64_FLAG_VARARG; } for (i = 0, nargs = cif->nargs; i < nargs; i++) { ffi_type *ty = cif->arg_types[i]; int t = ty->type; size_t n, s = ty->size; switch (t) { case FFI_TYPE_VOID: FFI_ASSERT (0); break; case FFI_TYPE_INT: case FFI_TYPE_UINT8: case FFI_TYPE_SINT8: case FFI_TYPE_UINT16: case FFI_TYPE_SINT16: case FFI_TYPE_UINT32: case FFI_TYPE_SINT32: case FFI_TYPE_UINT64: case FFI_TYPE_SINT64: case FFI_TYPE_POINTER: avalue[i] = allocate_int_to_reg_or_stack (context, &state, stack, s); break; case FFI_TYPE_FLOAT: case FFI_TYPE_DOUBLE: case FFI_TYPE_LONGDOUBLE: case FFI_TYPE_STRUCT: case FFI_TYPE_COMPLEX: h = is_vfp_type (ty); if (h) { n = 4 - (h & 3); if (cif->abi == FFI_WIN64 && isvariadic) { if (state.ngrn + n <= N_X_ARG_REG) { void *reg = &context->x[state.ngrn]; state.ngrn += (unsigned int)n; /* Eeek! We need a pointer to the structure, however the homogeneous float elements are being passed in individual registers, therefore for float and double the structure is not represented as a contiguous sequence of bytes in our saved register context. We don't need the original contents of the register storage, so we reformat the structure into the same memory. */ avalue[i] = compress_hfa_type(reg, reg, h); } else { state.ngrn = N_X_ARG_REG; state.nsrn = N_V_ARG_REG; avalue[i] = allocate_to_stack(&state, stack, ty->alignment, s); } } else { if (state.nsrn + n <= N_V_ARG_REG) { void *reg = &context->v[state.nsrn]; state.nsrn += (unsigned int)n; avalue[i] = compress_hfa_type(reg, reg, h); } else { state.nsrn = N_V_ARG_REG; avalue[i] = allocate_to_stack(&state, stack, ty->alignment, s); } } } else if (s > 16) { /* Replace Composite type of size greater than 16 with a pointer. */ avalue[i] = *(void **) allocate_int_to_reg_or_stack (context, &state, stack, sizeof (void *)); } else { n = (s + 7) / 8; if (state.ngrn + n <= N_X_ARG_REG) { avalue[i] = &context->x[state.ngrn]; state.ngrn += (unsigned int)n; } else { state.ngrn = N_X_ARG_REG; avalue[i] = allocate_to_stack(&state, stack, ty->alignment, s); } } break; default: abort(); } #if defined (__APPLE__) if (i + 1 == cif->aarch64_nfixedargs) { state.ngrn = N_X_ARG_REG; state.nsrn = N_V_ARG_REG; state.allocating_variadic = 1; } #endif } if (flags & AARCH64_RET_IN_MEM) rvalue = struct_rvalue; fun (cif, rvalue, avalue, user_data); return flags; } #if defined(FFI_EXEC_STATIC_TRAMP) void * ffi_tramp_arch (size_t *tramp_size, size_t *map_size) { extern void *trampoline_code_table; *tramp_size = AARCH64_TRAMP_SIZE; *map_size = AARCH64_TRAMP_MAP_SIZE; return &trampoline_code_table; } #endif #endif /* FFI_CLOSURES */ #endif /* (__aarch64__) || defined(__arm64__)|| defined (_M_ARM64)*/