micropython/py/nlraarch64.c

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2.6 KiB
C
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2021-02-17 23:28:42 +00:00
/*
* This file is part of the MicroPython project, http://micropython.org/
*
* The MIT License (MIT)
*
* Copyright (c) 2021 Yonatan Goldschmidt
*
* 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.
*/
#include "py/mpstate.h" // needed for NLR defs
#if MICROPY_NLR_AARCH64
// AArch64 callee-saved registers are x19-x29.
// https://en.wikipedia.org/wiki/Calling_convention#ARM_(A64)
// Implemented purely as inline assembly; inside a function, we have to deal with undoing the prologue, restoring
// SP and LR. This way, we don't.
__asm(
"nlr_push: \n"
".global nlr_push \n"
"mov x9, sp \n"
"stp lr, x9, [x0, #16]\n" // 16 == offsetof(nlr_buf_t, regs)
"stp x19, x20, [x0, #32]\n"
"stp x21, x22, [x0, #48]\n"
"stp x23, x24, [x0, #64]\n"
"stp x25, x26, [x0, #80]\n"
"stp x27, x28, [x0, #96]\n"
"str x29, [x0, #112]\n"
"b nlr_push_tail \n" // do the rest in C
);
NORETURN void nlr_jump(void *val) {
MP_NLR_JUMP_HEAD(val, top)
MP_STATIC_ASSERT(offsetof(nlr_buf_t, regs) == 16); // asm assumes it
__asm volatile (
"ldr x29, [%0, #112]\n"
"ldp x27, x28, [%0, #96]\n"
"ldp x25, x26, [%0, #80]\n"
"ldp x23, x24, [%0, #64]\n"
"ldp x21, x22, [%0, #48]\n"
"ldp x19, x20, [%0, #32]\n"
"ldp lr, x9, [%0, #16]\n" // 16 == offsetof(nlr_buf_t, regs)
"mov sp, x9 \n"
"mov x0, #1 \n" // non-local return
"ret \n"
:
: "r" (top)
:
);
MP_UNREACHABLE
}
#endif // MICROPY_NLR_AARCH64