5591bd237a
By adding __builtin_unreachable() at the end of nlr_push, we're essentially telling the compiler that this function will never return. When GCC LTO is in use, this means that any time nlr_push() is called (which is often), the compiler thinks this function will never return and thus eliminates all code following the call. Note: I've added a 'return 0' for older GCC versions like 4.6 which complain about not returning anything (which doesn't make sense in a naked function). Newer GCC versions (tested 4.8, 5.4 and some others) don't complain about this.
131 lines
5.0 KiB
C
131 lines
5.0 KiB
C
/*
|
|
* This file is part of the MicroPython project, http://micropython.org/
|
|
*
|
|
* The MIT License (MIT)
|
|
*
|
|
* Copyright (c) 2013-2017 Damien P. George
|
|
*
|
|
* 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"
|
|
|
|
#if MICROPY_NLR_THUMB
|
|
|
|
#undef nlr_push
|
|
|
|
// We only need the functions here if we are on arm/thumb, and we are not
|
|
// using setjmp/longjmp.
|
|
//
|
|
// For reference, arm/thumb callee save regs are:
|
|
// r4-r11, r13=sp
|
|
|
|
__attribute__((naked)) unsigned int nlr_push(nlr_buf_t *nlr) {
|
|
|
|
__asm volatile (
|
|
"str r4, [r0, #12] \n" // store r4 into nlr_buf
|
|
"str r5, [r0, #16] \n" // store r5 into nlr_buf
|
|
"str r6, [r0, #20] \n" // store r6 into nlr_buf
|
|
"str r7, [r0, #24] \n" // store r7 into nlr_buf
|
|
|
|
#if defined(__ARM_ARCH_6M__)
|
|
"mov r1, r8 \n"
|
|
"str r1, [r0, #28] \n" // store r8 into nlr_buf
|
|
"mov r1, r9 \n"
|
|
"str r1, [r0, #32] \n" // store r9 into nlr_buf
|
|
"mov r1, r10 \n"
|
|
"str r1, [r0, #36] \n" // store r10 into nlr_buf
|
|
"mov r1, r11 \n"
|
|
"str r1, [r0, #40] \n" // store r11 into nlr_buf
|
|
"mov r1, r13 \n"
|
|
"str r1, [r0, #44] \n" // store r13=sp into nlr_buf
|
|
"mov r1, lr \n"
|
|
"str r1, [r0, #8] \n" // store lr into nlr_buf
|
|
#else
|
|
"str r8, [r0, #28] \n" // store r8 into nlr_buf
|
|
"str r9, [r0, #32] \n" // store r9 into nlr_buf
|
|
"str r10, [r0, #36] \n" // store r10 into nlr_buf
|
|
"str r11, [r0, #40] \n" // store r11 into nlr_buf
|
|
"str r13, [r0, #44] \n" // store r13=sp into nlr_buf
|
|
"str lr, [r0, #8] \n" // store lr into nlr_buf
|
|
#endif
|
|
|
|
#if defined(__ARM_ARCH_6M__)
|
|
"ldr r1, nlr_push_tail_var \n"
|
|
"bx r1 \n" // do the rest in C
|
|
".align 2 \n"
|
|
"nlr_push_tail_var: .word nlr_push_tail \n"
|
|
#else
|
|
"b nlr_push_tail \n" // do the rest in C
|
|
#endif
|
|
);
|
|
|
|
#if defined(__GNUC__) && (__GNUC__ < 4 || (__GNUC__ == 4 && __GNUC_MINOR__ < 8))
|
|
// Older versions of gcc give an error when naked functions don't return a value
|
|
return 0;
|
|
#endif
|
|
}
|
|
|
|
NORETURN void nlr_jump(void *val) {
|
|
MP_NLR_JUMP_HEAD(val, top)
|
|
|
|
__asm volatile (
|
|
"mov r0, %0 \n" // r0 points to nlr_buf
|
|
"ldr r4, [r0, #12] \n" // load r4 from nlr_buf
|
|
"ldr r5, [r0, #16] \n" // load r5 from nlr_buf
|
|
"ldr r6, [r0, #20] \n" // load r6 from nlr_buf
|
|
"ldr r7, [r0, #24] \n" // load r7 from nlr_buf
|
|
|
|
#if defined(__ARM_ARCH_6M__)
|
|
"ldr r1, [r0, #28] \n" // load r8 from nlr_buf
|
|
"mov r8, r1 \n"
|
|
"ldr r1, [r0, #32] \n" // load r9 from nlr_buf
|
|
"mov r9, r1 \n"
|
|
"ldr r1, [r0, #36] \n" // load r10 from nlr_buf
|
|
"mov r10, r1 \n"
|
|
"ldr r1, [r0, #40] \n" // load r11 from nlr_buf
|
|
"mov r11, r1 \n"
|
|
"ldr r1, [r0, #44] \n" // load r13=sp from nlr_buf
|
|
"mov r13, r1 \n"
|
|
"ldr r1, [r0, #8] \n" // load lr from nlr_buf
|
|
"mov lr, r1 \n"
|
|
#else
|
|
"ldr r8, [r0, #28] \n" // load r8 from nlr_buf
|
|
"ldr r9, [r0, #32] \n" // load r9 from nlr_buf
|
|
"ldr r10, [r0, #36] \n" // load r10 from nlr_buf
|
|
"ldr r11, [r0, #40] \n" // load r11 from nlr_buf
|
|
"ldr r13, [r0, #44] \n" // load r13=sp from nlr_buf
|
|
"ldr lr, [r0, #8] \n" // load lr from nlr_buf
|
|
#endif
|
|
"movs r0, #1 \n" // return 1, non-local return
|
|
"bx lr \n" // return
|
|
: // output operands
|
|
: "r"(top) // input operands
|
|
: // clobbered registers
|
|
);
|
|
|
|
#if defined(__GNUC__)
|
|
__builtin_unreachable();
|
|
#else
|
|
for (;;); // needed to silence compiler warning
|
|
#endif
|
|
}
|
|
|
|
#endif // MICROPY_NLR_THUMB
|