cortex-m4/stm32f4 longjmp/setjmp implementation with FPU store/restore

gistfile1.c

/*
 * tested with gcc on an stm32f4
 * Michel Pollet <buserror@gmail.com>
 */

#if defined(__VFP_FP__)
typedef	long __jmp_buf[10 + 8 + 1];	// d8-d15 fpu + fpscr
#else
typedef	long __jmp_buf[10];
#endif

static int __setjmp(__jmp_buf buf) __attribute__ ((noinline));
static int __setjmp(__jmp_buf buf)
{
	register void * r0 __asm__("r0") = buf;
	__asm__(
		"mov     %%ip, %%sp\n"
		"stmia %[store]!, {%%r4-%%r9, %%sl, %%fp, %%ip, %%lr}\n"
#if defined(__VFP_FP__)
		"vstmia %[store]!, {%%d8-%%d15}\n"
		"vmrs    %%r1, fpscr\n"
		"str	 %%r1, [%[store]], #4\n"
#endif
		"mov.w		%r0, #0\n"
			: : [store] "r" (r0) :);
}

static void __longjmp(__jmp_buf buf, long value)  __attribute__((noreturn));

static void __longjmp(__jmp_buf buf, long value)
{
	__asm__(
		"ldmia %[load]!, {%%r4-%%r9, %%sl, %%fp, %%ip, %%lr}\n"
#if defined(__VFP_FP__)
		"vldmia	%[load]!, {%%d8-%%d15}\n"
		"ldr     %%r0, [%[load]], #4\n"
		"vmsr    fpscr, %%r0\n"
#endif
		"mov     %%sp, %%ip\n"
		"movs    %%r0, %%r1\n"
		"it      eq\n"
		"moveq   %%r0, #1\n"
		"bx      lr\n"
			: : [load] "r" (buf), [value] "r" (value):);
	__builtin_unreachable();
}