in include/asm/traps.h [57:101]
static inline void spill_registers(void)
{
#if defined(__XTENSA_WINDOWED_ABI__)
#if XCHAL_NUM_AREGS > 16
__asm__ __volatile__ (
" call8 1f\n"
" _j 2f\n"
" retw\n"
" .align 4\n"
"1:\n"
#if XCHAL_NUM_AREGS == 32
" _entry a1, 32\n"
" addi a8, a0, 3\n"
" _entry a1, 16\n"
" mov a12, a12\n"
" retw\n"
#else
" _entry a1, 48\n"
" call12 1f\n"
" retw\n"
" .align 4\n"
"1:\n"
" .rept (" __stringify(XCHAL_NUM_AREGS) " - 16) / 12\n"
" _entry a1, 48\n"
" mov a12, a0\n"
" .endr\n"
" _entry a1, 16\n"
#if XCHAL_NUM_AREGS % 12 == 0
" mov a12, a12\n"
#elif XCHAL_NUM_AREGS % 12 == 4
" mov a4, a4\n"
#elif XCHAL_NUM_AREGS % 12 == 8
" mov a8, a8\n"
#endif
" retw\n"
#endif
"2:\n"
: : : "a8", "a9", "memory");
#else
__asm__ __volatile__ (
" mov a12, a12\n"
: : : "memory");
#endif
#endif
}