_JBLEN
#define _JBLEN 64 /* size, in longs, of a jmp_buf */
#define _JBLEN 31
#define _JBLEN 25 /* Kernel doesn't save FP and Altivec regs */
#define _JBLEN 100
#define _JBLEN 63 /* sp, ra, [f]s0-11, magic val, sigmask */
#define _JBLEN 12 /* Size of the jmp_buf on AMD64. */