/* * Written by J.T. Conklin . * Changes for long double by Ulrich Drepper * Adapted for x86-64 by Andreas Jaeger . * Public domain. */ #include ENTRY(__ilogbl) fldt 8(%rsp) /* I added the following ugly construct because ilogb(+-Inf) is required to return INT_MAX in ISO C99. -- jakub@redhat.com. */ fxam /* Is NaN or +-Inf? */ fstsw %ax movb $0x45, %dh andb %ah, %dh cmpb $0x05, %dh je 1f /* Is +-Inf, jump. */ fxtract fstp %st fistpl -4(%rsp) fwait movl -4(%rsp),%eax ret 1: fstp %st movl $0x7fffffff, %eax ret END (__ilogbl) weak_alias (__ilogbl, ilogbl)