2 * Written by J.T. Conklin <jtc@netbsd.org>.
5 * Adapted for `long double' by Ulrich Drepper <drepper@cygnus.com>.
6 * Adapted for x86-64 by Andreas Jaeger <aj@suse.de>.
9 #include <machine/asm.h>
20 ASM_TYPE_DIRECTIVE(one,@object)
22 ASM_SIZE_DIRECTIVE(one)
23 /* It is not important that this constant is precise. It is only
24 a value which is known to be on the safe side for using the
25 fyl2xp1 instruction. */
26 ASM_TYPE_DIRECTIVE(limit,@object)
28 ASM_SIZE_DIRECTIVE(limit)
32 #define MO(op) op##(%rip)
40 fldt 8(%rsp) // x : log(2)
43 fld %st // x : x : log(2)
45 jnz 3f // in case x is NaN or +-Inf
46 4: fsubl MO(one) // x-1 : x : log(2)
47 fld %st // x-1 : x-1 : x : log(2)
48 fabs // |x-1| : x-1 : x : log(2)
49 fcompl MO(limit) // x-1 : x : log(2)
50 fnstsw // x-1 : x : log(2)
53 fstp %st(1) // x-1 : log(2)
57 2: fstp %st(0) // x : log(2)
62 jnz 4b // in case x is +-Inf