40 lines
778 B
ArmAsm
40 lines
778 B
ArmAsm
/*
|
|
* Written by J.T. Conklin <jtc@netbsd.org>.
|
|
* Changes for long double by Ulrich Drepper <drepper@cygnus.com>
|
|
* Adapted for x86-64 by Andreas Jaeger <aj@suse.de>.
|
|
* Public domain.
|
|
*/
|
|
|
|
#include <machine/asm.h>
|
|
|
|
ENTRY(__ieee754_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. */
|
|
cmpb $0x40, %dh
|
|
je 2f /* Is +-Inf, jump. */
|
|
|
|
fxtract
|
|
fstp %st
|
|
|
|
fistpl -4(%rsp)
|
|
fwait
|
|
movl -4(%rsp),%eax
|
|
|
|
ret
|
|
|
|
1: fstp %st
|
|
movl $0x7fffffff, %eax
|
|
ret
|
|
2: fstp %st
|
|
movl $0x80000000, %eax /* FP_ILOGB0 */
|
|
ret
|
|
END (__ieee754_ilogbl)
|