blob: 174647344dd4a87bd4e544d2f89d2e6187955481 (
plain) (
blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
|
/*
* 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)
|
