13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 *
19 * CDDL HEADER END
20 */
21 /*
22 * Copyright 2011 Nexenta Systems, Inc. All rights reserved.
23 */
24 /*
25 * Copyright 2006 Sun Microsystems, Inc. All rights reserved.
26 * Use is subject to license terms.
27 */
28
29 .file "ilogb.s"
30
31 #include "libm.h"
32 LIBM_ANSI_PRAGMA_WEAK(ilogb,function)
33 #include "libm_synonyms.h"
34 #include "xpg6.h"
35
36 .data
37 .align 8
38 two52: .long 0x0,0x43300000 / 2**52
39
40 ENTRY(ilogb)
41 movl 8(%esp),%eax / eax <-- hi_32(x)
42 andl $0x7fffffff,%eax / eax <-- hi_32(abs(x))
43 testl $0x7ff00000,%eax / is bexp(x) 0?
44 jz .bexp_0 / jump if x is 0 or subnormal
45 / biased exponent is non-zero
46 cmpl $0x7ff00000,%eax / is bexp(x) 0x7ff?
47 jae .bexp_all_1 / jump if x is NaN or Inf
48 shrl $20,%eax / eax <-- bexp(x)
49 subl $1023,%eax / unbias exponent by 1023
50 ret
51
52 .bexp_all_1:
53 movl $0x7fffffff,%eax / x is NaN or inf, so return 0x7fffffff
|
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 *
19 * CDDL HEADER END
20 */
21 /*
22 * Copyright 2011 Nexenta Systems, Inc. All rights reserved.
23 */
24 /*
25 * Copyright 2006 Sun Microsystems, Inc. All rights reserved.
26 * Use is subject to license terms.
27 */
28
29 .file "ilogb.s"
30
31 #include "libm.h"
32 LIBM_ANSI_PRAGMA_WEAK(ilogb,function)
33 #include "xpg6.h"
34
35 .data
36 .align 8
37 two52: .long 0x0,0x43300000 / 2**52
38
39 ENTRY(ilogb)
40 movl 8(%esp),%eax / eax <-- hi_32(x)
41 andl $0x7fffffff,%eax / eax <-- hi_32(abs(x))
42 testl $0x7ff00000,%eax / is bexp(x) 0?
43 jz .bexp_0 / jump if x is 0 or subnormal
44 / biased exponent is non-zero
45 cmpl $0x7ff00000,%eax / is bexp(x) 0x7ff?
46 jae .bexp_all_1 / jump if x is NaN or Inf
47 shrl $20,%eax / eax <-- bexp(x)
48 subl $1023,%eax / unbias exponent by 1023
49 ret
50
51 .bexp_all_1:
52 movl $0x7fffffff,%eax / x is NaN or inf, so return 0x7fffffff
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