4
// Copyright (c) 2000 - 2003, Intel Corporation
5
// All rights reserved.
7
// Contributed 2000 by the Intel Numerics Group, Intel Corporation
9
// Redistribution and use in source and binary forms, with or without
10
// modification, are permitted provided that the following conditions are
13
// * Redistributions of source code must retain the above copyright
14
// notice, this list of conditions and the following disclaimer.
16
// * Redistributions in binary form must reproduce the above copyright
17
// notice, this list of conditions and the following disclaimer in the
18
// documentation and/or other materials provided with the distribution.
20
// * The name of Intel Corporation may not be used to endorse or promote
21
// products derived from this software without specific prior written
24
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
25
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
26
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
27
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL INTEL OR ITS
28
// CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
29
// EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
30
// PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
31
// PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
32
// OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY OR TORT (INCLUDING
33
// NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
34
// SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
36
// Intel Corporation is the author of this code, and requests that all
37
// problem reports or change requests be submitted to it directly at
38
// http://www.intel.com/software/products/opensource/libraries/num.htm.
41
//==============================================================
42
// 02/02/00 Initial version
43
// 04/04/00 Unwind support added
44
// 05/31/00 Fixed bug when x a double-extended denormal
45
// 05/20/02 Cleaned up namespace and sf0 syntax
46
// 02/10/03 Reordered header: .section, .global, .proc, .align
49
//==============================================================
50
// double significand(double x)
52
// Overview of operation
53
//==============================================================
54
// If x = sig * 2**n with 1 <= sig < 2
55
// significand returns sig
57
// predicate registers used:
60
// floating-point registers used:
64
GLOBAL_LIBM_ENTRY(significand)
66
// qnan snan inf norm unorm 0 -+
69
// f10 gets f8(sign) with f1(exp,significand)
81
// Test for denormal input
84
fclass.m.unc p7,p0 = f8, 0x0b
88
// p6 = TRUE ==> x is not (nan,inf,0)
89
// return sign(f8) exp(f1) significand(f8)
90
// else x is (nan,inf,0)
91
// return sign(f8) exp(f8) significand(f8), normalized.
94
fclass.m.unc p0,p6 = f8, 0xe7
101
(p7) br.cond.spnt SIGNIFICAND_DENORM ;; // Branch if x denormal
106
(p6) fmerge.se f8 = f10,f8
120
fmerge.se f8 = f10,f9
124
// Check if fnorm(x) still denormal, means x double-extended denormal
127
fclass.m.unc p7,p0 = f9, 0x0b
131
// This will be the final result unless x double-extended denormal
138
// If x double-extended denorm, then significand ok, but must merge in
142
(p7) fmerge.se f8 = f10,f8
146
// Final normalization if x double-extended denorm
149
(p7) fnorm.d.s0 f8 = f8
153
GLOBAL_LIBM_END(significand)