about summary refs log tree commit diff
path: root/sysdeps/sparc/sparc32/sparcv9/fpu/s_ceilf.S
blob: fbc6faa7d79b54f2661975b1499026bce9e94d4a (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
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
/* Float ceil function, sparc32 v9 version.
   Copyright (C) 2012 Free Software Foundation, Inc.
   This file is part of the GNU C Library.
   Contributed by David S. Miller <davem@davemloft.net>, 2012.

   The GNU C Library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public
   License as published by the Free Software Foundation; either
   version 2.1 of the License, or (at your option) any later version.

   The GNU C Library is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public
   License along with the GNU C Library; if not, see
   <http://www.gnu.org/licenses/>.  */

#include <sysdep.h>

	/* Since changing the rounding mode is extremely expensive, we
	 * try to round up using a method that is rounding mode
	 * agnostic.
	 *
	 * We add then subtract (or subtract than add if the initial
	 * value was negative) 2**23 to the value, then subtract it
	 * back out.
	 *
	 * This will clear out the fractional portion of the value.
	 * One of two things will happen for non-whole initial values.
	 * Either the rounding mode will round it up, or it will be
	 * rounded down.  If the value started out whole, it will be
	 * equal after the addition and subtraction.  This means we
	 * can accurately detect with one test whether we need to add
	 * another 1.0 to round it up properly.
	 *
	 * We pop constants into the FPU registers using the incoming
	 * argument stack slots, since this avoid having to use any PIC
	 * references.  We also thus avoid having to allocate a register
	 * window.
	 *
	 * VIS instructions are used to facilitate the formation of
	 * easier constants, and the propagation of the sign bit.
	 */

#define TWO_TWENTYTHREE	0x4b000000		/* 2**23 */
#define ONE_DOT_ZERO	0x3f800000		/* 1.0 */

#define ZERO		%f10			/* 0.0 */
#define SIGN_BIT	%f12			/* -0.0 */

ENTRY (__ceilf)
	st	%o0, [%sp + 68]
	sethi	%hi(TWO_TWENTYTHREE), %o2
	sethi	%hi(ONE_DOT_ZERO), %o3
	fzeros	ZERO

	ld	[%sp + 68], %f0
	fnegs	ZERO, SIGN_BIT

	st	%o2, [%sp + 68]
	fabss	%f0, %f14

	ld	[%sp + 68], %f16
	fcmps	%fcc3, %f14, %f16

	fmovsuge %fcc3, ZERO, %f16
	fands	%f0, SIGN_BIT, SIGN_BIT

	fors	%f16, SIGN_BIT, %f16
	fadds	%f0, %f16, %f1
	fsubs	%f1, %f16, %f1
	fcmps	%fcc2, %f1, %f0
	st	%o3, [%fp + 68]

	ld	[%fp + 68], %f9
	fmovsuge %fcc2, ZERO, %f9
	fadds	%f1, %f9, %f0
	fabss	%f0, %f0
	retl
	 fors	%f0, SIGN_BIT, %f0
END (__ceilf)
weak_alias (__ceilf, ceilf)