xref: /freebsd/lib/libc/arm/aeabi/aeabi_asm_float.S (revision 43d55325406e96e37be661de52289c2592c82ec9)
1/*
2 * Copyright (C) 2014 Andrew Turner
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 *
26 */
27
28#include <machine/asm.h>
29__FBSDID("$FreeBSD$");
30
31#define	PCR_Z	(1 << 30)
32#define	PCR_C	(1 << 29)
33
34/*
35 * These functions return the result in the CPSR register.
36 *
37 * For __aeabi_cfcmple:
38 *      Z C
39 *   LT 0 0
40 *   EQ 1 1
41 * else 0 1
42 *
43 * __aeabi_cfrcmple is the same as __aeabi_cfcmple, however the arguments
44 * have been swapped.
45 */
46ENTRY(__aeabi_cfcmple)
47	push	{r4, r5, ip, lr}
48
49	/* Backup the input registers */
50	mov	r4, r0
51	mov	r5, r1
52	/* Is it less than? */
53	bl	__aeabi_fcmplt
54	cmp	r0, #1
55	bne	1f
56	/* Yes, clear Z and C */
57	msr	cpsr_c, #(0)
58	b	99f
59
601:
61	/* Restore the input regsters for the next function call */
62	mov	r0, r4
63	mov	r1, r5
64	/* Is it equal? */
65	bl	__aeabi_fcmpeq
66	cmp	r0, #1
67	bne	2f
68	/* Yes, set Z and C */
69	msr	cpsr_c, #(PCR_Z | PCR_C)
70	b 99f
71
722:
73	/* Not less than or equal, set C and clear Z */
74	msr	cpsr_c, #(PCR_C)
75
7699:
77	pop	{r4, r5, ip, pc}
78END(__aeabi_cfcmple)
79
80ENTRY(__aeabi_cfrcmple)
81	/* Swap the arguments */
82	mov	ip, r0
83	mov	r0, r1
84	mov	r1, ip
85
86	b	__aeabi_cfcmple
87END(__aeabi_cfrcmple)
88
89/*
90 * This is just like __aeabi_cfcmple except it will not throw an exception
91 * in the presence of a quiet NaN. If either argument is a signalling NaN we
92 * will still signal.
93 */
94ENTRY(__aeabi_cfcmpeq)
95	/* Check if we can call __aeabi_cfcmple safely */
96	push	{r0, r1, r2, lr}
97	bl	__aeabi_cfcmpeq_helper
98	cmp	r0, #1
99	pop	{r0, r1, r2, lr}
100	beq	1f
101
102	bl	__aeabi_cfcmple
103	RET
104
1051:
106	msreq	cpsr_c, #(PCR_C)
107	RET
108END(__aeabi_cfcmpeq)
109