xref: /netbsd-src/sys/arch/alpha/include/fpu.h (revision 90a2f3f5abfa5d17ac482bf11d5d1d4d1a916ffc)
1 /* $NetBSD: fpu.h,v 1.8 2021/07/22 01:39:18 thorpej Exp $ */
2 
3 /*-
4  * Copyright (c) 2001 Ross Harvey
5  * All rights reserved.
6  *
7  * This software was written for NetBSD.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  * 3. All advertising materials mentioning features or use of this software
18  *    must display the following acknowledgement:
19  *	This product includes software developed by the NetBSD
20  *	Foundation, Inc. and its contributors.
21  * 4. Neither the name of The NetBSD Foundation nor the names of its
22  *    contributors may be used to endorse or promote products derived
23  *    from this software without specific prior written permission.
24  *
25  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
26  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
27  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
28  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
29  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
30  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
31  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
32  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
33  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
34  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
35  * POSSIBILITY OF SUCH DAMAGE.
36  */
37 
38 #ifndef _ALPHA_FPU_H_
39 #define _ALPHA_FPU_H_
40 
41 /*
42  * Most of these next definitions were moved from <ieeefp.h>. Apparently the
43  * names happen to match those exported by Compaq and Linux from their fpu.h
44  * files.
45  */
46 
47 /*
48  * Bits in the Alpha Floating Point Control register.  This is the hardware
49  * register, and should not be directly manipulated by application software.
50  */
51 #define	FPCR_SUM	__BIT(63)	/* Summary (OR of all exception bits) */
52 #define	FPCR_INED	__BIT(62)	/* Inexact trap Disable */
53 #define	FPCR_UNFD	__BIT(61)	/* Underflow trap Disable */
54 #define	FPCR_UNDZ	__BIT(60)	/* Underflow to Zero */
55 #define	FPCR_DYN_RM	__BITS(58,59)	/* Dynamic Rounding Mode */
56 					/* 00 Chopped */
57 					/* 01 Minus Infinity */
58 					/* 10 Normal (round nearest) */
59 					/* 11 Plus Infinity */
60 #define	FPCR_IOV	__BIT(57)	/* Integer Overflow */
61 #define	FPCR_INE	__BIT(56)	/* Inexact Result */
62 #define	FPCR_UNF	__BIT(55)	/* Underflow */
63 #define	FPCR_OVF	__BIT(54)	/* Overflow */
64 #define	FPCR_DZE	__BIT(53)	/* Division By Zero */
65 #define	FPCR_INV	__BIT(52)	/* Invalid Operation */
66 #define	FPCR_OVFD	__BIT(51)	/* Overflow trap Disable */
67 #define	FPCR_DZED	__BIT(50)	/* Division By Zero trap Disable */
68 #define	FPCR_INVD	__BIT(49)	/* Invalid Operation trap Disable */
69 #define	FPCR_DNZ	__BIT(48)	/* Denormal Operands to Zero */
70 #define	FPCR_DNOD	__BIT(47)	/* Denormal Operation tap Disable */
71 
72 #define	FPCR_MIRRORED (FPCR_INE | FPCR_UNF | FPCR_OVF | FPCR_DZE | FPCR_INV)
73 #define FPCR_MIR_START 52
74 
75 /* NetBSD default - no traps enabled, round-to-nearest */
76 #define	FPCR_DEFAULT	(__SHIFTIN(FP_RN, FPCR_DYN_RM) |		\
77 			 FPCR_INED | FPCR_UNFD | FPCR_OVFD |		\
78 			 FPCR_DZED | FPCR_INVD | FPCR_DNOD)
79 
80 /*
81  * IEEE Floating Point Control (FP_C) Quadword.  This is a software
82  * virtual register that abstracts the FPCR and software complation
83  * performed by the kernel.
84  *
85  * The AARM specifies the bit positions of the software word used for
86  * user mode interface to the control and status of the kernel completion
87  * routines. Although it largely just redefines the FPCR, it shuffles
88  * the bit order. The names of the bits are defined in the AARM, and
89  * the definition prefix can easily be determined from public domain
90  * programs written to either the Compaq or Linux interfaces, which
91  * appear to be identical.
92  *
93  * Bits 63-48 are reserved for implementation software.
94  * Bits 47-23 are reserved for future archiecture definition.
95  * Bits 16-12 are reserved for implementation software.
96  * Bits 11-7 are reserved for future architecture definition.
97  * Bit 0 is reserved for implementation software.
98  */
99 
100 #define	IEEE_STATUS_DNO __BIT(22)	/* Denormal Operand */
101 #define	IEEE_STATUS_INE __BIT(21)	/* Inexact Result */
102 #define	IEEE_STATUS_UNF __BIT(20)	/* Underflow */
103 #define	IEEE_STATUS_OVF __BIT(19)	/* Overflow */
104 #define	IEEE_STATUS_DZE __BIT(18)	/* Division By Zero */
105 #define	IEEE_STATUS_INV __BIT(17)	/* Invalid Operation */
106 
107 #define	IEEE_TRAP_ENABLE_DNO __BIT(6)	/* Denormal Operation trap */
108 #define	IEEE_TRAP_ENABLE_INE __BIT(5)	/* Inexact Result trap */
109 #define	IEEE_TRAP_ENABLE_UNF __BIT(4)	/* Underflow trap */
110 #define	IEEE_TRAP_ENABLE_OVF __BIT(3)	/* Overflow trap */
111 #define	IEEE_TRAP_ENABLE_DZE __BIT(2)	/* Division By Zero trap */
112 #define	IEEE_TRAP_ENABLE_INV __BIT(1)	/* Invalid Operation trap */
113 
114 #define	IEEE_INHERIT __BIT(14)
115 #define	IEEE_MAP_UMZ __BIT(13)		/* Map underflowed outputs to zero */
116 #define	IEEE_MAP_DMZ __BIT(12)		/* Map denormal inputs to zero */
117 
118 #define	FP_C_ALLBITS	__BITS(1,22)
119 
120 #define	FP_C_MIRRORED	(IEEE_STATUS_INE | IEEE_STATUS_UNF | IEEE_STATUS_OVF \
121 			 | IEEE_STATUS_DZE | IEEE_STATUS_INV)
122 #define	FP_C_MIR_START 17
123 
124 /* NetBSD default - no traps enabled (see FPCR default) */
125 #define	FP_C_DEFAULT	0
126 
127 #ifdef _KERNEL
128 
129 #define	FLD_MASK(len) ((1UL << (len)) - 1)
130 #define FLD_CLEAR(obj, origin, len)	\
131 		((obj) & ~(FLD_MASK(len) << (origin)))
132 #define	FLD_INSERT(obj, origin, len, value)	\
133 		(FLD_CLEAR(obj, origin, len) | (value) << origin)
134 
135 #define	FP_C_TO_NETBSD_MASK(fp_c) 	((fp_c) >> 1 & 0x3f)
136 #define	FP_C_TO_NETBSD_FLAG(fp_c) 	((fp_c) >> 17 & 0x3f)
137 #define NETBSD_MASK_TO_FP_C(m)		(((m) & 0x3f) << 1)
138 #define NETBSD_FLAG_TO_FP_C(s)		(((s) & 0x3f) << 17)
139 #define	CLEAR_FP_C_MASK(fp_c)		((fp_c) & ~(0x3f << 1))
140 #define	CLEAR_FP_C_FLAG(fp_c)		((fp_c) & ~(0x3f << 17))
141 #define	SET_FP_C_MASK(fp_c, m) (CLEAR_FP_C_MASK(fp_c) | NETBSD_MASK_TO_FP_C(m))
142 #define	SET_FP_C_FLAG(fp_c, m) (CLEAR_FP_C_FLAG(fp_c) | NETBSD_FLAG_TO_FP_C(m))
143 
144 #endif /* _KERNEL */
145 
146 #endif /* _ALPHA_FPU_H_ */
147