uae_cpu/fpu/rounding.h

/*
 *  fpu/rounding.h - system-dependant FPU rounding mode and precision
 *
 *  Basilisk II (C) 1997-1999 Christian Bauer
 *
 *  MC68881/68040 fpu emulation
 *  
 *  Original UAE FPU, copyright 1996 Herman ten Brugge
 *  Rewrite for x86, copyright 1999-2000 Lauri Pesonen
 *  New framework, copyright 2000 Gwenole Beauchesne
 *  Adapted for JIT compilation (c) Bernd Meyer, 2000
 *  
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program 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 General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

#ifndef FPU_ROUNDING_H
#define FPU_ROUNDING_H

/* NOTE: this file shall be included from fpu/fpu_*.cpp */
#undef  PUBLIC
#define PUBLIC  extern

#undef  PRIVATE
#define PRIVATE static

#undef  FFPU
#define FFPU    /**/

#undef  FPU
#define FPU     fpu.

/* Defaults to generic rounding mode and precision handling */
#define FPU_USE_GENERIC_ROUNDING_MODE
#define FPU_USE_GENERIC_ROUNDING_PRECISION

/* -------------------------------------------------------------------------- */
/* --- Selection of floating-point rounding mode and precision            --- */
/* -------------------------------------------------------------------------- */

/* Optimized i386 fpu core must use native rounding mode */
#if defined(FPU_X86) && defined(USE_X87_ASSEMBLY)
# undef FPU_USE_GENERIC_ROUNDING_MODE
# define FPU_USE_X86_ROUNDING_MODE
#endif

/* Optimized i386 fpu core must use native rounding precision */
#if defined(FPU_X86) && defined(USE_X87_ASSEMBLY)
# undef FPU_USE_GENERIC_ROUNDING_PRECISION
# define FPU_USE_X86_ROUNDING_PRECISION
#endif

#if 0 // gb-- FIXME: that doesn't work
/* IEEE-based fpu core can have native rounding mode on i386 */
#if defined(FPU_IEEE) && defined(USE_X87_ASSEMBLY)
# undef FPU_USE_GENERIC_ROUNDING_MODE
# define FPU_USE_X86_ROUNDING_MODE
#endif

/* IEEE-based fpu core can have native rounding precision on i386 */
#if defined(FPU_IEEE) && defined(USE_X87_ASSEMBLY)
# undef FPU_USE_GENERIC_ROUNDING_PRECISION
# define FPU_USE_X86_ROUNDING_PRECISION
#endif
#endif

/* -------------------------------------------------------------------------- */
/* --- Sanity checks                                                      --- */
/* -------------------------------------------------------------------------- */

/* X86 rounding mode and precision work together */
#if defined(FPU_USE_X86_ROUNDING_MODE) && defined(FPU_USE_X86_ROUNDING_PRECISION)
# define FPU_USE_X86_ROUNDING
# define CW_INITIAL (CW_RESET|CW_X|CW_PC_EXTENDED|CW_RC_NEAR|CW_PM|CW_UM|CW_OM|CW_ZM|CW_DM|CW_IM)
  PRIVATE uae_u32 x86_control_word;
#endif

/* Control word -- rounding mode */
#ifdef FPU_USE_X86_ROUNDING_MODE
PUBLIC const uae_u32 x86_control_word_rm_mac2host[];
#endif

/* Control word -- rounding precision */
#ifdef FPU_USE_X86_ROUNDING_PRECISION
PUBLIC const uae_u32 x86_control_word_rp_mac2host[];
#endif

#if defined(FPU_USE_X86_ROUNDING_MODE) && defined(FPU_USE_X86_ROUNDING_PRECISION)
/* Set host control word for rounding mode and rounding precision */
PRIVATE inline void set_host_control_word(void)
{
        /*
                Exception enable byte is ignored, but the same value is returned
                that was previously set.
        */
        x86_control_word
                = (x86_control_word & ~(X86_ROUNDING_MODE|X86_ROUNDING_PRECISION))
                | x86_control_word_rm_mac2host[(FPU fpcr.rounding_mode & FPCR_ROUNDING_MODE) >> 4]
                | x86_control_word_rp_mac2host[(FPU fpcr.rounding_precision & FPCR_ROUNDING_PRECISION) >> 6]
                ;
        __asm__ __volatile__("fldcw %0" : : "m" (x86_control_word));
}
#endif

/* -------------------------------------------------------------------------- */
/* --- Generic rounding mode and precision                                --- */
/* -------------------------------------------------------------------------- */

#if defined(FPU_USE_GENERIC_ROUNDING_MODE) && defined(FPU_USE_GENERIC_ROUNDING_PRECISION)
/* Set host control word for rounding mode and rounding precision */
PRIVATE inline void set_host_control_word(void)
        { }
#endif

/* -------------------------------------------------------------------------- */
/* --- Common rounding mode and precision                                 --- */
/* -------------------------------------------------------------------------- */

#if defined(FPU_USE_GENERIC_ROUNDING_MODE) || defined(FPU_USE_X86_ROUNDING_MODE)

/* Return the current rounding mode in m68k format */
static inline uae_u32 FFPU get_rounding_mode(void)
        { return FPU fpcr.rounding_mode; }

/* Convert and set to native rounding mode */
static inline void FFPU set_rounding_mode(uae_u32 new_rounding_mode)
        { FPU fpcr.rounding_mode = new_rounding_mode; }

#endif

#if defined(FPU_USE_GENERIC_ROUNDING_PRECISION) || defined(FPU_USE_X86_ROUNDING_PRECISION)

/* Return the current rounding precision in m68k format */
static inline uae_u32 FFPU get_rounding_precision(void)
        { return FPU fpcr.rounding_precision; }

/* Convert and set to native rounding precision */
static inline void FFPU set_rounding_precision(uae_u32 new_rounding_precision)
        { FPU fpcr.rounding_precision = new_rounding_precision; }

#endif

#endif /* FPU_ROUNDING_H */
Revision:	1.3
Committed:	2002-11-16T15:28:25Z (22 years ago) by gbeauche
Content type:	text/plain
Branch:	MAIN
CVS Tags:	nigel-build-12, nigel-build-13
Changes since 1.2:	+4 -4 lines
Log Message:	Use old x87 FPU stack on x86-64 too because we now use long doubles there for better accuracy. Aka. prefer compatibility over speed.
#	Content
1	/*
2	* fpu/rounding.h - system-dependant FPU rounding mode and precision
3	*
4	* Basilisk II (C) 1997-1999 Christian Bauer
5	*
6	* MC68881/68040 fpu emulation
7	*
8	* Original UAE FPU, copyright 1996 Herman ten Brugge
9	* Rewrite for x86, copyright 1999-2000 Lauri Pesonen
10	* New framework, copyright 2000 Gwenole Beauchesne
11	* Adapted for JIT compilation (c) Bernd Meyer, 2000
12	*
13	* This program is free software; you can redistribute it and/or modify
14	* it under the terms of the GNU General Public License as published by
15	* the Free Software Foundation; either version 2 of the License, or
16	* (at your option) any later version.
17	*
18	* This program is distributed in the hope that it will be useful,
19	* but WITHOUT ANY WARRANTY; without even the implied warranty of
20	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
21	* GNU General Public License for more details.
22	*
23	* You should have received a copy of the GNU General Public License
24	* along with this program; if not, write to the Free Software
25	* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
26	*/
27
28	#ifndef FPU_ROUNDING_H
29	#define FPU_ROUNDING_H
30
31	/* NOTE: this file shall be included from fpu/fpu_.cpp /
32	#undef PUBLIC
33	#define PUBLIC extern
34
35	#undef PRIVATE
36	#define PRIVATE static
37
38	#undef FFPU
39	#define FFPU /**/
40
41	#undef FPU
42	#define FPU fpu.
43
44	/* Defaults to generic rounding mode and precision handling */
45	#define FPU_USE_GENERIC_ROUNDING_MODE
46	#define FPU_USE_GENERIC_ROUNDING_PRECISION
47
48	/* -------------------------------------------------------------------------- */
49	/* --- Selection of floating-point rounding mode and precision --- */
50	/* -------------------------------------------------------------------------- */
51
52	/* Optimized i386 fpu core must use native rounding mode */
53	#if defined(FPU_X86) && defined(USE_X87_ASSEMBLY)
54	# undef FPU_USE_GENERIC_ROUNDING_MODE
55	# define FPU_USE_X86_ROUNDING_MODE
56	#endif
57
58	/* Optimized i386 fpu core must use native rounding precision */
59	#if defined(FPU_X86) && defined(USE_X87_ASSEMBLY)
60	# undef FPU_USE_GENERIC_ROUNDING_PRECISION
61	# define FPU_USE_X86_ROUNDING_PRECISION
62	#endif
63
64	#if 0 // gb-- FIXME: that doesn't work
65	/* IEEE-based fpu core can have native rounding mode on i386 */
66	#if defined(FPU_IEEE) && defined(USE_X87_ASSEMBLY)
67	# undef FPU_USE_GENERIC_ROUNDING_MODE
68	# define FPU_USE_X86_ROUNDING_MODE
69	#endif
70
71	/* IEEE-based fpu core can have native rounding precision on i386 */
72	#if defined(FPU_IEEE) && defined(USE_X87_ASSEMBLY)
73	# undef FPU_USE_GENERIC_ROUNDING_PRECISION
74	# define FPU_USE_X86_ROUNDING_PRECISION
75	#endif
76	#endif
77
78	/* -------------------------------------------------------------------------- */
79	/* --- Sanity checks --- */
80	/* -------------------------------------------------------------------------- */
81
82	/* X86 rounding mode and precision work together */
83	#if defined(FPU_USE_X86_ROUNDING_MODE) && defined(FPU_USE_X86_ROUNDING_PRECISION)
84	# define FPU_USE_X86_ROUNDING
85	# define CW_INITIAL (CW_RESET\|CW_X\|CW_PC_EXTENDED\|CW_RC_NEAR\|CW_PM\|CW_UM\|CW_OM\|CW_ZM\|CW_DM\|CW_IM)
86	PRIVATE uae_u32 x86_control_word;
87	#endif
88
89	/* Control word -- rounding mode */
90	#ifdef FPU_USE_X86_ROUNDING_MODE
91	PUBLIC const uae_u32 x86_control_word_rm_mac2host[];
92	#endif
93
94	/* Control word -- rounding precision */
95	#ifdef FPU_USE_X86_ROUNDING_PRECISION
96	PUBLIC const uae_u32 x86_control_word_rp_mac2host[];
97	#endif
98
99	#if defined(FPU_USE_X86_ROUNDING_MODE) && defined(FPU_USE_X86_ROUNDING_PRECISION)
100	/* Set host control word for rounding mode and rounding precision */
101	PRIVATE inline void set_host_control_word(void)
102	{
103	/*
104	Exception enable byte is ignored, but the same value is returned
105	that was previously set.
106	*/
107	x86_control_word
108	= (x86_control_word & ~(X86_ROUNDING_MODE\|X86_ROUNDING_PRECISION))
109	\| x86_control_word_rm_mac2host[(FPU fpcr.rounding_mode & FPCR_ROUNDING_MODE) >> 4]
110	\| x86_control_word_rp_mac2host[(FPU fpcr.rounding_precision & FPCR_ROUNDING_PRECISION) >> 6]
111	;
112	__asm__ __volatile__("fldcw %0" : : "m" (x86_control_word));
113	}
114	#endif
115
116	/* -------------------------------------------------------------------------- */
117	/* --- Generic rounding mode and precision --- */
118	/* -------------------------------------------------------------------------- */
119
120	#if defined(FPU_USE_GENERIC_ROUNDING_MODE) && defined(FPU_USE_GENERIC_ROUNDING_PRECISION)
121	/* Set host control word for rounding mode and rounding precision */
122	PRIVATE inline void set_host_control_word(void)
123	{ }
124	#endif
125
126	/* -------------------------------------------------------------------------- */
127	/* --- Common rounding mode and precision --- */
128	/* -------------------------------------------------------------------------- */
129
130	#if defined(FPU_USE_GENERIC_ROUNDING_MODE) \|\| defined(FPU_USE_X86_ROUNDING_MODE)
131
132	/* Return the current rounding mode in m68k format */
133	static inline uae_u32 FFPU get_rounding_mode(void)
134	{ return FPU fpcr.rounding_mode; }
135
136	/* Convert and set to native rounding mode */
137	static inline void FFPU set_rounding_mode(uae_u32 new_rounding_mode)
138	{ FPU fpcr.rounding_mode = new_rounding_mode; }
139
140	#endif
141
142	#if defined(FPU_USE_GENERIC_ROUNDING_PRECISION) \|\| defined(FPU_USE_X86_ROUNDING_PRECISION)
143
144	/* Return the current rounding precision in m68k format */
145	static inline uae_u32 FFPU get_rounding_precision(void)
146	{ return FPU fpcr.rounding_precision; }
147
148	/* Convert and set to native rounding precision */
149	static inline void FFPU set_rounding_precision(uae_u32 new_rounding_precision)
150	{ FPU fpcr.rounding_precision = new_rounding_precision; }
151
152	#endif
153
154	#endif /* FPU_ROUNDING_H */