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/* |
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* fpu/rounding.h - system-dependant FPU rounding mode and precision |
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* |
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* Basilisk II (C) 1997-2008 Christian Bauer |
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* |
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* MC68881/68040 fpu emulation |
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* |
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* Original UAE FPU, copyright 1996 Herman ten Brugge |
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* Rewrite for x86, copyright 1999-2000 Lauri Pesonen |
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* New framework, copyright 2000 Gwenole Beauchesne |
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* Adapted for JIT compilation (c) Bernd Meyer, 2000 |
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* |
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* This program is free software; you can redistribute it and/or modify |
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* it under the terms of the GNU General Public License as published by |
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* the Free Software Foundation; either version 2 of the License, or |
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* (at your option) any later version. |
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* |
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* This program is distributed in the hope that it will be useful, |
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* but WITHOUT ANY WARRANTY; without even the implied warranty of |
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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* GNU General Public License for more details. |
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* |
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* You should have received a copy of the GNU General Public License |
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* along with this program; if not, write to the Free Software |
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
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*/ |
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|
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#ifndef FPU_ROUNDING_H |
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#define FPU_ROUNDING_H |
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|
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/* NOTE: this file shall be included from fpu/fpu_*.cpp */ |
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#undef PUBLIC |
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#define PUBLIC extern |
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|
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#undef PRIVATE |
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#define PRIVATE static |
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|
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#undef FFPU |
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#define FFPU /**/ |
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|
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#undef FPU |
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#define FPU fpu. |
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|
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/* Defaults to generic rounding mode and precision handling */ |
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#define FPU_USE_GENERIC_ROUNDING_MODE |
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#define FPU_USE_GENERIC_ROUNDING_PRECISION |
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|
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/* -------------------------------------------------------------------------- */ |
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/* --- Selection of floating-point rounding mode and precision --- */ |
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/* -------------------------------------------------------------------------- */ |
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|
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/* Optimized i386 fpu core must use native rounding mode */ |
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#if defined(FPU_X86) && defined(USE_X87_ASSEMBLY) |
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# undef FPU_USE_GENERIC_ROUNDING_MODE |
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# define FPU_USE_X86_ROUNDING_MODE |
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#endif |
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|
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/* Optimized i386 fpu core must use native rounding precision */ |
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#if defined(FPU_X86) && defined(USE_X87_ASSEMBLY) |
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# undef FPU_USE_GENERIC_ROUNDING_PRECISION |
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# define FPU_USE_X86_ROUNDING_PRECISION |
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#endif |
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|
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#if 0 // gb-- FIXME: that doesn't work |
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/* IEEE-based fpu core can have native rounding mode on i386 */ |
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#if defined(FPU_IEEE) && defined(USE_X87_ASSEMBLY) |
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# undef FPU_USE_GENERIC_ROUNDING_MODE |
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# define FPU_USE_X86_ROUNDING_MODE |
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#endif |
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|
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/* IEEE-based fpu core can have native rounding precision on i386 */ |
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#if defined(FPU_IEEE) && defined(USE_X87_ASSEMBLY) |
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# undef FPU_USE_GENERIC_ROUNDING_PRECISION |
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# define FPU_USE_X86_ROUNDING_PRECISION |
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#endif |
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#endif |
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|
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/* -------------------------------------------------------------------------- */ |
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/* --- Sanity checks --- */ |
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/* -------------------------------------------------------------------------- */ |
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|
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/* X86 rounding mode and precision work together */ |
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#if defined(FPU_USE_X86_ROUNDING_MODE) && defined(FPU_USE_X86_ROUNDING_PRECISION) |
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# define FPU_USE_X86_ROUNDING |
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# 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) |
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PRIVATE uae_u32 x86_control_word; |
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#endif |
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|
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/* Control word -- rounding mode */ |
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#ifdef FPU_USE_X86_ROUNDING_MODE |
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PUBLIC const uae_u32 x86_control_word_rm_mac2host[]; |
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#endif |
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|
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/* Control word -- rounding precision */ |
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#ifdef FPU_USE_X86_ROUNDING_PRECISION |
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PUBLIC const uae_u32 x86_control_word_rp_mac2host[]; |
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#endif |
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|
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#if defined(FPU_USE_X86_ROUNDING_MODE) && defined(FPU_USE_X86_ROUNDING_PRECISION) |
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/* Set host control word for rounding mode and rounding precision */ |
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PRIVATE inline void set_host_control_word(void) |
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{ |
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/* |
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Exception enable byte is ignored, but the same value is returned |
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that was previously set. |
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*/ |
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x86_control_word |
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= (x86_control_word & ~(X86_ROUNDING_MODE|X86_ROUNDING_PRECISION)) |
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| x86_control_word_rm_mac2host[(FPU fpcr.rounding_mode & FPCR_ROUNDING_MODE) >> 4] |
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| x86_control_word_rp_mac2host[(FPU fpcr.rounding_precision & FPCR_ROUNDING_PRECISION) >> 6] |
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; |
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__asm__ __volatile__("fldcw %0" : : "m" (x86_control_word)); |
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} |
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#endif |
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|
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/* -------------------------------------------------------------------------- */ |
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/* --- Generic rounding mode and precision --- */ |
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/* -------------------------------------------------------------------------- */ |
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|
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#if defined(FPU_USE_GENERIC_ROUNDING_MODE) && defined(FPU_USE_GENERIC_ROUNDING_PRECISION) |
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/* Set host control word for rounding mode and rounding precision */ |
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PRIVATE inline void set_host_control_word(void) |
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{ } |
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#endif |
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|
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/* -------------------------------------------------------------------------- */ |
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/* --- Common rounding mode and precision --- */ |
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/* -------------------------------------------------------------------------- */ |
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|
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#if defined(FPU_USE_GENERIC_ROUNDING_MODE) || defined(FPU_USE_X86_ROUNDING_MODE) |
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|
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/* Return the current rounding mode in m68k format */ |
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static inline uae_u32 FFPU get_rounding_mode(void) |
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{ return FPU fpcr.rounding_mode; } |
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|
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/* Convert and set to native rounding mode */ |
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static inline void FFPU set_rounding_mode(uae_u32 new_rounding_mode) |
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{ FPU fpcr.rounding_mode = new_rounding_mode; } |
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|
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#endif |
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|
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#if defined(FPU_USE_GENERIC_ROUNDING_PRECISION) || defined(FPU_USE_X86_ROUNDING_PRECISION) |
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|
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/* Return the current rounding precision in m68k format */ |
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static inline uae_u32 FFPU get_rounding_precision(void) |
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{ return FPU fpcr.rounding_precision; } |
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|
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/* Convert and set to native rounding precision */ |
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static inline void FFPU set_rounding_precision(uae_u32 new_rounding_precision) |
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{ FPU fpcr.rounding_precision = new_rounding_precision; } |
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|
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#endif |
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|
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#endif /* FPU_ROUNDING_H */ |
