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Annotation of tme/generic/float.c, revision 1.1

1.1     ! root        1: /* $Id: float.c,v 1.2 2005/05/14 22:08:07 fredette Exp $ */
        !             2: 
        !             3: /* generic/float.c - generic native floating-point support: */
        !             4: 
        !             5: /*
        !             6:  * Copyright (c) 2004 Matt Fredette
        !             7:  * All rights reserved.
        !             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 Matt Fredette.
        !            20:  * 4. The name of the author may not be used to endorse or promote products
        !            21:  *    derived from this software without specific prior written permission.
        !            22:  *
        !            23:  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
        !            24:  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
        !            25:  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
        !            26:  * DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
        !            27:  * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
        !            28:  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
        !            29:  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
        !            30:  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
        !            31:  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
        !            32:  * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
        !            33:  * POSSIBILITY OF SUCH DAMAGE.
        !            34:  */
        !            35: 
        !            36: #include <tme/common.h>
        !            37: _TME_RCSID("$Id: float.c,v 1.2 2005/05/14 22:08:07 fredette Exp $");
        !            38: 
        !            39: /* includes: */
        !            40: #include <tme/generic/float.h>
        !            41: #include <signal.h>
        !            42: 
        !            43: /* the mutex protecting the native floating point: */
        !            44: static tme_mutex_t _tme_float_mutex;
        !            45: 
        !            46: /* this is nonzero if the SIGFPE handler has been installed: */
        !            47: /* XXX FIXME this assumes that a handler installed once in one thread
        !            48:    will catch signals for all threads.  obviously, whether or not this
        !            49:    is true depends on how the threads package deals with signals: */
        !            50: static int _tme_float_sigfpe_handler_installed;
        !            51: 
        !            52: /* the current exceptions: */
        !            53: static int _tme_float_exceptions;
        !            54: 
        !            55: /* the user's exception handler: */
        !            56: static void (*_tme_float_exception_handler) _TME_P((int, void *));
        !            57: static void *_tme_float_exception_handler_private;
        !            58: 
        !            59: /* update the current exceptions: */
        !            60: static void
        !            61: _tme_float_exceptions_update(int at_least_one)
        !            62: {
        !            63:   int exceptions_new;
        !            64: #ifdef HAVE_FPGETSTICKY
        !            65:   int sticky;
        !            66: #endif /* HAVE_FPGETSTICKY */
        !            67: 
        !            68:   /* start with no new exceptions: */
        !            69:   exceptions_new = 0;
        !            70: 
        !            71:   /* get the exception status: */
        !            72: #ifdef HAVE_FPGETSTICKY
        !            73:   sticky = fpgetsticky();
        !            74: #define TME_FP_X_MAP(fp_x, float_x) if (sticky & (fp_x)) exceptions_new |= (float_x)
        !            75: #ifdef FP_X_INV
        !            76:   TME_FP_X_MAP(FP_X_INV, TME_FLOAT_EXCEPTION_INVALID);
        !            77: #endif
        !            78: #ifdef FP_X_DNML
        !            79:   TME_FP_X_MAP(FP_X_DNML, TME_FLOAT_EXCEPTION_DENORMAL);
        !            80: #endif
        !            81: #ifdef FP_X_DZ
        !            82:   TME_FP_X_MAP(FP_X_DZ, TME_FLOAT_EXCEPTION_DIVBYZERO);
        !            83: #endif
        !            84: #ifdef FP_X_OFL
        !            85:   TME_FP_X_MAP(FP_X_OFL, TME_FLOAT_EXCEPTION_OVERFLOW);
        !            86: #endif
        !            87: #ifdef FP_X_UFL
        !            88:   TME_FP_X_MAP(FP_X_UFL, TME_FLOAT_EXCEPTION_UNDERFLOW);
        !            89: #endif
        !            90: #ifdef FP_X_IMP
        !            91:   TME_FP_X_MAP(FP_X_IMP, TME_FLOAT_EXCEPTION_INEXACT);
        !            92: #endif
        !            93: #ifdef FP_X_IOV
        !            94:   TME_FP_X_MAP(FP_X_IOV, TME_FLOAT_EXCEPTION_OVERFLOW_INT);
        !            95: #endif
        !            96: #undef TME_FP_X_MAP
        !            97: #endif /* HAVE_FPGETSTICKY */
        !            98: 
        !            99:   /* if we have no new exceptions, but we should have at least one,
        !           100:      add in the generic exception: */
        !           101:   if (exceptions_new == 0
        !           102:       && at_least_one) {
        !           103:     exceptions_new |= TME_FLOAT_EXCEPTION_GENERIC;
        !           104:   }
        !           105: 
        !           106:   /* accumulate the new exceptions into the current exceptions: */
        !           107:   _tme_float_exceptions |= exceptions_new;
        !           108:   
        !           109:   /* clear the exception status: */
        !           110: #ifdef HAVE_FPSETSTICKY
        !           111:   fpsetsticky(0);
        !           112: #endif /* HAVE_FPSETSTICKY */
        !           113: }
        !           114: 
        !           115: /* our SIGFPE handler: */
        !           116: static RETSIGTYPE
        !           117: _tme_float_sigfpe_handler(int unused)
        !           118: {
        !           119: 
        !           120:   /* update the current exceptions: */
        !           121:   _tme_float_exceptions_update(TRUE);
        !           122: 
        !           123:   /* call any user exception handler with the new exceptions: */
        !           124:   if (_tme_float_exception_handler != NULL) {
        !           125:     (*_tme_float_exception_handler)(_tme_float_exceptions, _tme_float_exception_handler_private);
        !           126:   }
        !           127: }  
        !           128: 
        !           129: /* this enters native floating-point operation: */
        !           130: void
        !           131: tme_float_enter(int rounding_mode, void (*exception_handler)(int, void *), void *exception_handler_private)
        !           132: {
        !           133: 
        !           134:   /* lock the native floating-point mutex: */
        !           135:   tme_mutex_lock(&_tme_float_mutex);
        !           136: 
        !           137:   /* set any user exception handler: */
        !           138:   _tme_float_exception_handler = exception_handler;
        !           139:   _tme_float_exception_handler_private = exception_handler_private;
        !           140: 
        !           141:   /* establish a signal handler: */
        !           142:   /* XXX FIXME this assumes that a handler installed once in one thread
        !           143:      will catch signals for all threads.  obviously, whether or not this
        !           144:      is true depends on how the threads package deals with signals: */
        !           145:   if (!_tme_float_sigfpe_handler_installed) {
        !           146:     signal(SIGFPE, _tme_float_sigfpe_handler);
        !           147:     _tme_float_sigfpe_handler_installed = TRUE;
        !           148:   }
        !           149:   
        !           150:   /* set the rounding mode: */
        !           151: #ifdef HAVE_FPSETROUND
        !           152:   fpsetround(rounding_mode);
        !           153: #endif /* HAVE_FPSETROUND */
        !           154: 
        !           155:   /* clear the exception status: */
        !           156:   _tme_float_exceptions = 0;
        !           157: #ifdef HAVE_FPSETSTICKY
        !           158:   fpsetsticky(0);
        !           159: #endif /* HAVE_FPSETSTICKY */
        !           160: 
        !           161:   /* unmask all exceptions: */
        !           162: #ifdef HAVE_FPSETMASK
        !           163:   fpsetmask(0
        !           164: #ifdef FP_X_INV
        !           165:   | FP_X_INV
        !           166: #endif
        !           167: #ifdef FP_X_DNML
        !           168:   | FP_X_DNML
        !           169: #endif
        !           170: #ifdef FP_X_DZ
        !           171:   | FP_X_DZ
        !           172: #endif
        !           173: #ifdef FP_X_OFL
        !           174:   | FP_X_OFL
        !           175: #endif
        !           176: #ifdef FP_X_UFL
        !           177:   | FP_X_UFL
        !           178: #endif
        !           179: #ifdef FP_X_IMP
        !           180:   | FP_X_IMP
        !           181: #endif
        !           182: #ifdef FP_X_IOV
        !           183:   | FP_X_IOV
        !           184: #endif
        !           185:            );
        !           186: #endif /* HAVE_FPSETMASK */
        !           187: }
        !           188: 
        !           189: /* this returns the current native floating-point exceptions: */
        !           190: int
        !           191: tme_float_exceptions(void)
        !           192: {
        !           193:   /* update and return the current exceptions: */
        !           194:   _tme_float_exceptions_update(FALSE);
        !           195:   return (_tme_float_exceptions);
        !           196: }  
        !           197: 
        !           198: /* this leaves native floating-point operation: */
        !           199: int
        !           200: tme_float_leave(void)
        !           201: {
        !           202:   int exceptions;
        !           203: 
        !           204:   /* get the final set of exceptions: */
        !           205:   exceptions = tme_float_exceptions();
        !           206: 
        !           207:   /* clear any user exception handler: */
        !           208:   _tme_float_exception_handler = NULL;
        !           209: 
        !           210:   /* unlock the native floating-point mutex: */
        !           211:   tme_mutex_unlock(&_tme_float_mutex);
        !           212: 
        !           213:   /* return the final set of exceptions: */
        !           214:   return (exceptions);
        !           215: }
        !           216: 
        !           217: /* missing standard functions: */
        !           218: #ifndef HAVE_ISINFF
        !           219: int
        !           220: isinff(float x)
        !           221: {
        !           222:   return (x > FLOAT_MAX_FLOAT
        !           223:          || x < (-FLOAT_MAX_FLOAT));
        !           224: }
        !           225: #endif /* !HAVE_ISINFF */
        !           226: 
        !           227: /* include the automatically-generated code: */
        !           228: #include "float-auto.c"

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