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Revision cast RHS of >>= operation to unsigned int |

/* $NetBSD: fixunsgen_ieee754.c,v 1.3 2012/03/25 19:53:41 christos Exp $ */ /*- * Copyright (c) 1992, 1993 * The Regents of the University of California. All rights reserved. * * This software was developed by the Computer Systems Engineering group * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and * contributed to Berkeley. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ #include <sys/cdefs.h> #if !defined(FIXUNSNAME) && defined(LIBC_SCCS) && !defined(lint) __RCSID("$NetBSD: fixunsgen_ieee754.c,v 1.3 2012/03/25 19:53:41 christos Exp $"); #endif /* LIBC_SCCS and not lint */ #include <stddef.h> #include <stdint.h> #include <stdbool.h> #include <float.h> #ifndef FIXUNSNAME #define FIXUNSNAME(n) n##32 #define UINTXX_T uint32_t #endif __dso_hidden UINTXX_T FIXUNSNAME(__fixunsgen)(int, bool, size_t, size_t, const uint32_t *); /* * Convert double to (unsigned) int. All operations are done module 2^32. */ UINTXX_T FIXUNSNAME(__fixunsgen)(int exp, bool sign, size_t mant_dig, size_t fracbits, const uint32_t *frac) { UINTXX_T tmp; /* * If it's less than 1 (negative exponent), it's going to round * to zero. If the exponent is so large that it is a multiple of * 2^N, then x module 2^N will be 0. (we use the fact treating a * negative value as unsigned will be greater than nonnegative value) */ if (__predict_false((size_t)exp >= mant_dig + sizeof(UINTXX_T)*8)) return 0; /* * This is simplier than it seems. Basically we are constructing * fixed binary representation of the floating point number tossing * away bits that wont be in the modulis we return. */ tmp = 1; for (size_t ebits = exp;;) { if (ebits <= fracbits) { /* * The current fraction has more bits than we need. * Shift the current value over and insert the bits * we want. We're done. */ tmp <<= (unsigned int)ebits; tmp |= *frac >> (fracbits - ebits); break; } if (fracbits == sizeof(tmp)*4) { /* * Shifts must be < sizeof(type). If it's going to be * sizeof(type), just replace the value. */ tmp = *frac--; } else { tmp <<= (unsigned int)fracbits; tmp |= *frac--; } ebits -= fracbits; fracbits = sizeof(frac[0]) * 4; } /* * If the input was negative, make tmp negative module 2^32. */ if (sign) tmp = -tmp; return tmp; }