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csutil/csendian.h

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00001 /*
00002     Copyright (C) 1998 by Jorrit Tyberghein
00003 
00004     This library is free software; you can redistribute it and/or
00005     modify it under the terms of the GNU Library General Public
00006     License as published by the Free Software Foundation; either
00007     version 2 of the License, or (at your option) any later version.
00008 
00009     This library is distributed in the hope that it will be useful,
00010     but WITHOUT ANY WARRANTY; without even the implied warranty of
00011     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00012     Library General Public License for more details.
00013 
00014     You should have received a copy of the GNU Library General Public
00015     License along with this library; if not, write to the Free
00016     Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
00017 */
00018 
00019 #ifndef __CS_CSENDIAN_H__
00020 #define __CS_CSENDIAN_H__
00021 
00029 #include <math.h>
00030 #include "cstypes.h"
00031 #if defined(CS_HAVE_BYTESWAP_H)
00032 #include <byteswap.h>
00033 #endif
00034 
00035 #define csQroundSure(x) (int ((x) + ((x < 0) ? -0.5 : +0.5)))
00036 
00040 struct csSwapBytes
00041 {
00042 public:
00044 
00045   static CS_FORCEINLINE uint16 Swap (uint16 s) 
00046   { 
00047   #if defined(CS_COMPILER_MSVC) && (_MSC_VER >= 1300)
00048     return _byteswap_ushort (s);
00049   #elif defined(CS_HAVE_BYTESWAP_H)
00050     return bswap_16 (s);
00051   #else
00052     return (s >> 8) | (s << 8); 
00053   #endif
00054   }
00055   static CS_FORCEINLINE int16  Swap (int16 s)
00056   { return (int16)Swap ((uint16)s); }
00057   static CS_FORCEINLINE uint32 Swap (uint32 l)
00058   { 
00059   #if defined(CS_COMPILER_MSVC) && (_MSC_VER >= 1300)
00060     return _byteswap_ulong (l);
00061   #elif defined(CS_HAVE_BYTESWAP_H)
00062     return bswap_32 (l);
00063   #else
00064     return (l >> 24) | ((l >> 8) & 0xff00) | ((l << 8) & 0xff0000) | (l << 24); 
00065   #endif
00066   }
00067   static CS_FORCEINLINE int32  Swap (int32 l)
00068   { return (int32)Swap ((uint32)l); }
00069   static CS_FORCEINLINE uint64 Swap (uint64 l)
00070   {
00071   #if defined(CS_COMPILER_MSVC) && (_MSC_VER >= 1300)
00072     return _byteswap_uint64 (l);
00073   #elif defined(CS_HAVE_BYTESWAP_H) && !defined(__STRICT_ANSI__)
00074     return bswap_64 (l);
00075   #else
00076     union
00077     {
00078       uint64 ui64;
00079       uint32 ui32[2];
00080     } u1, u2;
00081     u1.ui64 = l;
00082     u2.ui32[0] = Swap (u1.ui32[1]);
00083     u2.ui32[1] = Swap (u1.ui32[0]);
00084     return u2.ui64;
00085   #endif
00086   }
00087   static CS_FORCEINLINE int64  Swap (int64 l)
00088   { return (int64)Swap ((uint64)l); }
00089   
00090   static CS_FORCEINLINE uint16 UInt16 (uint16 x) { return Swap (x); }
00091   static CS_FORCEINLINE int16  Int16  (int16 x)  { return Swap (x); }
00092   static CS_FORCEINLINE uint32 UInt32 (uint32 x) { return Swap (x); }
00093   static CS_FORCEINLINE int32  Int32  (int32 x)  { return Swap (x); }
00094   static CS_FORCEINLINE uint64 UInt64 (uint64 x) { return Swap (x); }
00095   static CS_FORCEINLINE int64  Int64  (int64 x)  { return Swap (x); }
00097 };
00098 
00099 #ifdef CS_BIG_ENDIAN
00100 struct csBigEndian
00101 #else
00107 struct csLittleEndian
00108 #endif
00109 {
00111 
00112   static CS_FORCEINLINE uint16 Convert (uint16 x) { return x; }
00113   static CS_FORCEINLINE int16  Convert (int16 x)  { return x; }
00114   static CS_FORCEINLINE uint32 Convert (uint32 x) { return x; }
00115   static CS_FORCEINLINE int32  Convert (int32 x)  { return x; }
00116   static CS_FORCEINLINE uint64 Convert (uint64 x) { return x; }
00117   static CS_FORCEINLINE int64  Convert (int64 x)  { return x; }
00118   
00119   static CS_FORCEINLINE uint16 UInt16 (uint16 x) { return Convert (x); }
00120   static CS_FORCEINLINE int16  Int16  (int16 x)  { return Convert (x); }
00121   static CS_FORCEINLINE uint32 UInt32 (uint32 x) { return Convert (x); }
00122   static CS_FORCEINLINE int32  Int32  (int32 x)  { return Convert (x); }
00123   static CS_FORCEINLINE uint64 UInt64 (uint64 x) { return Convert (x); }
00124   static CS_FORCEINLINE int64  Int64  (int64 x)  { return Convert (x); }
00126 };
00127 
00128 #ifdef CS_LITTLE_ENDIAN
00129 
00134 struct csBigEndian
00135 #else
00136 struct csLittleEndian
00137 #endif
00138 {
00139 public:
00141 
00142   static CS_FORCEINLINE uint16 Convert (uint16 s) 
00143   { return csSwapBytes::Swap (s); }
00144   static CS_FORCEINLINE int16  Convert (int16 s)
00145   { return csSwapBytes::Swap (s); }
00146   static CS_FORCEINLINE uint32 Convert (uint32 l)
00147   { return csSwapBytes::Swap (l); }
00148   static CS_FORCEINLINE int32  Convert (int32 l)
00149   { return csSwapBytes::Swap (l); }
00150   static CS_FORCEINLINE uint64 Convert (uint64 l)
00151   { return csSwapBytes::Swap (l); }
00152   static CS_FORCEINLINE int64  Convert (int64 l)
00153   { return csSwapBytes::Swap (l); }
00154   
00155   static CS_FORCEINLINE uint16 UInt16 (uint16 x) { return Convert (x); }
00156   static CS_FORCEINLINE int16  Int16  (int16 x)  { return Convert (x); }
00157   static CS_FORCEINLINE uint32 UInt32 (uint32 x) { return Convert (x); }
00158   static CS_FORCEINLINE int32  Int32  (int32 x)  { return Convert (x); }
00159   static CS_FORCEINLINE uint64 UInt64 (uint64 x) { return Convert (x); }
00160   static CS_FORCEINLINE int64  Int64  (int64 x)  { return Convert (x); }
00162 };
00163 
00167 struct csIEEEfloat
00168 {
00169   /* \todo It would be even better if we also check for sizeof (float)
00170    * in configure or so. */
00171 #ifdef CS_IEEE_DOUBLE_FORMAT
00173   static CS_FORCEINLINE uint32 FromNative (float f)
00174   { 
00175     union
00176     {
00177       float f;
00178       uint32 ui32;
00179     } u;
00180     u.f = f;
00181     return u.ui32; 
00182   }
00184   static CS_FORCEINLINE float ToNative (uint32 f)
00185   { 
00186     union
00187     {
00188       float f;
00189       uint32 ui32;
00190     } u;
00191     u.ui32 = f;
00192     return u.f; 
00193   }
00194 #else
00195   #error Do not know how to convert to IEEE floats
00196 #endif
00197 };
00198 
00207 struct csGetFromAddress
00208 {
00210 
00211   static CS_FORCEINLINE uint16 UInt16 (const void *buff)
00212   {
00213   #ifdef CS_STRICT_ALIGNMENT
00214     uint16 s; memcpy (&s, buff, sizeof (s));
00215     return s;
00216   #else
00217     return *(uint16 *)buff;
00218   #endif
00219   }
00220   static CS_FORCEINLINE int16  Int16 (const void *buff)
00221   { return (int16)UInt16 (buff); }
00222   static CS_FORCEINLINE uint32 UInt32 (const void *buff)
00223   {
00224   #ifdef CS_STRICT_ALIGNMENT
00225     uint32 s; memcpy (&s, buff, sizeof (s));
00226     return s;
00227   #else
00228     return *(uint32 *)buff;
00229   #endif
00230   }
00231   static CS_FORCEINLINE int32  Int32 (const void *buff)
00232   { return (int32)UInt32 (buff); }
00233   static CS_FORCEINLINE uint64 UInt64 (const void *buff)
00234   {
00235   #ifdef CS_STRICT_ALIGNMENT
00236     uint64 s; memcpy (&s, buff, sizeof (s));
00237     return s;
00238   #else
00239     return *(uint64 *)buff;
00240   #endif
00241   }
00242   static CS_FORCEINLINE int64  Int64 (const void *buff)
00243   { return (int64)UInt64 (buff); }
00245 };
00246 
00255 struct csSetToAddress
00256 {
00258 
00259   static CS_FORCEINLINE void UInt16 (void *buff, uint16 s)
00260   {
00261   #ifdef CS_STRICT_ALIGNMENT
00262     memcpy (buff, &s, sizeof (s));
00263   #else
00264     *((uint16 *)buff) = s;
00265   #endif
00266   }
00267   static CS_FORCEINLINE void Int16  (void *buff, int16 s)
00268   { UInt16 (buff, (uint16)s); }
00269   static CS_FORCEINLINE void UInt32 (void *buff, uint32 s)
00270   {
00271   #ifdef CS_STRICT_ALIGNMENT
00272     memcpy (buff, &s, sizeof (s));
00273   #else
00274     *((uint32 *)buff) = s;
00275   #endif
00276   }
00277   static CS_FORCEINLINE void Int32  (void *buff, int32 s)
00278   { UInt32 (buff, (uint32)s); }
00279   static CS_FORCEINLINE void UInt64 (void *buff, uint64 s)
00280   {
00281   #ifdef CS_STRICT_ALIGNMENT
00282     memcpy (buff, &s, sizeof (s));
00283   #else
00284     *((uint64 *)buff) = s;
00285   #endif
00286   }
00287   static CS_FORCEINLINE void Int64  (void *buff, int64 s)
00288   { UInt64 (buff, (uint64)s); }
00290 };
00291 
00297 
00298 CS_DEPRECATED_METHOD static inline uint64 csBigEndianLongLong (uint64 l)
00299 { return csBigEndian::Convert (l); }
00300 
00302 CS_DEPRECATED_METHOD static inline uint32 csBigEndianLong (uint32 l)
00303 { return csBigEndian::Convert (l); }
00304 
00306 CS_DEPRECATED_METHOD static inline uint16 csBigEndianShort (uint16 s)
00307 { return csBigEndian::Convert (s); }
00308 
00310 CS_DEPRECATED_METHOD static inline float csBigEndianFloat (float f)
00311 { 
00312   union
00313   {
00314     float f;
00315     uint32 ui32;
00316   } u;
00317   u.f = f;
00318   u.ui32 = csBigEndian::Convert (u.ui32); 
00319   return u.f;
00320 }
00321 
00323 CS_DEPRECATED_METHOD static inline uint64 csLittleEndianLongLong (uint64 l)
00324 { return csLittleEndian::Convert (l); }
00325 
00327 CS_DEPRECATED_METHOD static inline uint32 csLittleEndianLong (uint32 l)
00328 { return csLittleEndian::Convert (l); }
00329 
00331 CS_DEPRECATED_METHOD static inline uint16 csLittleEndianShort (uint16 s)
00332 { return csLittleEndian::Convert (s); }
00333 
00335 CS_DEPRECATED_METHOD static inline float csLittleEndianFloat (float f)
00336 { 
00337   union
00338   {
00339     float f;
00340     uint32 ui32;
00341   } u;
00342   u.f = f;
00343   u.ui32 = csLittleEndian::Convert (u.ui32); 
00344   return u.f;
00345 }
00346 
00347 /*
00348     To be able to painlessly transfer files betwen platforms, we should
00349     avoid using native floating-point format. Here are a couple of routines
00350     that are guaranteed to work on all platforms.
00351 
00352     The floating point is converted to a fixed 1.7.25 bits format
00353     (one bit sign, 7 bits exponent, 25 bits mantissa) and back,
00354     so that we can binary store floating-point number without
00355     cross-platform problems. If you wonder why 1+7+25 = 33 while we
00356     only have 32 bits, we'll ommit the most significant bit of mantissa
00357     since it is always 1 (we use normalized numbers). This increases the
00358     precision twice.
00359 
00360     For double, we use one bit sign, 15 bits exponent, 49 bits mantissa.
00361 */
00362 
00367 /*CS_DEPRECATED_METHOD*/ static inline int32 csFloatToLong (float f)
00368 {
00369   int exp;
00370   int32 mant = csQroundSure (frexp (f, &exp) * 0x1000000);
00371   int32 sign = mant & 0x80000000;
00372   if (mant < 0) mant = -mant;
00373   if (exp > 63) exp = 63; else if (exp < -64) exp = -64;
00374   return sign | ((exp & 0x7f) << 24) | (mant & 0xffffff);
00375 }
00376 
00381 /*CS_DEPRECATED_METHOD*/ static inline float csLongToFloat (int32 l)
00382 {
00383   int exp = (l >> 24) & 0x7f;
00384   if (exp & 0x40) exp = exp | ~0x7f;
00385   float mant = float (l & 0x00ffffff) / 0x1000000;
00386   if (l & 0x80000000) mant = -mant;
00387   return (float) ldexp (mant, exp);
00388 }
00389 
00390 /* Implementation note: csDoubleToLongLong() and csLongLongToDouble()
00391  *
00392  * We avoid use of CONST_INT64() because 64-bit constants are illegal with g++
00393  * under -ansi -pedantic, and we want this header to be useful to external
00394  * projects which use -ansi -pedantic.  Instead, we use bit shifts, such as (1
00395  * << 59), and construct `mask' manually.
00396  */
00397 
00402 /*CS_DEPRECATED_METHOD*/ static inline int64 csDoubleToLongLong (double d)
00403 {
00404   int exp;
00405   int64 mant = (int64) (frexp (d, &exp) * ((int64)1 << 48));
00406   int64 sign = mant & ((int64)1 << 59);
00407   if (mant < 0) mant = -mant;
00408   if (exp > 32767) exp = 32767; else if (exp < -32768) exp = -32768;
00409   int64 const mask = ((uint64)0xffff << 32) | (uint64)0xffffffff;
00410   return sign | ((int64 (exp) & 0x7fff) << 48) | (mant & mask);
00411 }
00412 
00417 /*CS_DEPRECATED_METHOD*/ static inline double csLongLongToDouble (int64 i)
00418 {
00419   int exp = (i >> 48) & 0x7fff;
00420   if (exp & 0x4000) exp = exp | ~0x7fff;
00421   int64 const mask = ((uint64)0xffff << 32) | (uint64)0xffffffff;
00422   double mant = double (i & mask) / ((int64)1 << 48);
00423   if (i & ((int64)1 << 59)) mant = -mant;
00424   return ldexp (mant, exp);
00425 }
00426 
00427 /* *\name Floating point conversions
00428  * These routines are used for converting floating-point numbers
00429  * into 16-bit shorts and back. This is useful for low-precision data.
00430  * They use the 1.4.12 format. The range of numbers that can be represented
00431  * in this format is from 2^-8 to 2^7. The precision for numbers near to
00432  * 2^-8 (0.00390625) is near 0.000001, for numbers near 2^7 (128) is near 0.03.
00433  * @{ */
00434 
00439 /*CS_DEPRECATED_METHOD*/ static inline short csFloatToShort (float f)
00440 {
00441   int exp;
00442   long mant = csQroundSure (frexp (f, &exp) * 0x1000);
00443   long sign = mant & 0x8000;
00444   if (mant < 0) mant = -mant;
00445   if (exp > 7) mant = 0x7ff, exp = 7; else if (exp < -8) mant = 0, exp = -8;
00446   return short(sign | ((exp & 0xf) << 11) | (mant & 0x7ff));
00447 }
00448 
00453 /*CS_DEPRECATED_METHOD*/ static inline float csShortToFloat (short s)
00454 {
00455   int exp = (s >> 11) & 0xf;
00456   if (exp & 0x8) exp = exp | ~0xf;
00457   float mant = float ((s & 0x07ff) | 0x0800) / 0x1000;
00458   if (s & 0x8000) mant = -mant;
00459   return (float) ldexp (mant, exp);
00460 }
00461 
00464 
00465 CS_DEPRECATED_METHOD static inline uint64 csConvertEndian (uint64 l)
00466 { return csLittleEndian::Convert (l); }
00467 
00469 CS_DEPRECATED_METHOD static inline int64 csConvertEndian (int64 l)
00470 { return csLittleEndian::Convert (l); }
00471 
00473 CS_DEPRECATED_METHOD static inline uint32 csConvertEndian (uint32 l)
00474 { return csLittleEndian::Convert (l); }
00475 
00477 CS_DEPRECATED_METHOD static inline int32 csConvertEndian (int32 l)
00478 { return csLittleEndian::Convert (l); }
00479 
00481 CS_DEPRECATED_METHOD static inline int16 csConvertEndian (int16 s)
00482 { return csLittleEndian::Convert (s); }
00483 
00485 CS_DEPRECATED_METHOD static inline uint16 csConvertEndian (uint16 s)
00486 { return csLittleEndian::Convert (s); }
00487 
00489 CS_DEPRECATED_METHOD static inline float csConvertEndian (float f)
00490 { 
00491   union
00492   {
00493     float f;
00494     uint32 ui32;
00495   } u;
00496   u.f = f;
00497   u.ui32 = csLittleEndian::Convert (u.ui32); 
00498   return u.f;
00499 }
00500 
00502 CS_DEPRECATED_METHOD inline uint16 csGetLittleEndianShort (const void *buff)
00503 {
00504   return csLittleEndian::Convert (csGetFromAddress::UInt16 (buff));
00505 }
00506 
00508 CS_DEPRECATED_METHOD inline uint32 csGetLittleEndianLong (const void *buff)
00509 {
00510   return csLittleEndian::Convert (csGetFromAddress::UInt32 (buff));
00511 }
00512 
00514 CS_DEPRECATED_METHOD inline float csGetLittleEndianFloat32 (const void *buff)
00515 { 
00516   uint32 l = csLittleEndian::Convert (csGetFromAddress::UInt32 (buff));
00517   return csLongToFloat (l); 
00518 }
00519 
00521 CS_DEPRECATED_METHOD inline float csGetLittleEndianFloat16 (const void *buff)
00522 { 
00523   uint16 s = csLittleEndian::Convert (csGetFromAddress::UInt16 (buff));
00524   return csShortToFloat (s); 
00525 }
00526 
00531 #endif // __CS_CSENDIAN_H__

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