core/GP_Common.h

   1 /*****************************************************************************
   2  * This file is part of gfxprim library.                                     *
   3  *                                                                           *
   4  * Gfxprim is free software; you can redistribute it and/or                  *
   5  * modify it under the terms of the GNU Lesser General Public                *
   6  * License as published by the Free Software Foundation; either              *
   7  * version 2.1 of the License, or (at your option) any later version.        *
   8  *                                                                           *
   9  * Gfxprim is distributed in the hope that it will be useful,                *
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of            *
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU         *
  12  * Lesser General Public License for more details.                           *
  13  *                                                                           *
  14  * You should have received a copy of the GNU Lesser General Public          *
  15  * License along with gfxprim; if not, write to the Free Software            *
  16  * Foundation, Inc., 51 Franklin Street, Fifth Floor,                        *
  17  * Boston, MA  02110-1301  USA                                               *
  18  *                                                                           *
  19  * Copyright (C) 2009-2010 Jiri "BlueBear" Dluhos                            *
  20  *                         <jiri.bluebear.dluhos@gmail.com>                  *
  21  *                                                                           *
  22  * Copyright (C) 2009-2010 Cyril Hrubis <metan@ucw.cz>                       *
  23  *                                                                           *
  24  *****************************************************************************/
  25
  26 #ifndef GP_COMMON_H
  27 #define GP_COMMON_H
  28
  29 #include <stdio.h>
  30 #include <stdint.h>
  31 #include <stdlib.h>
  32 #include <unistd.h>
  33
  34 /*
  35  * Returns a minimum of the two numbers.
  36  */
  37 #define GP_MIN(a, b) ({ \
  38         typeof(a) _a = (a); \
  39         typeof(b) _b = (b); \
  40         _a < _b ? _a : _b; \
  41 })
  42
  43 /*
  44  * Returns a maximum of the two numbers.
  45  */
  46 #define GP_MAX(a, b) ({ \
  47         typeof(a) _a = (a); \
  48         typeof(b) _b = (b); \
  49         _a > _b ? _a : _b; \
  50 })
  51
  52 /*
  53  * The standard likely() and unlikely() used in Kernel
  54  */
  55 #ifndef likely
  56         #ifdef __GNUC__
  57                 #define likely(x)       __builtin_expect(!!(x),1)
  58                 #define unlikely(x)     __builtin_expect(!!(x),0)
  59         #else
  60                 #define likely(x)       x
  61                 #define unlikely(x)     x
  62         #endif
  63 #endif
  64
  65 /*
  66  * Internal macros with common code for GP_ABORT, GP_ASSERT and GP_CHECK.
  67  * GP_INTERNAL_ABORT takes a message that may contain % (e.g. assert condition)
  68  * and prints:
  69  * "*** gfxprim: __FILE__:__LINE__: in __FUNCTION__: str_abort_msg_" format(__VA_ARGS__) "\n"
  70  *
  71  * GP_GENERAL_CHECK is a check with specified message prefix (for assert and check)
  72  */
  73
  74 #define GP_INTERNAL_ABORT(str_abort_msg_, ...) do { \
  75                 fprintf(stderr, "*** gfxprim: %s:%d: in %s: %s", \
  76                                 __FILE__, __LINE__, __FUNCTION__, str_abort_msg_); \
  77                 if (! (#__VA_ARGS__ [0])) \
  78                         fprintf(stderr, "abort()"); \
  79                 else \
  80                         fprintf(stderr, " " __VA_ARGS__); \
  81                 fprintf(stderr, "\n"); \
  82                 abort(); \
  83         } while (0)
  84
  85 #define GP_GENERAL_CHECK(check_cond_, check_message_, ...) do { \
  86                 if (unlikely(!(check_cond_))) { \
  87                         if (#__VA_ARGS__ [0]) \
  88                                 GP_INTERNAL_ABORT(check_message_ #check_cond_, "\n" __VA_ARGS__); \
  89                         else \
  90                                 GP_INTERNAL_ABORT(check_message_ #check_cond_, " "); \
  91                 } \
  92         } while (0)
  93
  94 /*
  95  * Aborts and prints the message along with the location in code
  96  * to stderr. Used for fatal errors.
  97  *
  98  * Use as either GP_ABORT(), GP_ABORT(msg) or GP_ABORT(format, params...) where
  99  * msg and format must be string constants.
 100  */
 101 #define GP_ABORT(...) GP_INTERNAL_ABORT("", ##__VA_ARGS__)
 102
 103 /*
 104  * Checks the condition and aborts immediately if it is not satisfied,
 105  * printing the condition and location in the source.
 106  * (Intended for checking for bugs within the library itself.)
 107  *
 108  * Use as either GP_ASSERT(cond), GP_ASSERT(cond, msg) or
 109  * GP_ASSERT(cond, format, params...) where msg and format must be string
 110  * constants.
 111  */
 112 #define GP_ASSERT(check_cond_, ...) \
 113         GP_GENERAL_CHECK(check_cond_, "asserion failed: ", ##__VA_ARGS__);
 114
 115 /*
 116  * Perform a runtime check, on failure abort and print a message.
 117  * (Intended for user-caused errors like invalid arguments.)
 118  *
 119  * Use as either GP_CHECK(cond), GP_CHECK(cond, msg) or
 120  * GP_CHECK(cond, format, params...) where msg and format must be string
 121  * constants.
 122  */
 123 #define GP_CHECK(check_cond_, ...) \
 124         GP_GENERAL_CHECK(check_cond_, "check failed: ", ##__VA_ARGS__);
 125
 126 /*
 127  * Swap a and b using an intermediate variable
 128  */
 129 #define GP_SWAP(a, b) do { \
 130         typeof(a) tmp = b; \
 131         b = a;             \
 132         a = tmp;           \
 133 } while (0)
 134
 135 /*
 136  * Helper macros to read/write parts of words
 137  *
 138  * Return (shifted) count bits at offset of value
 139  * Note: operates with value types same as val
 140  */
 141 #define GP_GET_BITS(offset, count, val) ( ( (val)>>(offset) ) & ( ((((typeof(val))1)<<(count)) - 1) ) )
 142
 143 /*
 144  * Set count bits of dest at ofset to val (shifted by offset)
 145  *
 146  * Does not check val for overflow
 147  * Operates on 8, 16, and 32 bit values, depending on the type of dest,
 148  * this should be unsigned
 149  *
 150  * GP_SET_BITS_OR anly sets (|=) the bits, assuming these are clear beforehand
 151  * GP_CLEAR_BITS sets the target bits to zero
 152  * GP_SET_BITS does both
 153  */
 154 #define GP_CLEAR_BITS(offset, count, dest) ( (dest) &= ~(((((typeof(dest))1) << (count)) - 1) << (offset)) )
 155
 156 #define GP_SET_BITS_OR(offset, dest, val) ( (dest) |= ((val)<<(offset)) )
 157
 158 #define GP_SET_BITS(offset, count, dest, val) (GP_CLEAR_BITS(offset, count, dest), \
 159                                                GP_SET_BITS_OR(offset, dest, val) )
 160
 161
 162 /* Determines the sign of the integer value; it is +1 if value is positive,
 163  * -1 if negative, and 0 if it is zero.
 164  */
 165 #define GP_SIGN(a) ({ \
 166         typeof(a) _a = a; \
 167         (_a > 0) ? 1 : ((_a < 0) ? -1 : 0); \
 168 })
 169
 170 #endif /* GP_COMMON_H */