diff options
Diffstat (limited to 'lib/util/intcode.h')
| -rw-r--r-- | lib/util/intcode.h | 228 |
1 files changed, 218 insertions, 10 deletions
diff --git a/lib/util/intcode.h b/lib/util/intcode.h index 4d9c83aa..dd42f669 100644 --- a/lib/util/intcode.h +++ b/lib/util/intcode.h @@ -1,7 +1,78 @@ #ifndef INTCODE_H_INCLUDED #define INTCODE_H_INCLUDED -#include "pm_config.h" /* For uint32_t, BYTE_ORDER */ +#include "pm_config.h" /* For uint32_t, BYTE_ORDER, HAVE_INT64 */ + +static unsigned int const pm_byteOrder = BYTE_ORDER; + +typedef struct { +/*---------------------------------------------------------------------------- + This is a big-endian representation of a 16 bit integer. I.e. + bytes[0] is the most significant 8 bits; bytes[1] is the least + significant 8 bits of the number in pure binary. + + On a big-endian machines, this is bit for bit identical to uint16_t. + On a little-endian machine, it isn't. + + This is an important data type because decent file formats use + big-endian -- they don't care if some CPU happens to use some other + code for its own work. +-----------------------------------------------------------------------------*/ + unsigned char bytes[2]; +} bigend16; + + +static __inline__ uint16_t +pm_uintFromBigend16(bigend16 const arg) { + + uint16_t retval; + + switch (pm_byteOrder) { + case BIG_ENDIAN: { + union { + bigend16 bigend; + uint16_t native; + } converter; + converter.bigend = arg; + retval = converter.native; + } break; + + default: { + retval = + (arg.bytes[0] << 8) | + (arg.bytes[1] << 0); + } + } + return retval; +} + + + +static __inline__ bigend16 +pm_bigendFromUint16(uint16_t const arg) { + + bigend16 retval; + + switch (pm_byteOrder) { + case BIG_ENDIAN: { + union { + bigend16 bigend; + uint16_t native; + } converter; + converter.native = arg; + retval = converter.bigend; + } break; + + default: { + uint16_t shift; + shift = arg; + retval.bytes[1] = shift; /* Takes lower 8 bits */ + shift >>= 8; + retval.bytes[0] = shift; /* Takes lower 8 bits */ + } + } + return retval; +} typedef struct { /*---------------------------------------------------------------------------- @@ -20,9 +91,6 @@ typedef struct { } bigend32; -unsigned int const pm_byteOrder = BYTE_ORDER; - - static __inline__ uint32_t pm_uintFromBigend32(bigend32 const arg) { @@ -34,19 +102,30 @@ pm_uintFromBigend32(bigend32 const arg) { bigend32 bigend; uint32_t native; } converter; - converter.bigend = arg; - retval = converter.native; - }; break; + } break; + +#if HAVE_GCC_BSWAP case LITTLE_ENDIAN: { + /* Use GCC built-in */ + union { + bigend32 bigend; + uint32_t native; + } converter; + converter.bigend = arg; + retval = __builtin_bswap32(converter.native); + } break; +#endif + + default: retval = (arg.bytes[0] << 24) | (arg.bytes[1] << 16) | (arg.bytes[2] << 8) | (arg.bytes[3] << 0); - } break; } + return retval; } @@ -63,12 +142,23 @@ pm_bigendFromUint32(uint32_t const arg) { bigend32 bigend; uint32_t native; } converter; - converter.native = arg; - retval = converter.bigend; } break; + +#if HAVE_GCC_BSWAP case LITTLE_ENDIAN: { + /* Use GCC built-in */ + union { + bigend32 bigend; + uint32_t native; + } converter; + converter.native = __builtin_bswap32(arg); + retval = converter.bigend; + } break; +#endif + + default: { uint32_t shift; shift = arg; retval.bytes[3] = shift; /* Takes lower 8 bits */ @@ -78,9 +168,127 @@ pm_bigendFromUint32(uint32_t const arg) { retval.bytes[1] = shift; /* Takes lower 8 bits */ shift >>= 8; retval.bytes[0] = shift; /* Takes lower 8 bits */ + } + } + return retval; +} + + +#if HAVE_INT64 + +typedef struct { +/*---------------------------------------------------------------------------- + This is a big-endian representation of a 64 bit integer. I.e. + bytes[0] is the most significant 8 bits; bytes[7] is the least + significant 8 bits of the number in pure binary. + + On a big-endian machines, this is bit for bit identical to uint64_t. + On a little-endian machine, it isn't. + + This is an important data type because decent file formats use + big-endian -- they don't care if some CPU happens to use some other + code for its own work. + + uint64_t is supported only when available. +-----------------------------------------------------------------------------*/ + unsigned char bytes[8]; +} bigend64; + + +static __inline__ uint64_t +pm_uintFromBigend64(bigend64 const arg) { + + uint64_t retval; + + switch (pm_byteOrder) { + case BIG_ENDIAN: { + union { + bigend64 bigend; + uint64_t native; + } converter; + converter.bigend = arg; + retval = converter.native; } break; + +#if HAVE_GCC_BSWAP + case LITTLE_ENDIAN: { + /* Use GCC built-in */ + union { + bigend64 bigend; + uint64_t native; + } converter; + converter.bigend = arg; + retval = __builtin_bswap64(converter.native); + } break; +#endif + default: + retval = + ((uint64_t)arg.bytes[0] << 56) | ((uint64_t)arg.bytes[1] << 48) | + ((uint64_t)arg.bytes[2] << 40) | ((uint64_t)arg.bytes[3] << 32) | + ((uint64_t)arg.bytes[4] << 24) | ((uint64_t)arg.bytes[5] << 16) | + ((uint64_t)arg.bytes[6] << 8) | ((uint64_t)arg.bytes[7] << 0); } return retval; } + + +static __inline__ bigend64 +pm_bigendFromUint64(uint64_t const arg) { + + bigend64 retval; + + switch (pm_byteOrder) { + case BIG_ENDIAN: { + union { + bigend64 bigend; + uint64_t native; + } converter; + converter.native = arg; + retval = converter.bigend; + } break; + +#if HAVE_GCC_BSWAP + case LITTLE_ENDIAN: { + + /* Use GCC built-in */ + union { + bigend64 bigend; + uint64_t native; + } converter; + converter.native = __builtin_bswap64(arg); + retval = converter.bigend; + } break; #endif + + default: { + uint64_t shift; + shift = arg; + retval.bytes[7] = shift; /* Takes lower 8 bits */ + shift >>= 8; + retval.bytes[6] = shift; /* Takes lower 8 bits */ + shift >>= 8; + retval.bytes[5] = shift; /* Takes lower 8 bits */ + shift >>= 8; + retval.bytes[4] = shift; /* Takes lower 8 bits */ + shift >>= 8; + retval.bytes[3] = shift; /* Takes lower 8 bits */ + shift >>= 8; + retval.bytes[2] = shift; /* Takes lower 8 bits */ + shift >>= 8; + retval.bytes[1] = shift; /* Takes lower 8 bits */ + shift >>= 8; + retval.bytes[0] = shift; /* Takes lower 8 bits */ + } + } + return retval; +} + +#endif /* HAVE_INT64 */ + +#endif + + + + + |