bits.h File Reference

(b76ad15ed0da636161de0243c547ee1e6fc95681)

Internal header for bitwise integer algorithms. More...

#include "ruby/internal/config.h"
#include <limits.h>
#include <stdint.h>
#include "internal/compilers.h"
#include "ruby/ruby.h"
#include "internal/static_assert.h"

Include dependency graph for bits.h:

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Macros
#define	HALF_LONG_MSB   ((SIGNED_VALUE)1<<((SIZEOF_LONG*CHAR_BIT-1)/2))
#define	SIGNED_INTEGER_TYPE_P(T)   (0 > ((T)0)-1)
#define	SIGNED_INTEGER_MIN(T)
#define	SIGNED_INTEGER_MAX(T)   ((T)(SIGNED_INTEGER_MIN(T) ^ ((T)~(T)0)))
#define	UNSIGNED_INTEGER_MAX(T)   ((T)~(T)0)
#define	MUL_OVERFLOW_P(a, b)   __builtin_mul_overflow_p((a), (b), (__typeof__(a * b))0)
#define	MUL_OVERFLOW_SIGNED_INTEGER_P(a, b, min, max)
#define	MUL_OVERFLOW_FIXNUM_P(a, b)
#define	MUL_OVERFLOW_LONG_LONG_P(a, b)   MUL_OVERFLOW_P(a, b)
#define	MUL_OVERFLOW_LONG_P(a, b)   MUL_OVERFLOW_P(a, b)
#define	MUL_OVERFLOW_INT_P(a, b)   MUL_OVERFLOW_P(a, b)
#define	bit_length(x)
#define	swap16   ruby_swap16
#define	swap32   ruby_swap32
#define	swap64   ruby_swap64

Detailed Description

Internal header for bitwise integer algorithms.

Author

Ruby developers ruby-.nosp@m.core.nosp@m.@ruby.nosp@m.-lan.nosp@m.g.org

Copyright

This file is a part of the programming language Ruby. Permission is hereby granted, to either redistribute and/or modify this file, provided that the conditions mentioned in the file COPYING are met. Consult the file for details.

See also

Henry S. Warren Jr., "Hacker's Delight" (2nd ed.), 2013.

SEI CERT C Coding Standard INT32-C. "Ensure that operations on signed integers do not result in overflow"

https://gcc.gnu.org/onlinedocs/gcc/Other-Builtins.html

https://clang.llvm.org/docs/LanguageExtensions.html#builtin-rotateleft

https://clang.llvm.org/docs/LanguageExtensions.html#builtin-rotateright

https://docs.microsoft.com/en-us/cpp/c-runtime-library/reference/byteswap-uint64-byteswap-ulong-byteswap-ushort

https://docs.microsoft.com/en-us/cpp/c-runtime-library/reference/rotl-rotl64-rotr-rotr64

https://docs.microsoft.com/en-us/cpp/intrinsics/bitscanforward-bitscanforward64

https://docs.microsoft.com/en-us/cpp/intrinsics/bitscanreverse-bitscanreverse64

https://docs.microsoft.com/en-us/cpp/intrinsics/lzcnt16-lzcnt-lzcnt64

https://docs.microsoft.com/en-us/cpp/intrinsics/popcnt16-popcnt-popcnt64

https://software.intel.com/sites/landingpage/IntrinsicsGuide/#text=_lzcnt_u32

https://software.intel.com/sites/landingpage/IntrinsicsGuide/#text=_tzcnt_u32

https://software.intel.com/sites/landingpage/IntrinsicsGuide/#text=_rotl64

https://software.intel.com/sites/landingpage/IntrinsicsGuide/#text=_rotr64

https://stackoverflow.com/a/776523

Definition in file bits.h.

Macro Definition Documentation

bit_length

#define bit_length

(

x

)

Value:

    (unsigned int) \
    (sizeof(x) <= sizeof(int32_t) ? 32 - nlz_int32((uint32_t)(x)) : \
                                    64 - nlz_int64((uint64_t)(x)))

Definition at line 140 of file bits.h.

HALF_LONG_MSB

#define HALF_LONG_MSB   ((SIGNED_VALUE)1<<((SIZEOF_LONG*CHAR_BIT-1)/2))

Definition at line 80 of file bits.h.

MUL_OVERFLOW_FIXNUM_P

#define MUL_OVERFLOW_FIXNUM_P	(		a,
			b
	)

Value:

    __extension__ ({ \
        struct { long fixnum : sizeof(long) * CHAR_BIT - 1; } c = { 0 }; \
        __builtin_mul_overflow_p((a), (b), c.fixnum); \
    })

Definition at line 113 of file bits.h.

MUL_OVERFLOW_INT_P

#define MUL_OVERFLOW_INT_P	(		a,
			b
	)		MUL_OVERFLOW_P(a, b)

Definition at line 126 of file bits.h.

MUL_OVERFLOW_LONG_LONG_P

#define MUL_OVERFLOW_LONG_LONG_P	(		a,
			b
	)		MUL_OVERFLOW_P(a, b)

Definition at line 124 of file bits.h.

MUL_OVERFLOW_LONG_P

#define MUL_OVERFLOW_LONG_P	(		a,
			b
	)		MUL_OVERFLOW_P(a, b)

Definition at line 125 of file bits.h.

MUL_OVERFLOW_P

#define MUL_OVERFLOW_P	(		a,
			b
	)		__builtin_mul_overflow_p((a), (b), (__typeof__(a * b))0)

Definition at line 96 of file bits.h.

MUL_OVERFLOW_SIGNED_INTEGER_P

#define MUL_OVERFLOW_SIGNED_INTEGER_P	(		a,
			b,
			min,
			max
	)

Value:

    ( \
    (a) == 0 ? 0 : \
    (a) == -1 ? (b) < -(max) : \
    (a) > 0 ? \
      ((b) > 0 ? (max) / (a) < (b) : (min) / (a) > (b)) : \
      ((b) > 0 ? (min) / (a) < (b) : (max) / (a) > (b)))

Definition at line 103 of file bits.h.

SIGNED_INTEGER_MAX

#define SIGNED_INTEGER_MAX

(

T

)

((T)(SIGNED_INTEGER_MIN(T) ^ ((T)~(T)0)))

Definition at line 91 of file bits.h.

SIGNED_INTEGER_MIN

#define SIGNED_INTEGER_MIN

(

T

)

Value:

    ((sizeof(T) == sizeof(int8_t))  ? ((T)INT8_MIN)  :  \
    ((sizeof(T) == sizeof(int16_t)) ? ((T)INT16_MIN) :  \
    ((sizeof(T) == sizeof(int32_t)) ? ((T)INT32_MIN) :  \
    ((sizeof(T) == sizeof(int64_t)) ? ((T)INT64_MIN) :  \
     0))))

Definition at line 84 of file bits.h.

SIGNED_INTEGER_TYPE_P

#define SIGNED_INTEGER_TYPE_P

(

T

)

(0 > ((T)0)-1)

Definition at line 82 of file bits.h.

swap16

#define swap16   ruby_swap16

Definition at line 147 of file bits.h.

swap32

#define swap32   ruby_swap32

Definition at line 151 of file bits.h.

swap64

#define swap64   ruby_swap64

Definition at line 155 of file bits.h.

UNSIGNED_INTEGER_MAX

#define UNSIGNED_INTEGER_MAX

(

T

)

((T)~(T)0)

Definition at line 93 of file bits.h.