Low-level integer routines with gcc

Gcc supports low-level integer routines similar to the FORTRAN routines POPCOUNT, ISHIFT... <source lang="cpp"> long long __ashlti3 (long long a, int b ) //These functions return the result of shifting a left by b bits. long long __ashrti3 (long long a, int b ) //These functions return the result of arithmetically shifting a right by b bits. long long __divti3 (long long a, long long b ) //These functions return the quotient of the signed division of a and b. long long __lshrti3 (long long a, int b ) //These functions return the result of logically shifting a right by b bits. int __clzti2 (long long a ) //These functions return the number of leading 0-bits in a, starting at the most significant bit position.

                           //If a is zero, the result is undefined.

int __ctzti2 (long long a ) //These functions return the number of trailing 0-bits in a, starting at the least significant bit position.

                           //If a is zero, the result is undefined.

int __ffsti2 (long long a ) //These functions return the index of the least significant 1-bit in a, or the value zero if a is zero.

                           // The least significant bit is index one.

int __parityti2 (long long a ) //These functions return the value zero if the number of bits set in a is even, and the value one otherwise. int __popcountti2 (long long a ) //These functions return the number of bits set in a. int64_t __bswapdi2 (int64 t a ) //These functions return the a byteswapped. </source>