basics · intermediate · ~15 min
Circularly shift bits toward the MSB.
Implement:
uint32_t rotl32(uint32_t x, int n);
Rotate x left by n positions (bits that fall off the top re-enter at the bottom). n>=0; rotation is mod 32.
A 32-bit value and a shift n.
The rotated value.
x is 32-bit unsigned integer; n is shift count.
#include <stdint.h>
/* Rotate x left by n positions (n>=0; rotation is mod 32). */
uint32_t rotl32(uint32_t x,int n){ (void)n; return x; }
Shifting by 32 or more bits, which invokes undefined behavior in C.
n == 0, n == 31, n >= 32 (needs normalization).
Solve this exercise in the browser editor — compile and run against the test harness, no setup required.