3.3.7 Bitwise shift operators

Syntax

shift-expression:
additive-expression
shift-expression << additive-expression
shift-expression >> additive-expression

Constraints

Each of the operands shall have integral type.

Semantics

The integral promotions are performed on each of the operands. The
type of the result is that of the promoted left operand. If the value
of the right operand is negative or is greater than or equal to the
width in bits of the promoted left operand, the behavior is undefined.

The result of E1 << E2 is E1 left-shifted E2 bit positions; vacated
bits are filled with zeros. If E1 has an unsigned type, the value of
the result is E1 multiplied by the quantity, 2 raised to the power E2,
reduced modulo ULONG_MAX+1 if E1 has type unsigned long, UINT_MAX+1
otherwise. (The constants ULONG_MAX and UINT_MAX are defined in the
header <limits.h> .)

The result of E1 >> E2 is E1 right-shifted E2 bit positions. If E1
has an unsigned type or if E1 has a signed type and a nonnegative
value, the value of the result is the integral part of the quotient of
E1 divided by the quantity, 2 raised to the power E2 . If E1 has a
signed type and a negative value, the resulting value is
implementation-defined.