DoxigAlpha
std › math › big › int › Mutable › shiftLeft

shiftLeft

r = a << shift, in other words, r = a * 2^shift

r and a may alias.

Asserts there is enough memory to fit the result. The upper bound Limb count is a.limbs.len + (shift / (@sizeOf(Limb) * 8)).

Function parameters

Parameters

#
r:*Mutable
shift:usize

Used to indicate either limit of a 2s-complement integer.

Types

#
TwosCompIntLimit
Used to indicate either limit of a 2s-complement integer.
Mutable
A arbitrary-precision big integer, with a fixed set of mutable limbs.
Const
A arbitrary-precision big integer, with a fixed set of immutable limbs.
Managed
An arbitrary-precision big integer along with an allocator which manages the memory.

Returns the number of limbs needed to store `scalar`, which must be a

Functions

#
calcLimbLen
Returns the number of limbs needed to store `scalar`, which must be a
calcSetStringLimbCount
Assumes `string_len` doesn't account for minus signs if the number is negative.
calcNonZeroTwosCompLimbCount
Compute the number of limbs required to store a 2s-complement number of `bit_count` bits.
calcTwosCompLimbCount
Compute the number of limbs required to store a 2s-complement number of `bit_count` bits.
addMulLimbWithCarry
a + b * c + *carry, sets carry to the overflow bits
llcmp
Returns -1, 0, 1 if |a| < |b|, |a| == |b| or |a| > |b| respectively for limbs.

Source

Implementation

#
pub fn shiftLeft(r: *Mutable, a: Const, shift: usize) void {
    const new_len = llshl(r.limbs, a.limbs, shift);
    r.normalize(new_len);
    r.positive = a.positive;
}