Function mulWrap [src]

rma = a * b with 2s-complement wrapping semantics. rma, a and b may be aliases. However, it is more efficient if rma does not alias a or b. Returns an error if memory could not be allocated. rma's allocator is used for temporary storage to speed up the multiplication.

Prototype

pub fn mulWrap( rma: *Managed, a: *const Managed, b: *const Managed, signedness: Signedness, bit_count: usize, ) !void

Parameters

rma: *Manageda: *const Managedb: *const Managedsignedness: Signednessbit_count: usize

Source

  pub fn mulWrap(
    rma: *Managed,
    a: *const Managed,
    b: *const Managed,
    signedness: Signedness,
    bit_count: usize,
) !void {
    var alias_count: usize = 0;
    if (rma.limbs.ptr == a.limbs.ptr)
        alias_count += 1;
    if (rma.limbs.ptr == b.limbs.ptr)
        alias_count += 1;

    try rma.ensureTwosCompCapacity(bit_count);
    var m = rma.toMutable();
    if (alias_count == 0) {
        m.mulWrapNoAlias(a.toConst(), b.toConst(), signedness, bit_count, rma.allocator);
    } else {
        const limb_count = calcMulWrapLimbsBufferLen(bit_count, a.len(), b.len(), alias_count);
        const limbs_buffer = try rma.allocator.alloc(Limb, limb_count);
        defer rma.allocator.free(limbs_buffer);
        m.mulWrap(a.toConst(), b.toConst(), signedness, bit_count, limbs_buffer, rma.allocator);
    }
    rma.setMetadata(m.positive, m.len);
}  