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use crate::core_crypto::gpu::vec::CudaVec;
use crate::core_crypto::gpu::CudaStreams;
use crate::core_crypto::prelude::{LweBskGroupingFactor, SignedNumeric};
use crate::integer::block_decomposition::{BlockDecomposer, DecomposableInto};
use crate::integer::gpu::ciphertext::boolean_value::CudaBooleanBlock;
use crate::integer::gpu::ciphertext::{
CudaIntegerRadixCiphertext, CudaSignedRadixCiphertext, CudaUnsignedRadixCiphertext,
};
use crate::integer::gpu::server_key::{
CudaBootstrappingKey, CudaDynamicKeyswitchingKey, CudaServerKey,
};
use crate::integer::gpu::{
cuda_backend_get_full_propagate_assign_size_on_gpu,
cuda_backend_get_propagate_single_carry_assign_size_on_gpu,
cuda_backend_scalar_addition_assign, PBSType,
};
use crate::integer::server_key::radix_parallel::OutputFlag;
use crate::prelude::CastInto;
use crate::shortint::ciphertext::NoiseLevel;
impl CudaServerKey {
/// Computes homomorphically an addition between a scalar and a ciphertext.
///
/// This function computes the operation without checking if it exceeds the capacity of the
/// ciphertext.
///
/// The result is returned as a new ciphertext.
///
/// # Example
///
/// ```rust
/// use tfhe::core_crypto::gpu::CudaStreams;
/// use tfhe::core_crypto::gpu::vec::GpuIndex;
/// use tfhe::integer::gpu::ciphertext::CudaUnsignedRadixCiphertext;
/// use tfhe::integer::gpu::gen_keys_radix_gpu;
/// use tfhe::shortint::parameters::PARAM_GPU_MULTI_BIT_GROUP_4_MESSAGE_2_CARRY_2_KS_PBS_TUNIFORM_2M128;
///
/// let gpu_index = 0;
/// let streams = CudaStreams::new_single_gpu(GpuIndex::new(gpu_index));
///
/// // We have 4 * 2 = 8 bits of message
/// let size = 4;
/// let (cks, sks) = gen_keys_radix_gpu(PARAM_GPU_MULTI_BIT_GROUP_4_MESSAGE_2_CARRY_2_KS_PBS_TUNIFORM_2M128, size, &streams);
///
/// let msg = 4;
/// let scalar = 40;
///
/// let ct = cks.encrypt(msg);
/// let d_ct = CudaUnsignedRadixCiphertext::from_radix_ciphertext(&ct, &streams);
///
/// // Compute homomorphically an addition:
/// let d_ct_res = sks.unchecked_scalar_add(&d_ct, scalar, &streams);
/// let ct_res = d_ct_res.to_radix_ciphertext(&streams);
///
/// // Decrypt:
/// let dec: u64 = cks.decrypt(&ct_res);
/// assert_eq!(msg + scalar, dec);
/// ```
pub fn unchecked_scalar_add<Scalar, T>(
&self,
ct: &T,
scalar: Scalar,
streams: &CudaStreams,
) -> T
where
Scalar: DecomposableInto<u8> + CastInto<u64>,
T: CudaIntegerRadixCiphertext,
{
let mut result = ct.duplicate(streams);
self.unchecked_scalar_add_assign(&mut result, scalar, streams);
result
}
pub fn unchecked_scalar_add_assign<Scalar, T>(
&self,
ct: &mut T,
scalar: Scalar,
streams: &CudaStreams,
) where
Scalar: DecomposableInto<u8> + CastInto<u64>,
T: CudaIntegerRadixCiphertext,
{
if scalar != Scalar::ZERO {
let bits_in_message = self.message_modulus.0.ilog2();
let mut d_decomposed_scalar = unsafe {
CudaVec::<u64>::new_async(ct.as_ref().d_blocks.lwe_ciphertext_count().0, streams, 0)
};
let decomposed_scalar =
BlockDecomposer::with_early_stop_at_zero(scalar, bits_in_message)
.iter_as::<u64>()
.take(d_decomposed_scalar.len())
.collect::<Vec<_>>();
unsafe {
d_decomposed_scalar.copy_from_cpu_async(decomposed_scalar.as_slice(), streams, 0);
}
// If the scalar is decomposed using less than the number of blocks our ciphertext
// has, we just don't touch ciphertext's last blocks
unsafe {
cuda_backend_scalar_addition_assign(
streams,
ct.as_mut(),
&d_decomposed_scalar,
&decomposed_scalar,
decomposed_scalar.len() as u32,
self.message_modulus.0 as u32,
self.carry_modulus.0 as u32,
);
}
}
}
/// Computes homomorphically an addition between a scalar and a ciphertext.
///
/// This function computes the operation without checking if it exceeds the capacity of the
/// ciphertext.
///
/// The result is returned as a new ciphertext.
///
/// # Example
///
/// ```rust
/// use tfhe::core_crypto::gpu::CudaStreams;
/// use tfhe::core_crypto::gpu::vec::GpuIndex;
/// use tfhe::integer::gpu::ciphertext::CudaUnsignedRadixCiphertext;
/// use tfhe::integer::gpu::gen_keys_radix_gpu;
/// use tfhe::shortint::parameters::PARAM_GPU_MULTI_BIT_GROUP_4_MESSAGE_2_CARRY_2_KS_PBS_TUNIFORM_2M128;
///
/// let gpu_index = 0;
/// let streams = CudaStreams::new_single_gpu(GpuIndex::new(gpu_index));
///
/// // We have 4 * 2 = 8 bits of message
/// let size = 4;
/// let (cks, sks) = gen_keys_radix_gpu(PARAM_GPU_MULTI_BIT_GROUP_4_MESSAGE_2_CARRY_2_KS_PBS_TUNIFORM_2M128, size, &streams);
///
/// let msg = 4;
/// let scalar = 40;
///
/// let ct = cks.encrypt(msg);
/// let d_ct = CudaUnsignedRadixCiphertext::from_radix_ciphertext(&ct, &streams);
///
/// // Compute homomorphically an addition:
/// let d_ct_res = sks.scalar_add(&d_ct, scalar, &streams);
/// let ct_res = d_ct_res.to_radix_ciphertext(&streams);
///
/// // Decrypt:
/// let dec: u64 = cks.decrypt(&ct_res);
/// assert_eq!(msg + scalar, dec);
/// ```
pub fn scalar_add<Scalar, T>(&self, ct: &T, scalar: Scalar, streams: &CudaStreams) -> T
where
Scalar: DecomposableInto<u8> + CastInto<u64>,
T: CudaIntegerRadixCiphertext,
{
let mut result = ct.duplicate(streams);
self.scalar_add_assign(&mut result, scalar, streams);
result
}
pub fn get_scalar_add_size_on_gpu<T: CudaIntegerRadixCiphertext>(
&self,
ct: &T,
streams: &CudaStreams,
) -> u64 {
self.get_scalar_add_assign_size_on_gpu(ct, streams)
}
pub fn scalar_add_assign<Scalar, T>(&self, ct: &mut T, scalar: Scalar, streams: &CudaStreams)
where
Scalar: DecomposableInto<u8> + CastInto<u64>,
T: CudaIntegerRadixCiphertext,
{
if !ct.block_carries_are_empty() {
self.full_propagate_assign(ct, streams);
}
self.unchecked_scalar_add_assign(ct, scalar, streams);
let _carry = self.propagate_single_carry_assign(ct, streams, None, OutputFlag::None);
}
pub fn get_scalar_add_assign_size_on_gpu<T>(&self, ct: &T, streams: &CudaStreams) -> u64
where
T: CudaIntegerRadixCiphertext,
{
let CudaDynamicKeyswitchingKey::Standard(computing_ks_key) = &self.key_switching_key else {
panic!("Only the standard atomic pattern is supported on GPU")
};
let full_prop_mem = if ct.block_carries_are_empty() {
0
} else {
match &self.bootstrapping_key {
CudaBootstrappingKey::Classic(d_bsk) => {
cuda_backend_get_full_propagate_assign_size_on_gpu(
streams,
d_bsk.input_lwe_dimension(),
d_bsk.glwe_dimension(),
d_bsk.polynomial_size(),
computing_ks_key.decomposition_level_count(),
computing_ks_key.decomposition_base_log(),
d_bsk.decomp_level_count(),
d_bsk.decomp_base_log(),
self.message_modulus,
self.carry_modulus,
PBSType::Classical,
LweBskGroupingFactor(0),
d_bsk.ms_noise_reduction_configuration.as_ref(),
)
}
CudaBootstrappingKey::MultiBit(d_multibit_bsk) => {
cuda_backend_get_full_propagate_assign_size_on_gpu(
streams,
d_multibit_bsk.input_lwe_dimension(),
d_multibit_bsk.glwe_dimension(),
d_multibit_bsk.polynomial_size(),
computing_ks_key.decomposition_level_count(),
computing_ks_key.decomposition_base_log(),
d_multibit_bsk.decomp_level_count(),
d_multibit_bsk.decomp_base_log(),
self.message_modulus,
self.carry_modulus,
PBSType::MultiBit,
d_multibit_bsk.grouping_factor,
None,
)
}
}
};
let num_blocks = ct.as_ref().d_blocks.lwe_ciphertext_count().0 as u32;
let single_carry_mem = match &self.bootstrapping_key {
CudaBootstrappingKey::Classic(d_bsk) => {
cuda_backend_get_propagate_single_carry_assign_size_on_gpu(
streams,
d_bsk.input_lwe_dimension(),
d_bsk.glwe_dimension(),
d_bsk.polynomial_size(),
computing_ks_key.decomposition_level_count(),
computing_ks_key.decomposition_base_log(),
d_bsk.decomp_level_count(),
d_bsk.decomp_base_log(),
num_blocks,
self.message_modulus,
self.carry_modulus,
PBSType::Classical,
LweBskGroupingFactor(0),
OutputFlag::None,
d_bsk.ms_noise_reduction_configuration.as_ref(),
)
}
CudaBootstrappingKey::MultiBit(d_multibit_bsk) => {
cuda_backend_get_propagate_single_carry_assign_size_on_gpu(
streams,
d_multibit_bsk.input_lwe_dimension(),
d_multibit_bsk.glwe_dimension(),
d_multibit_bsk.polynomial_size(),
computing_ks_key.decomposition_level_count(),
computing_ks_key.decomposition_base_log(),
d_multibit_bsk.decomp_level_count(),
d_multibit_bsk.decomp_base_log(),
num_blocks,
self.message_modulus,
self.carry_modulus,
PBSType::MultiBit,
d_multibit_bsk.grouping_factor,
OutputFlag::None,
None,
)
}
};
full_prop_mem.max(single_carry_mem)
}
pub fn unsigned_overflowing_scalar_add<Scalar>(
&self,
ct_left: &CudaUnsignedRadixCiphertext,
scalar: Scalar,
stream: &CudaStreams,
) -> (CudaUnsignedRadixCiphertext, CudaBooleanBlock)
where
Scalar: DecomposableInto<u8> + CastInto<u64>,
{
let mut result;
result = ct_left.duplicate(stream);
let overflowed = self.unsigned_overflowing_scalar_add_assign(&mut result, scalar, stream);
(result, overflowed)
}
pub fn unsigned_overflowing_scalar_add_assign<Scalar>(
&self,
ct_left: &mut CudaUnsignedRadixCiphertext,
scalar: Scalar,
stream: &CudaStreams,
) -> CudaBooleanBlock
where
Scalar: DecomposableInto<u8> + CastInto<u64>,
{
if !ct_left.block_carries_are_empty() {
self.full_propagate_assign(ct_left, stream);
}
self.unchecked_unsigned_overflowing_scalar_add_assign(ct_left, scalar, stream)
}
pub fn unchecked_unsigned_overflowing_scalar_add<Scalar>(
&self,
ct_left: &CudaUnsignedRadixCiphertext,
scalar: Scalar,
stream: &CudaStreams,
) -> (CudaUnsignedRadixCiphertext, CudaBooleanBlock)
where
Scalar: DecomposableInto<u8> + CastInto<u64>,
{
let mut result;
result = ct_left.duplicate(stream);
let overflowed =
self.unchecked_unsigned_overflowing_scalar_add_assign(&mut result, scalar, stream);
(result, overflowed)
}
pub fn unchecked_unsigned_overflowing_scalar_add_assign<Scalar>(
&self,
ct_left: &mut CudaUnsignedRadixCiphertext,
scalar: Scalar,
stream: &CudaStreams,
) -> CudaBooleanBlock
where
Scalar: DecomposableInto<u8> + CastInto<u64>,
{
self.unchecked_scalar_add_assign(ct_left, scalar, stream);
let mut carry_out;
carry_out = self.propagate_single_carry_assign(ct_left, stream, None, OutputFlag::Carry);
let num_scalar_blocks =
BlockDecomposer::with_early_stop_at_zero(scalar, self.message_modulus.0.ilog2())
.count();
if num_scalar_blocks > ct_left.ciphertext.d_blocks.0.lwe_ciphertext_count.0 {
let trivial: CudaUnsignedRadixCiphertext = self.create_trivial_radix(1, 1, stream);
CudaBooleanBlock::from_cuda_radix_ciphertext(trivial.ciphertext)
} else {
if ct_left.as_ref().info.blocks.last().unwrap().noise_level == NoiseLevel::ZERO {
carry_out.as_mut().info = carry_out.as_ref().info.boolean_info(NoiseLevel::ZERO);
}
CudaBooleanBlock::from_cuda_radix_ciphertext(carry_out.ciphertext)
}
}
/// ```rust
/// use tfhe::core_crypto::gpu::CudaStreams;
/// use tfhe::core_crypto::gpu::vec::GpuIndex;
/// use tfhe::integer::gpu::ciphertext::CudaSignedRadixCiphertext;
/// use tfhe::integer::gpu::gen_keys_radix_gpu;
/// use tfhe::shortint::parameters::PARAM_GPU_MULTI_BIT_GROUP_4_MESSAGE_2_CARRY_2_KS_PBS_TUNIFORM_2M128;
///
/// let gpu_index = 0;
/// let streams = CudaStreams::new_single_gpu(GpuIndex::new(gpu_index));
///
/// // Generate the client key and the server key:
/// let num_blocks = 4;
/// let (cks, sks) = gen_keys_radix_gpu(PARAM_GPU_MULTI_BIT_GROUP_4_MESSAGE_2_CARRY_2_KS_PBS_TUNIFORM_2M128, num_blocks, &streams);
///
/// let msg: i8 = 120;
/// let scalar: i8 = 8;
///
/// let ct1 = cks.encrypt_signed(msg);
///
/// // Copy to GPU
/// let d_ct1 = CudaSignedRadixCiphertext::from_signed_radix_ciphertext(&ct1, &streams);
///
/// // Compute homomorphically an overflowing addition:
/// let (d_ct_res, d_ct_overflowed) = sks.signed_overflowing_scalar_add(&d_ct1, scalar, &streams);
///
/// let ct_res = d_ct_res.to_signed_radix_ciphertext(&streams);
/// let ct_overflowed = d_ct_overflowed.to_boolean_block(&streams);
///
/// // Decrypt:
/// let dec_result: i8 = cks.decrypt_signed(&ct_res);
/// let dec_overflowed: bool = cks.decrypt_bool(&ct_overflowed);
/// let (clear_result, clear_overflowed) = msg.overflowing_add(scalar);
/// assert_eq!(dec_result, clear_result);
/// assert_eq!(dec_overflowed, clear_overflowed);
/// ```
pub fn signed_overflowing_scalar_add<Scalar>(
&self,
ct_left: &CudaSignedRadixCiphertext,
scalar: Scalar,
streams: &CudaStreams,
) -> (CudaSignedRadixCiphertext, CudaBooleanBlock)
where
Scalar: SignedNumeric + DecomposableInto<u64> + CastInto<u64>,
{
let mut tmp_lhs;
tmp_lhs = ct_left.duplicate(streams);
if !tmp_lhs.block_carries_are_empty() {
self.full_propagate_assign(&mut tmp_lhs, streams);
}
let trivial: CudaSignedRadixCiphertext = self.create_trivial_radix(
scalar,
ct_left.ciphertext.d_blocks.lwe_ciphertext_count().0,
streams,
);
let (result, overflowed) = self.signed_overflowing_add(&tmp_lhs, &trivial, streams);
let mut extra_scalar_block_iter =
BlockDecomposer::new(scalar, self.message_modulus.0.ilog2())
.iter_as::<u64>()
.skip(ct_left.ciphertext.d_blocks.lwe_ciphertext_count().0);
let extra_blocks_have_correct_value = if scalar < Scalar::ZERO {
extra_scalar_block_iter.all(|block| block == (self.message_modulus.0 - 1))
} else {
extra_scalar_block_iter.all(|block| block == 0)
};
if extra_blocks_have_correct_value {
(result, overflowed)
} else {
let trivial_one: CudaSignedRadixCiphertext = self.create_trivial_radix(1, 1, streams);
// Scalar has more blocks so addition counts as overflowing
(
result,
CudaBooleanBlock::from_cuda_radix_ciphertext(trivial_one.ciphertext),
)
}
}
}