XCORE SDK
XCORE Software Development Kit
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Enumerations | |
enum | pad_mode_e { PAD_MODE_REFLECT = (INT32_MAX-0) , PAD_MODE_EXTEND = (INT32_MAX-1) , PAD_MODE_ZERO = 0 } |
Supported padding modes for convolutions in "same" mode. More... | |
Functions | |
headroom_t | xs3_vect_complex_s32_add (complex_s32_t a[], const complex_s32_t b[], const complex_s32_t c[], const unsigned length, const right_shift_t b_shr, const right_shift_t c_shr) |
Add one complex 32-bit vector to another. More... | |
headroom_t | xs3_vect_complex_s32_add_scalar (complex_s32_t a[], const complex_s32_t b[], const complex_s32_t c, const unsigned length, const right_shift_t b_shr) |
Add a scalar to a complex 32-bit vector. More... | |
headroom_t | xs3_vect_complex_s32_conj_mul (complex_s32_t a[], const complex_s32_t b[], const complex_s32_t c[], const unsigned length, const right_shift_t b_shr, const right_shift_t c_shr) |
Multiply one complex 32-bit vector element-wise by the complex conjugate of another. More... | |
headroom_t | xs3_vect_complex_s32_headroom (const complex_s32_t x[], const unsigned length) |
Calculate the headroom of a complex 32-bit array. More... | |
headroom_t | xs3_vect_complex_s32_macc (complex_s32_t acc[], const complex_s32_t b[], const complex_s32_t c[], const unsigned length, const right_shift_t acc_shr, const right_shift_t b_shr, const right_shift_t c_shr) |
Multiply one complex 32-bit vector element-wise by another, and add the result to an accumulator. More... | |
headroom_t | xs3_vect_complex_s32_nmacc (complex_s32_t acc[], const complex_s32_t b[], const complex_s32_t c[], const unsigned length, const right_shift_t acc_shr, const right_shift_t b_shr, const right_shift_t c_shr) |
Multiply one complex 32-bit vector element-wise by another, and subtract the result from an accumulator. More... | |
headroom_t | xs3_vect_complex_s32_conj_macc (complex_s32_t acc[], const complex_s32_t b[], const complex_s32_t c[], const unsigned length, const right_shift_t acc_shr, const right_shift_t b_shr, const right_shift_t c_shr) |
Multiply one complex 32-bit vector element-wise by the complex conjugate of another, and add the result to an accumulator. More... | |
headroom_t | xs3_vect_complex_s32_conj_nmacc (complex_s32_t acc[], const complex_s32_t b[], const complex_s32_t c[], const unsigned length, const right_shift_t acc_shr, const right_shift_t b_shr, const right_shift_t c_shr) |
Multiply one complex 32-bit vector element-wise by the complex conjugate of another, and subtract the result from an accumulator. More... | |
headroom_t | xs3_vect_complex_s32_mag (int32_t a[], const complex_s32_t b[], const unsigned length, const right_shift_t b_shr, const complex_s32_t *rot_table, const unsigned table_rows) |
Compute the magnitude of each element of a complex 32-bit vector. More... | |
headroom_t | xs3_vect_complex_s32_mul (complex_s32_t a[], const complex_s32_t b[], const complex_s32_t c[], const unsigned length, const right_shift_t b_shr, const right_shift_t c_shr) |
Multiply one complex 32-bit vector element-wise by another. More... | |
headroom_t | xs3_vect_complex_s32_real_mul (complex_s32_t a[], const complex_s32_t b[], const int32_t c[], const unsigned length, const right_shift_t b_shr, const right_shift_t c_shr) |
Multiply a complex 32-bit vector element-wise by a real 32-bit vector. More... | |
headroom_t | xs3_vect_complex_s32_real_scale (complex_s32_t a[], const complex_s32_t b[], const int32_t c, const unsigned length, const right_shift_t b_shr, const right_shift_t c_shr) |
Multiply a complex 32-bit vector by a real scalar. More... | |
headroom_t | xs3_vect_complex_s32_scale (complex_s32_t a[], const complex_s32_t b[], const int32_t c_real, const int32_t c_imag, const unsigned length, const right_shift_t b_shr, const right_shift_t c_shr) |
Multiply a complex 32-bit vector by a complex 32-bit scalar. More... | |
void | xs3_vect_complex_s32_set (complex_s32_t a[], const int32_t b_real, const int32_t b_imag, const unsigned length) |
Set each element of a complex 32-bit vector to a specified value. More... | |
headroom_t | xs3_vect_complex_s32_shl (complex_s32_t a[], const complex_s32_t b[], const unsigned length, const left_shift_t b_shl) |
Left-shift each element of a complex 32-bit vector by a specified number of bits. More... | |
headroom_t | xs3_vect_complex_s32_shr (complex_s32_t a[], const complex_s32_t b[], const unsigned length, const right_shift_t b_shr) |
Right-shift each element of a complex 32-bit vector by a specified number of bits. More... | |
headroom_t | xs3_vect_complex_s32_squared_mag (int32_t a[], const complex_s32_t b[], const unsigned length, const right_shift_t b_shr) |
Computes the squared magnitudes of elements of a complex 32-bit vector. More... | |
headroom_t | xs3_vect_complex_s32_sub (complex_s32_t a[], const complex_s32_t b[], const complex_s32_t c[], const unsigned length, const right_shift_t b_shr, const right_shift_t c_shr) |
Subtract one complex 32-bit vector from another. More... | |
void | xs3_vect_complex_s32_sum (complex_s64_t *a, const complex_s32_t b[], const unsigned length, const right_shift_t b_shr) |
Compute the sum of elements of a complex 32-bit vector. More... | |
void | xs3_vect_complex_s32_tail_reverse (complex_s32_t x[], const unsigned length) |
Reverses the order of the tail of a complex 32-bit vector. More... | |
headroom_t | xs3_vect_complex_s32_conjugate (complex_s32_t a[], const complex_s32_t b[], const unsigned length) |
Get the complex conjugate of a complex 32-bit vector. More... | |
headroom_t | xs3_vect_s32_copy (int32_t a[], const int32_t b[], const unsigned length) |
Copy one 32-bit vector to another. More... | |
headroom_t | xs3_vect_s32_abs (int32_t a[], const int32_t b[], const unsigned length) |
Compute the element-wise absolute value of a 32-bit vector. More... | |
int64_t | xs3_vect_s32_abs_sum (const int32_t b[], const unsigned length) |
Compute the sum of the absolute values of elements of a 32-bit vector. More... | |
headroom_t | xs3_vect_s32_add (int32_t a[], const int32_t b[], const int32_t c[], const unsigned length, const right_shift_t b_shr, const right_shift_t c_shr) |
Add together two 32-bit vectors. More... | |
headroom_t | xs3_vect_s32_add_scalar (int32_t a[], const int32_t b[], const int32_t c, const unsigned length, const right_shift_t b_shr) |
Add a scalar to a 32-bit vector. More... | |
unsigned | xs3_vect_s32_argmin (const int32_t b[], const unsigned length) |
Obtain the array index of the minimum element of a 32-bit vector. More... | |
headroom_t | xs3_vect_s32_clip (int32_t a[], const int32_t b[], const unsigned length, const int32_t lower_bound, const int32_t upper_bound, const right_shift_t b_shr) |
Clamp the elements of a 32-bit vector to a specified range. More... | |
int64_t | xs3_vect_s32_dot (const int32_t b[], const int32_t c[], const unsigned length, const right_shift_t b_shr, const right_shift_t c_shr) |
Compute the inner product between two 32-bit vectors. More... | |
int64_t | xs3_vect_s32_energy (const int32_t b[], const unsigned length, const right_shift_t b_shr) |
Calculate the energy (sum of squares of elements) of a 32-bit vector. More... | |
headroom_t | xs3_vect_s32_headroom (const int32_t x[], const unsigned length) |
Calculate the headroom of a 32-bit vector. More... | |
headroom_t | xs3_vect_s32_inverse (int32_t a[], const int32_t b[], const unsigned length, const unsigned scale) |
Compute the inverse of elements of a 32-bit vector. More... | |
int32_t | xs3_vect_s32_max (const int32_t b[], const unsigned length) |
Find the maximum value in a 32-bit vector. More... | |
headroom_t | xs3_vect_s32_max_elementwise (int32_t a[], const int32_t b[], const int32_t c[], const unsigned length, const right_shift_t b_shr, const right_shift_t c_shr) |
Get the element-wise maximum of two 32-bit vectors. More... | |
int32_t | xs3_vect_s32_min (const int32_t b[], const unsigned length) |
Find the minimum value in a 32-bit vector. More... | |
headroom_t | xs3_vect_s32_min_elementwise (int32_t a[], const int32_t b[], const int32_t c[], const unsigned length, const right_shift_t b_shr, const right_shift_t c_shr) |
Get the element-wise minimum of two 32-bit vectors. More... | |
headroom_t | xs3_vect_s32_mul (int32_t a[], const int32_t b[], const int32_t c[], const unsigned length, const right_shift_t b_shr, const right_shift_t c_shr) |
Multiply one 32-bit vector element-wise by another. More... | |
headroom_t | xs3_vect_s32_macc (int32_t acc[], const int32_t b[], const int32_t c[], const unsigned length, const right_shift_t acc_shr, const right_shift_t b_shr, const right_shift_t c_shr) |
[xs3_vect_s32_mul] More... | |
headroom_t | xs3_vect_s32_nmacc (int32_t acc[], const int32_t b[], const int32_t c[], const unsigned length, const right_shift_t acc_shr, const right_shift_t b_shr, const right_shift_t c_shr) |
Multiply one 32-bit vector element-wise by another, and subtract the result from an accumulator. More... | |
headroom_t | xs3_vect_s32_rect (int32_t a[], const int32_t b[], const unsigned length) |
Rectify the elements of a 32-bit vector. More... | |
headroom_t | xs3_vect_s32_scale (int32_t a[], const int32_t b[], const unsigned length, const int32_t c, const right_shift_t b_shr, const right_shift_t c_shr) |
Multiply a 32-bit vector by a scalar. More... | |
void | xs3_vect_s32_set (int32_t a[], const int32_t b, const unsigned length) |
Set all elements of a 32-bit vector to the specified value. More... | |
headroom_t | xs3_vect_s32_shl (int32_t a[], const int32_t b[], const unsigned length, const left_shift_t b_shl) |
Left-shift the elements of a 32-bit vector by a specified number of bits. More... | |
headroom_t | xs3_vect_s32_shr (int32_t a[], const int32_t b[], const unsigned length, const right_shift_t b_shr) |
Right-shift the elements of a 32-bit vector by a specified number of bits. More... | |
headroom_t | xs3_vect_s32_sqrt (int32_t a[], const int32_t b[], const unsigned length, const right_shift_t b_shr, const unsigned depth) |
Compute the square root of elements of a 32-bit vector. More... | |
headroom_t | xs3_vect_s32_sub (int32_t a[], const int32_t b[], const int32_t c[], const unsigned length, const right_shift_t b_shr, const right_shift_t c_shr) |
Subtract one 32-bit vector from another. More... | |
int64_t | xs3_vect_s32_sum (const int32_t b[], const unsigned length) |
Sum the elements of a 32-bit vector. More... | |
void | xs3_vect_s32_zip (complex_s32_t a[], const int32_t b[], const int32_t c[], const unsigned length, const right_shift_t b_shr, const right_shift_t c_shr) |
Interleave the elements of two vectors into a single vector. More... | |
void | xs3_vect_s32_unzip (int32_t a[], int32_t b[], const complex_s32_t c[], const unsigned length) |
Deinterleave the real and imaginary parts of a complex 32-bit vector into two separate vectors. More... | |
headroom_t | xs3_vect_s32_convolve_valid (int32_t y[], const int32_t x[], const int32_t b_q30[], const unsigned x_length, const unsigned b_length) |
Convolve a 32-bit vector with a short kernel. More... | |
headroom_t | xs3_vect_s32_convolve_same (int32_t y[], const int32_t x[], const int32_t b_q30[], const unsigned x_length, const unsigned b_length, const pad_mode_e padding_mode) |
Convolve a 32-bit vector with a short kernel. More... | |
void | xs3_vect_s32_merge_accs (int32_t a[], const xs3_split_acc_s32_t b[], const unsigned length) |
Merge a vector of split 32-bit accumulators into a vector of int32_t's. More... | |
void | xs3_vect_s32_split_accs (xs3_split_acc_s32_t a[], const int32_t b[], const unsigned length) |
Split a vector of int32_t 's into a vector of xs3_split_acc_s32_t . More... | |
enum pad_mode_e |
Supported padding modes for convolutions in "same" mode.
headroom_t xs3_vect_complex_s32_add | ( | complex_s32_t | a[], |
const complex_s32_t | b[], | ||
const complex_s32_t | c[], | ||
const unsigned | length, | ||
const right_shift_t | b_shr, | ||
const right_shift_t | c_shr | ||
) |
Add one complex 32-bit vector to another.
a[]
, b[]
and c[]
represent the complex 32-bit mantissa vectors \(\bar a\), \(\bar b\) and \(\bar c\)
respectively. Each must begin at a word-aligned address. This operation can be performed safely in-place on b[]
or c[]
.
length
is the number of elements in each of the vectors.
b_shr
and c_shr
are the signed arithmetic right-shifts applied to each element of \(\bar b\) and \(\bar c\) respectively.
\begin{align*} & b_k' \leftarrow sat_{32}(\lfloor b_k \cdot 2^{-b\_shr} \rfloor) \\ & c_k' \leftarrow sat_{32}(\lfloor c_k \cdot 2^{-c\_shr} \rfloor) \\ & Re\{a_k\} \leftarrow Re\{b_k'\} + Re\{c_k'\} \\ & Im\{a_k\} \leftarrow Im\{b_k'\} + Im\{c_k'\} \\ & \qquad\text{ for }k\in 0\ ...\ (length-1) \end{align*}
If \(\bar b\) and \(\bar c\) are the complex 32-bit mantissas of BFP vectors \( \bar{b} \cdot 2^{b\_exp} \) and \(\bar{c} \cdot 2^{c\_exp}\), then the resulting vector \(\bar a\) are the complex 32-bit mantissas of BFP vector \(\bar{a} \cdot 2^{a\_exp}\).
In this case, \(b\_shr\) and \(c\_shr\) must be chosen so that \(a\_exp = b\_exp + b\_shr = c\_exp + c\_shr\). Adding or subtracting mantissas only makes sense if they are associated with the same exponent.
The function xs3_vect_complex_s32_add_prepare() can be used to obtain values for \(a\_exp\), \(b\_shr\) and \(c\_shr\) based on the input exponents \(b\_exp\) and \(c\_exp\) and the input headrooms \(b\_hr\) and \(c\_hr\).
[out] | a | Complex output vector \(\bar a\) |
[in] | b | Complex input vector \(\bar b\) |
[in] | c | Complex input vector \(\bar c\) |
[in] | length | Number of elements in vectors \(\bar a\), \(\bar b\) and \(\bar c\) |
[in] | b_shr | Right-shift applied to \(\bar b\) |
[in] | c_shr | Right-shift applied to \(\bar c\) |
ET_LOAD_STORE | Raised if a , b or c is not word-aligned (See Note: Vector Alignment) |
headroom_t xs3_vect_complex_s32_add_scalar | ( | complex_s32_t | a[], |
const complex_s32_t | b[], | ||
const complex_s32_t | c, | ||
const unsigned | length, | ||
const right_shift_t | b_shr | ||
) |
Add a scalar to a complex 32-bit vector.
a[]
and b[]
represent the complex 32-bit mantissa vectors \(\bar a\) and \(\bar b\) respectively. Each must begin at a word-aligned address. This operation can be performed safely in-place on b[]
.
c
is the complex scalar \(c\)to be added to each element of \(\bar b\).
length
is the number of elements in each of the vectors.
b_shr
is the signed arithmetic right-shift applied to each element of \(\bar b\).
\begin{align*} & b_k' \leftarrow sat_{32}(\lfloor b_k \cdot 2^{-b\_shr} \rfloor) \\ & Re\{a_k\} \leftarrow Re\{b_k'\} + Re\{c\} \\ & Im\{a_k\} \leftarrow Im\{b_k'\} + Im\{c\} \\ & \qquad\text{ for }k\in 0\ ...\ (length-1) \end{align*}
If elements of \(\bar b\) are the complex mantissas of BFP vector \( \bar{b} \cdot 2^{b\_exp}\), and \(c\) is the mantissa of floating-point value \(c \cdot 2^{c\_exp}\), then the resulting vector \(\bar a\) are the mantissas of BFP vector \(\bar{a} \cdot 2^{a\_exp}\).
In this case, \(b\_shr\) and \(c\_shr\) must be chosen so that \(a\_exp = b\_exp + b\_shr = c\_exp + c\_shr\). Adding or subtracting mantissas only makes sense if they are associated with the same exponent.
The function xs3_vect_complex_s32_add_scalar_prepare() can be used to obtain values for \(a\_exp\), \(b\_shr\) and \(c\_shr\) based on the input exponents \(b\_exp\) and \(c\_exp\) and the input headrooms \(b\_hr\) and \(c\_hr\).
Note that \(c\_shr\) is an output of xs3_vect_complex_s32_add_scalar_prepare()
, but is not a parameter to this function. The \(c\_shr\) produced by xs3_vect_complex_s32_add_scalar_prepare()
is to be applied by the user, and the result passed as input c
.
[out] | a | Complex output vector \(\bar a\) |
[in] | b | Complex input vector \(\bar b\) |
[in] | c | Complex input scalar \(c\) |
[in] | length | Number of elements in vectors \(\bar a\) and \(\bar b\) |
[in] | b_shr | Right-shift applied to \(\bar b\) |
ET_LOAD_STORE | Raised if a or b is not word-aligned (See Note: Vector Alignment) |
headroom_t xs3_vect_complex_s32_conj_macc | ( | complex_s32_t | acc[], |
const complex_s32_t | b[], | ||
const complex_s32_t | c[], | ||
const unsigned | length, | ||
const right_shift_t | acc_shr, | ||
const right_shift_t | b_shr, | ||
const right_shift_t | c_shr | ||
) |
Multiply one complex 32-bit vector element-wise by the complex conjugate of another, and add the result to an accumulator.
acc[]
represents the complex 32-bit accumulator mantissa vector \(\bar a\). Each \(a_k\) is acc[k]
.
b[]
and c[]
represent the complex 32-bit input mantissa vectors \(\bar b\) and \(\bar c\), where each \(b_k\) is b[k]
and each \(c_k\) is c[k]
.
Each of the input vectors must begin at a word-aligned address.
length
is the number of elements in each of the vectors.
acc_shr
, b_shr
and c_shr
are the signed arithmetic right-shifts applied to input elements \(a_k\), \(b_k\) and \(c_k\).
\begin{align*} & \tilde{b}_k \leftarrow sat_{32}( b_k \cdot 2^{-b\_shr} ) \\ & \tilde{c}_k \leftarrow sat_{32}( c_k \cdot 2^{-c\_shr} ) \\ & \tilde{a}_k \leftarrow sat_{32}( a_k \cdot 2^{-acc\_shr} ) \\ & v_k \leftarrow round( sat_{32}( ( Re\{\tilde{b}_k\} \cdot Re\{\tilde{c}_k\} + Im\{\tilde{b}_k\} \cdot Im\{\tilde{c}_k\} ) \cdot 2^{-30}) ) \\ & s_k \leftarrow round( sat_{32}( ( Im\{\tilde{b}_k\} \cdot Re\{\tilde{c}_k\} - Re\{\tilde{b}_k\} \cdot Im\{\tilde{c}_k\} ) \cdot 2^{-30}) ) \\ & Re\{a_k\} \leftarrow sat_{32}( Re\{\tilde{a}_k\} + v_k ) \\ & Im\{a_k\} \leftarrow sat_{32}( Im\{\tilde{a}_k\} + s_k ) \\ & \qquad\text{ for }k\in 0\ ...\ (length-1) \end{align*}
If inputs \(\bar b\) and \(\bar c\) are the mantissas of BFP vectors \( \bar{b} \cdot 2^{b\_exp} \) and \(\bar{c} \cdot 2^{c\_exp}\), and input \(\bar a\) is the accumulator BFP vector \(\bar{a} \cdot 2^{a\_exp}\), then the output values of \(\bar a\) have the exponent \(2^{a\_exp + acc\_shr}\).
For accumulation to make sense mathematically, \(bc\_sat\) must be chosen such that \( a\_exp + acc\_shr = b\_exp + c\_exp + b\_shr + c\_shr \).
The function xs3_vect_complex_s32_conj_macc_prepare() can be used to obtain values for \(a\_exp\), \(acc\_shr\), \(b\_shr\) and \(c\_shr\) based on the input exponents \(a\_exp\), \(b\_exp\) and \(c\_exp\) and the input headrooms \(a\_hr\), \(b\_hr\) and \(c\_hr\).
[in,out] | acc | Complex accumulator \(\bar a\) |
[in] | b | Complex input vector \(\bar b\) |
[in] | c | Complex input vector \(\bar c\) |
[in] | length | Number of elements in vectors \(\bar a\), \(\bar b\) and \(\bar c\) |
[in] | acc_shr | Signed arithmetic right-shift applied to accumulator elements. |
[in] | b_shr | Signed arithmetic right-shift applied to elements of \(\bar b\) |
[in] | c_shr | Signed arithmetic right-shift applied to elements of \(\bar c\) |
ET_LOAD_STORE | Raised if acc , b or c is not word-aligned (See Note: Vector Alignment) |
headroom_t xs3_vect_complex_s32_conj_mul | ( | complex_s32_t | a[], |
const complex_s32_t | b[], | ||
const complex_s32_t | c[], | ||
const unsigned | length, | ||
const right_shift_t | b_shr, | ||
const right_shift_t | c_shr | ||
) |
Multiply one complex 32-bit vector element-wise by the complex conjugate of another.
a[]
, b[]
and c[]
represent the 32-bit mantissa vectors \(\bar a\), \(\bar b\) and \(\bar c\) respectively. Each must begin at a word-aligned address. This operation can be performed safely in-place on b[]
or c[]
.
length
is the number of elements in each of the vectors.
b_shr
and c_shr
are the signed arithmetic right-shifts applied to each element of \(\bar b\) and \(\bar c\) respectively.
\begin{align*} & b_k' \leftarrow sat_{32}(\lfloor b_k \cdot 2^{-b\_shr} \rfloor) \\ & c_k' \leftarrow sat_{32}(\lfloor c_k \cdot 2^{-c\_shr} \rfloor) \\ & Re\{a_k\} \leftarrow \left( Re\{b_k'\} \cdot Re\{c_k'\} + Im\{b_k'\} \cdot Im\{c_k'\} \right) \cdot 2^{-30} \\ & Im\{a_k\} \leftarrow \left( Im\{b_k'\} \cdot Re\{c_k'\} - Re\{b_k'\} \cdot Im\{c_k'\} \right) \cdot 2^{-30} \\ & \qquad\text{ for }k\in 0\ ...\ (length-1) \end{align*}
If \(\bar b\) are the complex 32-bit mantissas of a BFP vector \( \bar{b} \cdot 2^{b\_exp} \) and \(c\) is the complex 32-bit mantissa of floating-point value \(c \cdot 2^{c\_exp}\), then the resulting vector \(\bar a\) are the mantissas of BFP vector \(\bar{a} \cdot 2^{a\_exp}\), where \(a\_exp = b\_exp + c\_exp + a\_shr\).
The function xs3_vect_complex_s32_conj_mul_prepare() can be used to obtain values for \(a\_exp\) and \(a\_shr\) based on the input exponents \(b\_exp\) and \(c\_exp\) and the input headrooms \(b\_hr\) and \(c\_hr\).
[out] | a | Complex output vector \(\bar a\) |
[in] | b | Complex input vector \(\bar b\) |
[in] | c | Complex input vector \(\bar c\) |
[in] | length | Number of elements in vectors \(\bar a\), \(\bar b\) and \(\bar c\) |
[in] | b_shr | Right-shift applied to elements of \(\bar b\). |
[in] | c_shr | Right-shift applied to elements of \(\bar c\). |
ET_LOAD_STORE | Raised if a , b or c is not word-aligned (See Note: Vector Alignment) |
headroom_t xs3_vect_complex_s32_conj_nmacc | ( | complex_s32_t | acc[], |
const complex_s32_t | b[], | ||
const complex_s32_t | c[], | ||
const unsigned | length, | ||
const right_shift_t | acc_shr, | ||
const right_shift_t | b_shr, | ||
const right_shift_t | c_shr | ||
) |
Multiply one complex 32-bit vector element-wise by the complex conjugate of another, and subtract the result from an accumulator.
acc[]
represents the complex 32-bit accumulator mantissa vector \(\bar a\). Each \(a_k\) is acc[k]
.
b[]
and c[]
represent the complex 32-bit input mantissa vectors \(\bar b\) and \(\bar c\), where each \(b_k\) is b[k]
and each \(c_k\) is c[k]
.
Each of the input vectors must begin at a word-aligned address.
length
is the number of elements in each of the vectors.
acc_shr
, b_shr
and c_shr
are the signed arithmetic right-shifts applied to input elements \(a_k\), \(b_k\) and \(c_k\).
\begin{align*} & \tilde{b}_k \leftarrow sat_{32}( b_k \cdot 2^{-b\_shr} ) \\ & \tilde{c}_k \leftarrow sat_{32}( c_k \cdot 2^{-c\_shr} ) \\ & \tilde{a}_k \leftarrow sat_{32}( a_k \cdot 2^{-acc\_shr} ) \\ & v_k \leftarrow round( sat_{32}( ( Re\{\tilde{b}_k\} \cdot Re\{\tilde{c}_k\} + Im\{\tilde{b}_k\} \cdot Im\{\tilde{c}_k\} ) \cdot 2^{-30}) ) \\ & s_k \leftarrow round( sat_{32}( ( Im\{\tilde{b}_k\} \cdot Re\{\tilde{c}_k\} - Re\{\tilde{b}_k\} \cdot Im\{\tilde{c}_k\} ) \cdot 2^{-30}) ) \\ & Re\{a_k\} \leftarrow sat_{32}( Re\{\tilde{a}_k\} - v_k ) \\ & Im\{a_k\} \leftarrow sat_{32}( Im\{\tilde{a}_k\} - s_k ) \\ & \qquad\text{ for }k\in 0\ ...\ (length-1) \end{align*}
If inputs \(\bar b\) and \(\bar c\) are the mantissas of BFP vectors \( \bar{b} \cdot 2^{b\_exp} \) and \(\bar{c} \cdot 2^{c\_exp}\), and input \(\bar a\) is the accumulator BFP vector \(\bar{a} \cdot 2^{a\_exp}\), then the output values of \(\bar a\) have the exponent \(2^{a\_exp + acc\_shr}\).
For accumulation to make sense mathematically, \(bc\_sat\) must be chosen such that \( a\_exp + acc\_shr = b\_exp + c\_exp + b\_shr + c\_shr \).
The function xs3_vect_complex_s32_conj_nmacc_prepare() can be used to obtain values for \(a\_exp\), \(acc\_shr\), \(b\_shr\) and \(c\_shr\) based on the input exponents \(a\_exp\), \(b\_exp\) and \(c\_exp\) and the input headrooms \(a\_hr\), \(b\_hr\) and \(c\_hr\).
[in,out] | acc | Complex accumulator \(\bar a\) |
[in] | b | Complex input vector \(\bar b\) |
[in] | c | Complex input vector \(\bar c\) |
[in] | length | Number of elements in vectors \(\bar a\), \(\bar b\) and \(\bar c\) |
[in] | acc_shr | Signed arithmetic right-shift applied to accumulator elements. |
[in] | b_shr | Signed arithmetic right-shift applied to elements of \(\bar b\) |
[in] | c_shr | Signed arithmetic right-shift applied to elements of \(\bar c\) |
ET_LOAD_STORE | Raised if acc , b or c is not word-aligned (See Note: Vector Alignment) |
headroom_t xs3_vect_complex_s32_conjugate | ( | complex_s32_t | a[], |
const complex_s32_t | b[], | ||
const unsigned | length | ||
) |
Get the complex conjugate of a complex 32-bit vector.
The complex conjugate of a complex scalar \(z = x + yi\) is \(z^* = x - yi\). This function computes the complex conjugate of each element of \(\bar b\) (negates the imaginary part of each element) and places the result in \(\bar a\).
a[]
is the complex 32-bit output vector \(\bar a\).
b[]
is the complex 32-bit input vector \(\bar b\).
Both a
and b
must point to word-aligned addresses.
length
is the number of elements in \(\bar a\) and \(\bar b\).
\begin{align*} & Re\{a_k\} \leftarrow Re\{b_k\} \\ & Im\{a_k\} \leftarrow - Im\{b_k\} \\ & \qquad\text{ for }k\in 1\ ...\ (length-1) \end{align*}
[out] | a | Complex 32-bit output vector \(\bar a\) |
[in] | b | Complex 32-bit input vector \(\bar b\) |
[in] | length | Number of elements in vectors \(\bar a\) and \(\bar b\) |
ET_LOAD_STORE | Raised if a or b is not word-aligned (See Note: Vector Alignment) |
headroom_t xs3_vect_complex_s32_headroom | ( | const complex_s32_t | x[], |
const unsigned | length | ||
) |
Calculate the headroom of a complex 32-bit array.
The headroom of an N-bit integer is the number of bits that the integer's value may be left-shifted without any information being lost. Equivalently, it is one less than the number of leading sign bits.
The headroom of a complex_s32_t
struct is the minimum of the headroom of each of its 32-bit fields, re
and im
.
The headroom of a complex_s32_t
array is the minimum of the headroom of each of its complex_s32_t
elements.
This function efficiently traverses the elements of \(\bar x\) to determine its headroom.
x[]
represents the complex 32-bit vector \(\bar x\). x[]
must begin at a word-aligned address.
length
is the number of elements in x[]
.
\begin{align*} min\!\{ HR_{32}\left(x_0\right), HR_{32}\left(x_1\right), ..., HR_{32}\left(x_{length-1}\right) \} \end{align*}
[in] | x | Complex input vector \(\bar x\) |
[in] | length | Number of elements in \(\bar x\) |
ET_LOAD_STORE | Raised if x is not word-aligned (See Note: Vector Alignment) |
headroom_t xs3_vect_complex_s32_macc | ( | complex_s32_t | acc[], |
const complex_s32_t | b[], | ||
const complex_s32_t | c[], | ||
const unsigned | length, | ||
const right_shift_t | acc_shr, | ||
const right_shift_t | b_shr, | ||
const right_shift_t | c_shr | ||
) |
Multiply one complex 32-bit vector element-wise by another, and add the result to an accumulator.
acc[]
represents the complex 32-bit accumulator mantissa vector \(\bar a\). Each \(a_k\) is acc[k]
.
b[]
and c[]
represent the complex 32-bit input mantissa vectors \(\bar b\) and \(\bar c\), where each \(b_k\) is b[k]
and each \(c_k\) is c[k]
.
Each of the input vectors must begin at a word-aligned address.
length
is the number of elements in each of the vectors.
acc_shr
, b_shr
and c_shr
are the signed arithmetic right-shifts applied to input elements \(a_k\), \(b_k\) and \(c_k\).
\begin{align*} & \tilde{b}_k \leftarrow sat_{32}( b_k \cdot 2^{-b\_shr} ) \\ & \tilde{c}_k \leftarrow sat_{32}( c_k \cdot 2^{-c\_shr} ) \\ & \tilde{a}_k \leftarrow sat_{32}( a_k \cdot 2^{-acc\_shr} ) \\ & v_k \leftarrow round( sat_{32}( ( Re\{\tilde{b}_k\} \cdot Re\{\tilde{c}_k\} - Im\{\tilde{b}_k\} \cdot Im\{\tilde{c}_k\} ) \cdot 2^{-30}) ) \\ & s_k \leftarrow round( sat_{32}( ( Im\{\tilde{b}_k\} \cdot Re\{\tilde{c}_k\} + Re\{\tilde{b}_k\} \cdot Im\{\tilde{c}_k\} ) \cdot 2^{-30}) ) \\ & Re\{a_k\} \leftarrow sat_{32}( Re\{\tilde{a}_k\} + v_k ) \\ & Im\{a_k\} \leftarrow sat_{32}( Im\{\tilde{a}_k\} + s_k ) \\ & \qquad\text{ for }k\in 0\ ...\ (length-1) \end{align*}
If inputs \(\bar b\) and \(\bar c\) are the mantissas of BFP vectors \( \bar{b} \cdot 2^{b\_exp} \) and \(\bar{c} \cdot 2^{c\_exp}\), and input \(\bar a\) is the accumulator BFP vector \(\bar{a} \cdot 2^{a\_exp}\), then the output values of \(\bar a\) have the exponent \(2^{a\_exp + acc\_shr}\).
For accumulation to make sense mathematically, \(bc\_sat\) must be chosen such that \( a\_exp + acc\_shr = b\_exp + c\_exp + b\_shr + c\_shr \).
The function xs3_vect_complex_s32_macc_prepare() can be used to obtain values for \(a\_exp\), \(acc\_shr\), \(b\_shr\) and \(c\_shr\) based on the input exponents \(a\_exp\), \(b\_exp\) and \(c\_exp\) and the input headrooms \(a\_hr\), \(b\_hr\) and \(c\_hr\).
[in,out] | acc | Complex accumulator \(\bar a\) |
[in] | b | Complex input vector \(\bar b\) |
[in] | c | Complex input vector \(\bar c\) |
[in] | length | Number of elements in vectors \(\bar a\), \(\bar b\) and \(\bar c\) |
[in] | acc_shr | Signed arithmetic right-shift applied to accumulator elements. |
[in] | b_shr | Signed arithmetic right-shift applied to elements of \(\bar b\) |
[in] | c_shr | Signed arithmetic right-shift applied to elements of \(\bar c\) |
ET_LOAD_STORE | Raised if acc , b or c is not word-aligned (See Note: Vector Alignment) |
headroom_t xs3_vect_complex_s32_mag | ( | int32_t | a[], |
const complex_s32_t | b[], | ||
const unsigned | length, | ||
const right_shift_t | b_shr, | ||
const complex_s32_t * | rot_table, | ||
const unsigned | table_rows | ||
) |
Compute the magnitude of each element of a complex 32-bit vector.
a[]
represents the real 32-bit output mantissa vector \(\bar a\).
b[]
represents the complex 32-bit input mantissa vector \(\bar b\).
a[]
and b[]
must each begin at a word-aligned address.
length
is the number of elements in each of the vectors.
b_shr
is the signed arithmetic right-shift applied to elements of \(\bar b\).
rot_table
must point to a pre-computed table of complex vectors used in calculating the magnitudes. table_rows
is the number of rows in the table. This library is distributed with a default version of the required rotation table. The following symbols can be used to refer to it in user code:
Faster computation (with reduced precision) can be achieved by generating a smaller version of the table. A python script is provided to generate this table.
\begin{align*} & v_k \leftarrow b_k \cdot 2^{-b\_shr} \\ & a_k \leftarrow \sqrt { {\left( Re\{v_k\} \right)}^2 + {\left( Im\{v_k\} \right)}^2 } & \qquad\text{ for }k\in 0\ ...\ (length-1) \end{align*}
If \(\bar b\) are the complex 32-bit mantissas of a BFP vector \( \bar{b} \cdot 2^{b\_exp} \), then the resulting vector \(\bar a\) are the real 32-bit mantissas of BFP vector \(\bar{a} \cdot 2^{a\_exp}\), where \(a\_exp = b\_exp + b\_shr\).
The function xs3_vect_complex_s32_mag_prepare() can be used to obtain values for \(a\_exp\) and \(b\_shr\) based on the input exponent \(b\_exp\) and headroom \(b\_hr\).
[out] | a | Real output vector \(\bar a\) |
[in] | b | Complex input vector \(\bar b\) |
[in] | length | Number of elements in vectors \(\bar a\) and \(\bar b\) |
[in] | b_shr | Right-shift appled to \(\bar b\) |
[in] | rot_table | Pre-computed rotation table required for calculating magnitudes |
[in] | table_rows | Number of rows in rot_table |
ET_LOAD_STORE | Raised if a or b is not word-aligned (See Note: Vector Alignment) |
headroom_t xs3_vect_complex_s32_mul | ( | complex_s32_t | a[], |
const complex_s32_t | b[], | ||
const complex_s32_t | c[], | ||
const unsigned | length, | ||
const right_shift_t | b_shr, | ||
const right_shift_t | c_shr | ||
) |
Multiply one complex 32-bit vector element-wise by another.
a[]
, b[]
and c[]
represent the 32-bit mantissa vectors \(\bar a\), \(\bar b\) and \(\bar c\) respectively. Each must begin at a word-aligned address. This operation can be performed safely in-place on b[]
or c[]
.
length
is the number of elements in each of the vectors.
b_shr
and c_shr
are the signed arithmetic right-shifts applied to each element of \(\bar b\) and \(\bar c\) respectively.
\begin{align*} & b_k' \leftarrow sat_{32}(\lfloor b_k \cdot 2^{-b\_shr} \rfloor) \\ & c_k' \leftarrow sat_{32}(\lfloor c_k \cdot 2^{-c\_shr} \rfloor) \\ & Re\{a_k\} \leftarrow \left( Re\{b_k'\} \cdot Re\{c_k'\} - Im\{b_k'\} \cdot Im\{c_k'\} \right) \cdot 2^{-30} \\ & Im\{a_k\} \leftarrow \left( Im\{b_k'\} \cdot Re\{c_k'\} + Re\{b_k'\} \cdot Im\{c_k'\} \right) \cdot 2^{-30} \\ & \qquad\text{ for }k\in 0\ ...\ (length-1) \end{align*}
If \(\bar b\) are the complex 32-bit mantissas of a BFP vector \( \bar{b} \cdot 2^{b\_exp} \) and \(c\) is the complex 32-bit mantissa of floating-point value \(c \cdot 2^{c\_exp}\), then the resulting vector \(\bar a\) are the mantissas of BFP vector \(\bar{a} \cdot 2^{a\_exp}\), where \(a\_exp = b\_exp + c\_exp + b\_shr + c\_shr\).
The function xs3_vect_complex_s32_mul_prepare() can be used to obtain values for \(a\_exp\), \(b\_shr\) and \(c\_shr\) based on the input exponents \(b\_exp\) and \(c\_exp\) and the input headrooms \(b\_hr\) and \(c\_hr\).
[out] | a | Complex output vector \(\bar a\) |
[in] | b | Complex input vector \(\bar b\) |
[in] | c | Complex input vector \(\bar c\) |
[in] | length | Number of elements in vectors \(\bar a\), \(\bar b\), and \(\bar c\) |
[in] | b_shr | Right-shift appled to \(\bar b\) |
[in] | c_shr | Right-shift appled to \(\bar c\) |
ET_LOAD_STORE | Raised if a , b or c is not word-aligned (See Note: Vector Alignment) |
headroom_t xs3_vect_complex_s32_nmacc | ( | complex_s32_t | acc[], |
const complex_s32_t | b[], | ||
const complex_s32_t | c[], | ||
const unsigned | length, | ||
const right_shift_t | acc_shr, | ||
const right_shift_t | b_shr, | ||
const right_shift_t | c_shr | ||
) |
Multiply one complex 32-bit vector element-wise by another, and subtract the result from an accumulator.
acc[]
represents the complex 32-bit accumulator mantissa vector \(\bar a\). Each \(a_k\) is acc[k]
.
b[]
and c[]
represent the complex 32-bit input mantissa vectors \(\bar b\) and \(\bar c\), where each \(b_k\) is b[k]
and each \(c_k\) is c[k]
.
Each of the input vectors must begin at a word-aligned address.
length
is the number of elements in each of the vectors.
acc_shr
, b_shr
and c_shr
are the signed arithmetic right-shifts applied to input elements \(a_k\), \(b_k\) and \(c_k\).
\begin{align*} & \tilde{b}_k \leftarrow sat_{32}( b_k \cdot 2^{-b\_shr} ) \\ & \tilde{c}_k \leftarrow sat_{32}( c_k \cdot 2^{-c\_shr} ) \\ & \tilde{a}_k \leftarrow sat_{32}( a_k \cdot 2^{-acc\_shr} ) \\ & v_k \leftarrow round( sat_{32}( ( Re\{\tilde{b}_k\} \cdot Re\{\tilde{c}_k\} - Im\{\tilde{b}_k\} \cdot Im\{\tilde{c}_k\} ) \cdot 2^{-30}) ) \\ & s_k \leftarrow round( sat_{32}( ( Im\{\tilde{b}_k\} \cdot Re\{\tilde{c}_k\} + Re\{\tilde{b}_k\} \cdot Im\{\tilde{c}_k\} ) \cdot 2^{-30}) ) \\ & Re\{a_k\} \leftarrow sat_{32}( Re\{\tilde{a}_k\} - v_k ) \\ & Im\{a_k\} \leftarrow sat_{32}( Im\{\tilde{a}_k\} - s_k ) \\ & \qquad\text{ for }k\in 0\ ...\ (length-1) \end{align*}
If inputs \(\bar b\) and \(\bar c\) are the mantissas of BFP vectors \( \bar{b} \cdot 2^{b\_exp} \) and \(\bar{c} \cdot 2^{c\_exp}\), and input \(\bar a\) is the accumulator BFP vector \(\bar{a} \cdot 2^{a\_exp}\), then the output values of \(\bar a\) have the exponent \(2^{a\_exp + acc\_shr}\).
For accumulation to make sense mathematically, \(bc\_sat\) must be chosen such that \( a\_exp + acc\_shr = b\_exp + c\_exp + b\_shr + c\_shr \).
The function xs3_vect_complex_s32_macc_prepare() can be used to obtain values for \(a\_exp\), \(acc\_shr\), \(b\_shr\) and \(c\_shr\) based on the input exponents \(a\_exp\), \(b\_exp\) and \(c\_exp\) and the input headrooms \(a\_hr\), \(b\_hr\) and \(c\_hr\).
[in,out] | acc | Complex accumulator \(\bar a\) |
[in] | b | Complex input vector \(\bar b\) |
[in] | c | Complex input vector \(\bar c\) |
[in] | length | Number of elements in vectors \(\bar a\), \(\bar b\) and \(\bar c\) |
[in] | acc_shr | Signed arithmetic right-shift applied to accumulator elements. |
[in] | b_shr | Signed arithmetic right-shift applied to elements of \(\bar b\) |
[in] | c_shr | Signed arithmetic right-shift applied to elements of \(\bar c\) |
ET_LOAD_STORE | Raised if acc , b or c is not word-aligned (See Note: Vector Alignment) |
headroom_t xs3_vect_complex_s32_real_mul | ( | complex_s32_t | a[], |
const complex_s32_t | b[], | ||
const int32_t | c[], | ||
const unsigned | length, | ||
const right_shift_t | b_shr, | ||
const right_shift_t | c_shr | ||
) |
Multiply a complex 32-bit vector element-wise by a real 32-bit vector.
a[]
and b[]
represent the complex 32-bit mantissa vectors \(\bar a\) and \(\bar b\) respectively.
c[]
represents the real 32-bit mantissa vector \(\bar c\).
a[]
, b[]
, and c[]
each must begin at a word-aligned address. This operation can be performed safely in-place on b[]
.
length
is the number of elements in each of the vectors.
b_shr
and c_shr
are the signed arithmetic right-shifts applied to each element of \(\bar b\) and \(\bar c\) respectively.
\begin{align*} & b_k' \leftarrow sat_{32}(\lfloor b_k \cdot 2^{-b\_shr} \rfloor) \\ & c_k' \leftarrow sat_{32}(\lfloor c_k \cdot 2^{-c\_shr} \rfloor) \\ & Re\{a_k\} \leftarrow \left( Re\{b_k'\} \cdot c_k' \right) \cdot 2^{-30} \\ & Im\{a_k\} \leftarrow \left( Im\{b_k'\} \cdot c_k' \right) \cdot 2^{-30} \\ & \qquad\text{ for }k\in 0\ ...\ (length-1) \end{align*}
If \(\bar b\) are the complex 32-bit mantissas of a BFP vector \( \bar{b} \cdot 2^{b\_exp} \) and \(c\) is the complex 32-bit mantissa of floating-point value \(c \cdot 2^{c\_exp}\), then the resulting vector \(\bar a\) are the mantissas of BFP vector \(\bar{a} \cdot 2^{a\_exp}\), where \(a\_exp = b\_exp + c\_exp + b\_shr + c\_shr\).
The function xs3_vect_complex_s32_real_mul_prepare() can be used to obtain values for \(a\_exp\), \(b\_shr\) and \(c\_shr\) based on the input exponents \(b\_exp\) and \(c\_exp\) and the input headrooms \(b\_hr\) and \(c\_hr\).
[out] | a | Complex output vector \(\bar a\). |
[in] | b | Complex input vector \(\bar b\). |
[in] | c | Real input vector \(\bar c\). |
[in] | length | Number of elements in vectors \(\bar a\), \(\bar b\), and \(\bar c\). |
[in] | b_shr | Right-shift appled to \(\bar b\). |
[in] | c_shr | Right-shift appled to \(\bar c\). |
ET_LOAD_STORE | Raised if a , b or c is not word-aligned (See Note: Vector Alignment) |
headroom_t xs3_vect_complex_s32_real_scale | ( | complex_s32_t | a[], |
const complex_s32_t | b[], | ||
const int32_t | c, | ||
const unsigned | length, | ||
const right_shift_t | b_shr, | ||
const right_shift_t | c_shr | ||
) |
Multiply a complex 32-bit vector by a real scalar.
a[]
and b[]
represent the complex 32-bit mantissa vectors \(\bar a\) and \(\bar b\) respectively.
c
represents the real 32-bit scale factor \(c\).
a[]
and b[]
each must begin at a word-aligned address. This operation can be performed safely in-place on b[]
.
length
is the number of elements in each of the vectors.
b_shr
and c_shr
are the signed arithmetic right-shift applied to each element of \(\bar b\) and to \(c\).
\begin{align*} & b_k' \leftarrow sat_{32}(\lfloor b_k \cdot 2^{-b\_shr} \rfloor) \\ & Re\{a_k\} \leftarrow Re\{b_k'\} \cdot c \\ & Im\{a_k\} \leftarrow Im\{b_k'\} \cdot c \\ & \qquad\text{ for }k\in 0\ ...\ (length-1) \end{align*}
If \(\bar b\) are the complex 16-bit mantissas of a BFP vector \( \bar{b} \cdot 2^{b\_exp} \) and \(c\) is the complex 16-bit mantissa of floating-point value \(c \cdot 2^{c\_exp}\), then the resulting vector \(\bar a\) are the mantissas of BFP vector \(\bar{a} \cdot 2^{a\_exp}\), where \(a\_exp = b\_exp + c\_exp + b\_shr + c\_shr\).
The function xs3_vect_complex_s32_real_scale_prepare() can be used to obtain values for \(a\_exp\), \(b\_shr\) and \(c\_shr\) based on the input exponents \(b\_exp\) and \(c\_exp\) and the input headrooms \(b\_hr\) and \(c\_hr\).
[out] | a | Complex output vector \(\bar a\) |
[in] | b | Complex input vector \(\bar b\) |
[in] | c | Complex input vector \(\bar c\) |
[in] | length | Number of elements in vectors \(\bar a\), \(\bar b\), and \(\bar c\) |
[in] | b_shr | Right-shift applied to \(\bar b\) |
[in] | c_shr | Right-shift applied to \(c\) |
ET_LOAD_STORE | Raised if a or b is not word-aligned (See Note: Vector Alignment) |
headroom_t xs3_vect_complex_s32_scale | ( | complex_s32_t | a[], |
const complex_s32_t | b[], | ||
const int32_t | c_real, | ||
const int32_t | c_imag, | ||
const unsigned | length, | ||
const right_shift_t | b_shr, | ||
const right_shift_t | c_shr | ||
) |
Multiply a complex 32-bit vector by a complex 32-bit scalar.
a[]
and b[]
represent the complex 32-bit mantissa vectors \(\bar a\) and \(\bar b\) respectively.
c
represents the complex 32-bit scale factor \(c\).
a[]
and b[]
each must begin at a word-aligned address. This operation can be performed safely in-place on b[]
.
length
is the number of elements in each of the vectors.
b_shr
and c_shr
are the signed arithmetic right-shifts applied to each element of \(\bar b\) and to \(c\).
\begin{align*} & b_k' \leftarrow sat_{32}(\lfloor b_k \cdot 2^{-b\_shr} \rfloor) \\ & Re\{a_k\} \leftarrow \left( Re\{v_k\} \cdot Re\{c\} - Im\{v_k\} \cdot Im\{c\} \right) \cdot 2^{-30} \\ & Im\{a_k\} \leftarrow \left( Re\{v_k\} \cdot Im\{c\} + Im\{v_k\} \cdot Re\{c\} \right) \cdot 2^{-30} \\ & \qquad\text{ for }k\in 0\ ...\ (length-1) \end{align*}
If \(\bar b\) are the complex 32-bit mantissas of a BFP vector \( \bar{b} \cdot 2^{b\_exp} \) and \(c\) is the complex 32-bit mantissa of floating-point value \(c \cdot 2^{c\_exp}\), then the resulting vector \(\bar a\) are the mantissas of BFP vector \(\bar{a} \cdot 2^{a\_exp}\), where \(a\_exp = b\_exp + c\_exp + b\_shr + c\_shr\).
The function xs3_vect_complex_s32_mul_prepare() can be used to obtain values for \(a\_exp\), \(b\_shr\) and \(c\_shr\) based on the input exponents \(b\_exp\) and \(c\_exp\) and the input headrooms \(b\_hr\) and \(c\_hr\).
[out] | a | Complex output vector \(\bar a\). |
[in] | b | Complex input vector \(\bar b\). |
[in] | c_real | Real part of \(c\) |
[in] | c_imag | Imaginary part of \(c\) |
[in] | length | Number of elements in vectors \(\bar a\) and \(\bar b\). |
[in] | b_shr | Right-shift appled to \(\bar b\). |
[in] | c_shr | Right-shift applied to \(c\). |
ET_LOAD_STORE | Raised if a or b is not word-aligned (See Note: Vector Alignment) |
void xs3_vect_complex_s32_set | ( | complex_s32_t | a[], |
const int32_t | b_real, | ||
const int32_t | b_imag, | ||
const unsigned | length | ||
) |
Set each element of a complex 32-bit vector to a specified value.
a[]
represents a complex 32-bit vector \(\bar a\). a[]
must begin at a word-aligned address.
b_real
and b_imag
are the real and imaginary parts to which each element will be set.
length
is the number of elements in a[]
.
\begin{align*} & a_k \leftarrow b\_real + j\cdot b\_imag \\ & \qquad\text{ for }k\in 0\ ...\ (length-1) \\ & \qquad\text{ where } j^2 = -1 \end{align*}
If \(b\) is the mantissa of floating-point value \(b \cdot 2^{b\_exp}\), then the output vector \(\bar a\) are the mantissas of BFP vector \(\bar{a} \cdot 2^{a\_exp}\), where \(a\_exp = b\_exp\).
[out] | a | Complex output vector \(\bar a\) |
[in] | b_real | Value to set real part of elements of \(\bar a\) to |
[in] | b_imag | Value to set imaginary part of elements of \(\bar a\) to |
[in] | length | Number of elements in \(\bar a\) |
ET_LOAD_STORE | Raised if a is not word-aligned (See Note: Vector Alignment) |
headroom_t xs3_vect_complex_s32_shl | ( | complex_s32_t | a[], |
const complex_s32_t | b[], | ||
const unsigned | length, | ||
const left_shift_t | b_shl | ||
) |
Left-shift each element of a complex 32-bit vector by a specified number of bits.
a[]
and b[]
represent the complex 32-bit mantissa vectors \(\bar a\) and \(\bar b\) respectively. Each must begin at a word-aligned address. This operation can be performed safely in-place on b[]
.
length
is the number of elements in \(\bar a\) and \(\bar b\).
b_shl
is the signed arithmetic left-shift applied to each element of \(\bar b\).
\begin{align*} & Re\{a_k\} \leftarrow sat_{32}(\lfloor Re\{b_k\} \cdot 2^{b\_shl} \rfloor) \\ & Im\{a_k\} \leftarrow sat_{32}(\lfloor Im\{b_k\} \cdot 2^{b\_shl} \rfloor) \\ & \qquad\text{ for }k\in 0\ ...\ (length-1) \end{align*}
If \(\bar b\) are the complex 32-bit mantissas of a BFP vector \( \bar{b} \cdot 2^{b\_exp} \), then the resulting vector \(\bar a\) are the complex 32-bit mantissas of BFP vector \(\bar{a} \cdot 2^{a\_exp}\), where \(\bar{a} = \bar{b} \cdot 2^{b\_shl}\) and \(a\_exp = b\_exp\).
[out] | a | Complex output vector \(\bar a\) |
[in] | b | Complex input vector \(\bar b\) |
[in] | length | Number of elements in vector \(\bar b\) |
[in] | b_shl | Left-shift applied to \(\bar b\) |
ET_LOAD_STORE | Raised if a or b is not word-aligned (See Note: Vector Alignment) |
headroom_t xs3_vect_complex_s32_shr | ( | complex_s32_t | a[], |
const complex_s32_t | b[], | ||
const unsigned | length, | ||
const right_shift_t | b_shr | ||
) |
Right-shift each element of a complex 32-bit vector by a specified number of bits.
a[]
and b[]
represent the complex 32-bit mantissa vectors \(\bar a\) and \(\bar b\) respectively. Each must begin at a word-aligned address. This operation can be performed safely in-place on b[]
.
length
is the number of elements in \(\bar a\) and \(\bar b\).
b_shr
is the signed arithmetic right-shift applied to each element of \(\bar b\).
\begin{align*} & Re\{a_k\} \leftarrow sat_{32}(\lfloor Re\{b_k\} \cdot 2^{-b\_shr} \rfloor) \\ & Im\{a_k\} \leftarrow sat_{32}(\lfloor Im\{b_k\} \cdot 2^{-b\_shr} \rfloor) \\ & \qquad\text{ for }k\in 0\ ...\ (length-1) \end{align*}
If \(\bar b\) are the complex 32-bit mantissas of a BFP vector \( \bar{b} \cdot 2^{b\_exp} \), then the resulting vector \(\bar a\) are the complex 32-bit mantissas of BFP vector \(\bar{a} \cdot 2^{a\_exp}\), where \(\bar{a} = \bar{b} \cdot 2^{-b\_shr}\) and \(a\_exp = b\_exp\).
[out] | a | Complex output vector \(\bar a\) |
[in] | b | Complex input vector \(\bar b\) |
[in] | length | Number of elements in vector \(\bar b\) |
[in] | b_shr | Right-shift applied to \(\bar b\) |
ET_LOAD_STORE | Raised if a or b is not word-aligned (See Note: Vector Alignment) |
headroom_t xs3_vect_complex_s32_squared_mag | ( | int32_t | a[], |
const complex_s32_t | b[], | ||
const unsigned | length, | ||
const right_shift_t | b_shr | ||
) |
Computes the squared magnitudes of elements of a complex 32-bit vector.
a[]
represents the complex 32-bit mantissa vector \(\bar a\). b[]
represents the real 32-bit mantissa vector \(\bar b\). Each must begin at a word-aligned address.
length
is the number of elements in each of the vectors.
b_shr
is the signed arithmetic right-shift appled to each element of \(\bar b\).
\begin{align*} & b_k' \leftarrow sat_{32}(\lfloor b_k \cdot 2^{-b\_shr} \rfloor) \\ & a_k \leftarrow ((Re\{b_k'\})^2 + (Im\{b_k'\})^2)\cdot 2^{-30} \\ & \qquad\text{ for }k\in 0\ ...\ (length-1) \end{align*}
If \(\bar b\) are the complex 32-bit mantissas of a BFP vector \( \bar{b} \cdot 2^{b\_exp} \), then the resulting vector \(\bar a\) are the real 32-bit mantissas of BFP vector \(\bar{a} \cdot 2^{a\_exp}\), where \(a\_exp = 2 \cdot (b\_exp + b\_shr)\).
The function xs3_vect_complex_s32_squared_mag_prepare() can be used to obtain values for \(a\_exp\) and \(b\_shr\) based on the input exponent \(b\_exp\) and headroom \(b\_hr\).
[out] | a | Complex output vector \(\bar a\) |
[in] | b | Complex input vector \(\bar b\) |
[in] | length | Number of elements in vectors \(\bar a\) and \(\bar b\) |
[in] | b_shr | Right-shift appled to \(\bar b\) |
ET_LOAD_STORE | Raised if a is not double word-aligned or b is not word-aligned (See Note: Vector Alignment) |
headroom_t xs3_vect_complex_s32_sub | ( | complex_s32_t | a[], |
const complex_s32_t | b[], | ||
const complex_s32_t | c[], | ||
const unsigned | length, | ||
const right_shift_t | b_shr, | ||
const right_shift_t | c_shr | ||
) |
Subtract one complex 32-bit vector from another.
a[]
, b[]
and c[]
represent the complex 32-bit mantissa vectors \(\bar a\), \(\bar b\) and \(\bar c\)
respectively. Each must begin at a word-aligned address. This operation can be performed safely in-place on b[]
or c[]
.
length
is the number of elements in each of the vectors.
b_shr
and c_shr
are the signed arithmetic right-shifts applied to each element of \(\bar b\) and \(\bar c\) respectively.
\begin{align*} & b_k' \leftarrow sat_{32}(\lfloor b_k \cdot 2^{-b\_shr} \rfloor) \\ & c_k' \leftarrow sat_{32}(\lfloor c_k \cdot 2^{-c\_shr} \rfloor) \\ & Re\{a_k\} \leftarrow Re\{b_k'\} - Re\{c_k'\} \\ & Im\{a_k\} \leftarrow Im\{b_k'\} - Im\{c_k'\} \\ & \qquad\text{ for }k\in 0\ ...\ (length-1) \end{align*}
If \(\bar b\) and \(\bar c\) are the complex 32-bit mantissas of BFP vectors \( \bar{b} \cdot 2^{b\_exp} \) and \(\bar{c} \cdot 2^{c\_exp}\), then the resulting vector \(\bar a\) are the complex 32-bit mantissas of BFP vector \(\bar{a} \cdot 2^{a\_exp}\).
In this case, \(b\_shr\) and \(c\_shr\) must be chosen so that \(a\_exp = b\_exp + b\_shr = c\_exp + c\_shr\). Adding or subtracting mantissas only makes sense if they are associated with the same exponent.
The function xs3_vect_complex_s32_sub_prepare() can be used to obtain values for \(a\_exp\), \(b\_shr\) and \(c\_shr\) based on the input exponents \(b\_exp\) and \(c\_exp\) and the input headrooms \(b\_hr\) and \(c\_hr\).
[out] | a | Complex output vector \(\bar a\) |
[in] | b | Complex input vector \(\bar b\) |
[in] | c | Complex input vector \(\bar c\) |
[in] | length | Number of elements in vectors \(\bar a\), \(\bar b\) and \(\bar c\) |
[in] | b_shr | Right-shift applied to \(\bar b\) |
[in] | c_shr | Right-shift applied to \(\bar c\) |
ET_LOAD_STORE | Raised if a , b or c is not word-aligned (See Note: Vector Alignment) |
void xs3_vect_complex_s32_sum | ( | complex_s64_t * | a, |
const complex_s32_t | b[], | ||
const unsigned | length, | ||
const right_shift_t | b_shr | ||
) |
Compute the sum of elements of a complex 32-bit vector.
a
is the complex 64-bit mantissa of the resulting sum.
b[]
represents the complex 32-bit mantissa vector \(\bar b\). b[]
must begin at a word-aligned address.
length
is the number of elements in \(\bar b\).
b_shr
is the unsigned arithmetic right-shift appled to each element of \(\bar b\). b_shr
cannot be negative.
\begin{align*} & b_k' \leftarrow b_k \cdot 2^{-b\_shr} \\ & Re\{a\} \leftarrow \sum_{k=0}^{length-1} \left( Re\{b_k'\} \right) \\ & Im\{a\} \leftarrow \sum_{k=0}^{length-1} \left( Im\{b_k'\} \right) \end{align*}
If \(\bar b\) are the mantissas of BFP vector \(\bar{b} \cdot 2^{b\_exp}\), then \(a\) is the complex 64-bit mantissa of floating-point value \(a \cdot 2^{a\_exp}\), where \(a\_exp = b\_exp + b\_shr\).
The function xs3_vect_complex_s32_sum_prepare() can be used to obtain values for \(a\_exp\) and \(b\_shr\) based on the input exponents \(b\_exp\) and \(c\_exp\) and the input headrooms \(b\_hr\) and \(c\_hr\).
Internally the sum accumulates into four separate complex 40-bit accumulators. These accumulators apply symmetric 40-bit saturation logic (with bounds \(\pm 2^{39}-1\)) with each added element. At the end, the 4 accumulators are summed together into the 64-bit fields of a
. No saturation logic is applied at this final step.
In the most extreme case, each \(b_k\) may be \(-2^{31}\). \(256\) of these added into the same accumulator is \(-2^{39}\) which would saturate to \(-2^{39}+1\), introducing 1 LSb of error (which may or may not be acceptable given a particular circumstance). The final result for each part then may be as large as \(4\cdot(-2^{39}+1) = -2^{41}+4 \), each fitting into a 42-bit signed integer.
[out] | a | Complex sum \(a\) |
[in] | b | Complex input vector \(\bar b\). |
[in] | length | Number of elements in vector \(\bar b\). |
[in] | b_shr | Right-shift appled to \(\bar b\). |
ET_LOAD_STORE | Raised if b is not word-aligned (See Note: Vector Alignment) |
void xs3_vect_complex_s32_tail_reverse | ( | complex_s32_t | x[], |
const unsigned | length | ||
) |
Reverses the order of the tail of a complex 32-bit vector.
Reverses the order of elements in the tail of the complex 32-bit vector \(\bar x\). The tail of \(\bar x\), in this context, is all elements of \(\bar x\) except for \(x_0\). In other words, the first element \(x_0\) remains where it is, and the remaining \(length-1\) elements are rearranged to have their order reversed.
This function is used when performing a forward or inverse FFT on a single sequence of real values (i.e. the mono FFT), and operates in-place on x[]
.
x[]
represents the complex 32-bit vector \(\bar x\), which is both an input to and an output of this function. x[]
must begin at a word-aligned address.
length
is the number of elements in \(\bar x\).
\begin{align*} & x_0 \leftarrow x_0 \\ & x_k \leftarrow x_{length - k} \\ & \qquad\text{ for }k\in 1\ ...\ (length-1) \end{align*}
[in,out] | x | Complex vector to have its tail reversed. |
[in] | length | Number of elements in \(\bar x\) |
ET_LOAD_STORE | Raised if x is not word-aligned (See Note: Vector Alignment) |
headroom_t xs3_vect_s32_abs | ( | int32_t | a[], |
const int32_t | b[], | ||
const unsigned | length | ||
) |
Compute the element-wise absolute value of a 32-bit vector.
a[]
and b[]
represent the 32-bit vectors \(\bar a\) and \(\bar b\) respectively. Each must begin at a word-aligned address. This operation can be performed safely in-place on b[]
.
length
is the number of elements in each of the vectors.
\begin{align*} & a_k \leftarrow sat_{32}(\left| b_k \right|) \\ & \qquad\text{ for }k\in 0\ ...\ (length-1) \end{align*}
If \(\bar b\) are the mantissas of BFP vector \(\bar{b} \cdot 2^{b\_exp}\), then the output vector \(\bar a\) are the mantissas of BFP vector \(\bar{a} \cdot 2^{a\_exp}\), where \(a\_exp = b\_exp\).
[out] | a | Output vector \(\bar a\) |
[in] | b | Input vector \(\bar b\) |
[in] | length | Number of elements in vectors \(\bar a\) and \(\bar b\) |
ET_LOAD_STORE | Raised if a or b is not word-aligned (See Note: Vector Alignment) |
int64_t xs3_vect_s32_abs_sum | ( | const int32_t | b[], |
const unsigned | length | ||
) |
Compute the sum of the absolute values of elements of a 32-bit vector.
b[]
represents the 32-bit mantissa vector \(\bar b\). b[]
must begin at a word-aligned address.
length
is the number of elements in \(\bar b\).
\begin{align*} \sum_{k=0}^{length-1} sat_{32}(\left| b_k \right|) \end{align*}
If \(\bar b\) are the mantissas of BFP vector \(\bar{b} \cdot 2^{b\_exp}\), then the returned value \(a\) is the 64-bit mantissa of floating-point value \(a \cdot 2^{a\_exp}\), where \(a\_exp = b\_exp\).
Internally the sum accumulates into 8 separate 40-bit accumulators. These accumulators apply symmetric 40-bit saturation logic (with bounds \(\pm (2^{39}-1)\)) with each added element. At the end, the 8 accumulators are summed together into the 64-bit value \(a\) which is returned by this function. No saturation logic is applied at this final step.
Because symmetric 32-bit saturation logic is applied when computing the absolute value, in the corner case where each element is INT32_MIN
, each of the 8 accumulators can accumulate \(256\) elements before saturation is possible. Therefore, with \(b\_hr\) bits of headroom, no saturation of intermediate results is possible with fewer than \(2^{11 + b\_hr}\) elements in \(\bar b\).
If the length of \(\bar b\) is greater than \(2^{11 + b\_hr}\), the sum can be computed piece-wise in several calls to this function, with the partial results summed in user code.
[in] | b | Input vector \(\bar b\) |
[in] | length | Number of elements in \(\bar b\) |
ET_LOAD_STORE | Raised if b is not word-aligned (See Note: Vector Alignment) |
headroom_t xs3_vect_s32_add | ( | int32_t | a[], |
const int32_t | b[], | ||
const int32_t | c[], | ||
const unsigned | length, | ||
const right_shift_t | b_shr, | ||
const right_shift_t | c_shr | ||
) |
Add together two 32-bit vectors.
a[]
, b[]
and c[]
represent the 32-bit mantissa vectors \(\bar a\), \(\bar b\) and \(\bar c\) respectively. Each must begin at a word-aligned address. This operation can be performed safely in-place on b[]
or c[]
.
length
is the number of elements in each of the vectors.
b_shr
and c_shr
are the signed arithmetic right-shifts applied to each element of \(\bar b\) and \(\bar c\) respectively.
\begin{align*} & b_k' = sat_{32}(\lfloor b_k \cdot 2^{-b\_shr} \rfloor) \\ & c_k' = sat_{32}(\lfloor c_k \cdot 2^{-c\_shr} \rfloor) \\ & a_k \leftarrow sat_{32}\!\left( b_k' + c_k' \right) \\ & \qquad\text{ for }k\in 0\ ...\ (length-1) \end{align*}
If \(\bar b\) and \(\bar c\) are the mantissas of BFP vectors \( \bar{b} \cdot 2^{b\_exp} \) and \(\bar{c} \cdot 2^{c\_exp}\), then the resulting vector \(\bar a\) are the mantissas of BFP vector \(\bar{a} \cdot 2^{a\_exp}\).
In this case, \(b\_shr\) and \(c\_shr\) must be chosen so that \(a\_exp = b\_exp + b\_shr = c\_exp + c\_shr\). Adding or subtracting mantissas only makes sense if they are associated with the same exponent.
The function xs3_vect_s32_add_prepare() can be used to obtain values for \(a\_exp\), \(b\_shr\) and \(c\_shr\) based on the input exponents \(b\_exp\) and \(c\_exp\) and the input headrooms \(b\_hr\) and \(c\_hr\).
[out] | a | Output vector \(\bar a\) |
[in] | b | Input vector \(\bar b\) |
[in] | c | Input vector \(\bar c\) |
[in] | length | Number of elements in vectors \(\bar a\), \(\bar b\) and \(\bar c\) |
[in] | b_shr | Right-shift appled to \(\bar b\) |
[in] | c_shr | Right-shift appled to \(\bar c\) |
ET_LOAD_STORE | Raised if a , b or c is not word-aligned (See Note: Vector Alignment) |
headroom_t xs3_vect_s32_add_scalar | ( | int32_t | a[], |
const int32_t | b[], | ||
const int32_t | c, | ||
const unsigned | length, | ||
const right_shift_t | b_shr | ||
) |
Add a scalar to a 32-bit vector.
a[]
, b[]
represent the 32-bit mantissa vectors \(\bar a\) and \(\bar b\) respectively. Each must begin at a word-aligned address. This operation can be performed safely in-place on b[]
.
c
is the scalar \(c\) to be added to each element of \(\bar b\).
length
is the number of elements in each of the vectors.
b_shr
is the signed arithmetic right-shift applied to each element of \(\bar b\).
\begin{align*} & b_k' = sat_{32}(\lfloor b_k \cdot 2^{-b\_shr} \rfloor) \\ & a_k \leftarrow sat_{32}\!\left( b_k' + c \right) \\ & \qquad\text{ for }k\in 0\ ...\ (length-1) \end{align*}
If elements of \(\bar b\) are the mantissas of BFP vector \( \bar{b} \cdot 2^{b\_exp} \), and \(c\) is the mantissa of floating-point value \(c \cdot 2^{c\_exp}\), then the resulting vector \(\bar a\) are the mantissas of BFP vector \(\bar{a} \cdot 2^{a\_exp}\).
In this case, \(b\_shr\) and \(c\_shr\) must be chosen so that \(a\_exp = b\_exp + b\_shr = c\_exp + c\_shr\). Adding or subtracting mantissas only makes sense if they are associated with the same exponent.
The function xs3_vect_s32_add_scalar_prepare() can be used to obtain values for \(a\_exp\), \(b\_shr\) and \(c\_shr\) based on the input exponents \(b\_exp\) and \(c\_exp\) and the input headrooms \(b\_hr\) and \(c\_hr\).
Note that \(c\_shr\) is an output of xs3_vect_s32_add_scalar_prepare()
, but is not a parameter to this function. The \(c\_shr\) produced by xs3_vect_s32_add_scalar_prepare()
is to be applied by the user, and the result passed as input c
.
[out] | a | Output vector \(\bar a\) |
[in] | b | Input vector \(\bar b\) |
[in] | c | Input scalar \(c\) |
[in] | length | Number of elements in vectors \(\bar a\) and \(\bar b\) |
[in] | b_shr | Right-shift appled to \(\bar b\) |
ET_LOAD_STORE | Raised if a or b is not word-aligned (See Note: Vector Alignment) |
unsigned xs3_vect_s32_argmin | ( | const int32_t | b[], |
const unsigned | length | ||
) |
Obtain the array index of the minimum element of a 32-bit vector.
b[]
represents the 32-bit input vector \(\bar b\). It must begin at a word-aligned address.
length
is the number of elements in \(\bar b\).
\begin{align*} & a \leftarrow argmin_k\{ b_k \} \\ & \qquad\text{ for }k\in 0\ ...\ (length-1) \end{align*}
[in] | b | Input vector \(\bar b\) |
[in] | length | Number of elemetns in \(\bar b\) |
ET_LOAD_STORE | Raised if b is not word-aligned (See Note: Vector Alignment) |
headroom_t xs3_vect_s32_clip | ( | int32_t | a[], |
const int32_t | b[], | ||
const unsigned | length, | ||
const int32_t | lower_bound, | ||
const int32_t | upper_bound, | ||
const right_shift_t | b_shr | ||
) |
Clamp the elements of a 32-bit vector to a specified range.
a[]
and b[]
represent the 32-bit vectors \(\bar a\) and \(\bar b\) respectively. Each must begin at a word-aligned address. This operation can be performed safely in-place on b[]
.
length
is the number of elements in each of the vectors.
lower_bound
and upper_bound
are the lower and upper bounds of the clipping range respectively. These bounds are checked for each element of \(\bar b\) only after b_shr
is applied.
b_shr
is the signed arithmetic right-shift applied to elements of \(\bar b\) before being compared to the upper and lower bounds.
If \(\bar b\) are the mantissas for a BFP vector \(\bar{b} \cdot 2^{b\_exp}\), then the exponent \(a\_exp\) of the output BFP vector \(\bar{a} \cdot 2^{a\_exp}\) is given by \(a\_exp = b\_exp + b\_shr\).
\begin{align*} & b_k' \leftarrow sat_{32}(\lfloor b_k \cdot 2^{-b\_shr} \rfloor) \\ & a_k \leftarrow \begin{cases} lower\_bound & b_k' \le lower\_bound \\ & upper\_bound & b_k' \ge upper\_bound \\ & b_k' & otherwise \end{cases} \\ & \qquad\text{ for }k\in 0\ ...\ (length-1) \end{align*}
If \(\bar b\) are the mantissas of BFP vector \(\bar{b} \cdot 2^{b\_exp}\), then the output vector \(\bar a\) are the mantissas of BFP vector \(\bar{a} \cdot 2^{a\_exp}\), where \(a\_exp = b\_exp + b\_shr\).
[out] | a | Output vector \(\bar a\) |
[in] | b | Input vector \(\bar b\) |
[in] | length | Number of elements in vectors \(\bar a\) and \(\bar b\) |
[in] | lower_bound | Lower bound of clipping range |
[in] | upper_bound | Upper bound of clipping range |
[in] | b_shr | Arithmetic right-shift applied to elements of \(\bar b\) prior to clipping |
ET_LOAD_STORE | Raised if a or b is not word-aligned (See Note: Vector Alignment) |
headroom_t xs3_vect_s32_convolve_same | ( | int32_t | y[], |
const int32_t | x[], | ||
const int32_t | b_q30[], | ||
const unsigned | x_length, | ||
const unsigned | b_length, | ||
const pad_mode_e | padding_mode | ||
) |
Convolve a 32-bit vector with a short kernel.
32-bit input vector \(\bar x\) is convolved with a short fixed-point kernel \(\bar b\) to produce 32-bit output vector \(\bar y\). In other words, this function applies the \(K\)th-order FIR filter with coefficients given by \(\bar b\) to the input signal \(\bar x\). The convolution mode is "same" in that the input vector is effectively padded such that the input and output vectors are the same length. The padding behavior is one of those given by pad_mode_e.
The maximum filter order \(K\) supported by this function is \(7\).
y[]
and x[]
are the output and input vectors \(\bar y\) and \(\bar x\) respectively.
b_q30[]
is the vector \(\bar b\) of filter coefficients. The coefficients of \(\bar b\) are encoded in a Q2.30 fixed-point format. The effective value of the \(i\)th coefficient is then \(b_i \cdot 2^{-30}\).
x_length
is the length \(N\) of \(\bar x\) and \(\bar y\) in elements.
b_length
is the length \(K\) of \(\bar b\) in elements (i.e. the number of filter taps). b_length
must be one of \( \{ 1, 3, 5, 7 \} \).
padding_mode
is one of the values from the pad_mode_e enumeration. The padding mode indicates the filter input values for filter taps that have extended beyond the bounds of the input vector \(\bar x\). See pad_mode_e for a list of supported padding modes and associated behaviors.
\begin{align*} & \tilde{x}_i = \begin{cases} \text{determined by padding mode} & i \lt 0 \\ \text{determined by padding mode} & i \ge N \\ x_i & otherwise \end{cases} \\ & y_k \leftarrow \sum_{l=0}^{K-1} (\tilde{x}_{(k+l-P)} \cdot b_l \cdot 2^{-30} ) \\ & \qquad\text{ for }k\in 0\ ...\ (N-2P) \\ & \qquad\text{ where }P = \lfloor K/2 \rfloor \end{align*}
To avoid the possibility of saturating any output elements, \(\bar b\) may be constrained such that \( \sum_{i=0}^{K-1} \left|b_i\right| \leq 2^{30} \).
x[]
[out] | y | Output vector \(\bar y\) |
[in] | x | Input vector \(\bar x\) |
[in] | b_q30 | Filter coefficient vector \(\bar b\) |
[in] | x_length | The number of elements \(N\) in vector \(\bar x\) |
[in] | b_length | The number of elements \(K\) in \(\bar b\) |
[in] | padding_mode | The padding mode to be applied at signal boundaries |
ET_LOAD_STORE | Raised if x or y or b_q30 is not word-aligned (See Note: Vector Alignment) |
headroom_t xs3_vect_s32_convolve_valid | ( | int32_t | y[], |
const int32_t | x[], | ||
const int32_t | b_q30[], | ||
const unsigned | x_length, | ||
const unsigned | b_length | ||
) |
Convolve a 32-bit vector with a short kernel.
32-bit input vector \(\bar x\) is convolved with a short fixed-point kernel \(\bar b\) to produce 32-bit output vector \(\bar y\). In other words, this function applies the \(K\)th-order FIR filter with coefficients given by \(\bar b\) to the input signal \(\bar x\). The convolution is "valid" in the sense that no output elements are emitted where the filter taps extend beyond the bounds of the input vector, resulting in an output vector \(\bar y\) with fewer elements.
The maximum filter order \(K\) supported by this function is \(7\).
y[]
is the output vector \(\bar y\). If input \(\bar x\) has \(N\) elements, and the filter has \(K\) elements, then \(\bar y\) has \(N-2P\) elements, where \(P = \lfloor K / 2 \rfloor\).
x[]
is the input vector \(\bar x\) with length \(N\).
b_q30[]
is the vector \(\bar b\) of filter coefficients. The coefficients of \(\bar b\) are encoded in a Q2.30 fixed-point format. The effective value of the \(i\)th coefficient is then \(b_i \cdot 2^{-30}\).
x_length
is the length \(N\) of \(\bar x\) in elements.
b_length
is the length \(K\) of \(\bar b\) in elements (i.e. the number of filter taps). b_length
must be one of \( \{ 1, 3, 5, 7 \} \).
\begin{align*} & y_k \leftarrow \sum_{l=0}^{K-1} (x_{(k+l)} \cdot b_l \cdot 2^{-30} ) \\ & \qquad\text{ for }k\in 0\ ...\ (N-2P) \\ & \qquad\text{ where }P = \lfloor K/2 \rfloor \end{align*}
To avoid the possibility of saturating any output elements, \(\bar b\) may be constrained such that \( \sum_{i=0}^{K-1} \left|b_i\right| \leq 2^{30} \).
This operation can be applied safely in-place on x[]
.
[out] | y | Output vector \(\bar y\) |
[in] | x | Input vector \(\bar x\) |
[in] | b_q30 | Filter coefficient vector \(\bar b\) |
[in] | x_length | The number of elements \(N\) in vector \(\bar x\) |
[in] | b_length | The number of elements \(K\) in \(\bar b\) |
ET_LOAD_STORE | Raised if x or y or b_q30 is not word-aligned (See Note: Vector Alignment) |
headroom_t xs3_vect_s32_copy | ( | int32_t | a[], |
const int32_t | b[], | ||
const unsigned | length | ||
) |
Copy one 32-bit vector to another.
This function is effectively a constrained version of memcpy
.
With the constraints below met, this function should be modestly faster than memcpy
.
a[]
is the output vector to which elements are copied.
b[]
is the input vector from which elements are copied.
a
and b
each must begin at a word-aligned address.
length
is the number of elements to be copied. length
must be a multiple of 8.
\begin{align*} & a_k \leftarrow b_k \\ & \qquad\text{ for }k\in 0\ ...\ (length-1) \end{align*}
[out] | a | Output vector \(\bar a\) |
[in] | b | Input vector \(\bar b\) |
[in] | length | Number of elements in \(\bar a\) and \(\bar b\) |
ET_LOAD_STORE | Raised if a or b is not word-aligned (See Note: Vector Alignment) |
int64_t xs3_vect_s32_dot | ( | const int32_t | b[], |
const int32_t | c[], | ||
const unsigned | length, | ||
const right_shift_t | b_shr, | ||
const right_shift_t | c_shr | ||
) |
Compute the inner product between two 32-bit vectors.
b[]
and c[]
represent the 32-bit mantissa vectors \(\bar b\) and \(\bar c\) respectively. Each must begin at a word-aligned address.
length
is the number of elements in each of the vectors.
b_shr
and c_shr
are the signed arithmetic right-shifts applied to each element of \(\bar b\) and \(\bar c\) respectively.
\begin{align*} & b_k' \leftarrow sat_{32}(\lfloor b_k \cdot 2^{-b\_shr} \rfloor) \\ & c_k' \leftarrow sat_{32}(\lfloor c_k \cdot 2^{-c\_shr} \rfloor) \\ & a \leftarrow \sum_{k=0}^{length-1}\left(round( b_k' \cdot c_k' \cdot 2^{-30} ) \right) \\ & \qquad\text{where } a \text{ is returned} \end{align*}
If \(\bar b\) and \(\bar c\) are the mantissas of the BFP vectors \( \bar{b} \cdot 2^{b\_exp} \) and \(\bar{c}\cdot 2^{c\_exp}\), then result \(a\) is the 64-bit mantissa of the result \(a \cdot 2^{a\_exp}\), where \(a\_exp = b\_exp + c\_exp + b\_shr + c\_shr + 30\).
If needed, the bit-depth of \(a\) can then be reduced to 32 bits to get a new result \(a' \cdot 2^{a\_exp'}\) where \(a' = a \cdot 2^{-a\_shr}\) and \(a\_exp' = a\_exp + a\_shr\).
The function xs3_vect_s32_dot_prepare() can be used to obtain values for \(a\_exp\), \(b\_shr\) and \(c\_shr\) based on the input exponents \(b\_exp\) and \(c\_exp\) and the input headrooms \(b\_hr\) and \(c\_hr\).
The 30-bit rounding right-shift applied to each of the 64-bit products \(b_k \cdot c_k\) is a feature of the hardware and cannot be avoided. As such, if the input vectors \(\bar b\) and \(\bar c\) together have too much headroom (i.e. \(b\_hr + c\_hr\)), the sum may effectively vanish. To avoid this situation, negative values of b_shr
and c_shr
may be used (with the stipulation that \(b\_shr \ge -b\_hr\) and \(c\_shr \ge -c\_hr\) if saturation of \(b_k'\) and \(c_k'\) is to be avoided). The less headroom \(b_k'\) and \(c_k'\) have, the greater the precision of the final result.
Internally, each product \((b_k' \cdot c_k' \cdot 2^{-30})\) accumulates into one of eight 40-bit accumulators (which are all used simultaneously) which apply symmetric 40-bit saturation logic (with bounds \(\approx 2^{39}\)) with each value added. The saturating arithmetic employed is not associative and no indication is given if saturation occurs at an intermediate step. To avoid satuation errors, length
should be no greater than \(2^{10+b\_hr+c\_hr}\), where \(b\_hr\) and \(c\_hr\) are the headroom of \(\bar b\) and \(\bar c\) respectively.
If the caller's mantissa vectors are longer than that, the full inner product can be found by calling this function multiple times for partial inner products on sub-sequences of the input vectors, and adding the results in user code.
In many situations the caller may have a priori knowledge that saturation is impossible (or very nearly so), in which case this guideline may be disregarded. However, such situations are application-specific and are well beyond the scope of this documentation, and as such are left to the user's discretion.
[in] | b | Input vector \(\bar b\) |
[in] | c | Input vector \(\bar c\) |
[in] | length | Number of elements in vectors \(\bar b\) and \(\bar c\) |
[in] | b_shr | Right-shift appled to \(\bar b\) |
[in] | c_shr | Right-shift appled to \(\bar c\) |
ET_LOAD_STORE | Raised if b or c is not word-aligned (See Note: Vector Alignment) |
int64_t xs3_vect_s32_energy | ( | const int32_t | b[], |
const unsigned | length, | ||
const right_shift_t | b_shr | ||
) |
Calculate the energy (sum of squares of elements) of a 32-bit vector.
b[]
represents the 32-bit mantissa vector \(\bar b\). b[]
must begin at a word-aligned address.
length
is the number of elements in \(\bar b\).
b_shr
is the signed arithmetic right-shift applied to elements of \(\bar b\).
\begin{align*} & b_k' \leftarrow sat_{32}(\lfloor b_k \cdot 2^{-b\_shr} \rfloor) \\ & a \leftarrow \sum_{k=0}^{length-1} round((b_k')^2 \cdot 2^{-30}) \end{align*}
If \(\bar b\) are the mantissas of the BFP vector \(\bar{b} \cdot 2^{b\_exp}\), then floating-point result is \(a \cdot 2^{a\_exp}\), where the 64-bit mantissa \(a\) is returned by this function, and \(a\_exp = 30 + 2 \cdot (b\_exp + b\_shr) \).
The function xs3_vect_s32_energy_prepare() can be used to obtain values for \(a\_exp\), \(b\_shr\) and \(c\_shr\) based on the input exponents \(b\_exp\) and \(c\_exp\) and the input headrooms \(b\_hr\) and \(c\_hr\).
The 30-bit rounding right-shift applied to each element of the 64-bit products \((b_k')^2\) is a feature of the hardware and cannot be avoided. As such, if the input vector \(\bar b\) has too much headroom (i.e. \(2\cdot b\_hr\)), the sum may effectively vanish. To avoid this situation, negative values of b_shr
may be used (with the stipulation that \(b\_shr \ge -b\_hr\) if satuartion of \(b_k'\) is to be avoided). The less headroom \(b_k'\) has, the greater the precision of the final result.
Internally, each product \((b_k')^2 \cdot 2^{-30}\) accumulates into one of eight 40-bit accumulators (which are all used simultaneously) which apply symmetric 40-bit saturation logic (with bounds \(\approx 2^{39}\)) with each value added. The saturating arithmetic employed is not associative and no indication is given if saturation occurs at an intermediate step. To avoid saturation errors, length
should be no greater than \(2^{10+2\cdotb\_hr}\), where \(b\_hr\) is the headroom of \(\bar b\).
If the caller's mantissa vector is longer than that, the full result can be found by calling this function multiple times for partial results on sub-sequences of the input, and adding the results in user code.
In many situations the caller may have a priori knowledge that saturation is impossible (or very nearly so), in which case this guideline may be disregarded. However, such situations are application-specific and are well beyond the scope of this documentation, and as such are left to the user's discretion.
[in] | b | Input vector \(\bar b\) |
[in] | length | Number of elements in \(\bar b\) |
[in] | b_shr | Right-shift appled to \(\bar b\) |
ET_LOAD_STORE | Raised if b is not word-aligned (See Note: Vector Alignment) |
headroom_t xs3_vect_s32_headroom | ( | const int32_t | x[], |
const unsigned | length | ||
) |
Calculate the headroom of a 32-bit vector.
The headroom of an N-bit integer is the number of bits that the integer's value may be left-shifted without any information being lost. Equivalently, it is one less than the number of leading sign bits.
The headroom of an int32_t
array is the minimum of the headroom of each of its int32_t
elements.
This function efficiently traverses the elements of a[]
to determine its headroom.
x[]
represents the 32-bit vector \(\bar x\). x[]
must begin at a word-aligned address.
length
is the number of elements in x[]
.
\begin{align*} min\!\{ HR_{32}\left(x_0\right), HR_{32}\left(x_1\right), ..., HR_{32}\left(x_{length-1}\right) \} \end{align*}
[in] | x | Input vector \(\bar x\) |
[in] | length | The number of elements in x[] |
ET_LOAD_STORE | Raised if x is not word-aligned (See Note: Vector Alignment) |
headroom_t xs3_vect_s32_inverse | ( | int32_t | a[], |
const int32_t | b[], | ||
const unsigned | length, | ||
const unsigned | scale | ||
) |
Compute the inverse of elements of a 32-bit vector.
a[]
and b[]
represent the 32-bit mantissa vectors \(\bar a\) and \(\bar b\) respectively. Each vector must begin at a word-aligned address. This operation can be performed safely in-place on b[]
.
length
is the number of elements in each of the vectors.
scale
is a scaling parameter used to maximize the precision of the result.
\begin{align*} & a_k \leftarrow \lfloor\frac{2^{scale}}{b_k}\rfloor \\ & \qquad\text{ for }k\in 0\ ...\ (length-1) \end{align*}
If \(\bar b\) are the mantissas of BFP vector \(\bar{b} \cdot 2^{b\_exp}\), then the resulting vector \(\bar a\) are the mantissas of BFP vector \(\bar{a} \cdot 2^{a\_exp}\), where \(a\_exp = scale - b\_exp\).
The function xs3_vect_s32_inverse_prepare() can be used to obtain values for \(a\_exp\) and \(scale\).
[out] | a | Output vector \(\bar a\) |
[in] | b | Input vector \(\bar b\) |
[in] | length | Number of elements in vectors \(\bar a\) and \(\bar b\) |
[in] | scale | Scale factor applied to dividend when computing inverse |
ET_LOAD_STORE | Raised if a or b is not word-aligned (See Note: Vector Alignment) |
headroom_t xs3_vect_s32_macc | ( | int32_t | acc[], |
const int32_t | b[], | ||
const int32_t | c[], | ||
const unsigned | length, | ||
const right_shift_t | acc_shr, | ||
const right_shift_t | b_shr, | ||
const right_shift_t | c_shr | ||
) |
[xs3_vect_s32_mul]
Multiply one 32-bit vector element-wise by another, and add the result to an accumulator.
acc[]
represents the 32-bit accumulator mantissa vector \(\bar a\). Each \(a_k\) is acc[k]
.
b[]
and c[]
represent the 32-bit input mantissa vectors \(\bar b\) and \(\bar c\), where each \(b_k\) is b[k]
and each \(c_k\) is c[k]
.
Each of the input vectors must begin at a word-aligned address.
length
is the number of elements in each of the vectors.
acc_shr
, b_shr
and c_shr
are the signed arithmetic right-shifts applied to input elements \(a_k\), \(b_k\) and \(c_k\).
\begin{align*} & \tilde{b}_k \leftarrow sat_{32}( b_k \cdot 2^{-b\_shr} ) \\ & \tilde{c}_k \leftarrow sat_{32}( c_k \cdot 2^{-c\_shr} ) \\ & \tilde{a}_k \leftarrow sat_{32}( a_k \cdot 2^{-acc\_shr} ) \\ & v_k \leftarrow round( sat_{32}( \tilde{b}_k \cdot \tilde{c}_k \cdot 2^{-30} ) ) \\ & a_k \leftarrow sat_{32}( \tilde{a}_k + v_k ) \\ & \qquad\text{ for }k\in 0\ ...\ (length-1) \end{align*}
If inputs \(\bar b\) and \(\bar c\) are the mantissas of BFP vectors \( \bar{b} \cdot 2^{b\_exp} \) and \(\bar{c} \cdot 2^{c\_exp}\), and input \(\bar a\) is the accumulator BFP vector \(\bar{a} \cdot 2^{a\_exp}\), then the output values of \(\bar a\) have the exponent \(2^{a\_exp + acc\_shr}\).
For accumulation to make sense mathematically, \(bc\_sat\) must be chosen such that \( a\_exp + acc\_shr = b\_exp + c\_exp + bc\_sat \).
The function xs3_vect_complex_s16_macc_prepare() can be used to obtain values for \(a\_exp\), \(acc\_shr\) and \(bc\_sat\) based on the input exponents \(a\_exp\), \(b\_exp\) and \(c\_exp\) and the input headrooms \(a\_hr\), \(b\_hr\) and \(c\_hr\).
[in,out] | acc | Accumulator \(\bar a\) |
[in] | b | Input vector \(\bar b\) |
[in] | c | Input vector \(\bar c\) |
[in] | length | Number of elements in vectors \(\bar a\), \(\bar b\) and \(\bar c\) |
[in] | acc_shr | Signed arithmetic right-shift applied to accumulator elements. |
[in] | b_shr | Signed arithmetic right-shift applied to elements of \(\bar b\) |
[in] | c_shr | Signed arithmetic right-shift applied to elements of \(\bar c\) |
ET_LOAD_STORE | Raised if acc , b or c is not word-aligned (See Note: Vector Alignment) |
int32_t xs3_vect_s32_max | ( | const int32_t | b[], |
const unsigned | length | ||
) |
Find the maximum value in a 32-bit vector.
b[]
represents the 32-bit vector \(\bar b\). It must begin at a word-aligned address.
length
is the number of elements in \(\bar b\).
\begin{align*} max\{ x_0, x_1, ..., x_{length-1} \} \end{align*}
If \(\bar b\) are the mantissas of BFP vector \(\bar{b} \cdot 2^{b\_exp}\), then the returned value \(a\) is the 32-bit mantissa of floating-point value \(a \cdot 2^{a\_exp}\), where \(a\_exp = b\_exp\).
[in] | b | Input vector \(\bar b\) |
[in] | length | Number of elements in \(\bar b\) |
ET_LOAD_STORE | Raised if b is not word-aligned (See Note: Vector Alignment) |
headroom_t xs3_vect_s32_max_elementwise | ( | int32_t | a[], |
const int32_t | b[], | ||
const int32_t | c[], | ||
const unsigned | length, | ||
const right_shift_t | b_shr, | ||
const right_shift_t | c_shr | ||
) |
Get the element-wise maximum of two 32-bit vectors.
a[]
, b[]
and c[]
represent the 32-bit mantissa vectors \(\bar a\), \(\bar b\) and \(\bar c\) respectively. Each must begin at a word-aligned address. This operation can be performed safely in-place on b[]
, but not on c[]
.
length
is the number of elements in each of the vectors.
b_shr
and c_shr
are the signed arithmetic right-shifts applied to each element of \(\bar b\) and \(\bar c\) respectively.
\begin{align*} & b_k' \leftarrow sat_{32}(\lfloor b_k \cdot 2^{-b\_shr} \rfloor) \\ & c_k' \leftarrow sat_{32}(\lfloor c_k \cdot 2^{-c\_shr} \rfloor) \\ & a_k \leftarrow max(b_k', c_k') \\ & \qquad\text{ for }k\in 0\ ...\ (length-1) \end{align*}
If \(\bar b\) and \(\bar c\) are the mantissas of BFP vectors \( \bar{b} \cdot 2^{b\_exp} \) and \(\bar{c} \cdot 2^{c\_exp}\), then the resulting vector \(\bar a\) are the mantissas of BFP vector \(\bar{a} \cdot 2^{a\_exp}\), where \(a\_exp = b\_exp + b\_shr = c\_exp + c\_shr\).
The function xs3_vect_2vec_prepare() can be used to obtain values for \(a\_exp\), \(b\_shr\) and \(c\_shr\) based on the input exponents \(b\_exp\) and \(c\_exp\) and the input headrooms \(b\_hr\) and \(c\_hr\).
[out] | a | Output vector \(\bar a\) |
[in] | b | Input vector \(\bar b\) |
[in] | c | Input vector \(\bar c\) |
[in] | length | Number of elements in vectors \(\bar a\), \(\bar b\) and \(\bar c\) |
[in] | b_shr | Right-shift appled to \(\bar b\) |
[in] | c_shr | Right-shift appled to \(\bar c\) |
ET_LOAD_STORE | Raised if a , b or c is not word-aligned (See Note: Vector Alignment) |
void xs3_vect_s32_merge_accs | ( | int32_t | a[], |
const xs3_split_acc_s32_t | b[], | ||
const unsigned | length | ||
) |
Merge a vector of split 32-bit accumulators into a vector of int32_t's.
Convert a vector of xs3_split_acc_s32_t into a vector of int32_t
. This is useful when a function (e.g. xs3_mat_mul_s8_x_s8_yield_s32
) outputs a vector of accumulators in the XS3 VPU's native split 32-bit format, which has the upper half of each accumulator in the first 32 bytes and the lower half in the following 32 bytes.
This function is most efficient (in terms of cycles/accumulator) when length
is a multiple of
length
will be rounded up such that a multiple of 16 accumulators will always be merged.This function can safely merge accumulators in-place.
[out] | a | Output vector of int32_t |
[in] | b | Input vector of xs3_split_acc_s32_t |
[in] | length | Number of accumulators to merge |
ET_LOAD_STORE | Raised if b or a is not word-aligned (See Note: Vector Alignment) |
int32_t xs3_vect_s32_min | ( | const int32_t | b[], |
const unsigned | length | ||
) |
Find the minimum value in a 32-bit vector.
b[]
represents the 32-bit vector \(\bar b\). It must begin at a word-aligned address.
length
is the number of elements in \(\bar b\).
\begin{align*} max\{ x_0, x_1, ..., x_{length-1} \} \end{align*}
If \(\bar b\) are the mantissas of BFP vector \(\bar{b} \cdot 2^{b\_exp}\), then the returned value \(a\) is the 32-bit mantissa of floating-point value \(a \cdot 2^{a\_exp}\), where \(a\_exp = b\_exp\).
[in] | b | Input vector \(\bar b\) |
[in] | length | Number of elements in \(\bar b\) |
ET_LOAD_STORE | Raised if b is not word-aligned (See Note: Vector Alignment) |
headroom_t xs3_vect_s32_min_elementwise | ( | int32_t | a[], |
const int32_t | b[], | ||
const int32_t | c[], | ||
const unsigned | length, | ||
const right_shift_t | b_shr, | ||
const right_shift_t | c_shr | ||
) |
Get the element-wise minimum of two 32-bit vectors.
a[]
, b[]
and c[]
represent the 32-bit mantissa vectors \(\bar a\), \(\bar b\) and \(\bar c\) respectively. Each must begin at a word-aligned address. This operation can be performed safely in-place on b[]
, but not on c[]
.
length
is the number of elements in each of the vectors.
b_shr
and c_shr
are the signed arithmetic right-shifts applied to each element of \(\bar b\) and \(\bar c\) respectively.
\begin{align*} & b_k' \leftarrow sat_{32}(\lfloor b_k \cdot 2^{-b\_shr} \rfloor) \\ & c_k' \leftarrow sat_{32}(\lfloor c_k \cdot 2^{-c\_shr} \rfloor) \\ & a_k \leftarrow min(b_k', c_k') \\ & \qquad\text{ for }k\in 0\ ...\ (length-1) \end{align*}
If \(\bar b\) and \(\bar c\) are the mantissas of BFP vectors \( \bar{b} \cdot 2^{b\_exp} \) and \(\bar{c} \cdot 2^{c\_exp}\), then the resulting vector \(\bar a\) are the mantissas of BFP vector \(\bar{a} \cdot 2^{a\_exp}\), where \(a\_exp = b\_exp + b\_shr = c\_exp + c\_shr\).
The function xs3_vect_2vec_prepare() can be used to obtain values for \(a\_exp\), \(b\_shr\) and \(c\_shr\) based on the input exponents \(b\_exp\) and \(c\_exp\) and the input headrooms \(b\_hr\) and \(c\_hr\).
[out] | a | Output vector \(\bar a\) |
[in] | b | Input vector \(\bar b\) |
[in] | c | Input vector \(\bar c\) |
[in] | length | Number of elements in vectors \(\bar a\), \(\bar b\) and \(\bar c\) |
[in] | b_shr | Right-shift appled to \(\bar b\) |
[in] | c_shr | Right-shift appled to \(\bar c\) |
ET_LOAD_STORE | Raised if a , b or c is not word-aligned (See Note: Vector Alignment) |
headroom_t xs3_vect_s32_mul | ( | int32_t | a[], |
const int32_t | b[], | ||
const int32_t | c[], | ||
const unsigned | length, | ||
const right_shift_t | b_shr, | ||
const right_shift_t | c_shr | ||
) |
Multiply one 32-bit vector element-wise by another.
a[]
, b[]
and c[]
represent the 32-bit mantissa vectors \(\bar a\), \(\bar b\) and \(\bar c\) respectively. Each must begin at a word-aligned address. This operation can be performed safely in-place on b[]
or c[]
.
length
is the number of elements in each of the vectors.
b_shr
and c_shr
are the signed arithmetic right-shifts applied to each element of \(\bar b\) and \(\bar c\) respectively.
\begin{align*} & b_k' \leftarrow sat_{32}(\lfloor b_k \cdot 2^{-b\_shr} \rfloor) \\ & c_k' \leftarrow sat_{32}(\lfloor c_k \cdot 2^{-c\_shr} \rfloor) \\ & a_k \leftarrow sat_{32}(round(b_k' \cdot c_k' \cdot 2^{-30})) \\ & \qquad\text{ for }k\in 0\ ...\ (length-1) \end{align*}
If \(\bar b\) and \(\bar c\) are the mantissas of BFP vectors \( \bar{b} \cdot 2^{b\_exp} \) and \(\bar{c} \cdot 2^{c\_exp}\), then the resulting vector \(\bar a\) are the mantissas of BFP vector \(\bar{a} \cdot 2^{a\_exp}\), where \(a\_exp = b\_exp + c\_exp + b\_shr + c\_shr + 30\).
The function xs3_vect_s32_mul_prepare() can be used to obtain values for \(a\_exp\), \(b\_shr\) and \(c\_shr\) based on the input exponents \(b\_exp\) and \(c\_exp\) and the input headrooms \(b\_hr\) and \(c\_hr\).
[out] | a | Output vector \(\bar a\) |
[in] | b | Input vector \(\bar b\) |
[in] | c | Input vector \(\bar c\) |
[in] | length | Number of elements in vectors \(\bar a\), \(\bar b\) and \(\bar c\) |
[in] | b_shr | Right-shift appled to \(\bar b\) |
[in] | c_shr | Right-shift appled to \(\bar c\) |
ET_LOAD_STORE | Raised if a , b or c is not word-aligned (See Note: Vector Alignment) [xs3_vect_s32_mul] |
headroom_t xs3_vect_s32_nmacc | ( | int32_t | acc[], |
const int32_t | b[], | ||
const int32_t | c[], | ||
const unsigned | length, | ||
const right_shift_t | acc_shr, | ||
const right_shift_t | b_shr, | ||
const right_shift_t | c_shr | ||
) |
Multiply one 32-bit vector element-wise by another, and subtract the result from an accumulator.
acc[]
represents the 32-bit accumulator mantissa vector \(\bar a\). Each \(a_k\) is acc[k]
.
b[]
and c[]
represent the 32-bit input mantissa vectors \(\bar b\) and \(\bar c\), where each \(b_k\) is b[k]
and each \(c_k\) is c[k]
.
Each of the input vectors must begin at a word-aligned address.
length
is the number of elements in each of the vectors.
acc_shr
, b_shr
and c_shr
are the signed arithmetic right-shifts applied to input elements \(a_k\), \(b_k\) and \(c_k\).
\begin{align*} & \tilde{b}_k \leftarrow sat_{32}( b_k \cdot 2^{-b\_shr} ) \\ & \tilde{c}_k \leftarrow sat_{32}( c_k \cdot 2^{-c\_shr} ) \\ & \tilde{a}_k \leftarrow sat_{32}( a_k \cdot 2^{-acc\_shr} ) \\ & v_k \leftarrow round( sat_{32}( \tilde{b}_k \cdot \tilde{c}_k \cdot 2^{-30} ) ) \\ & a_k \leftarrow sat_{32}( \tilde{a}_k - v_k ) \\ & \qquad\text{ for }k\in 0\ ...\ (length-1) \end{align*}
If inputs \(\bar b\) and \(\bar c\) are the mantissas of BFP vectors \( \bar{b} \cdot 2^{b\_exp} \) and \(\bar{c} \cdot 2^{c\_exp}\), and input \(\bar a\) is the accumulator BFP vector \(\bar{a} \cdot 2^{a\_exp}\), then the output values of \(\bar a\) have the exponent \(2^{a\_exp + acc\_shr}\).
For accumulation to make sense mathematically, \(bc\_sat\) must be chosen such that \( a\_exp + acc\_shr = b\_exp + c\_exp + bc\_sat \).
The function xs3_vect_complex_s16_macc_prepare() can be used to obtain values for \(a\_exp\), \(acc\_shr\) and \(bc\_sat\) based on the input exponents \(a\_exp\), \(b\_exp\) and \(c\_exp\) and the input headrooms \(a\_hr\), \(b\_hr\) and \(c\_hr\).
[in,out] | acc | Accumulator \(\bar a\) |
[in] | b | Input vector \(\bar b\) |
[in] | c | Input vector \(\bar c\) |
[in] | length | Number of elements in vectors \(\bar a\), \(\bar b\) and \(\bar c\) |
[in] | acc_shr | Signed arithmetic right-shift applied to accumulator elements. |
[in] | b_shr | Signed arithmetic right-shift applied to elements of \(\bar b\) |
[in] | c_shr | Signed arithmetic right-shift applied to elements of \(\bar c\) |
ET_LOAD_STORE | Raised if acc , b or c is not word-aligned (See Note: Vector Alignment) |
headroom_t xs3_vect_s32_rect | ( | int32_t | a[], |
const int32_t | b[], | ||
const unsigned | length | ||
) |
Rectify the elements of a 32-bit vector.
a[]
and b[]
represent the 32-bit mantissa vectors \(\bar a\) and \(\bar b\) respectively. Each must begin at a word-aligned address. This operation can be performed safely in-place on b[]
.
length
is the number of elements in each of the vectors.
\begin{align*} & a_k \leftarrow \begin{cases} b_k & b_k \gt 0 \\ & 0 & b_k \leq 0 \end{cases} \\ & \qquad\text{ for }k\in 0\ ...\ (length-1) \end{align*}
If \(\bar b\) are the mantissas of BFP vector \(\bar{b} \cdot 2^{b\_exp}\), then the output vector \(\bar a\) are the mantissas of BFP vector \(\bar{a} \cdot 2^{a\_exp}\), where \(a\_exp = b\_exp\).
[out] | a | Output vector \(\bar a\) |
[in] | b | Input vector \(\bar b\) |
[in] | length | Number of elements in vectors \(\bar a\) and \(\bar b\) |
ET_LOAD_STORE | Raised if a or b is not word-aligned (See Note: Vector Alignment) |
headroom_t xs3_vect_s32_scale | ( | int32_t | a[], |
const int32_t | b[], | ||
const unsigned | length, | ||
const int32_t | c, | ||
const right_shift_t | b_shr, | ||
const right_shift_t | c_shr | ||
) |
Multiply a 32-bit vector by a scalar.
a[]
and b[]
represent the 32-bit mantissa vectors \(\bar a\) and \(\bar b\) respectively. Each must begin at a word-aligned address. This operation can be performed safely in-place on b[]
.
length
is the number of elements in each of the vectors.
c
is the 32-bit scalar \(c\) by which each element of \(\bar b\) is multiplied.
b_shr
and c_shr
are the signed arithmetic right-shifts applied to each element of \(\bar b\) and to \(c\).
\begin{align*} & b_k' \leftarrow sat_{32}(\lfloor b_k \cdot 2^{-b\_shr} \rfloor) \\ & a_k \leftarrow sat_{32}(round(c \cdot b_k' \cdot 2^{-30})) \\ & \qquad\text{ for }k\in 0\ ...\ (length-1) \end{align*}
If \(\bar b\) are the mantissas of a BFP vector \( \bar{b} \cdot 2^{b\_exp} \) and \(c\) is the mantissa of floating-point value \(c \cdot 2^{c\_exp}\), then the resulting vector \(\bar a\) are the mantissas of BFP vector \(\bar{a} \cdot 2^{a\_exp}\), where \(a\_exp = b\_exp + c\_exp + b\_shr + c\_shr + 30\).
The function xs3_vect_s32_scale_prepare() can be used to obtain values for \(a\_exp\), \(b\_shr\) and \(c\_shr\) based on the input exponents \(b\_exp\) and \(c\_exp\) and the input headrooms \(b\_hr\) and \(c\_hr\).
[out] | a | Output vector \(\bar a\) |
[in] | b | Input vector \(\bar b\) |
[in] | length | Number of elements in vectors \(\bar a\) and \(\bar b\) |
[in] | c | Scalar to be multiplied by elements of \(\bar b\) |
[in] | b_shr | Right-shift appled to \(\bar b\) |
[in] | c_shr | Right-shift applied to \(c\) |
ET_LOAD_STORE | Raised if a or b is not word-aligned (See Note: Vector Alignment) |
void xs3_vect_s32_set | ( | int32_t | a[], |
const int32_t | b, | ||
const unsigned | length | ||
) |
Set all elements of a 32-bit vector to the specified value.
a[]
represents the 32-bit output vector \(\bar a\). a[]
must begin at a word-aligned address.
b
is the new value to set each element of \(\bar a\) to.
\begin{align*} & a_k \leftarrow b \\ & \qquad\text{ for }k\in 0\ ...\ (length-1) \end{align*}
If \(b\) is the mantissa of floating-point value \(b \cdot 2^{b\_exp}\), then the output vector \(\bar a\) are the mantissas of BFP vector \(\bar{a} \cdot 2^{a\_exp}\), where \(a\_exp = b\_exp\).
[out] | a | Output vector \(\bar a\) |
[in] | b | New value for the elements of \(\bar a\) |
[in] | length | Number of elements in \(\bar a\) |
ET_LOAD_STORE | Raised if a is not word-aligned (See Note: Vector Alignment) |
headroom_t xs3_vect_s32_shl | ( | int32_t | a[], |
const int32_t | b[], | ||
const unsigned | length, | ||
const left_shift_t | b_shl | ||
) |
Left-shift the elements of a 32-bit vector by a specified number of bits.
a[]
and b[]
represent the 32-bit vectors \(\bar a\) and \(\bar b\) respectively. Each must begin at a word-aligned address. This operation can be performed safely in-place on b[]
.
length
is the number of elements in vectors \(\bar a\) and \(\bar b\).
b_shl
is the signed arithmetic left-shift applied to each element of \(\bar b\).
\begin{align*} & a_k \leftarrow sat_{32}(\lfloor b_k \cdot 2^{b\_shl} \rfloor) \\ & \qquad\text{ for }k\in 0\ ...\ (length-1) \end{align*}
If \(\bar b\) are the mantissas of a BFP vector \( \bar{b} \cdot 2^{b\_exp} \), then the resulting vector \(\bar a\) are the mantissas of BFP vector \(\bar{a} \cdot 2^{a\_exp}\), where \(\bar{a} = \bar{b} \cdot 2^{b\_shl}\) and \(a\_exp = b\_exp\).
[out] | a | Output vector \(\bar a\) |
[in] | b | Input vector \(\bar b\) |
[in] | length | Number of elements in vectors \(\bar a\) and \(\bar b\) |
[in] | b_shl | Arithmetic left-shift applied to elements of \(\bar b\) |
ET_LOAD_STORE | Raised if a or b is not word-aligned (See Note: Vector Alignment) |
headroom_t xs3_vect_s32_shr | ( | int32_t | a[], |
const int32_t | b[], | ||
const unsigned | length, | ||
const right_shift_t | b_shr | ||
) |
Right-shift the elements of a 32-bit vector by a specified number of bits.
a[]
and b[]
represent the 32-bit vectors \(\bar a\) and \(\bar b\) respectively. Each must begin at a word-aligned address. This operation can be performed safely in-place on b[]
.
length
is the number of elements in vectors \(\bar a\) and \(\bar b\).
b_shr
is the signed arithmetic right-shift applied to each element of \(\bar b\).
\begin{align*} & a_k \leftarrow sat_{32}(\lfloor b_k \cdot 2^{-b\_shr} \rfloor) \\ & \qquad\text{ for }k\in 0\ ...\ (length-1) \end{align*}
If \(\bar b\) are the mantissas of a BFP vector \( \bar{b} \cdot 2^{b\_exp} \), then the resulting vector \(\bar a\) are the mantissas of BFP vector \(\bar{a} \cdot 2^{a\_exp}\), where \(\bar{a} = \bar{b} \cdot 2^{-b\_shr}\) and \(a\_exp = b\_exp\).
[out] | a | Output vector \(\bar a\) |
[in] | b | Input vector \(\bar b\) |
[in] | length | Number of elements in vectors \(\bar a\) and \(\bar b\) |
[in] | b_shr | Arithmetic right-shift applied to elements of \(\bar b\) |
ET_LOAD_STORE | Raised if a or b is not word-aligned (See Note: Vector Alignment) |
void xs3_vect_s32_split_accs | ( | xs3_split_acc_s32_t | a[], |
const int32_t | b[], | ||
const unsigned | length | ||
) |
Split a vector of int32_t
's into a vector of xs3_split_acc_s32_t
.
Convert a vector of int32_t
into a vector of xs3_split_acc_s32_t, the native format for the XS3 VPU's 32-bit accumulators. This is useful when a function (e.g. xs3_mat_mul_s8_x_s8_yield_s32
) takes in a vector of accumulators in that native format.
This function is most efficient (in terms of cycles/accumulator) when length
is a multiple of
length
will be rounded up such that a multiple of 16 accumulators will always be merged.This function can safely split accumulators in-place.
[out] | a | Output vector of xs3_split_acc_s32_t |
[in] | b | Input vector of int32_t |
[in] | length | Number of accumulators to merge |
ET_LOAD_STORE | Raised if b or a is not word-aligned (See Note: Vector Alignment) |
headroom_t xs3_vect_s32_sqrt | ( | int32_t | a[], |
const int32_t | b[], | ||
const unsigned | length, | ||
const right_shift_t | b_shr, | ||
const unsigned | depth | ||
) |
Compute the square root of elements of a 32-bit vector.
a[]
and b[]
represent the 32-bit mantissa vectors \(\bar a\) and \(\bar b\) respectively. Each vector must begin at a word-aligned address. This operation can be performed safely in-place on b[]
.
length
is the number of elements in each of the vectors.
b_shr
is the signed arithmetic right-shift applied to elements of \(\bar b\).
depth
is the number of most significant bits to calculate of each \(a_k\). For example, a depth
value of 8 will only compute the 8 most significant byte of the result, with the remaining 3 bytes as 0. The maximum value for this parameter is XS3_VECT_SQRT_S32_MAX_DEPTH
(31). The time cost of this operation is approximately proportional to the number of bits computed.
\begin{align*} & b_k' \leftarrow sat_{32}(\lfloor b_k \cdot 2^{-b\_shr} \rfloor) \\ & a_k \leftarrow \sqrt{ b_k' } \\ & \qquad\text{ for }k\in 0\ ...\ (length-1) \\ & \qquad\text{ where } sqrt() \text{ computes the first } depth \text{ bits of the square root.} \end{align*}
If \(\bar b\) are the mantissas of BFP vector \(\bar{b} \cdot 2^{b\_exp}\), then the resulting vector \(\bar a\) are the mantissas of BFP vector \(\bar{a} \cdot 2^{a\_exp}\), where \(a\_exp = (b\_exp + b\_shr - 30)/2\).
Note that because exponents must be integers, that means \(b\_exp + b\_shr\) must be even.
The function xs3_vect_s32_sqrt_prepare() can be used to obtain values for \(a\_exp\) and \(b\_shr\) based on the input exponent \(b\_exp\) and headroom \(b\_hr\).
[out] | a | Output vector \(\bar a\) |
[in] | b | Input vector \(\bar b\) |
[in] | length | Number of elements in vectors \(\bar a\) and \(\bar b\) |
[in] | b_shr | Right-shift appled to \(\bar b\) |
[in] | depth | Number of bits of each output value to compute |
ET_LOAD_STORE | Raised if a or b is not word-aligned (See Note: Vector Alignment) |
headroom_t xs3_vect_s32_sub | ( | int32_t | a[], |
const int32_t | b[], | ||
const int32_t | c[], | ||
const unsigned | length, | ||
const right_shift_t | b_shr, | ||
const right_shift_t | c_shr | ||
) |
Subtract one 32-bit vector from another.
a[]
, b[]
and c[]
represent the 32-bit mantissa vectors \(\bar a\), \(\bar b\) and \(\bar c\) respectively. Each must begin at a word-aligned address. This operation can be performed safely in-place on b[]
or c[]
.
length
is the number of elements in each of the vectors.
b_shr
and c_shr
are the signed arithmetic right-shifts applied to each element of \(\bar b\) and \(\bar c\) respectively.
\begin{align*} & b_k' = sat_{32}(\lfloor b_k \cdot 2^{-b\_shr} \rfloor) \\ & c_k' = sat_{32}(\lfloor c_k \cdot 2^{-c\_shr} \rfloor) \\ & a_k \leftarrow sat_{32}\!\left( b_k' - c_k' \right) \\ & \qquad\text{ for }k\in 0\ ...\ (length-1) \end{align*}
If \(\bar b\) and \(\bar c\) are the mantissas of BFP vectors \( \bar{b} \cdot 2^{b\_exp} \) and \(\bar{c} \cdot 2^{c\_exp}\), then the resulting vector \(\bar a\) are the mantissas of BFP vector \(\bar{a} \cdot 2^{a\_exp}\).
In this case, \(b\_shr\) and \(c\_shr\) must be chosen so that \(a\_exp = b\_exp + b\_shr = c\_exp + c\_shr\). Adding or subtracting mantissas only makes sense if they are associated with the same exponent.
The function xs3_vect_s32_sub_prepare() can be used to obtain values for \(a\_exp\), \(b\_shr\) and * \(c\_shr\) based on the input exponents \(b\_exp\) and \(c\_exp\) and the input headrooms \(b\_hr\) and \(c\_hr\).
[out] | a | Output vector \(\bar a\) |
[in] | b | Input vector \(\bar b\) |
[in] | c | Input vector \(\bar c\) |
[in] | length | Number of elements in vectors \(\bar a\), \(\bar b\) and \(\bar c\) |
[in] | b_shr | Right-shift appled to \(\bar b\) |
[in] | c_shr | Right-shift appled to \(\bar c\) |
ET_LOAD_STORE | Raised if a , b or c is not word-aligned (See Note: Vector Alignment) |
int64_t xs3_vect_s32_sum | ( | const int32_t | b[], |
const unsigned | length | ||
) |
Sum the elements of a 32-bit vector.
b[]
represents the 32-bit mantissa vector \(\bar b\). b[]
must begin at a word-aligned address.
length
is the number of elements in \(\bar b\).
\begin{align*} a \leftarrow \sum_{k=0}^{length-1} b_k \end{align*}
If \(\bar b\) are the mantissas of BFP vector \(\bar{b} \cdot 2^{b\_exp}\), then the returned value \(a\) is the 64-bit mantissa of floating-point value \(a \cdot 2^{a\_exp}\), where \(a\_exp = b\_exp\).
Internally, each element accumulates into one of eight 40-bit accumulators (which are all used simultaneously) which apply symmetric 40-bit saturation logic (with bounds \(\approx 2^{39}\)) with each value added. The saturating arithmetic employed is not associative and no indication is given if saturation occurs at an intermediate step. To avoid the possibility of saturation errors, length
should be no greater than \(2^{11+b\_hr}\), where \(b\_hr\) is the headroom of \(\bar b\).
If the caller's mantissa vector is longer than that, the full result can be found by calling this function multiple times for partial results on sub-sequences of the input, and adding the results in user code.
In many situations the caller may have a priori knowledge that saturation is impossible (or very nearly so), in which case this guideline may be disregarded. However, such situations are application-specific and are well beyond the scope of this documentation, and as such are left to the user's discretion.
[in] | b | Input vector \(\bar b\) |
[in] | length | Number of elements in vector \(\bar b\) |
ET_LOAD_STORE | Raised if b is not word-aligned (See Note: Vector Alignment) |
void xs3_vect_s32_unzip | ( | int32_t | a[], |
int32_t | b[], | ||
const complex_s32_t | c[], | ||
const unsigned | length | ||
) |
Deinterleave the real and imaginary parts of a complex 32-bit vector into two separate vectors.
Complex 32-bit input vector \(\bar c\) has its real and imaginary parts (which correspond to the even and odd-indexed elements, if reinterpreted as an int32_t
array) split apart to create real 32-bit output vectors \(\bar a\) and \(\bar b\), such that \(\bar{a} = Re{\bar{c}}\) and \(\bar{b} = Im{\bar{c}}\).
a[]
and b[]
are the real output vectors \(\bar a\) and \(\bar b\) which receive the real and imaginary parts respectively of \(\bar c\). a
and b
must each begin at a word-aligned address.
c[]
is the complex input vector \(\bar c\). c
must begin at a double word-aligned address.
length
is the number \(N\) of int32_t
elements in \(\bar a\) and \(\bar b\) and the number of complex_s32_t
in \(\bar c\).
\begin{align*} & a_k = Re\{c_k\} \\ & b_k = Im\{c_k\} \\ & \qquad\text{ for }k\in 0\ ...\ (N-1) \end{align*}
[out] | a | Output vector \(\bar a\) |
[out] | b | Output vector \(\bar b\) |
[in] | c | Input vector \(\bar c\) |
[in] | length | The number of elements \(N\) in vectors \(\bar a\), \(\bar b\) and \(\bar c\) |
ET_LOAD_STORE | Raised if a or b is not word-aligned (See Note: Vector Alignment) |
ET_LOAD_STORE | Raised if c is not double word-aligned (See Note: Vector Alignment) |
void xs3_vect_s32_zip | ( | complex_s32_t | a[], |
const int32_t | b[], | ||
const int32_t | c[], | ||
const unsigned | length, | ||
const right_shift_t | b_shr, | ||
const right_shift_t | c_shr | ||
) |
Interleave the elements of two vectors into a single vector.
Elements of 32-bit input vectors \(\bar b\) and \(\bar c\) are interleaved into 32-bit output vector \(\bar a\). Each element of \(\bar b\) has a right-shift of \(b\_shr\) applied, and each element of \(\bar c\) has a right-shift of \(c\_shr\) applied.
Alternatively (and equivalently), this function can be conceived of as taking two real vectors \(\bar b\) and \(\bar c\) and forming a new complex vector \(\bar a\) where \(\bar{a} = \bar{b} + i\cdot\bar{c}\).
If vectors \(\bar b\) and \(\bar c\) each have \(N\) elements, then the resulting \(\bar a\) will have either \(2N\) int32_t
elements or (equivalently) \(N\) complex_s32_t
elements (and must have space for such).
Each element \(b_k\) of \(\bar b\) will end up as end up as element \(a_{2k}\) of \(\bar a\) (with the bit-shift applied). Each element \(c_k\) will end up as element \(a_{2k+1}\) of \(\bar a\).
a[]
is the output vector \(\bar a\).
b[]
and c[]
are the input vectors \(\bar b\) and \(\bar c\) respectively.
a
, b
and c
must each begin at a double word-aligned (8 byte) address. (see DWORD_ALIGNED).
length
is the number \(N\) of int32_t
elements in \(\bar b\) and \(\bar c\).
b_shr
is the signed arithmetic right-shift applied to elements of \(\bar b\).
c_shr
is the signed arithmetic right-shift applied to elements of \(\bar c\).
\begin{align*} & Re{a_{k}} \leftarrow sat_{32}( b_k \cdot 2^{-b\_shr} \\ & Im{a_{k}} \leftarrow sat_{32}( c_k \cdot 2^{-c\_shr} \\ & \qquad\text{ for }k\in 0\ ...\ (N-1) \end{align*}
[out] | a | Output vector \(\bar a\) |
[in] | b | Input vector \(\bar b\) |
[in] | c | Input vector \(\bar c\) |
[in] | length | Number of elements \(N\) in vectors \(\bar a\), \(\bar b\) and \(\bar c\) |
[in] | b_shr | Signed arithmetic right-shift applied to elements of \(\bar b\) |
[in] | c_shr | Signed arithmetic right-shift applied to elements of \(\bar c\) |
ET_LOAD_STORE | Raised if a , b or c is not double word-aligned (See Note: Vector Alignment) |