rocblas_gemm_batched_ex Interface Reference

rocblas_gemm_batched_ex Interface Reference#

HIPFORT API Reference: hipfort_rocblas::rocblas_gemm_batched_ex Interface Reference

BLAS EX API. More...

Public Member Functions
integer(kind(rocblas_status_success)) function	rocblas_gemm_batched_ex_ (handle, transA, transB, m, n, k, alpha, a, a_type, lda, b, b_type, ldb, beta, c, c_type, ldc, d, d_type, ldd, batch_count, compute_type, algo, solution_index, flags)

Detailed Description

BLAS EX API.

gemm_batched_ex performs one of the batched matrix-matrix operations D_i = alpha*op(A_i)*op(B_i) + beta*C_i, for i = 1, ..., batch_count. where op( X ) is one of op( X ) = X or op( X ) = X**T or op( X ) = X**H, alpha and beta are scalars, and A, B, C, and D are batched pointers to matrices, with op( A ) an m by k by batch_count batched matrix, op( B ) a k by n by batch_count batched matrix and C and D are m by n by batch_count batched matrices. The batched matrices are an array of pointers to matrices. The number of pointers to matrices is batch_count. Supported types are as follows:

rocblas_datatype_f64_r = a_type = b_type = c_type = d_type = compute_type
rocblas_datatype_f32_r = a_type = b_type = c_type = d_type = compute_type
rocblas_datatype_f16_r = a_type = b_type = c_type = d_type = compute_type
rocblas_datatype_f16_r = a_type = b_type = c_type = d_type; rocblas_datatype_f32_r = compute_type
rocblas_datatype_bf16_r = a_type = b_type = c_type = d_type; rocblas_datatype_f32_r = compute_type
rocblas_datatype_i8_r = a_type = b_type; rocblas_datatype_i32_r = c_type = d_type = compute_type
rocblas_datatype_f32_c = a_type = b_type = c_type = d_type = compute_type
rocblas_datatype_f64_c = a_type = b_type = c_type = d_type = compute_type

ROCm 4.2 supports two different versions of a = b = i8_r (in) and c = d = i32_r (out):

Both versions are rocblas_datatype_i8_r = a_type = b_type; rocblas_datatype_i32_r = c_type = d_type = compute_type, in addition to a last flag param indicating packing input or not.
```
 - Without setting the last param 'flags' (default=none), this is supported for gfx908 or
```
later GPUs only. Input a/b won't be packed into int8x4. So the following size restrictions and packing pseudo-code is not neccessary.
```
 - Set the last param 'flags' |= rocblas_gemm_flags_pack_int8x4. Input a/b would be packed
```
into int8x4, and this will impose some size restrictions on A or B (See below.) For GPUs before gfx908, only packed-int8 version is supported so this flag and packing is required, while gfx908 GPUs support both versions.

Below are restrictions for rocblas_datatype_i8_r = a_type = b_type; rocblas_datatype_i32_r = c_type = d_type = compute_type; flags |= rocblas_gemm_flags_pack_int8x4:

k must be a multiple of 4
lda must be a multiple of 4 if transA == rocblas_operation_transpose
ldb must be a multiple of 4 if transB == rocblas_operation_none

for transA == rocblas_operation_none or transB == rocblas_operation_transpose the matrices A and B must have each 4 consecutive values in the k dimension packed. This packing can be achieved with the following pseudo-code. The code assumes the original matrices are in A and B, and the packed matrices are A_packed and B_packed. The size of the A_packed matrix is the same as the size of the A matrix, and the size of the B_packed matrix is the same as the size of the B matrix.

if(transa == rocblas_operation_none)
{
    int nb = 4;
    for(int i_m = 0; i_m < m; i_m++)
    {
        for(int i_k = 0; i_k < k; i_k++)
        {
            a_packed[i_k % nb + (i_m + (i_k nb) * lda) * nb] = a[i_m + i_k * lda];
        }
    }
}
else
{
    a_packed = a;
}
if(transb == rocblas_operation_transpose)
{
    int nb = 4;
    for(int i_n = 0; i_n < m; i_n++)
    {
        for(int i_k = 0; i_k < k; i_k++)
        {
            b_packed[i_k % nb + (i_n + (i_k nb) * ldb) * nb] = b[i_n + i_k * ldb];
        }
    }
}
else
{
    b_packed = b;
}

Parameters

[in]	handle	[rocblas_handle] handle to the rocblas library context queue.
[in]	transA	[rocblas_operation] specifies the form of op( A ).
[in]	transB	[rocblas_operation] specifies the form of op( B ).
[in]	m	[rocblas_int] matrix dimension m.
[in]	n	[rocblas_int] matrix dimension n.
[in]	k	[rocblas_int] matrix dimension k.
[in]	alpha	[ void *] device pointer or host pointer specifying the scalar alpha. Same datatype as compute_type.
[in]	a	[void *] device pointer storing array of pointers to each matrix A_i.
[in]	a_type	[rocblas_datatype] specifies the datatype of each matrix A_i.
[in]	lda	[rocblas_int] specifies the leading dimension of each A_i.
[in]	b	[void *] device pointer storing array of pointers to each matrix B_i.
[in]	b_type	[rocblas_datatype] specifies the datatype of each matrix B_i.
[in]	ldb	[rocblas_int] specifies the leading dimension of each B_i.
[in]	beta	[ void *] device pointer or host pointer specifying the scalar beta. Same datatype as compute_type.
[in]	c	[void *] device array of device pointers to each matrix C_i.
[in]	c_type	[rocblas_datatype] specifies the datatype of each matrix C_i.
[in]	ldc	[rocblas_int] specifies the leading dimension of each C_i.
[out]	d	[void *] device array of device pointers to each matrix D_i.
[in]	d_type	[rocblas_datatype] specifies the datatype of each matrix D_i.
[in]	ldd	[rocblas_int] specifies the leading dimension of each D_i.
[in]	batch_count	[rocblas_int] number of gemm operations in the batch.
[in]	compute_type	[rocblas_datatype] specifies the datatype of computation.
[in]	algo	[rocblas_gemm_algo] enumerant specifying the algorithm type.
[in]	solution_index	[int32_t] reserved for future use.
[in]	flags	[uint32_t] optional gemm flags.

Member Function/Subroutine Documentation