topic Re: Uninitialised memory access in 'cblas_cgemm' in Intel® oneAPI Math Kernel Library

Uninitialised memory access in 'cblas_cgemm'

Chandrakant_19 — Mon, 29 Apr 2024 10:25:12 GMT

Hi Intel Support Team,

I am working on a project using mkl library. I am using the 'cblas_cgemm' mkl routine for complex matrix multiplication.

I have initilaized the input parameters before before calling the api.

Code Snippet:
int m = 2, n = 2, k = 2;
int lda = 2, ldb = 2, ldc = 2;
MKL_Complex8 alpha = {1.0, 0.0};
MKL_Complex8 beta = {0.0, 0.0};

MKL_Complex8 A[4] = {};
MKL_Complex8 B[4] = {};
MKL_Complex8 C[4] = {};

A, B is overwritten with actual data.

cblas_cgemm(CblasRowMajor, CblasNoTrans, CblasNoTrans, m, n, k, &alpha, A,
lda, B, ldb, &beta, C, ldc);

On Intel Inspector in windows envirounment, we are observing following error

"Uninitialized memory access"

Thanking you.

Re: Uninitialised memory access in 'cblas_cgemm'

Gennady_F_Intel — Tue, 30 Apr 2024 04:32:25 GMT

It might be the same issue as you reported against Lapack cheev routine. Which version of Inspector do you use?

and again - is that oneMKL 2024u1?

Could you show how do you link against oneMKL?

Re: Uninitialised memory access in 'cblas_cgemm'

Chandrakant_19 — Thu, 02 May 2024 07:36:43 GMT

Hi,

Please find below details about compilers and libraries.

IntelSWTools (Linux) - compilers_and_libraries_2016.2.181

IntelSWTools (Windows) - compilers_and_libraries_2017.1.143

Intel Inspector 2023.0

Thanking You.

Re:Uninitialised memory access in 'cblas_cgemm'

Gennady_F_Intel — Mon, 06 May 2024 04:53:58 GMT

Checking the problem you reported with the current version of oneMKL ( 2024u1), I see no problem.

Here is the log file

$ valgrind --tool=memcheck --track-origins=yes --leak-check=full ./a.out cblas_cgemmx.d > 2.log 2>&1

============================

==1172046== Memcheck, a memory error detector

==1172046== Using Valgrind-3.18.1 and LibVEX; rerun with -h for copyright info

==1172046== Command: ./a.out cblas_cgemmx.d

==1172046==

C B L A S _ C G E M M EXAMPLE PROGRAM

INPUT DATA

M=2 N=4 K=3

ALPHA =( 0.5, 0.0 ) BETA =( 1.2, 0.0 )

TransA = CblasTrans TransB = CblasTrans

LAYOUT = CblasRowMajor

ARRAY A LDA=2

( 1.00, 0.10) ( 2.00, 0.00)

( -3.20, 0.40) ( -2.70, 1.10)

( 0.00, 0.70) ( 4.00, 0.00)

ARRAY B LDB=3

( 1.00, -1.00) ( 2.00, 2.30) ( 3.00, 0.00)

( 1.00, 1.00) ( 2.00, 0.00) ( 3.00, 0.80)

( 1.00, -1.00) ( 2.00, 0.60) ( 3.00, 0.00)

( 1.00, -1.00) ( 2.00, 0.10) ( 3.00, 0.10)

ARRAY C LDC=4

( 0.00, 0.00) ( 0.00, 0.10) ( 1.00, 0.10) ( 1.00, 0.00)

OUTPUT DATA

ARRAY C LDC=4

( -3.11, -2.68) ( -3.03, 2.12) ( -1.57, 0.16) ( -1.51, 0.84)

( 3.04, -3.01) ( 4.30, 3.82) ( 5.17, -0.59) ( 5.45, 0.17) ==1172046==

==1172046== HEAP SUMMARY:

==1172046== in use at exit: 11,803 bytes in 31 blocks

==1172046== total heap usage: 99 allocs, 68 frees, 4,410,855 bytes allocated

==1172046==

==1172046== LEAK SUMMARY:

==1172046== definitely lost: 0 bytes in 0 blocks

==1172046== indirectly lost: 0 bytes in 0 blocks

==1172046== possibly lost: 0 bytes in 0 blocks

==1172046== still reachable: 11,803 bytes in 31 blocks

==1172046== suppressed: 0 bytes in 0 blocks

==1172046== Reachable blocks (those to which a pointer was found) are not shown.

==1172046== To see them, rerun with: --leak-check=full --show-leak-kinds=all

==1172046==

==1172046== For lists of detected and suppressed errors, rerun with: -s

==1172046== ERROR SUMMARY: 0 errors from 0 contexts (suppressed: 0 from 0)

Re:Uninitialised memory access in 'cblas_cgemm'

Gennady_F_Intel — Tue, 07 May 2024 10:53:35 GMT

this thread is closing.