[BUG, CUDA backend] af::shift cannot shift an array with one row

[Filip Matzner]

af::shift produces invalid result (a single repeating value) when shifting an array made of a single row on CUDA backend. On CPU backend, it works correctly.

#include <arrayfire.h>

int main() {
    af::info();

    af::array A = af::randu(1, 10);
    af::print("A", A);

    af::array A_shifted = af::shift(A, 0, 1);
    af::print("A shifted", A_shifted);

    A_shifted = af::shift(A, 1, 0);
    af::print("A shifted", A_shifted);
}

Compile and run:

$ g++ -lafcuda bug.cpp && ./a.out

Output:

ArrayFire v3.8.3 (CUDA, 64-bit Linux, build default)
Platform: CUDA Runtime 12.0, Driver: 545.29.06
[0] NVIDIA RTX A500 Laptop GPU, 3905 MB, CUDA Compute 8.6
A
[1 10 1 1]
   Offset: 0
   Strides: [1 1 10 10]
    0.6010     0.0278     0.9806     0.2126     0.0655     0.5497     0.2864     0.3410     0.7509     0.4105
A shifted
[1 10 1 1]
   Offset: 0
   Strides: [1 1 10 10]
    0.4105     0.4105     0.4105     0.4105     0.4105     0.4105     0.4105     0.4105     0.4105     0.4105
A shifted
[1 10 1 1]
   Offset: 0
   Strides: [1 1 10 10]
    0.6010     0.6010     0.6010     0.6010     0.6010     0.6010     0.6010     0.6010     0.6010     0.6010

System:

Linux pine 6.7.2-arch1-2 #1 SMP PREEMPT_DYNAMIC Wed, 31 Jan 2024 09:22:15 +0000 x86_64 GNU/Linux
ArrayFire v3.8.3 (CUDA, 64-bit Linux, build default)
Platform: CUDA Runtime 12.0, Driver: 545.29.06
NVIDIA RTX A500 Laptop GPU, 3905 MB, CUDA Compute 8.6

[willy born]

Filip, PR #3513 should fix this problem. With this PR, I get following result: ArrayFire v3.9.0 (CUDA, 64-bit Windows, build a015130) Platform: CUDA Runtime 11.8, Driver: 12020 [0] NVIDIA GeForce GTX 750 Ti, 2048 MB, CUDA Compute 5.0 A [1 10 1 1] 0.6010 0.0278 0.9806 0.2126 0.0655 0.5497 0.2864 0.3410 0.7509 0.4105 A shifted [1 10 1 1] 0.4105 0.6010 0.0278 0.9806 0.2126 0.0655 0.5497 0.2864 0.3410 0.7509 A shifted [1 10 1 1] 0.6010 0.0278 0.9806 0.2126 0.0655 0.5497 0.2864 0.3410 0.7509 0.4105 BR, Willy

…

On Sun, 11 Feb 2024 at 12:04, Filip Matzner ***@***.***> wrote: af::shift produces invalid result (a single repeating value) when shifting an array made of a single row on CUDA backend. On CPU backend, it works correctly. #include <arrayfire.h> int main() { af::info(); af::array A = af::randu(1, 10); af::print("A", A); af::array A_shifted = af::shift(A, 0, 1); af::print("A shifted", A_shifted); A_shifted = af::shift(A, 1, 0); af::print("A shifted", A_shifted); } Compile and run: $ g++ -lafcuda bug.cpp && ./a.out Output: ArrayFire v3.8.3 (CUDA, 64-bit Linux, build default) Platform: CUDA Runtime 12.0, Driver: 545.29.06 [0] NVIDIA RTX A500 Laptop GPU, 3905 MB, CUDA Compute 8.6 A [1 10 1 1] Offset: 0 Strides: [1 1 10 10] 0.6010 0.0278 0.9806 0.2126 0.0655 0.5497 0.2864 0.3410 0.7509 0.4105 A shifted [1 10 1 1] Offset: 0 Strides: [1 1 10 10] 0.4105 0.4105 0.4105 0.4105 0.4105 0.4105 0.4105 0.4105 0.4105 0.4105 A shifted [1 10 1 1] Offset: 0 Strides: [1 1 10 10] 0.6010 0.6010 0.6010 0.6010 0.6010 0.6010 0.6010 0.6010 0.6010 0.6010 System: Linux pine 6.7.2-arch1-2 #1 SMP PREEMPT_DYNAMIC Wed, 31 Jan 2024 09:22:15 +0000 x86_64 GNU/Linux ArrayFire v3.8.3 (CUDA, 64-bit Linux, build default) Platform: CUDA Runtime 12.0, Driver: 545.29.06 NVIDIA RTX A500 Laptop GPU, 3905 MB, CUDA Compute 8.6 — Reply to this email directly, view it on GitHub <#3532>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AQ2WGPBKGPW7FU6SD7GNF6LYTCQVNAVCNFSM6AAAAABDDOMGPGVHI2DSMVQWIX3LMV43ASLTON2WKOZSGEZDQOJUGE3DGNA> . You are receiving this because you are subscribed to this thread.Message ID: ***@***.***>

[Filip Matzner]

Nice catch, that was a tricky one, thanks! Let's hope the PR will get a review from one of the maintainers soon.

[willy born]

Filip, I tested your error with the official release 3.9.0 and it works there as well, so upgrading to the latest version should help you. No need for the PR.

…

On Tue, 13 Feb 2024 at 21:57, Filip Matzner ***@***.***> wrote: Nice catch, that was a tricky one, thanks! Let's hope the PR will get a review from one of the maintainers soon. — Reply to this email directly, view it on GitHub <#3532 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AQ2WGPFNMS2NTHVGZAYO4YDYTPHS7AVCNFSM6AAAAABDDOMGPGVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMYTSNBSGQ4TGNBXGA> . You are receiving this because you commented.Message ID: ***@***.***>

[Filip Matzner]

Seems to be fixed in 3.9.0 indeed, thanks for testing!