PR #11524: [ROCM] added flag limiting the number of gemm solutions to be checked & get real IDs for hipblas-lt
PR #11524: [ROCM] added flag limiting the number of gemm solutions to be checked & get real IDs for hipblas-lt

Imported from GitHub PR https://github.com/openxla/xla/pull/11524

In this PR I add a new XLA flag **xla_gpu_autotune_max_solutions** which limits the number of GEMM solutions to be using for GEMM autotuning. This is a temporary measure while rocBLAS returns way too many solutions which can significantly slow-down autotuning for real applications.

Besides, I also added a "workaround" to obtain the real solution IDs for hipblas-lt which might be later used for deterministic autotuning.

@xla-rotation: would you have a look please ?
Copybara import of the project:

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b8d2a95773ca80d8cb4a2fdac1d2624e4ae2d5c8 by Pavel Emeliyanenko <pavel.emeliyanenko@amd.com>:

added flag limiting the number of gemm solutions to be checked & get real solution IDs for hipblas-lt

Merging this change closes #11524

FUTURE_COPYBARA_INTEGRATE_REVIEW=https://github.com/openxla/xla/pull/11524 from ROCm:ci_gemm_limit_solutions b8d2a95773ca80d8cb4a2fdac1d2624e4ae2d5c8
