[ROCm] Fix HIP version check for HIPBLAS V2 API compatibility

[danielholanda]

Description

This PR updates the HIP version check from:

#if defined(__HIP_PLATFORM_AMD__) && HIP_VERSION >= 70000000

to:

#if defined(__HIP_PLATFORM_AMD__) && HIP_VERSION >= 50600000

🛠 Why

The original condition seems to intend enabling support for HIPBLAS V2 API types (hipblasComputeType_t, HIPBLAS_COMPUTE_*, hipDataType), which replaced the deprecated hipblasDatatype_t and HIPBLAS_R_*. However, the check for HIP_VERSION >= 70000000 likely overshoots the required version.

I believe HIP_VERSION >= 50600000 is a more appropriate threshold:

• HIPBLAS V2 features were introduced around ROCm 5.x.
• Version 50600000 is already used throughout the codebase for similar feature gating.
• This change aligns the version check with actual usage and enables proper builds on current ROCm versions.

This change allowed me to build llama.cpp with ROCm and HIPBLAS V2 support on bleeding-edge ROCm releases from TheRock.

@ggerganov

[CISC]

A few preliminary searches seem to suggest that ROCm 6.0.0 is the (at least official) release where HIPBLAS V2 was introduced.

[IMbackK]

So wont compile as afaik in the entire rocm 6.x series HIPBLAS_R_32F and friends are hipblasDatatype_t unless the hipblas header is included with HIPBLAS_V2 defined.

Rocm 7.0 (or current git) is the earliest this will work as is.

see https://raw.githubusercontent.com/ROCm/hipBLAS/refs/heads/release-staging/rocm-rel-6.4/library/include/hipblas.h

#ifdef HIPBLAS_V2

// Replacing use of hipblasDatatype_t with hipDataType which will be used in a future release.
typedef hipDataType hipblasDatatype_t;

#define HIPBLAS_R_16F HIP_R_16F
...

[IMbackK]

This wont compile on rocm <7.0 unless HIPBLAS_V2 is visible during inclusion of the hipblas header.