Welcome back folks!! In our quest to implement Automatic Function Multi-Versioning (AFMV) for AArch64, one of the critical challenges has been dealing with compiler attribute errors. The target("sve2") attribute error was a particular stumbling block. Here’s how I tackled it.

Initial Error Message:

error: pragma or attribute ‘target("sve2")’ is not valid

Steps to Resolve:

1. GCC Version and Compatibility Check:

Verified that my GCC version supports SVE2 with gcc --version.
Updated GCC to the latest version to ensure full support for the attribute.

2. Correct Usage of Attributes:

Adjusted the context in which the target attribute was applied, ensuring it was used correctly in the function definition.

3. Compilation Flags:

Added -march=armv8.5-a+sve2 to the GCC command to explicitly enable SVE2 support.

4. Code Adjustment:

#include <stdio.h>

__attribute__((target("sve2")))
void my_function() {
    printf("This function uses SVE2 instructions.\n");
}

int main() {
    my_function();
    return 0;
}

With these adjustments, the attribute error was resolved, allowing me to continue with the AFMV implementation. This process underscored the importance of aligning compiler settings with the specific architectural requirements.

Until next time , happy coding 🚀!!