Diagnostic 15133: vectorization support: reference xxxx has aligned access (Fortran)

Cause:

The vectorizer was able to generate code for this memory access assuming the data to be aligned to an n-byte boundary in memory. The value of n depends on the targeted instruction set and corresponds to the width of the vector instructions: 16 for Intel® SSE, 32 for Intel® AVX and 64 for Intel® AVX-512 instructions. Data alignment may have been determined by the compiler's own analysis, or may have been specified by the user using a directive. The compiler may not necessarily use an aligned load or store instruction, but generated code that assumes data alignment may be more efficient than code that must allow for unaligned data.

Example:

See the example provided for Diagnostic 15134: vectorization support: reference xxxx has unaligned access (Fortran). Once the alignment directives are uncommented as explained in the Resolution section, the compiler generates aligned memory accesses which produce the message "vectorization support: reference xxxx has aligned access", provided the option -vec-report6 has been set.

Resolution:

None. This is an informational message that does not of itself suggest a need for action by the programmer. In conjunction with the corresponding diagnostics for unaligned memory accesses, it can help the programmer to understand memory access patterns and look for improvements.

Pour de plus amples informations sur les optimisations de compilation, consultez notre Avertissement concernant les optimisations.