Issue: Serialized user function call(s) present

User-defined functions in the loop body are not vectorized.

Recommendation: Enable inline expansion

Inlining of user-defined functions is disabled by compiler option. To fix: When using the Ob or inline-level compiler option to control inline expansion, replace the 0 argument with the 1 argument to enable inlining when an inline keyword or attribute is specified or the 2 argument to enable inlining of any function at compiler discretion.

Read More:

• Vectorization Resources for Intel® Advisor Users

Recommendation: Vectorize serialized function(s) inside loop

Some user-defined function(s) are not vectorized or inlined by the compiler. To fix: Do one of the following:

• Enforce vectorization of the source loop by means of SIMD instructions and/or create a SIMD version of the function(s) using a directive:

  Target	Directive
  Source loop	#pragma simd or #pragma omp simd
  Inner function definition or declaration	#pragma omp declare simd

• If using the Ob or inline-level compiler option to control inline expansion with the 1 argument, use an inline keyword to enable inlining or replace the 1 argument with 2 to enable inlining of any function at compiler discretion.

Example:

#pragma omp declare simd 
int f (int x) 
{
    return x+1;
}
#pragma omp simd
for (int k = 0; k < N; k++)
{
    a[k] = f(k);
}

Read More:

• Getting Started with Intel Compiler Pragmas and Directives and Vectorization Resources for Intel® Advisor Users