# novector

Specifies that a particular loop should never be vectorized.

## Syntax

#pragma novector

## Arguments

None

## Description

The novector pragma specifies that a particular loop should never be vectorized, even if it is legal to do so. When avoiding vectorization of a loop is desirable (when vectorization results in a performance regression rather than improvement), the novector pragma can be used in the source text to disable vectorization of a loop. This behavior is in contrast to the vector always pragma.

Example: Using the novector pragma
    void foo(int lb, int ub) {
      #pragma novector
      for(j=lb; j<ub; j++) { a[j]=a[j]+b[j]; }
    }

When the trip count (`ub - lb`) is too low to make vectorization worthwhile, you can use the novector pragma to tell the compiler not to vectorize, even if the loop is considered vectorizable.

Parent topic: Intel-Specific Pragma Reference

## See Also

Function Annotations and the SIMD Directive for Vectorization
vector pragma