Overview: Vectorization

The vectorizer is a component of the Intel® C++ Compiler that automatically uses SIMD instructions in the MMX(TM), SSE, and SSE2 instruction sets. The vectorizer detects operations in the program that can be done in parallel, and then converts the sequential program to process 2, 4, 8, or 16 elements in one operation, depending on the data type.

This section provides guidelines, option descriptions, and examples for the Intel C++ Compiler vectorization on IA-32 systems only. The following list summarizes this section's contents.

• a quick reference of vectorization functionality and features
• descriptions of compiler switches to control vectorization
• descriptions of the C++ language features to control vectorization
• discussion and general guidelines on vectorization levels:
• automatic vectorization
• vectorization with user intervention
• examples demonstrating typical vectorization issues and resolutions