基于数据对齐属性指导的GCC自动向量化优化

主流通用处理器都已经实现了多核并行以及处理器核内的SIMD并行。虽然GCC编译器实现了面向SIMD并行的自动向量化，但是编译器针对OpenMP并行程序的自动向量化效果仍很不理想。针对多线程并行的OpenMP程序，基于GCC的OpenMP编译实现，扩展了数据对齐属性指导语句，使编译器在自动向量化时能够进行更准确的数据对齐与否的判断，优化了GCC编译器的自动向量化。

Optimizing the auto-vectorization in GCC based on data-alignment directives

The general purpose processors support multi core parallelism on a chip and SIMD parallelism in each core. Although GCC complier makes use of the auto-vectorization for SIMD parallelism, the effects of auto vectorization for OpenMP program is far from the expectation. Based on the implementation of the OpenMP compilation in GCC, we extend complier directives with data alignment attribute directive for OpenMP program. Our work enables GCC to make a more accurate estimation on the alignment of data access, and optimizes the auto-vectorization in GCC.