__ECC __ECL __ICC __ICL Intel C++ Compiler

有关opencv cxtypes.h中的解释：

#if defined __ICL
#define CV_ICC __ICL
#elif defined __ICC
#define CV_ICC __ICC
#elif defined __ECL
#define CV_ICC __ECL
#elif defined __ECC
#define CV_ICC __ECC
#endif

Intel C++ Compiler (also known as icc or icl) describes a group of C/C++ compilers from Intel. Compilers are available for Linux, Microsoft Windows and Mac OS X.

Intel supports compilation for its IA-32, Intel 64, Itanium 2, and XScale processors. The Intel C++ Compiler for x86 and Intel 64 features an automatic vectorizer that can generate SSE, SSE2, and SSE3 SIMD instructions, the embedded variant for Intel Wireless MMX and MMX 2.[1] Since its introduction, the Intel C++ Compiler for IA-32 has greatly increased adoption of SSE2 in Windows application development.[citation needed]

Intel C++ Compiler further supports both OpenMP and automatic parallelization for symmetric multiprocessing. With the add-on product Cluster OpenMP, the compiler can also automatically generate Message Passing Interface calls for distributed memory multiprocessing from OpenMP directives.

Intel C++ Compiler belongs to the family of compilers with the Edison Design Group frontend (like the SGI MIPSpro, Comeau C++, Portland Group, and others). The compiler is also notable for being widely used for SPEC CPU Benchmarks of IA-32, x86-64, and Itanium 2 architectures.