This section describes the C++ language-level features supporting the IntelŪ PentiumŪ 4 processor Streaming SIMD Extensions 2 (SSE2) in the IntelŪ C++ Compiler, which are divided into two categories:
The Pentium 4 processor SSE2 intrinsics are defined only for IA-32 platforms, not ItaniumŪ-based platforms. Pentium 4 processor SSE2 operate on 128 bit quantities -- 2 64-bit double precision floating point values. The Itanium processor does not support parallel double precision computation, so Pentium 4 processor SSE2 are not implemented on Itanium-based systems.
For more details, refer to the PentiumŪ 4 processor Streaming SIMD Extensions 2 External Architecture Specification (EAS) and other Pentium 4 processor manuals available for download from the developer.intel.com web site. You should be familiar with the hardware features provided by the StSE2 when writing programs with the intrinsics. The following are three important issues to keep in mind:
The prototypes for SSE2 intrinsics are in the emmintrin.h header file.
You can also use the single ia32intrin.h header file for any IA-32 intrinsics.