AMD 250 manual Moving Data Between XMM Registers and GPRs, 360

Software Optimization Guide for AMD64 Processors 25112 Rev. 3.06 September 2005

E.4 Moving Data Between XMM Registers and GPRs

Optimization

Store a register that needs to be spilled in memory, rather than moved to a different register file.

Application

This optimization applies to:

•32-bit software

•64-bit software

Rationale

While register moves within a given register file are very efficient (XMM to XMM, GPR to GPR), moves between register files (XMM to GPR, GPR to XMM) are not. .

360 SSE and SSE2 Optimizations Appendix E