On 05/04/2011 12:35 PM, Blue Swirl wrote: > On Wed, May 4, 2011 at 3:59 AM, Max Filippov <jcmvb...@gmail.com> wrote: >> See ISA, 4.7.1 for details. >> >> Physical registers and currently visible window are separate fields in >> CPUEnv. Only current window is accessible to TCG. On operations that >> change window base helpers copy current window to and from physical >> registers. > > I'm not sure how the register windows work, but maybe you could use > the same trick used for Sparc. There is a pool of registers > (env->regbase[]), a register window pointer (env->regwptr, > cpu_regwptr) tracks which are the currently accessible ones. The > advantage is to avoid copying (not entirely for Sparc due to the > window overlap).
Sparc loses out on some TCG optimizations because of that, although to be fair the most effective of these are still in Aurlien's trees. That said, I still would not recommend a new port to follow suit. r~
