On 06/19/2014 12:36 PM, Jan Hubicka wrote: >> On 06/19/2014 09:06 AM, Tom de Vries wrote: >>> >>> 2014-06-19 Tom de Vries <t...@codesourcery.com> >>> >>> * final.c (collect_fn_hard_reg_usage): Don't save function_used_regs if >>> it contains all call_used_regs. >> >> Ok. > > When we now have way to represent different reg usages for functions, what > would be best > way to make local functions to default into saving some SSE registers on > x86/x86-64?
I wouldn't do that at all. Leave all sse registers call-clobbered. This way you don't need to have different entry points (or one possibly less efficient entry point) when a function is used both locally and globally. What I would investigate is how to use this hard reg usage data in the register allocator. If we know that the callee only uses xmm0-xmm4, then we can keep xmm5-xmm15 live across the call. r~
