[patch] tuning gcc for Intel Core2

Menezes, Evandro evandro.menezes@amd.com
Tue Nov 14 00:58:00 GMT 2006


Andi, 

> > +const int x86_accumulate_outgoing_args = m_ATHLON_K8 | 
> m_CORE2 | m_PENT4 | m_NOCONA | m_PPRO | m_GENERIC;
> > +const int x86_prologue_using_move = m_ATHLON_K8 | m_PPRO | 
> m_CORE2 | m_GENERIC;
> > +const int x86_epilogue_using_move = m_ATHLON_K8 | m_PPRO | 
> m_CORE2 | m_GENERIC;
> 
> Are you sure this is correct? Using moves in epilogue/prolgue
> generates much bigger code and AFAIK Core2 has special hardware
> to avoid any dependencies on the stack pointer, so shorter push/pop
> should be as fast here and use less icache.

With this option, GCC uses heuristics to figure out if the prolog and epilog take a significant time in the function and decides which one is best.

-- 
_______________________________________________________
Evandro Menezes               AMD            Austin, TX





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