[PATCH] Add support for lzd and popc instructions on sparc.

David Miller davem@davemloft.net
Thu Oct 6 18:41:00 GMT 2011


From: Richard Henderson <rth@redhat.com>
Date: Thu, 06 Oct 2011 10:47:28 -0700

> You've said that POPC only operates on the full 64-bit register,
> but I see no zero-extend of the SImode input?  Similarly for 
> the clzsi patterns.

Thanks for catching this.

I guess if I emit the zero-extend, the compiler will eliminate it if
possible.

This is another reason why I want to do v8plus differently.  The
compiler would take care to optimize away zero and sign extensions
instead of how we use that sparc_check_64 () thing now.

> If it weren't for the v8plus ugliness, it would be sufficient to
> only expose the DImode patterns, and let optabs.c do the work to
> extend from SImode...

Understood.



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