[PATCH] [POWERPC] Emulate isel (Integer Select) instruction

Kumar Gala galak at kernel.crashing.org
Wed Nov 21 08:01:11 EST 2007

On Nov 20, 2007, at 11:54 AM, Scott Wood wrote:

> On Mon, Nov 19, 2007 at 09:36:57PM -0600, Kumar Gala wrote:
>> isel (Integer Select) is a new user space instruction in the
>> PowerISA 2.04 spec.  Not all processors implement it so lets emulate
>> to ensure code built with isel will run everywhere.
> Given that the instruction is meant to be a performance enhancement,
> we should probably warn the first few times it's emulated, so the user
> knows they should change their toolchain setup if possible.

The same is true of mcrxr, popcntb, and possibly string ld/st.

Feel free to submit a patch that warns about their usage.

- k

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