[PATCH 0/5] powerpc: Implement masked user access

Segher Boessenkool segher at kernel.crashing.org
Tue Jun 24 23:17:14 AEST 2025


On Tue, Jun 24, 2025 at 07:27:47AM +0200, Christophe Leroy wrote:
> Ah ok, I overlooked that, I didn't know the cmove instruction, seem 
> similar to the isel instruction on powerpc e500.

cmove does a move (register or memory) when some condition is true.
isel (which is base PowerPC, not something "e500" only) is a
computational instruction, it copies one of two registers to a third,
which of the two is decided by any bit in the condition register.

But sure, seen from very far off both isel and cmove can be used to
implemente the ternary operator ("?:"), are similar in that way :-)


Segher


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