[PATCH 1/2] powerpc: rewrite LOAD_REG_IMMEDIATE() as an intelligent macro

Segher Boessenkool segher at kernel.crashing.org
Thu Aug 15 06:10:42 AEST 2019


Hi Christophe,

On Tue, Aug 13, 2019 at 09:59:35AM +0000, Christophe Leroy wrote:
> +		rldicr	\r, \r, 32, 31

Could you please write this as
		sldi	\r, \r, 32
?  It's much easier to read, imo (it's the exact same instruction).

You can do a lot cheaper sequences if you have a temporary reg, as well
(longest path of 3 insns instead of 5):
	lis rt,A
	ori rt,B
	lis rd,C
	ori rd,D
	rldimi rd,rt,32,0
to load ABCD.


Segher


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