Re: [PATCH] powerpc32: use stmw/lmw for non volatile registers save/restore

2016-05-24 Thread Gabriel Paubert
On Mon, May 23, 2016 at 10:46:36AM +0200, Christophe Leroy wrote: > lmw/stmw have a 1 cycle (2 cycles for lmw on some ppc) in addition > and implies serialising, however it reduces the amount of instructions > hence the amount of instruction fetch compared to the equivalent > operation with

Re: [PATCH] powerpc32: use stmw/lmw for non volatile registers save/restore

2016-05-23 Thread Segher Boessenkool
On Mon, May 23, 2016 at 10:46:36AM +0200, Christophe Leroy wrote: > lmw/stmw have a 1 cycle (2 cycles for lmw on some ppc) in addition > and implies serialising, however it reduces the amount of instructions > hence the amount of instruction fetch compared to the equivalent > operation with

[PATCH] powerpc32: use stmw/lmw for non volatile registers save/restore

2016-05-23 Thread Christophe Leroy
lmw/stmw have a 1 cycle (2 cycles for lmw on some ppc) in addition and implies serialising, however it reduces the amount of instructions hence the amount of instruction fetch compared to the equivalent operation with several lzw/stw. It means less pressure on cache and less fetching delays on