Messages in this thread | | | Date | Mon, 5 Nov 2018 13:13:05 -0800 | From | Andrew Morton <> | Subject | Re: [PATCH] slab.h: Avoid using & for logical and of booleans |
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On Mon, 5 Nov 2018 12:40:00 -0800 Bart Van Assche <bvanassche@acm.org> wrote:
> This patch suppresses the following sparse warning: > > ./include/linux/slab.h:332:43: warning: dubious: x & !y > > ... > > --- a/include/linux/slab.h > +++ b/include/linux/slab.h > @@ -329,7 +329,7 @@ static __always_inline enum kmalloc_cache_type kmalloc_type(gfp_t flags) > * If an allocation is both __GFP_DMA and __GFP_RECLAIMABLE, return > * KMALLOC_DMA and effectively ignore __GFP_RECLAIMABLE > */ > - return type_dma + (is_reclaimable & !is_dma) * KMALLOC_RECLAIM; > + return type_dma + is_reclaimable * !is_dma * KMALLOC_RECLAIM; > } > > /*
I suppose so.
That function seems too clever for its own good :(. I wonder if these branch-avoiding tricks are really worthwhile.
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