Re: [PATCH] zsmalloc: use U suffix for negative literals being shifted

From: Matthew Wilcox
Date: Sat Dec 23 2017 - 22:24:47 EST


On Sat, Dec 23, 2017 at 09:33:40PM -0500, Nick Desaulniers wrote:
> Fixes warnings about shifting unsigned literals being undefined
> behavior.

Do you mean signed literals?

> */
> - link->next = -1 << OBJ_TAG_BITS;
> + link->next = -1U << OBJ_TAG_BITS;
> }

I don't understand what -1U means. Seems like a contradiction in terms,
a negative unsigned number. Is this supposed to be ~0U?