[Patch, MIPS] Fix warning from malloc/malloc.c

[Joseph Myers]

On Wed, 10 Dec 2014, Carlos O'Donell wrote:

> On 12/10/2014 06:13 PM, Steve Ellcey  wrote:
> > Here is a fix for another warning (now error) found in my MIPS build.
> > 
> > 	malloc.c: In function '__posix_memalign':
> > 	malloc.c:4976:50: error: logical not is only applied to the left hand side of comparison [-Werror=logical-not-parentheses]
> > 		|| !powerof2 (alignment / sizeof (void *)) != 0
> >                                                   ^
> > 	cc1: all warnings being treated as errors
> > 
> > 
> > The fix is to remove the '!= 0' comparision since it is redundant.
> 
> Removing '!= 0' creates a boolean coersion from the int type and we avoid
> this in glibc because it is clearer to say exactly what you mean e.g. != 0 or == 0.
> 
> Is not the right fix to add a bracket to clarify the `!` is applied to the left
> side only e.g. "|| (!powerof2 (alignment / sizeof (void *))) != 0"?

The result of "!" is boolean; no implicit boolean conversion is involved 
(unless you do "!non_boolean", but then you should write "non_boolean == 
0" not "(!non_boolean) != 0").

-- 
Joseph S. Myers
joseph@codesourcery.com