avoid useless if-before-free tests

[Joseph S. Myers]

On Sat, 5 Mar 2011, Jim Meyering wrote:

> diff --git a/gcc/config/i386/gmm_malloc.h b/gcc/config/i386/gmm_malloc.h
> index 7a7e840..8993fc7 100644
> --- a/gcc/config/i386/gmm_malloc.h
> +++ b/gcc/config/i386/gmm_malloc.h
> @@ -67,8 +67,7 @@ _mm_malloc (size_t size, size_t align)
>  static __inline__ void
>  _mm_free (void * aligned_ptr)
>  {
> -  if (aligned_ptr)
> -    free (((void **) aligned_ptr) [-1]);
> +  free (((void **) aligned_ptr) [-1]);
>  }

This one looks suspicious; it's not if (p) free (p); but if (p) free 
(something-derived-from-p);.

> diff --git a/libjava/classpath/native/fdlibm/dtoa.c b/libjava/classpath/native/fdlibm/dtoa.c
> index 458e629..92aa793 100644

http://gcc.gnu.org/codingconventions.html says Classpath changes should go 
via Classpath upstream, not directly into GCC.  I don't know if that's 
still accurate.

> diff --git a/zlib/contrib/minizip/unzip.c b/zlib/contrib/minizip/unzip.c
> index 9ad4766..644ef1b 100644

We definitely don't want to make local changes to zlib for this sort of 
issue, though importing a new upstream version of zlib (making sure the 
local configure code still works) should be fine for 4.7.

-- 
Joseph S. Myers
joseph@codesourcery.com