Messages in this thread |  | | | Date | Mon, 26 Oct 2009 15:40:55 -0700 (PDT) | | Subject | Re: [PATCH] perf tools: Kill off -Wcast-align | | From | David Miller <> |
| |
From: Paul Mundt <lethal@linux-sh.org> Date: Mon, 26 Oct 2009 18:47:30 +0900
> On Mon, Oct 26, 2009 at 07:25:20AM +0100, Ingo Molnar wrote: >> >> * Paul Mundt <lethal@linux-sh.org> wrote: >> >> > The present use of -Wcast-align causes the build to blow up on SH due to >> > generating a "cast increases required alignment of target type" error on >> > each invocation of list_for_each_entry(). >> > >> > It seems that this was previously reported and killed off in the ia64 >> > support patch, but nothing seems to have happened with that. Presumably >> > the same problem still remains there, too. >> > >> > Signed-off-by: Paul Mundt <lethal@linux-sh.org> >> >> Is this a GCC bug producing false positive warnings? The GCC manpage >> says: >> >> -Wcast-align >> Warn whenever a pointer is cast such that the required alignment of the >> target is increased. For example, warn if a "char *" is cast to an >> "int *" on machines where integers can only be accessed at two- or >> four-byte boundaries. >> >> Which looks moderately useful - if it works. >> > Well, both ia64 and sh have hit this in the current compilers, and it > doesn't seem to pose any code generation issues. In the areas where it is > generated it seems to relate to 64-bit data types in the data structures, > which in itself doesn't seem inherently problematic.
sparc64 hits this too when building 32-bit perf binary, the first thing I do after a pull is remove this warning option from the Makefile :-)
|  |