Re: [PULL v2 05/13] target/rx: CPU definitions

[Peter Maydell]

On Fri, 20 Mar 2020 at 16:19, Richard Henderson
<address@hidden> wrote:
>
> On 3/20/20 9:04 AM, Philippe Mathieu-Daudé wrote:
> > Not related to this patch, but this line generates a warning with Clang:
> >
> >   CC      rx-softmmu/target/rx/cpu.o
> > target/rx/cpu.c:158:33: warning: The result of the left shift is undefined
> > because the left operand is negative
> >     address = physical = addr & TARGET_PAGE_MASK;
> >                                 ^~~~~~~~~~~~~~~~
> > include/exec/cpu-all.h:234:45: note: expanded from macro 'TARGET_PAGE_MASK'
> > #define TARGET_PAGE_MASK   ((target_long)-1 << TARGET_PAGE_BITS)
> >                             ~~~~~~~~~~~~~~~ ^
> > 1 warning generated.
>
> >From configure:
>
> > # We use -fwrapv to tell the compiler that we require a C dialect where
> > # left shift of signed integers is well defined and has the expected
> > # 2s-complement style results. (Both clang and gcc agree that it
> > # provides these semantics.)
>
> Clang is *supposed* to be not generating those warnings.

I do have clang in my build tests, so at least some versions of
clang do indeed correctly handle -fwrapv. What version are
you using, Philippe ?

thanks
-- PMM