[U-Boot] [PATCH 7/7] GCC4.6: Squash warning in cmd_mem.c

Marek Vasut
2011-09-26T18:34:48Z

On Monday, September 26, 2011 08:29:22 PM Simon Glass wrote:
> Hi Merek,
>
> On Mon, Sep 26, 2011 at 11:24 AM, Marek Vasut <marek.vasut@gmail.com> wrote:
> > On Monday, September 26, 2011 08:05:43 PM Simon Glass wrote:
> >> Hi Marek,
> >>
> >> On Sun, Sep 25, 2011 at 5:26 PM, Marek Vasut <marek.vasut@gmail.com> wrote:
> >> > cmd_mem.c: In function ?do_mem_loop?:
> >> > cmd_mem.c:474:25: warning: variable ?junk? set but not used
> >> > [-Wunused-but-set-variable]
> >> >
> >> > The assigned variable can be removed because the pointers are volatile
> >> > so accesses to their addresses are always generated.
> >> >
> >> > Signed-off-by: Marek Vasut <marek.vasut@gmail.com>
> >> > ---
> >> > common/cmd_mem.c | 8 ++++----
> >> > 1 files changed, 4 insertions(+), 4 deletions(-)
> >> >
> >> > diff --git a/common/cmd_mem.c b/common/cmd_mem.c
> >> > index 4daa1b3..e84cc4e 100644
> >> > --- a/common/cmd_mem.c
> >> > +++ b/common/cmd_mem.c
> >> > @@ -471,7 +471,7 @@ int do_mem_base (cmd_tbl_t *cmdtp, int flag, int
> >> > argc, char * const argv[])
> >> >
> >> > int do_mem_loop (cmd_tbl_t *cmdtp, int flag, int argc, char * const
> >> > argv[]) {
> >> > - ulong addr, length, i, junk;
> >> > + ulong addr, length, i;
> >> > int size;
> >> > volatile uint *longp;
> >> > volatile ushort *shortp;
> >> > @@ -518,7 +518,7 @@ int do_mem_loop (cmd_tbl_t *cmdtp, int flag, int
> >> > argc, char * const argv[]) longp = (uint *)addr;
> >> > i = length;
> >> > while (i-- > 0)
> >> > - junk = *longp++;
> >> > + *longp++;
> >> > }
> >> > }
> >> > if (size == 2) {
> >> > @@ -526,14 +526,14 @@ int do_mem_loop (cmd_tbl_t *cmdtp, int flag, int
> >> > argc, char * const argv[]) shortp = (ushort *)addr;
> >> > i = length;
> >> > while (i-- > 0)
> >> > - junk = *shortp++;
> >> > + *shortp++;
> >> > }
> >> > }
> >> > for (;;) {
> >> > cp = (u_char *)addr;
> >> > i = length;
> >> > while (i-- > 0)
> >> > - junk = *cp++;
> >> > + *cp++;
> >> > }
> >> > }
> >>
> >> I checked the ARM assembler output and it looks fine.
> >>
> >> Acked-by: Simon Glass <sjg@chromium.org>
> >>
> >> Re the 'length == 1' case (above your patch) site, it is assigning to
> >> 'i' here. Could/should we remove that assignment also?
> >
> > The loop below depends on that ... ?
>
> Which loop? It doesn't look like the value of i is used?

i = length;
while (i-- > 0)

This loop

>
> Regards,
> Simon
>
> >> Regards,
> >> Simon
> >>
> >> > --
> >> > 1.7.5.4
> >> >
> >> > _______________________________________________
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