Re: Ping: [PATCH v2] Analyze niter for until-wrap condition [PR101145]

["Bin.Cheng" <amker.cheng@gmail.com>]

On Wed, Aug 25, 2021 at 11:26 AM guojiufu <guojiufu@linux.ibm.com> wrote:
>
> On 2021-08-16 09:33, Bin.Cheng wrote:
> > On Wed, Aug 4, 2021 at 10:42 AM guojiufu <guojiufu@linux.ibm.com>
> > wrote:
> >>
> ...
> >> >> diff --git a/gcc/testsuite/gcc.dg/vect/pr101145.inc
> >> >> b/gcc/testsuite/gcc.dg/vect/pr101145.inc
> >> >> new file mode 100644
> >> >> index 00000000000..6eed3fa8aca
> >> >> --- /dev/null
> >> >> +++ b/gcc/testsuite/gcc.dg/vect/pr101145.inc
> >> >> @@ -0,0 +1,63 @@
> >> >> +TYPE __attribute__ ((noinline))
> >> >> +foo_sign (int *__restrict__ a, int *__restrict__ b, TYPE l, TYPE n)
> >> >> +{
> >> >> +  for (l = L_BASE; n < l; l += C)
> >> >> +    *a++ = *b++ + 1;
> >> >> +  return l;
> >> >> +}
> >> >> +
> >> >> +TYPE __attribute__ ((noinline))
> >> >> +bar_sign (int *__restrict__ a, int *__restrict__ b, TYPE l, TYPE n)
> >> >> +{
> >> >> +  for (l = L_BASE_DOWN; l < n; l -= C)
> > I noticed that both L_BASE and L_BASE_DOWN are defined as l, which
> > makes this test a bit confusing.  Could you clean the use of l, for
> > example, by using an auto var for the loop index invariable?
> > Otherwise the patch looks good to me.  Thanks very much for the work.
>
> Hi,
>
> Sorry for bothering you here.
> I feel this would be an approval (with the comment) already :)
>
> With the change code to make it a little clear as:
>    TYPE i;
>    for (i = l; n < i; i += C)
>
> it may be ok to commit the patch to the trunk, right?
Yes please.  Thanks again for working on this.

Thanks,
bin
>
> BR,
> Jiufu
>
> >
> > Thanks,
> > bin
> >> >> +    *a++ = *b++ + 1;
> >> >> +  return l;
> >> >> +}
> >> >> +
> >> >> +int __attribute__ ((noinline)) neq (int a, int b) { return a != b; }
> >> >> +
> >> >> +int a[1000], b[1000];
> >> >> +int fail;
> >> >> +
> >> >> +int
> ...
> >> >> diff --git a/gcc/testsuite/gcc.dg/vect/pr101145_1.c
> >> >> b/gcc/testsuite/gcc.dg/vect/pr101145_1.c
> >> >> new file mode 100644
> >> >> index 00000000000..94f6b99b893
> >> >> --- /dev/null
> >> >> +++ b/gcc/testsuite/gcc.dg/vect/pr101145_1.c
> >> >> @@ -0,0 +1,15 @@
> >> >> +/* { dg-require-effective-target vect_int } */
> >> >> +/* { dg-options "-O3 -fdump-tree-vect-details" } */
> >> >> +#define TYPE signed char
> >> >> +#define MIN -128
> >> >> +#define MAX 127
> >> >> +#define N_BASE (MAX - 32)
> >> >> +#define N_BASE_DOWN (MIN + 32)
> >> >> +
> >> >> +#define C 3
> >> >> +#define L_BASE l
> >> >> +#define L_BASE_DOWN l
> >> >> +