On Mon, Feb 2, 2015 at 9:19 AM, Ilya Enkovich <enkovich....@gmail.com> wrote:
> On 27 Jan 12:29, Richard Biener wrote:
>> On Tue, Jan 27, 2015 at 11:47 AM, Ilya Enkovich <enkovich....@gmail.com>
>> wrote:
>> > On 27 Jan 12:40, Ilya Enkovich wrote:
>> >> Hi,
>> >>
>> >> This patch was supposed to fix PR tree-optimization/64277. Tracker is
>> >> now fixed by warnings disabling but I think patch is still useful to
>> >> avoid dead code generated by complete unroll.
>> >>
>> >> Bootstrapped and tested on x86_64-unknown-linux-gnu.
>> >>
>> >> Thanks,
>> >> Ilya
>> >> --
>> >> gcc/
>> >>
>> >> 2015-01-27 Ilya Enkovich <ilya.enkov...@intel.com>
>> >>
>> >> * tree-ssa-loop-niter.c (record_nonwrapping_iv): Use base
>> >> range info when possible to refine estimation.
>> >>
>> >> gcc/testsuite/
>> >>
>> >> 2015-01-27 Ilya Enkovich <ilya.enkov...@intel.com>
>> >>
>> >> * gcc.dg/pr64277.c: New.
>> >>
>> >>
>> >
>> > Here is a new version fixed according to comments in the tracker. I also
>> > fixed a test to scan cunroll dumps. Does it look OK?
>>
>> Minor comments below.
>>
>> > What are possible branches for this patch?
>>
>> You can probably create a testcase that shows code-size regressions
>> against a version that didn't peel completely (GCC 4.7). Thus I'd say
>> it would apply to 4.9 as well (4.8 doesn't have range information).
>>
>> > Thanks,
>> > Ilya
>> > --
>> > diff --git a/gcc/testsuite/gcc.dg/pr64277.c
>> > b/gcc/testsuite/gcc.dg/pr64277.c
>> > new file mode 100644
>> > index 0000000..c6ef331
>> > --- /dev/null
>> > +++ b/gcc/testsuite/gcc.dg/pr64277.c
>> > @@ -0,0 +1,23 @@
>> > +/* PR tree-optimization/64277 */
>> > +/* { dg-do compile } */
>> > +/* { dg-options "-O3 -Wall -Werror -fdump-tree-cunroll-details" } */
>> > +/* { dg-final { scan-tree-dump "loop with 5 iterations completely
>> > unrolled" "cunroll" } } */
>> > +/* { dg-final { scan-tree-dump "loop with 6 iterations completely
>> > unrolled" "cunroll" } } */
>> > +/* { dg-final { cleanup-tree-dump "cunroll" } } */
>> > +
>> > +int f1[10];
>> > +void test1 (short a[], short m, unsigned short l)
>> > +{
>> > + int i = l;
>> > + for (i = i + 5; i < m; i++)
>> > + f1[i] = a[i]++;
>> > +}
>> > +
>> > +void test2 (short a[], short m, short l)
>> > +{
>> > + int i;
>> > + if (m > 5)
>> > + m = 5;
>> > + for (i = m; i > l; i--)
>> > + f1[i] = a[i]++;
>> > +}
>> > diff --git a/gcc/tree-ssa-loop-niter.c b/gcc/tree-ssa-loop-niter.c
>> > index 919f5c0..1cd297d 100644
>> > --- a/gcc/tree-ssa-loop-niter.c
>> > +++ b/gcc/tree-ssa-loop-niter.c
>> > @@ -2754,6 +2754,7 @@ record_nonwrapping_iv (struct loop *loop, tree base,
>> > tree step, gimple stmt,
>> > {
>> > tree niter_bound, extreme, delta;
>> > tree type = TREE_TYPE (base), unsigned_type;
>> > + tree orig_base = base;
>> >
>> > if (TREE_CODE (step) != INTEGER_CST || integer_zerop (step))
>> > return;
>> > @@ -2777,16 +2778,30 @@ record_nonwrapping_iv (struct loop *loop, tree
>> > base, tree step, gimple stmt,
>> >
>> > if (tree_int_cst_sign_bit (step))
>> > {
>> > + wide_int min, max;
>> > extreme = fold_convert (unsigned_type, low);
>> > - if (TREE_CODE (base) != INTEGER_CST)
>> > + if (TREE_CODE (orig_base) == SSA_NAME
>> > + && TREE_CODE (high) == INTEGER_CST
>> > + && INTEGRAL_TYPE_P (TREE_TYPE (orig_base))
>> > + && get_range_info (orig_base, &min, &max) == VR_RANGE
>> > + && wi::gts_p (wide_int (high), max))
>>
>> For me a simple wi::gts_p (high, max) worked fine.
>>
>> > + base = wide_int_to_tree (unsigned_type, max);
>> > + else if (TREE_CODE (base) != INTEGER_CST)
>> > base = fold_convert (unsigned_type, high);
>> > delta = fold_build2 (MINUS_EXPR, unsigned_type, base, extreme);
>> > step = fold_build1 (NEGATE_EXPR, unsigned_type, step);
>> > }
>> > else
>> > {
>> > + wide_int min, max;
>> > extreme = fold_convert (unsigned_type, high);
>> > - if (TREE_CODE (base) != INTEGER_CST)
>> > + if (TREE_CODE (orig_base) == SSA_NAME
>> > + && TREE_CODE (low) == INTEGER_CST
>> > + && INTEGRAL_TYPE_P (TREE_TYPE (orig_base))
>> > + && get_range_info (orig_base, &min, &max) == VR_RANGE
>> > + && wi::gts_p (min, wide_int (low)))
>>
>> Likewise.
>>
>> Ok for trunk with that changes. For the 4.9 branch you need to adjust
>> the patch to not use wide-ints. I'd leave it on trunk for a while and
>> eventually open a bugreport for the size regression to keep track of it.
>>
>> Thanks,
>> Richard.
>>
>
> Here is a version for 4.9 branch. Does it look OK? Bootstrapped and tested
> on x86_64-unknown-linux-gnu.
I don't think we want this kind of fixes on the branch.
Thanks,
Richard.
> Thanks,
> Ilya
> --
> gcc/
>
> 2015-02-02 Ilya Enkovich <ilya.enkov...@intel.com>
>
> PR tree-optimization/64277
> * tree-ssa-loop-niter.c (record_nonwrapping_iv): Use base
> range info when possible to refine estimation.
>
> gcc/testsuite/
>
> 2015-02-02 Ilya Enkovich <ilya.enkov...@intel.com>
>
> PR tree-optimization/64277
> * gcc.dg/pr64277.c: New.
>
>
> diff --git a/gcc/testsuite/gcc.dg/pr64277.c b/gcc/testsuite/gcc.dg/pr64277.c
> new file mode 100644
> index 0000000..c6ef331
> --- /dev/null
> +++ b/gcc/testsuite/gcc.dg/pr64277.c
> @@ -0,0 +1,23 @@
> +/* PR tree-optimization/64277 */
> +/* { dg-do compile } */
> +/* { dg-options "-O3 -Wall -Werror -fdump-tree-cunroll-details" } */
> +/* { dg-final { scan-tree-dump "loop with 5 iterations completely unrolled"
> "cunroll" } } */
> +/* { dg-final { scan-tree-dump "loop with 6 iterations completely unrolled"
> "cunroll" } } */
> +/* { dg-final { cleanup-tree-dump "cunroll" } } */
> +
> +int f1[10];
> +void test1 (short a[], short m, unsigned short l)
> +{
> + int i = l;
> + for (i = i + 5; i < m; i++)
> + f1[i] = a[i]++;
> +}
> +
> +void test2 (short a[], short m, short l)
> +{
> + int i;
> + if (m > 5)
> + m = 5;
> + for (i = m; i > l; i--)
> + f1[i] = a[i]++;
> +}
> diff --git a/gcc/tree-ssa-loop-niter.c b/gcc/tree-ssa-loop-niter.c
> index 897b8f5..8fb72b6 100644
> --- a/gcc/tree-ssa-loop-niter.c
> +++ b/gcc/tree-ssa-loop-niter.c
> @@ -2727,6 +2727,7 @@ record_nonwrapping_iv (struct loop *loop, tree base,
> tree step, gimple stmt,
> tree niter_bound, extreme, delta;
> tree type = TREE_TYPE (base), unsigned_type;
> double_int max;
> + tree orig_base = base;
>
> if (TREE_CODE (step) != INTEGER_CST || integer_zerop (step))
> return;
> @@ -2750,7 +2751,14 @@ record_nonwrapping_iv (struct loop *loop, tree base,
> tree step, gimple stmt,
>
> if (tree_int_cst_sign_bit (step))
> {
> + double_int min, max;
> extreme = fold_convert (unsigned_type, low);
> + if (TREE_CODE (orig_base) == SSA_NAME
> + && TREE_CODE (high) == INTEGER_CST
> + && INTEGRAL_TYPE_P (TREE_TYPE (orig_base))
> + && get_range_info (orig_base, &min, &max) == VR_RANGE
> + && max.slt (TREE_INT_CST (high)))
> + base = double_int_to_tree (unsigned_type, max);
> if (TREE_CODE (base) != INTEGER_CST)
> base = fold_convert (unsigned_type, high);
> delta = fold_build2 (MINUS_EXPR, unsigned_type, base, extreme);
> @@ -2758,8 +2766,15 @@ record_nonwrapping_iv (struct loop *loop, tree base,
> tree step, gimple stmt,
> }
> else
> {
> + double_int min, max;
> extreme = fold_convert (unsigned_type, high);
> - if (TREE_CODE (base) != INTEGER_CST)
> + if (TREE_CODE (orig_base) == SSA_NAME
> + && TREE_CODE (low) == INTEGER_CST
> + && INTEGRAL_TYPE_P (TREE_TYPE (orig_base))
> + && get_range_info (orig_base, &min, &max) == VR_RANGE
> + && min.sgt (TREE_INT_CST (low)))
> + base = double_int_to_tree (unsigned_type, min);
> + else if (TREE_CODE (base) != INTEGER_CST)
> base = fold_convert (unsigned_type, low);
> delta = fold_build2 (MINUS_EXPR, unsigned_type, extreme, base);
> }
