diff mbox

Fold (a > 0 ? 1.0 : -1.0) into copysign (1.0, a) and a * copysign (1.0, a) into abs(a)

Message ID 20170628073745.GW2123@tucnak
State New
Headers show

Commit Message

Jakub Jelinek June 28, 2017, 7:37 a.m. UTC 
On Tue, Jun 27, 2017 at 10:52:47AM -0700, Andrew Pinski wrote:
> On Tue, Jun 27, 2017 at 7:56 AM, Richard Biener
> <richard.guenther@gmail.com> wrote:
> > On June 27, 2017 4:52:28 PM GMT+02:00, Tamar Christina <Tamar.Christina@arm.com> wrote:
> >>> >> +(for cmp (gt ge lt le)
> >>> >> +     outp (convert convert negate negate)
> >>> >> +     outn (negate negate convert convert)
> >>> >> + /* Transform (X > 0.0 ? 1.0 : -1.0) into copysign(1, X). */
> >>> >> + /* Transform (X >= 0.0 ? 1.0 : -1.0) into copysign(1, X). */
> >>> >> + /* Transform (X < 0.0 ? 1.0 : -1.0) into copysign(1,-X). */
> >>> >> + /* Transform (X <= 0.0 ? 1.0 : -1.0) into copysign(1,-X). */
> >>> >> +(simplify
> >>> >> +  (cond (cmp @0 real_zerop) real_onep real_minus_onep)
> >>> >> +  (if (!HONOR_NANS (type) && !HONOR_SIGNED_ZEROS (type)
> >>> >> +       && types_match (type, TREE_TYPE (@0)))
> >>> >> +   (switch
> >>> >> +    (if (types_match (type, float_type_node))
> >>> >> +     (BUILT_IN_COPYSIGNF { build_one_cst (type); } (outp @0)))
> >>> >> +    (if (types_match (type, double_type_node))
> >>> >> +     (BUILT_IN_COPYSIGN { build_one_cst (type); } (outp @0)))
> >>> >> +    (if (types_match (type, long_double_type_node))
> >>> >> +     (BUILT_IN_COPYSIGNL { build_one_cst (type); } (outp @0))))))

The patch regressed the gcc.target/i386/cmov7.c testcase.
From the description in the testcase it was testing the combiner, so I've
transformed it into something that also tests the combiner the same way,
ok for trunk?  That said, for copysign if we match it we don't emit a fcmov
while it might be a good idea.

2017-06-28  Jakub Jelinek  <jakub@redhat.com>

	* gcc.target/i386/cmov7.c (sgn): Renamed to ...
	(foo): ... this.  Change constants such that it isn't matched
	as __builtin_copysign, yet tests the combiner the same.



	Jakub

Comments

Uros Bizjak June 28, 2017, 7:57 a.m. UTC | #1 
On Wed, Jun 28, 2017 at 9:37 AM, Jakub Jelinek <jakub@redhat.com> wrote:
> On Tue, Jun 27, 2017 at 10:52:47AM -0700, Andrew Pinski wrote:
>> On Tue, Jun 27, 2017 at 7:56 AM, Richard Biener
>> <richard.guenther@gmail.com> wrote:
>> > On June 27, 2017 4:52:28 PM GMT+02:00, Tamar Christina <Tamar.Christina@arm.com> wrote:
>> >>> >> +(for cmp (gt ge lt le)
>> >>> >> +     outp (convert convert negate negate)
>> >>> >> +     outn (negate negate convert convert)
>> >>> >> + /* Transform (X > 0.0 ? 1.0 : -1.0) into copysign(1, X). */
>> >>> >> + /* Transform (X >= 0.0 ? 1.0 : -1.0) into copysign(1, X). */
>> >>> >> + /* Transform (X < 0.0 ? 1.0 : -1.0) into copysign(1,-X). */
>> >>> >> + /* Transform (X <= 0.0 ? 1.0 : -1.0) into copysign(1,-X). */
>> >>> >> +(simplify
>> >>> >> +  (cond (cmp @0 real_zerop) real_onep real_minus_onep)
>> >>> >> +  (if (!HONOR_NANS (type) && !HONOR_SIGNED_ZEROS (type)
>> >>> >> +       && types_match (type, TREE_TYPE (@0)))
>> >>> >> +   (switch
>> >>> >> +    (if (types_match (type, float_type_node))
>> >>> >> +     (BUILT_IN_COPYSIGNF { build_one_cst (type); } (outp @0)))
>> >>> >> +    (if (types_match (type, double_type_node))
>> >>> >> +     (BUILT_IN_COPYSIGN { build_one_cst (type); } (outp @0)))
>> >>> >> +    (if (types_match (type, long_double_type_node))
>> >>> >> +     (BUILT_IN_COPYSIGNL { build_one_cst (type); } (outp @0))))))
>
> The patch regressed the gcc.target/i386/cmov7.c testcase.
> From the description in the testcase it was testing the combiner, so I've
> transformed it into something that also tests the combiner the same way,
> ok for trunk?  That said, for copysign if we match it we don't emit a fcmov
> while it might be a good idea.
>
> 2017-06-28  Jakub Jelinek  <jakub@redhat.com>
>
>         * gcc.target/i386/cmov7.c (sgn): Renamed to ...
>         (foo): ... this.  Change constants such that it isn't matched
>         as __builtin_copysign, yet tests the combiner the same.

OK.

Thanks,
Uros.

> --- gcc/testsuite/gcc.target/i386/cmov7.c.jj    2016-05-22 12:20:23.000000000 +0200
> +++ gcc/testsuite/gcc.target/i386/cmov7.c       2017-06-28 09:20:24.000000000 +0200
> @@ -10,7 +10,7 @@
>     (set (reg:DF) (float_extend:DF (mem:SF (symbol_ref...)))).  */
>
>  double
> -sgn (double __x)
> +foo (double __x)
>  {
> -  return __x >= 0.0 ? 1.0 : -1.0;
> +  return __x >= 1.0 ? 0.0 : -1.0;
>  }
>
>
>         Jakub
diff mbox

Patch

--- gcc/testsuite/gcc.target/i386/cmov7.c.jj	2016-05-22 12:20:23.000000000 +0200
+++ gcc/testsuite/gcc.target/i386/cmov7.c	2017-06-28 09:20:24.000000000 +0200
@@ -10,7 +10,7 @@ 
    (set (reg:DF) (float_extend:DF (mem:SF (symbol_ref...)))).  */
 
 double
-sgn (double __x)
+foo (double __x)
 {
-  return __x >= 0.0 ? 1.0 : -1.0;
+  return __x >= 1.0 ? 0.0 : -1.0;
 }