Re: Canonicalize X u< X to UNORDERED_EXPR

[Richard Biener <richard.guenther@gmail.com>]

On Sat, Apr 30, 2016 at 8:44 PM, Marc Glisse <marc.glisse@inria.fr> wrote:
> Hello,
>
> this case seemed to be missing in the various X cmp X transformations. It
> does not change the generated code in the testcase.
>
> The missing :c is rather trivial. I can commit it separately if you prefer.

I think it's not missing.  Commutating the first one is enough to eventually
make the @1s match up.  I think you should get a diagnostic on a duplicate
pattern when adding another :c (hmm, no, it's indeed "different" patterns but
still redundant).

> Bootstrap+regtest on powerpc64le-unknown-linux-gnu.

Ok for the new pattern.

Thanks,
Richard.

> 2016-05-02  Marc Glisse  <marc.glisse@inria.fr>
>
> gcc/
>         * match.pd ((A & B) OP (C & B)): Mark '&' as commutative.
>         (X u< X, X u> X): New transformations
>
> gcc/testsuite/
>         * gcc.dg/tree-ssa/unord.c: New testcase.
>
> --
> Marc Glisse
> Index: trunk/gcc/match.pd
> ===================================================================
> --- trunk/gcc/match.pd  (revision 235654)
> +++ trunk/gcc/match.pd  (working copy)
> @@ -783,21 +783,21 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
>    @0)
>   /* (~x | y) & x -> x & y */
>   /* (~x & y) | x -> x | y */
>   (simplify
>    (bitop:c (rbitop:c (bit_not @0) @1) @0)
>    (bitop @0 @1)))
>
>  /* Simplify (A & B) OP0 (C & B) to (A OP0 C) & B. */
>  (for bitop (bit_and bit_ior bit_xor)
>   (simplify
> -  (bitop (bit_and:c @0 @1) (bit_and @2 @1))
> +  (bitop (bit_and:c @0 @1) (bit_and:c @2 @1))
>    (bit_and (bitop @0 @2) @1)))
>
>  /* (x | CST1) & CST2 -> (x & CST2) | (CST1 & CST2) */
>  (simplify
>    (bit_and (bit_ior @0 CONSTANT_CLASS_P@1) CONSTANT_CLASS_P@2)
>    (bit_ior (bit_and @0 @2) (bit_and @1 @2)))
>
>  /* Combine successive equal operations with constants.  */
>  (for bitop (bit_and bit_ior bit_xor)
>   (simplify
> @@ -1914,20 +1914,24 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
>   (simplify
>    (cmp @0 @0)
>    (if (cmp != NE_EXPR
>         || ! FLOAT_TYPE_P (TREE_TYPE (@0))
>         || ! HONOR_NANS (@0))
>     { constant_boolean_node (false, type); })))
>  (for cmp (unle unge uneq)
>   (simplify
>    (cmp @0 @0)
>    { constant_boolean_node (true, type); }))
> +(for cmp (unlt ungt)
> + (simplify
> +  (cmp @0 @0)
> +  (unordered @0 @0)))
>  (simplify
>   (ltgt @0 @0)
>   (if (!flag_trapping_math)
>    { constant_boolean_node (false, type); }))
>
>  /* Fold ~X op ~Y as Y op X.  */
>  (for cmp (simple_comparison)
>   (simplify
>    (cmp (bit_not@2 @0) (bit_not@3 @1))
>    (if (single_use (@2) && single_use (@3))
> Index: trunk/gcc/testsuite/gcc.dg/tree-ssa/unord.c
> ===================================================================
> --- trunk/gcc/testsuite/gcc.dg/tree-ssa/unord.c (revision 0)
> +++ trunk/gcc/testsuite/gcc.dg/tree-ssa/unord.c (working copy)
> @@ -0,0 +1,7 @@
> +/* { dg-do compile } */
> +/* { dg-options "-O -fdump-tree-optimized" } */
> +
> +int f(double a){double b=a;return !__builtin_islessequal(a,b);}
> +int g(double a){double b=a;return !__builtin_isgreaterequal(a,b);}
> +
> +/* { dg-final { scan-tree-dump-times " unord " 2 "optimized" } } */
>