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Re: Canonicalize X u< X to UNORDERED_EXPR
- From: Richard Biener <richard dot guenther at gmail dot com>
- To: Marc Glisse <marc dot glisse at inria dot fr>
- Cc: GCC Patches <gcc-patches at gcc dot gnu dot org>
- Date: Mon, 2 May 2016 10:37:44 +0200
- Subject: Re: Canonicalize X u< X to UNORDERED_EXPR
- Authentication-results: sourceware.org; auth=none
- References: <alpine dot DEB dot 2 dot 02 dot 1604302026470 dot 16157 at laptop-mg dot saclay dot inria dot fr>
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" } } */
>