On Sun, Jun 25, 2017 at 2:28 PM, Andrew Pinski <pins...@gmail.com> wrote: > On Sun, Jun 25, 2017 at 11:18 AM, Andrew Pinski <pins...@gmail.com> wrote: >> On Sun, Jun 25, 2017 at 1:28 AM, Marc Glisse <marc.gli...@inria.fr> 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)))))) >>> >>> There is already a 1.0 of the right type in the input, it would be easier to >>> reuse it in the output than build a new one. >> >> Right. Fixed. >> >>> >>> Non-generic builtins like copysign are such a pain... We also end up missing >>> the 128-bit case that way (pre-existing problem, not your patch). We seem to >>> have a corresponding internal function, but apparently it is not used until >>> expansion (well, maybe during vectorization). >> >> Yes I noticed that while working on a different patch related to >> copysign; The generic version of a*copysign(1.0, b) [see the other >> thread where the ARM folks started a patch for it; yes it was by pure >> accident that I was working on this and really did not notice that >> thread until yesterday]. >> I was looking into a nice way of creating copysign without having to >> do the switch but I could not find one. In the end I copied was done >> already in a different location in match.pd; this is also the reason >> why I had the build_one_cst there. >> >>> >>> + /* 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_minus_onep real_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); } (outn @0))) >>> + (if (types_match (type, double_type_node)) >>> + (BUILT_IN_COPYSIGN { build_one_cst (type); } (outn @0))) >>> + (if (types_match (type, long_double_type_node)) >>> + (BUILT_IN_COPYSIGNL { build_one_cst (type); } (outn @0))))))) >>> + >>> +/* Transform X * copysign (1.0, X) into abs(X). */ >>> +(simplify >>> + (mult:c @0 (COPYSIGN real_onep @0)) >>> + (if (!HONOR_NANS (type) && !HONOR_SIGNED_ZEROS (type)) >>> + (abs @0))) >>> >>> I would have expected it do to the right thing for signed zero and qNaN. Can >>> you describe a case where it would give the wrong result, or are the >>> conditions just conservative? >> >> I was just being conservative; maybe too conservative but I was a bit >> worried I could get it incorrect. >> >>> >>> +/* Transform X * copysign (1.0, -X) into -abs(X). */ >>> +(simplify >>> + (mult:c @0 (COPYSIGN real_onep (negate @0))) >>> + (if (!HONOR_NANS (type) && !HONOR_SIGNED_ZEROS (type)) >>> + (negate (abs @0)))) >>> + >>> +/* Transform copysign (-1.0, X) into copysign (1.0, X). */ >>> +(simplify >>> + (COPYSIGN real_minus_onep @0) >>> + (COPYSIGN { build_one_cst (type); } @0)) >>> >>> (simplify >>> (COPYSIGN REAL_CST@0 @1) >>> (if (REAL_VALUE_NEGATIVE (TREE_REAL_CST (@0))) >>> (COPYSIGN (negate @0) @1))) >>> ? Or does that create trouble with sNaN and only the 1.0 case is worth >>> the trouble? >> >> No that is the correct way; I Noticed the other thread about copysign >> had something similar as what should be done too. >> >> I will send out a new patch after testing soon. > > New patch. > OK? Bootstrapped and tested on aarch64-linux-gnu with no regressions. > > Thanks, > Andrew Pinski > > ChangeLog: > * match.pd (X >/>=/</<= 0 ? 1.0 : -1.0): New patterns. > (X * copysign (1.0, X)): New pattern. > (X * copysign (1.0, -X)): New pattern. > (copysign (-1.0, CST)): New pattern. > > testsuite/ChangeLog: > * gcc.dg/tree-ssa/copy-sign-1.c: New testcase. > * gcc.dg/tree-ssa/copy-sign-2.c: New testcase. > * gcc.dg/tree-ssa/mult-abs-2.c: New testcase. >
This caused: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81255 -- H.J.