From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ed1-x531.google.com (mail-ed1-x531.google.com [IPv6:2a00:1450:4864:20::531]) by sourceware.org (Postfix) with ESMTPS id 9C854385C406 for ; Tue, 16 Nov 2021 10:03:32 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org 9C854385C406 Received: by mail-ed1-x531.google.com with SMTP id g14so21568402edb.8 for ; Tue, 16 Nov 2021 02:03:32 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=WjpS/SzPDm0JHVJlzTxd8rqflY/qgacXy4fBWXF0fvA=; b=ijyhJZ/vq3ygpUIUlR353BEVZ5KBzmrVyShmDeYjIaxACwY4dHQPna6Ge3tsbU1e2J ZdslfyDNDpc8TxLtB2eIm4f6n3hVZD7V4C4r8WRizVUrv28tIur3rloXpoAncrnjh0YC gnepVT6N463R7poD9J9+w0LMQ7V5AgGIbh9wsp84SbLba2TrzMUuaKAxup9lCAulcEC5 uIIxhfdqbQnhnOAqya9TLp/hbd9kYQNzKX3nkvONgZ+x9pcEAUTOXsJKSfbG2swrxvJ0 I4IDWV9stXcCcqQyZ06q0oZ6q6fOHtCCUfgSmyAORmt6fsOmYWPJQVE9/uZOdXDrjy8q LJ9w== X-Gm-Message-State: AOAM532KWcVrvqO4ucLdxfY8gLnMiALzAR9hYHudM5D+xPgENk9e9HuP f0EQ6r8Rt1A5kvt3zIcIPG8kiNVEx04Rgb+Qtro= X-Google-Smtp-Source: ABdhPJyydl8sYmjPM4+hhROkSL9GX/iv4eScZOago/746D6TJcgwWIQHucYgX+3KSj+oZtvuJbZzeFpdsNgbSRRkMCM= X-Received: by 2002:a05:6402:50d0:: with SMTP id h16mr8626369edb.70.1637057011654; Tue, 16 Nov 2021 02:03:31 -0800 (PST) MIME-Version: 1.0 References: <1636834427-22589-1-git-send-email-apinski@marvell.com> In-Reply-To: <1636834427-22589-1-git-send-email-apinski@marvell.com> From: Richard Biener Date: Tue, 16 Nov 2021 11:03:21 +0100 Message-ID: Subject: Re: [PATCH] tree-optimization: [PR103218] Fold ((type)(a<0)) << SIGNBITOFA into ((type)a) & signbit To: Andrew Pinski Cc: GCC Patches Content-Type: text/plain; charset="UTF-8" X-Spam-Status: No, score=-8.4 required=5.0 tests=BAYES_00, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, FREEMAIL_FROM, GIT_PATCH_0, RCVD_IN_DNSWL_NONE, SPF_HELO_NONE, SPF_PASS, TXREP autolearn=ham autolearn_force=no version=3.4.4 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on server2.sourceware.org X-BeenThere: gcc-patches@gcc.gnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Gcc-patches mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 16 Nov 2021 10:03:38 -0000 On Sat, Nov 13, 2021 at 9:14 PM apinski--- via Gcc-patches wrote: > > From: Andrew Pinski > > This folds Fold ((type)(a<0)) << SIGNBITOFA into ((type)a) & signbit inside match.pd. > This was already handled in fold-cost by: > /* A < 0 ? : 0 is simply (A & ). */ > I have not removed as we only simplify "a ? POW2 : 0" at the gimple level to "a << CST1" > and fold actually does the reverse of folding "(a<0)< OK? Bootstrapped and tested on x86_64-linux-gnu with no regressions. OK. Thanks, Richard. > PR tree-optimization/103218 > > gcc/ChangeLog: > > * match.pd: New pattern for "((type)(a<0)) << SIGNBITOFA". > > gcc/testsuite/ChangeLog: > > * gcc.dg/tree-ssa/pr103218-1.c: New test. > --- > gcc/match.pd | 10 ++++++++ > gcc/testsuite/gcc.dg/tree-ssa/pr103218-1.c | 28 ++++++++++++++++++++++ > 2 files changed, 38 insertions(+) > create mode 100644 gcc/testsuite/gcc.dg/tree-ssa/pr103218-1.c > > diff --git a/gcc/match.pd b/gcc/match.pd > index a319aefa808..df31964e02f 100644 > --- a/gcc/match.pd > +++ b/gcc/match.pd > @@ -865,6 +865,16 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT) > { tree utype = unsigned_type_for (type); } > (convert (rshift (lshift (convert:utype @0) @2) @3)))))) > > +/* Fold ((type)(a<0)) << SIGNBITOFA into ((type)a) & signbit. */ > +(simplify > + (lshift (convert (lt @0 integer_zerop@1)) INTEGER_CST@2) > + (if (TYPE_SIGN (TREE_TYPE (@0)) == SIGNED > + && wi::eq_p (wi::to_wide (@2), TYPE_PRECISION (TREE_TYPE (@0)) - 1)) > + (with { wide_int wone = wi::one (TYPE_PRECISION (type)); } > + (bit_and (convert @0) > + { wide_int_to_tree (type, > + wi::lshift (wone, wi::to_wide (@2))); })))) > + > /* Fold (-x >> C) into -(x > 0) where C = precision(type) - 1. */ > (for cst (INTEGER_CST VECTOR_CST) > (simplify > diff --git a/gcc/testsuite/gcc.dg/tree-ssa/pr103218-1.c b/gcc/testsuite/gcc.dg/tree-ssa/pr103218-1.c > new file mode 100644 > index 00000000000..f086f073b38 > --- /dev/null > +++ b/gcc/testsuite/gcc.dg/tree-ssa/pr103218-1.c > @@ -0,0 +1,28 @@ > +/* { dg-do compile } */ > +/* { dg-options "-O2 -fdump-tree-optimized" } */ > +/* PR tree-optimization/103218 */ > + > +/* These first two are removed during forwprop1 */ > +signed char f(signed char a) > +{ > + signed char t = a < 0; > + int tt = (unsigned char)(t << 7); > + return tt; > +} > +signed char f0(signed char a) > +{ > + unsigned char t = a < 0; > + int tt = (unsigned char)(t << 7); > + return tt; > +} > + > +/* This one is removed during phiopt. */ > +signed char f1(signed char a) > +{ > + if (a < 0) > + return 1u<<7; > + return 0; > +} > + > +/* These three examples should remove "a < 0" by optimized. */ > +/* { dg-final { scan-tree-dump-times "< 0" 0 "optimized"} } */ > -- > 2.17.1 >