From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ej1-x62a.google.com (mail-ej1-x62a.google.com [IPv6:2a00:1450:4864:20::62a]) by sourceware.org (Postfix) with ESMTPS id 000D33858D20; Sun, 11 Jun 2023 01:20:47 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org 000D33858D20 Authentication-Results: sourceware.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=gmail.com Received: by mail-ej1-x62a.google.com with SMTP id a640c23a62f3a-97467e06511so510955866b.2; Sat, 10 Jun 2023 18:20:47 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20221208; t=1686446445; x=1689038445; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:from:to:cc:subject:date:message-id:reply-to; bh=Jk6Je6CIz7nRNl5AirfYUAmlWGEVQDS9Vmk1OP+mWMw=; b=Friyxt4zz14GvXqJdwX3lCQtA/Y3aqeN+rvKhEEUqd0M0H90RSGo0IwjeaDQXFg/sn tOmahDPjDDBHA3pMPwa6LCzhbgxRjDVeRYaMg3HKkzfmhyy8OE5a0cxTX1YKOzaLB8pe so9ZN979ZlCYeIBEkIbHJig9u3fNiw5UT1tLtanaOfoXVlA6hckt6BjfSXXvIOQzvJcv /7mFMLjCes65LueXXTNR9iHAVgLF6r/ipO39gnyMct71ohhtCbr8m7fxChN3qMTvKt7K Ie2vSGac5usr/t4xcgHDSa4B0jX9QgdcK7blGwUvmkhew2oe6HFtJczlSLhjBPXH+PpG uRYQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1686446445; x=1689038445; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=Jk6Je6CIz7nRNl5AirfYUAmlWGEVQDS9Vmk1OP+mWMw=; b=E2LUra6yHF0oJOednOHjjthC3XgNcFgb5QCEMZxFAmws2AtOry9HyXk8IWWgfuMy/L /HYeqKskbGD4Ed4zvHq0xz7oR+5c6xwe2oBtKVzyRRBr2R5sgpF5wrt3kUFaRVL8fUxC bXKBLqstlSsNeTxZB8JvoA7SlwzILESslL6+NL/Uk6+MOyvDB6Kea/bxaVciu4Z0se5i xltBfkyY793CwOjQnAcD9tRVvjcL1r7RaDnTzPIU9Ly3knwEM7VGJAPVQVS+BVA9pWc0 EMX5JjuvgYTKQyKB+fT+eN6a7pJqNMZZWgm35zBA1EFoJjJKJmRc1lhOFP8Ta2XhSHmm 7ekw== X-Gm-Message-State: AC+VfDwBYVSMdSualkHvP8vqnKQYPkMjGLeDMEGyINtTv49W9Y4pTeV2 xQYXpRXs8QZAHWfuX9XZYFvyLokGQwEZarqTGYY= X-Google-Smtp-Source: ACHHUZ4/v0uUAkx1sR2MhcSU4t86k2npEmLCzwwf+iIkWF0+Yaepv2wF0fagl4PJa4KlTdX75I4GfWOfdHT88ui/E8Y= X-Received: by 2002:a17:906:dac7:b0:94a:56ec:7f12 with SMTP id xi7-20020a170906dac700b0094a56ec7f12mr5789537ejb.30.1686446445470; Sat, 10 Jun 2023 18:20:45 -0700 (PDT) MIME-Version: 1.0 References: <20230608015547.3432691-1-guojiufu@linux.ibm.com> <20230608015547.3432691-3-guojiufu@linux.ibm.com> In-Reply-To: <20230608015547.3432691-3-guojiufu@linux.ibm.com> From: David Edelsohn Date: Sat, 10 Jun 2023 21:20:33 -0400 Message-ID: Subject: Re: [PATCH 2/4] rs6000: build constant via lis;rotldi To: Jiufu Guo Cc: gcc-patches@gcc.gnu.org, segher@kernel.crashing.org, linkw@gcc.gnu.org, bergner@linux.ibm.com Content-Type: multipart/alternative; boundary="00000000000050a8d805fdd06909" X-Spam-Status: No, score=-7.4 required=5.0 tests=BAYES_00,DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,FREEMAIL_FROM,GIT_PATCH_0,HTML_MESSAGE,KAM_SHORT,RCVD_IN_DNSWL_NONE,SPF_HELO_NONE,SPF_PASS,TXREP,T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on server2.sourceware.org List-Id: --00000000000050a8d805fdd06909 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On Wed, Jun 7, 2023 at 9:55=E2=80=AFPM Jiufu Guo w= rote: > Hi, > > This patch checks if a constant is possible to be rotated to/from a > negative > value from "lis". If so, we could use "lis;rotldi" to build it. > The positive value of "lis" does not need to be analyzed. Because if a > constant can be rotated from the positive value of "lis", it also can be > rotated from a positive value of "li". > > Bootstrap and regtest pass on ppc64{,le}. > Is this ok for trunk? > > BR, > Jeff (Jiufu) > > gcc/ChangeLog: > > * config/rs6000/rs6000.cc (can_be_rotated_to_negative_lis): New > function. > (can_be_built_by_li_and_rotldi): Rename to ... > (can_be_built_by_li_lis_and_rotldi): ... this function. > (rs6000_emit_set_long_const): Call > can_be_built_by_li_lis_and_rotldi. > This patch is okay. Thanks, David > > gcc/testsuite/ChangeLog: > > * gcc.target/powerpc/const-build.c: Add more tests. > --- > gcc/config/rs6000/rs6000.cc | 42 ++++++++++++++++--- > .../gcc.target/powerpc/const-build.c | 16 ++++++- > 2 files changed, 52 insertions(+), 6 deletions(-) > > diff --git a/gcc/config/rs6000/rs6000.cc b/gcc/config/rs6000/rs6000.cc > index 1dd0072350a..03cd9d5e952 100644 > --- a/gcc/config/rs6000/rs6000.cc > +++ b/gcc/config/rs6000/rs6000.cc > @@ -10278,19 +10278,51 @@ can_be_rotated_to_negative_li (HOST_WIDE_INT c, > int *rot) > return can_be_rotated_to_lowbits (~c, 15, rot); > } > > -/* Check if value C can be built by 2 instructions: one is 'li', another > is > - rotldi. > +/* Check if C can be rotated to a negative value which 'lis' instruction > is > + able to load: 1..1xx0..0. If so, set *ROT to the number by which C is > + rotated, and return true. Return false otherwise. */ > + > +static bool > +can_be_rotated_to_negative_lis (HOST_WIDE_INT c, int *rot) > +{ > + /* case a. 1..1xxx0..01..1: up to 15 x's, at least 16 0's. */ > + int leading_ones =3D clz_hwi (~c); > + int tailing_ones =3D ctz_hwi (~c); > + int middle_zeros =3D ctz_hwi (c >> tailing_ones); > + if (middle_zeros >=3D 16 && leading_ones + tailing_ones >=3D 33) > + { > + *rot =3D HOST_BITS_PER_WIDE_INT - tailing_ones; > + return true; > + } > + > + /* case b. xx0..01..1xx: some of 15 x's (and some of 16 0's) are > + rotated over the highest bit. */ > + int pos_one =3D clz_hwi ((c << 16) >> 16); > + middle_zeros =3D ctz_hwi (c >> (HOST_BITS_PER_WIDE_INT - pos_one)); > + int middle_ones =3D clz_hwi (~(c << pos_one)); > + if (middle_zeros >=3D 16 && middle_ones >=3D 33) > + { > + *rot =3D pos_one; > + return true; > + } > + > + return false; > +} > + > +/* Check if value C can be built by 2 instructions: one is 'li or lis', > + another is rotldi. > > If so, *SHIFT is set to the shift operand of rotldi(rldicl), and *MASK > is set to -1, and return true. Return false otherwise. */ > > static bool > -can_be_built_by_li_and_rotldi (HOST_WIDE_INT c, int *shift, > +can_be_built_by_li_lis_and_rotldi (HOST_WIDE_INT c, int *shift, > HOST_WIDE_INT *mask) > { > int n; > if (can_be_rotated_to_positive_li (c, &n) > - || can_be_rotated_to_negative_li (c, &n)) > + || can_be_rotated_to_negative_li (c, &n) > + || can_be_rotated_to_negative_lis (c, &n)) > { > *mask =3D HOST_WIDE_INT_M1; > *shift =3D HOST_BITS_PER_WIDE_INT - n; > @@ -10346,7 +10378,7 @@ rs6000_emit_set_long_const (rtx dest, > HOST_WIDE_INT c) > emit_move_insn (dest, gen_rtx_XOR (DImode, temp, > GEN_INT ((ud2 ^ 0xffff) << 16))); > } > - else if (can_be_built_by_li_and_rotldi (c, &shift, &mask)) > + else if (can_be_built_by_li_lis_and_rotldi (c, &shift, &mask)) > { > temp =3D !can_create_pseudo_p () ? dest : gen_reg_rtx (DImode); > unsigned HOST_WIDE_INT imm =3D (c | ~mask); > diff --git a/gcc/testsuite/gcc.target/powerpc/const-build.c > b/gcc/testsuite/gcc.target/powerpc/const-build.c > index 70f095f6bf2..c38a1dd91f2 100644 > --- a/gcc/testsuite/gcc.target/powerpc/const-build.c > +++ b/gcc/testsuite/gcc.target/powerpc/const-build.c > @@ -34,14 +34,28 @@ li_rotldi_4 (void) > return 0x21ffffffffffff94LL; > } > > +long long NOIPA > +lis_rotldi_5 (void) > +{ > + return 0xffff85310000ffffLL; > +} > + > +long long NOIPA > +lis_rotldi_6 (void) > +{ > + return 0x5310000ffffffff8LL; > +} > + > struct fun arr[] =3D { > {li_rotldi_1, 0x7531000000000LL}, > {li_rotldi_2, 0x2100000000000064LL}, > {li_rotldi_3, 0xffff8531ffffffffLL}, > {li_rotldi_4, 0x21ffffffffffff94LL}, > + {lis_rotldi_5, 0xffff85310000ffffLL}, > + {lis_rotldi_6, 0x5310000ffffffff8LL}, > }; > > -/* { dg-final { scan-assembler-times {\mrotldi\M} 4 } } */ > +/* { dg-final { scan-assembler-times {\mrotldi\M} 6 } } */ > > int > main () > -- > 2.39.1 > > --00000000000050a8d805fdd06909--