From patchwork Thu May 25 15:16:32 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Fangrui Song X-Patchwork-Id: 70086 Return-Path: X-Original-To: patchwork@sourceware.org Delivered-To: patchwork@sourceware.org Received: from server2.sourceware.org (localhost [IPv6:::1]) by sourceware.org (Postfix) with ESMTP id 1E3233858C2C for ; Thu, 25 May 2023 15:17:05 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 1E3233858C2C DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gcc.gnu.org; s=default; t=1685027825; bh=+W+SbQv0sqfQ0bUdUK5vauE8idO105aUoj3MPH79S8A=; h=Date:Subject:To:Cc:List-Id:List-Unsubscribe:List-Archive: List-Post:List-Help:List-Subscribe:From:Reply-To:From; b=aYdQ6q6plFPDlrE2nzyzciaPb2geSbb/WZFbIvpE/Dc8BL2UxT7qyagX6BIE7fjNc U0Vh0HaZRvlATG0ZLT/+yxbUY8iDx3W2U8hwGTZKn1Wp2mT+yFRGMFFB00OVLBpFFy ZAGeIgE/rS8VwR04dU+19Dnj1nLTAqM/cOW7ljKQ= X-Original-To: gcc-patches@gcc.gnu.org Delivered-To: gcc-patches@gcc.gnu.org Received: from mail-yw1-x114a.google.com (mail-yw1-x114a.google.com [IPv6:2607:f8b0:4864:20::114a]) by sourceware.org (Postfix) with ESMTPS id 25B263858D32 for ; Thu, 25 May 2023 15:16:36 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org 25B263858D32 Received: by mail-yw1-x114a.google.com with SMTP id 00721157ae682-5657f376d8dso17092837b3.2 for ; Thu, 25 May 2023 08:16:36 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1685027795; x=1687619795; h=cc:to:from:subject:message-id:mime-version:date:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=+W+SbQv0sqfQ0bUdUK5vauE8idO105aUoj3MPH79S8A=; b=K4SJ921p94TuBMAREYyrjkZj3BwmACmNObq/DtzA6IXeGMBTfsUrfbyvR+WJD8QoDV H8Fb/mQiy01TjYsPqoEKi1V1Dzrctge075Awk70V+ysYd9Og7YI3Gbayvgwo3H5fLCDI rPwsnGzFNZG1UrAq0ChWik81AYxVpWs5kh9uvXAt1mc68GxdBMizriLS6a9a0sw1tCrS HEmuEk2WLRNchYT4SEjGlheSBBw1YifC5dowdw3YDw+1M91v6y1JzlgDbeMg4R8dYn+F IVhKFg+COYftD6EQ3kSM0vg+8WWOHVzJJboYRnrKVuD490l8n2wv/stMd/GZUrPhmFas LXOw== X-Gm-Message-State: AC+VfDw4Hf7825HgJfbXJ2LZ+MN+dUcmdcTOf33VIZ6WGk7v4zWdzzVH seR+f0zgwimYh8Im5rRAyOBNPZ1Hau+kOaOiue/aHTEB/f2v6G5IOr0G6X4bnp8jMrIlXue/3gt ss0Q+gbi0STXHUi9jPm1B0vJwyeVOSBByYDPg4k0xvhoqRulTOquuJi5q6qgR85GrGQ== X-Google-Smtp-Source: ACHHUZ6ShT8U4NX5EeHrJoa9IkUf8wjp8IAfxsgrPB9hGJZaSjlkAXpIt6IKBKiFPXB/tcdREQ8TG57Q9w1r X-Received: from maskray.svl.corp.google.com ([2620:15c:2d3:205:3741:a7cf:4f6f:d596]) (user=maskray job=sendgmr) by 2002:a81:b14a:0:b0:55d:ea61:d8e9 with SMTP id p71-20020a81b14a000000b0055dea61d8e9mr13840718ywh.7.1685027795461; Thu, 25 May 2023 08:16:35 -0700 (PDT) Date: Thu, 25 May 2023 08:16:32 -0700 Mime-Version: 1.0 Message-ID: <20230525151632.3567825-1-maskray@google.com> Subject: [PATCH v2] i386: Allow -mlarge-data-threshold with -mcmodel=large To: gcc-patches@gcc.gnu.org, Florian Weimer , "H.J. Lu" , Jan Beulich , Jan Hubicka , Michael Matz , Uros Bizjak Cc: Fangrui Song X-Spam-Status: No, score=-18.8 required=5.0 tests=BAYES_00, DKIMWL_WL_MED, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, GIT_PATCH_0, KAM_MANYTO, KAM_SHORT, RCVD_IN_DNSWL_NONE, SPF_HELO_NONE, SPF_PASS, TXREP, T_SCC_BODY_TEXT_LINE, URIBL_BLACK, USER_IN_DEF_DKIM_WL autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) 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-Patchwork-Original-From: Fangrui Song via Gcc-patches From: Fangrui Song Reply-To: Fangrui Song Errors-To: gcc-patches-bounces+patchwork=sourceware.org@gcc.gnu.org Sender: "Gcc-patches" When using -mcmodel=medium, large data objects larger than the -mlarge-data-threshold threshold are placed into large data sections (.lrodata, .ldata, .lbss and some variants). GNU ld and ld.lld 17 place .l* sections into separate output sections. If small and medium code model object files are mixed, the .l* sections won't exert relocation overflow pressure on sections in object files built with -mcmodel=small. However, when using -mcmodel=large, -mlarge-data-threshold doesn't apply. This means that the .rodata/.data/.bss sections may exert relocation overflow pressure on sections in -mcmodel=small object files. This patch allows -mcmodel=large to generate .l* sections. Link: https://groups.google.com/g/x86-64-abi/c/jnQdJeabxiU ("Large data sections for the large code model") Signed-off-by: Fangrui Song --- Changes from v1 (https://gcc.gnu.org/pipermail/gcc-patches/2023-April/616947.html): * Clarify commit message. Add link to https://groups.google.com/g/x86-64-abi/c/jnQdJeabxiU --- gcc/config/i386/i386.cc | 15 +++++++++------ gcc/config/i386/i386.opt | 2 +- gcc/doc/invoke.texi | 7 ++++--- gcc/testsuite/gcc.target/i386/large-data.c | 13 +++++++++++++ 4 files changed, 27 insertions(+), 10 deletions(-) create mode 100644 gcc/testsuite/gcc.target/i386/large-data.c diff --git a/gcc/config/i386/i386.cc b/gcc/config/i386/i386.cc index 202abf0b39c..3568da4f053 100644 --- a/gcc/config/i386/i386.cc +++ b/gcc/config/i386/i386.cc @@ -637,7 +637,8 @@ ix86_can_inline_p (tree caller, tree callee) static bool ix86_in_large_data_p (tree exp) { - if (ix86_cmodel != CM_MEDIUM && ix86_cmodel != CM_MEDIUM_PIC) + if (ix86_cmodel != CM_MEDIUM && ix86_cmodel != CM_MEDIUM_PIC && + ix86_cmodel != CM_LARGE && ix86_cmodel != CM_LARGE_PIC) return false; if (exp == NULL_TREE) @@ -848,8 +849,9 @@ x86_elf_aligned_decl_common (FILE *file, tree decl, const char *name, unsigned HOST_WIDE_INT size, unsigned align) { - if ((ix86_cmodel == CM_MEDIUM || ix86_cmodel == CM_MEDIUM_PIC) - && size > (unsigned int)ix86_section_threshold) + if ((ix86_cmodel == CM_MEDIUM || ix86_cmodel == CM_MEDIUM_PIC || + ix86_cmodel == CM_LARGE || ix86_cmodel == CM_LARGE_PIC) && + size > (unsigned int)ix86_section_threshold) { switch_to_section (get_named_section (decl, ".lbss", 0)); fputs (LARGECOMM_SECTION_ASM_OP, file); @@ -869,9 +871,10 @@ void x86_output_aligned_bss (FILE *file, tree decl, const char *name, unsigned HOST_WIDE_INT size, unsigned align) { - if ((ix86_cmodel == CM_MEDIUM || ix86_cmodel == CM_MEDIUM_PIC) - && size > (unsigned int)ix86_section_threshold) - switch_to_section (get_named_section (decl, ".lbss", 0)); + if ((ix86_cmodel == CM_MEDIUM || ix86_cmodel == CM_MEDIUM_PIC || + ix86_cmodel == CM_LARGE || ix86_cmodel == CM_LARGE_PIC) && + size > (unsigned int)ix86_section_threshold) + switch_to_section(get_named_section(decl, ".lbss", 0)); else switch_to_section (bss_section); ASM_OUTPUT_ALIGN (file, floor_log2 (align / BITS_PER_UNIT)); diff --git a/gcc/config/i386/i386.opt b/gcc/config/i386/i386.opt index d74f6b1f8fc..de8e722cd62 100644 --- a/gcc/config/i386/i386.opt +++ b/gcc/config/i386/i386.opt @@ -282,7 +282,7 @@ Branches are this expensive (arbitrary units). mlarge-data-threshold= Target RejectNegative Joined UInteger Var(ix86_section_threshold) Init(DEFAULT_LARGE_SECTION_THRESHOLD) --mlarge-data-threshold= Data greater than given threshold will go into .ldata section in x86-64 medium model. +-mlarge-data-threshold= Data greater than given threshold will go into a large data section in x86-64 medium and large code models. mcmodel= Target RejectNegative Joined Enum(cmodel) Var(ix86_cmodel) Init(CM_32) diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi index ee78591c73e..4b5391e12b5 100644 --- a/gcc/doc/invoke.texi +++ b/gcc/doc/invoke.texi @@ -32942,9 +32942,10 @@ the cache line size. @samp{compat} is the default. @opindex mlarge-data-threshold @item -mlarge-data-threshold=@var{threshold} -When @option{-mcmodel=medium} is specified, data objects larger than -@var{threshold} are placed in the large data section. This value must be the -same across all objects linked into the binary, and defaults to 65535. +When @option{-mcmodel=medium} or @option{-mcmodel=large} is specified, data +objects larger than @var{threshold} are placed in large data sections. This +value must be the same across all objects linked into the binary, and defaults +to 65535. @opindex mrtd @item -mrtd diff --git a/gcc/testsuite/gcc.target/i386/large-data.c b/gcc/testsuite/gcc.target/i386/large-data.c new file mode 100644 index 00000000000..09a917431d4 --- /dev/null +++ b/gcc/testsuite/gcc.target/i386/large-data.c @@ -0,0 +1,13 @@ +/* { dg-do compile } */ +/* { dg-require-effective-target lp64 } */ +/* { dg-options "-O2 -mcmodel=large -mlarge-data-threshold=4" } */ +/* { dg-final { scan-assembler ".lbss" } } */ +/* { dg-final { scan-assembler ".bss" } } */ +/* { dg-final { scan-assembler ".ldata" } } */ +/* { dg-final { scan-assembler ".data" } } */ +/* { dg-final { scan-assembler ".lrodata" } } */ +/* { dg-final { scan-assembler ".rodata" } } */ + +const char rodata_a[] = "abc", rodata_b[] = "abcd"; +char data_a[4] = {1}, data_b[5] = {1}; +char bss_a[4], bss_b[5];