From patchwork Mon Jun 20 17:05:02 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "H.J. Lu" X-Patchwork-Id: 638148 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from sourceware.org (server1.sourceware.org [209.132.180.131]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 3rYHKw5VhPz9sBf for ; Tue, 21 Jun 2016 03:05:24 +1000 (AEST) Authentication-Results: ozlabs.org; dkim=pass (1024-bit key; unprotected) header.d=gcc.gnu.org header.i=@gcc.gnu.org header.b=p2WsvFQI; dkim-atps=neutral DomainKey-Signature: a=rsa-sha1; c=nofws; d=gcc.gnu.org; h=list-id :list-unsubscribe:list-archive:list-post:list-help:sender:date :from:to:cc:subject:message-id:reply-to:mime-version :content-type; q=dns; s=default; b=Ku5JesvNth2wjorjdcXdOlg74Kixr EcCUw6GrzvCLg/YrLuHl5soT4F/AC5KfPraMu1HmD5x2FdbG6JkXM3ZXTbSvG7gr 1qnPfBMJfOHFgiuEcS9hWOgF/Ssxm3iBOWubXBucLAPtlMy3+exKeE/3Z1l5NIMl tMXxQPwBId6dG8= DKIM-Signature: v=1; a=rsa-sha1; c=relaxed; d=gcc.gnu.org; h=list-id :list-unsubscribe:list-archive:list-post:list-help:sender:date :from:to:cc:subject:message-id:reply-to:mime-version :content-type; s=default; bh=2JfKo889lW/F3BGqf9jFnWy0vRY=; b=p2W svFQIgbZTXSttylQ6+zevBk3koFXO6V3itHughKgVeDwKKpqJCWJ2VsCXXLLW5mV +t/MbJpVYff075TizMY3Zb0aoMa8ft9YtJdjD+1Vp+nRKkUygvcpZQ60r/n7tXPd XuSUOihYxIIEUimUv5Nunmy61uqrBzE2sbJdV/+A= Received: (qmail 76681 invoked by alias); 20 Jun 2016 17:05:14 -0000 Mailing-List: contact gcc-patches-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Id: List-Unsubscribe: List-Archive: List-Post: List-Help: Sender: gcc-patches-owner@gcc.gnu.org Delivered-To: mailing list gcc-patches@gcc.gnu.org Received: (qmail 76601 invoked by uid 89); 20 Jun 2016 17:05:13 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-0.6 required=5.0 tests=AWL, BAYES_00, KAM_LAZY_DOMAIN_SECURITY, KAM_STOCKGEN, NO_DNS_FOR_FROM, RCVD_IN_DNSWL_NONE, RP_MATCHES_RCVD autolearn=no version=3.3.2 spammy=symbol_ref, CONST, SYMBOL_REF, gen_rtx_SET X-HELO: mga04.intel.com Received: from mga04.intel.com (HELO mga04.intel.com) (192.55.52.120) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with ESMTP; Mon, 20 Jun 2016 17:05:03 +0000 Received: from fmsmga004.fm.intel.com ([10.253.24.48]) by fmsmga104.fm.intel.com with ESMTP; 20 Jun 2016 10:05:02 -0700 X-ExtLoop1: 1 Received: from gnu-6.sc.intel.com ([172.25.70.218]) by fmsmga004.fm.intel.com with ESMTP; 20 Jun 2016 10:05:02 -0700 Received: by gnu-6.sc.intel.com (Postfix, from userid 1000) id 0B0E22002AE; Mon, 20 Jun 2016 10:05:02 -0700 (PDT) Date: Mon, 20 Jun 2016 10:05:02 -0700 From: "H.J. Lu" To: gcc-patches@gcc.gnu.org Cc: Jakub Jelinek , Uros Bizjak Subject: [PATCH] x86-64: Load external function address via GOT slot Message-ID: <20160620170501.GA18281@intel.com> Reply-To: "H.J. Lu" MIME-Version: 1.0 Content-Disposition: inline User-Agent: Mutt/1.6.1 (2016-04-27) Hi, This patch implements the alternate code sequence recommended in https://groups.google.com/forum/#!topic/x86-64-abi/de5_KnLHxtI to load external function address via GOT slot with movq func@GOTPCREL(%rip), %rax so that linker won't create an PLT entry for extern function address. Tested on x86-64. OK for trunk? H.J. --- gcc/ PR target/67400 * config/i386/i386-protos.h (ix86_force_load_from_GOT_p): New. * config/i386/i386.c (ix86_force_load_from_GOT_p): New function. (ix86_legitimate_address_p): Allow UNSPEC_GOTPCREL if ix86_force_load_from_GOT_p returns true. (ix86_print_operand_address): Support UNSPEC_GOTPCREL if ix86_force_load_from_GOT_p returns true. (ix86_expand_move): Load the external function address via the GOT slot if ix86_force_load_from_GOT_p returns true. * config/i386/predicates.md (x86_64_immediate_operand): Return false if ix86_force_load_from_GOT_p returns true. gcc/testsuite/ PR target/67400 * gcc.target/i386/pr67400-1.c: New test. * gcc.target/i386/pr67400-2.c: Likewise. * gcc.target/i386/pr67400-3.c: Likewise. * gcc.target/i386/pr67400-4.c: Likewise. * gcc.target/i386/pr67400-5.c: Likewise. * gcc.target/i386/pr67400-6.c: Likewise. --- gcc/config/i386/i386-protos.h | 1 + gcc/config/i386/i386.c | 51 +++++++++++++++++++++++++++++++ gcc/config/i386/predicates.md | 4 +++ gcc/testsuite/gcc.target/i386/pr67400-1.c | 13 ++++++++ gcc/testsuite/gcc.target/i386/pr67400-2.c | 14 +++++++++ gcc/testsuite/gcc.target/i386/pr67400-3.c | 16 ++++++++++ gcc/testsuite/gcc.target/i386/pr67400-4.c | 13 ++++++++ gcc/testsuite/gcc.target/i386/pr67400-5.c | 11 +++++++ gcc/testsuite/gcc.target/i386/pr67400-6.c | 13 ++++++++ 9 files changed, 136 insertions(+) create mode 100644 gcc/testsuite/gcc.target/i386/pr67400-1.c create mode 100644 gcc/testsuite/gcc.target/i386/pr67400-2.c create mode 100644 gcc/testsuite/gcc.target/i386/pr67400-3.c create mode 100644 gcc/testsuite/gcc.target/i386/pr67400-4.c create mode 100644 gcc/testsuite/gcc.target/i386/pr67400-5.c create mode 100644 gcc/testsuite/gcc.target/i386/pr67400-6.c diff --git a/gcc/config/i386/i386-protos.h b/gcc/config/i386/i386-protos.h index 9fd14f6..8130161 100644 --- a/gcc/config/i386/i386-protos.h +++ b/gcc/config/i386/i386-protos.h @@ -70,6 +70,7 @@ extern bool ix86_expand_set_or_movmem (rtx, rtx, rtx, rtx, rtx, rtx, extern bool constant_address_p (rtx); extern bool legitimate_pic_operand_p (rtx); extern bool legitimate_pic_address_disp_p (rtx); +extern bool ix86_force_load_from_GOT_p (rtx); extern void print_reg (rtx, int, FILE*); extern void ix86_print_operand (FILE *, rtx, int); diff --git a/gcc/config/i386/i386.c b/gcc/config/i386/i386.c index 56a5b9c..c8c5081 100644 --- a/gcc/config/i386/i386.c +++ b/gcc/config/i386/i386.c @@ -15182,6 +15182,24 @@ ix86_legitimate_constant_p (machine_mode mode, rtx x) return true; } +/* True if operand X should be loaded from GOT. */ + +bool +ix86_force_load_from_GOT_p (rtx x) +{ + /* External function symbol should be loaded via the GOT slot for + -fno-plt. */ + return (!flag_plt + && !flag_pic + && ix86_cmodel != CM_LARGE + && TARGET_64BIT + && !TARGET_PECOFF + && !TARGET_MACHO + && GET_CODE (x) == SYMBOL_REF + && SYMBOL_REF_FUNCTION_P (x) + && !SYMBOL_REF_LOCAL_P (x)); +} + /* Determine if it's legal to put X into the constant pool. This is not possible for the address of thread-local symbols, which is checked above. */ @@ -15560,6 +15578,10 @@ ix86_legitimate_address_p (machine_mode, rtx addr, bool strict) return false; case UNSPEC_GOTPCREL: + gcc_assert (flag_pic + || ix86_force_load_from_GOT_p (XVECEXP (XEXP (disp, 0), 0, 0))); + goto is_legitimate_pic; + case UNSPEC_PCREL: gcc_assert (flag_pic); goto is_legitimate_pic; @@ -18130,6 +18152,12 @@ ix86_print_operand_address_as (FILE *file, rtx addr, } else if (flag_pic) output_pic_addr_const (file, disp, 0); + else if (GET_CODE (disp) == CONST + && GET_CODE (XEXP (disp, 0)) == UNSPEC + && (XINT (XEXP (disp, 0), 1) == UNSPEC_GOTPCREL + || XINT (XEXP (disp, 0), 1) == UNSPEC_GOT) + && ix86_force_load_from_GOT_p (XVECEXP (XEXP (disp, 0), 0, 0))) + output_pic_addr_const (file, XEXP (disp, 0), code); else output_addr_const (file, disp); } @@ -19448,6 +19476,29 @@ ix86_expand_move (machine_mode mode, rtx operands[]) op1 = convert_to_mode (mode, op1, 1); } } + } + else if (ix86_force_load_from_GOT_p (op1)) + { + /* Load the external function address via the GOT slot to + avoid PLT. */ + op1 = gen_rtx_UNSPEC (Pmode, gen_rtvec (1, op1), + (TARGET_64BIT + ? UNSPEC_GOTPCREL + : UNSPEC_GOT)); + op1 = gen_rtx_CONST (Pmode, op1); + op1 = gen_const_mem (Pmode, op1); + /* This symbol must be referenced via a load from the Global + Offset Table. */ + set_mem_alias_set (op1, ix86_GOT_alias_set ()); + op1 = convert_to_mode (mode, op1, 1); + op1 = force_reg (mode, op1); + emit_insn (gen_rtx_SET (op0, op1)); + /* Generate a CLOBBER so that there will be no REG_EQUAL note + on the last insn to prevent cse and fwprop from replacing + a GOT load with a constant. */ + rtx tmp = gen_reg_rtx (Pmode); + emit_clobber (tmp); + return; } else { diff --git a/gcc/config/i386/predicates.md b/gcc/config/i386/predicates.md index b3cf2a3..06a0002 100644 --- a/gcc/config/i386/predicates.md +++ b/gcc/config/i386/predicates.md @@ -149,6 +149,10 @@ (define_predicate "x86_64_immediate_operand" (match_code "const_int,symbol_ref,label_ref,const") { + /* Load the external function address via the GOT slot to avoid PLT. */ + if (ix86_force_load_from_GOT_p (op)) + return false; + if (!TARGET_64BIT) return immediate_operand (op, mode); diff --git a/gcc/testsuite/gcc.target/i386/pr67400-1.c b/gcc/testsuite/gcc.target/i386/pr67400-1.c new file mode 100644 index 0000000..a875b76 --- /dev/null +++ b/gcc/testsuite/gcc.target/i386/pr67400-1.c @@ -0,0 +1,13 @@ +/* { dg-do compile { target *-*-linux* } } */ +/* { dg-options "-O2 -fno-pic -fno-plt" } */ + +extern void bar (void); + +void * +foo (void) +{ + return &bar; +} + +/* { dg-final { scan-assembler "mov\(l|q\)\[ \t\]*bar@GOTPCREL" { target { ! ia32 } } } } */ +/* { dg-final { scan-assembler-not "mov\(l|q\)\[ \t\]*\\\$bar," { target { ! ia32 } } } } */ diff --git a/gcc/testsuite/gcc.target/i386/pr67400-2.c b/gcc/testsuite/gcc.target/i386/pr67400-2.c new file mode 100644 index 0000000..9f3f4bc --- /dev/null +++ b/gcc/testsuite/gcc.target/i386/pr67400-2.c @@ -0,0 +1,14 @@ +/* { dg-do compile { target *-*-linux* } } */ +/* { dg-options "-O2 -fno-pic -fno-plt" } */ + +extern void bar (void); +extern void *p; + +void +foo (void) +{ + p = &bar; +} + +/* { dg-final { scan-assembler "mov\(l|q\)\[ \t\]*bar@GOTPCREL" { target { ! ia32 } } } } */ +/* { dg-final { scan-assembler-not "mov\(l|q\)\[ \t\]*\\\$bar," { target { ! ia32 } } } } */ diff --git a/gcc/testsuite/gcc.target/i386/pr67400-3.c b/gcc/testsuite/gcc.target/i386/pr67400-3.c new file mode 100644 index 0000000..045974e --- /dev/null +++ b/gcc/testsuite/gcc.target/i386/pr67400-3.c @@ -0,0 +1,16 @@ +/* { dg-do compile { target *-*-linux* } } */ +/* { dg-options "-O2 -fno-pic -fno-plt" } */ + +static void +bar (void) +{ +} + +void * +foo (void) +{ + return &bar; +} + +/* { dg-final { scan-assembler "mov\(l|q\)\[ \t\]*\\\$bar," } } */ +/* { dg-final { scan-assembler-not "mov\(l|q\)\[ \t\]*bar@GOTPCREL" { target { ! ia32 } } } } */ diff --git a/gcc/testsuite/gcc.target/i386/pr67400-4.c b/gcc/testsuite/gcc.target/i386/pr67400-4.c new file mode 100644 index 0000000..fd373db --- /dev/null +++ b/gcc/testsuite/gcc.target/i386/pr67400-4.c @@ -0,0 +1,13 @@ +/* { dg-do compile { target *-*-linux* } } */ +/* { dg-options "-O2 -fno-pic -fno-plt" } */ + +extern void bar (void) __attribute__ ((visibility ("hidden"))); + +void * +foo (void) +{ + return &bar; +} + +/* { dg-final { scan-assembler "mov\(l|q\)\[ \t\]*\\\$bar," } } */ +/* { dg-final { scan-assembler-not "mov\(l|q\)\[ \t\]*bar@GOTPCREL" { target { ! ia32 } } } } */ diff --git a/gcc/testsuite/gcc.target/i386/pr67400-5.c b/gcc/testsuite/gcc.target/i386/pr67400-5.c new file mode 100644 index 0000000..9bb98dc --- /dev/null +++ b/gcc/testsuite/gcc.target/i386/pr67400-5.c @@ -0,0 +1,11 @@ +/* { dg-do compile { target *-*-linux* } } */ +/* { dg-options "-O2 -fno-pic -fno-plt" } */ + +extern void foo (void); +extern void bar (int, int, int, int, int, int, void *); + +void +x (void) +{ + bar (1, 2, 3, 4, 5, 6, foo); +} diff --git a/gcc/testsuite/gcc.target/i386/pr67400-6.c b/gcc/testsuite/gcc.target/i386/pr67400-6.c new file mode 100644 index 0000000..b84196a --- /dev/null +++ b/gcc/testsuite/gcc.target/i386/pr67400-6.c @@ -0,0 +1,13 @@ +/* { dg-do compile { target *-*-linux* } } */ +/* { dg-options "-O2 -fno-pic -fno-plt" } */ + +extern int bar (void); + +int +check (void *p) +{ + return p != &bar; +} + +/* { dg-final { scan-assembler "cmp\(l|q\)\[ \t\]*.*bar@GOTPCREL" { target { ! ia32 } } } } */ +/* { dg-final { scan-assembler-not "mov\(l|q\)\[ \t\]*\\\$bar," { target { ! ia32 } } } } */