From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 16868 invoked by alias); 18 May 2018 14:48:58 -0000 Mailing-List: contact gcc-patches-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Id: List-Archive: List-Post: List-Help: Sender: gcc-patches-owner@gcc.gnu.org Received: (qmail 16854 invoked by uid 89); 18 May 2018 14:48:57 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-26.9 required=5.0 tests=BAYES_00,GIT_PATCH_0,GIT_PATCH_1,GIT_PATCH_2,GIT_PATCH_3,SPF_PASS autolearn=ham version=3.3.2 spammy=mcmodel, UD:pr84882.c, UD:aarch64-common.c, mstrictalign X-HELO: foss.arm.com Received: from foss.arm.com (HELO foss.arm.com) (217.140.101.70) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with ESMTP; Fri, 18 May 2018 14:48:55 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 315CC1596; Fri, 18 May 2018 07:48:54 -0700 (PDT) Received: from e120077-lin.cambridge.arm.com (e120077-lin.cambridge.arm.com [10.2.206.221]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 08B193F24A; Fri, 18 May 2018 07:48:52 -0700 (PDT) Subject: Re: [PATCH][AARCH64][PR target/84882] Add mno-strict-align To: Sudakshina Das , "gcc-patches@gcc.gnu.org" Cc: James Greenhalgh , Marcus Shawcroft , nd References: <8a3653bb-be32-d53f-7611-a16eac233483@arm.com> From: "Richard Earnshaw (lists)" Openpgp: preference=signencrypt Message-ID: Date: Fri, 18 May 2018 14:51:00 -0000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.7.0 MIME-Version: 1.0 In-Reply-To: <8a3653bb-be32-d53f-7611-a16eac233483@arm.com> Content-Type: text/plain; charset=iso-8859-15 Content-Transfer-Encoding: 8bit X-SW-Source: 2018-05/txt/msg00927.txt.bz2 On 27/03/18 13:58, Sudakshina Das wrote: > Hi > > This patch adds the no variant to -mstrict-align and the corresponding > function attribute. To enable the function attribute, I have modified > aarch64_can_inline_p () to allow checks even when the callee function > has no attribute. The need for this is shown by the new test > target_attr_18.c. > > Testing: Bootstrapped, regtested and added new tests that are copies > of earlier tests checking -mstrict-align with opposite scan directives. > > Is this ok for trunk? > > Sudi > > > *** gcc/ChangeLog *** > > 2018-03-27  Sudakshina Das  > >     * common/config/aarch64/aarch64-common.c (aarch64_handle_option): >     Check val before adding MASK_STRICT_ALIGN to opts->x_target_flags. >     * config/aarch64/aarch64.opt (mstrict-align): Remove RejectNegative. >     * config/aarch64/aarch64.c (aarch64_attributes): Mark allow_neg >     as true for strict-align. >     (aarch64_can_inline_p): Perform checks even when callee has no >     attributes to check for strict alignment. >     * doc/extend.texi (AArch64 Function Attributes): Document >     no-strict-align. >     * doc/invoke.texi: (AArch64 Options): Likewise. > > *** gcc/testsuite/ChangeLog *** > > 2018-03-27  Sudakshina Das  > >     * gcc.target/aarch64/pr84882.c: New test. >     * gcc.target/aarch64/target_attr_18.c: Likewise. > > strict-align.diff > > > diff --git a/gcc/common/config/aarch64/aarch64-common.c b/gcc/common/config/aarch64/aarch64-common.c > index 7fd9305..d5655a0 100644 > --- a/gcc/common/config/aarch64/aarch64-common.c > +++ b/gcc/common/config/aarch64/aarch64-common.c > @@ -97,7 +97,10 @@ aarch64_handle_option (struct gcc_options *opts, > return true; > > case OPT_mstrict_align: > - opts->x_target_flags |= MASK_STRICT_ALIGN; > + if (val) > + opts->x_target_flags |= MASK_STRICT_ALIGN; > + else > + opts->x_target_flags &= ~MASK_STRICT_ALIGN; > return true; > > case OPT_momit_leaf_frame_pointer: > diff --git a/gcc/config/aarch64/aarch64.c b/gcc/config/aarch64/aarch64.c > index 4b5183b..4f35a6c 100644 > --- a/gcc/config/aarch64/aarch64.c > +++ b/gcc/config/aarch64/aarch64.c > @@ -11277,7 +11277,7 @@ static const struct aarch64_attribute_info aarch64_attributes[] = > { "fix-cortex-a53-843419", aarch64_attr_bool, true, NULL, > OPT_mfix_cortex_a53_843419 }, > { "cmodel", aarch64_attr_enum, false, NULL, OPT_mcmodel_ }, > - { "strict-align", aarch64_attr_mask, false, NULL, OPT_mstrict_align }, > + { "strict-align", aarch64_attr_mask, true, NULL, OPT_mstrict_align }, > { "omit-leaf-frame-pointer", aarch64_attr_bool, true, NULL, > OPT_momit_leaf_frame_pointer }, > { "tls-dialect", aarch64_attr_enum, false, NULL, OPT_mtls_dialect_ }, > @@ -11640,16 +11640,13 @@ aarch64_can_inline_p (tree caller, tree callee) > tree caller_tree = DECL_FUNCTION_SPECIFIC_TARGET (caller); > tree callee_tree = DECL_FUNCTION_SPECIFIC_TARGET (callee); > > - /* If callee has no option attributes, then it is ok to inline. */ > - if (!callee_tree) > - return true; I think it's still useful to spot the case where both callee_tree and caller_tree are NULL. In that case both options will pick up target_option_default_node and will always be compatible; so you can short-circuit that case, which is the most likely scenario. > - > struct cl_target_option *caller_opts > = TREE_TARGET_OPTION (caller_tree ? caller_tree > : target_option_default_node); > > - struct cl_target_option *callee_opts = TREE_TARGET_OPTION (callee_tree); > - > + struct cl_target_option *callee_opts > + = TREE_TARGET_OPTION (callee_tree ? callee_tree > + : target_option_default_node); > > /* Callee's ISA flags should be a subset of the caller's. */ > if ((caller_opts->x_aarch64_isa_flags & callee_opts->x_aarch64_isa_flags) > diff --git a/gcc/config/aarch64/aarch64.opt b/gcc/config/aarch64/aarch64.opt > index 52eaf8c..1426b45 100644 > --- a/gcc/config/aarch64/aarch64.opt > +++ b/gcc/config/aarch64/aarch64.opt > @@ -85,7 +85,7 @@ Target RejectNegative Joined Enum(cmodel) Var(aarch64_cmodel_var) Init(AARCH64_C > Specify the code model. > > mstrict-align > -Target Report RejectNegative Mask(STRICT_ALIGN) Save > +Target Report Mask(STRICT_ALIGN) Save > Don't assume that unaligned accesses are handled by the system. > > momit-leaf-frame-pointer > diff --git a/gcc/doc/extend.texi b/gcc/doc/extend.texi > index 93a0ebc..dcda216 100644 > --- a/gcc/doc/extend.texi > +++ b/gcc/doc/extend.texi > @@ -3605,8 +3605,10 @@ for the command line option @option{-mcmodel=}. > @item strict-align Other targets add an @itemx for the no-variant. > @cindex @code{strict-align} function attribute, AArch64 > Indicates that the compiler should not assume that unaligned memory references > -are handled by the system. The behavior is the same as for the command-line > -option @option{-mstrict-align}. > +are handled by the system. To allow the compiler to assume that aligned memory > +references are handled by the system, the inverse attribute > +@code{no-strict-align} can be specified. The behavior is the same as for the > +command-line option @option{-mstrict-align} and @option{-mno-strict-align}. You've two options now, so 'options'. > > @item omit-leaf-frame-pointer > @cindex @code{omit-leaf-frame-pointer} function attribute, AArch64 > diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi > index feacd56..0574d21 100644 > --- a/gcc/doc/invoke.texi > +++ b/gcc/doc/invoke.texi > @@ -596,7 +596,7 @@ Objective-C and Objective-C++ Dialects}. > @gccoptlist{-mabi=@var{name} -mbig-endian -mlittle-endian @gol > -mgeneral-regs-only @gol > -mcmodel=tiny -mcmodel=small -mcmodel=large @gol > --mstrict-align @gol > +-mstrict-align -mno-strict-align @gol > -momit-leaf-frame-pointer @gol > -mtls-dialect=desc -mtls-dialect=traditional @gol > -mtls-size=@var{size} @gol > @@ -14601,9 +14601,11 @@ Generate code for the large code model. This makes no assumptions about > addresses and sizes of sections. Programs can be statically linked only. > > @item -mstrict-align > +@itemx -mno-strict-align > @opindex mstrict-align > -Avoid generating memory accesses that may not be aligned on a natural object > -boundary as described in the architecture specification. > +@opindex mno-strict-align > +Avoid or allow generating memory accesses that may not be aligned on a natural > +object boundary as described in the architecture specification. > > @item -momit-leaf-frame-pointer > @itemx -mno-omit-leaf-frame-pointer > diff --git a/gcc/testsuite/gcc.target/aarch64/pr84882.c b/gcc/testsuite/gcc.target/aarch64/pr84882.c > new file mode 100644 > index 0000000..ffc7d55 > --- /dev/null > +++ b/gcc/testsuite/gcc.target/aarch64/pr84882.c > @@ -0,0 +1,33 @@ > +/* This is a copy of pr71727.c with scanning reversed. */ > +/* { dg-do compile } */ > +/* { dg-options "-mstrict-align -O3 -mno-strict-align" } */ > + > +struct test_struct_s > +{ > + long a; > + long b; > + long c; > + long d; > + unsigned long e; > +}; > + > + > +char _a; > +struct test_struct_s xarray[128]; > + > +void > +_start (void) > +{ > + struct test_struct_s *new_entry; > + > + new_entry = &xarray[0]; > + new_entry->a = 1; > + new_entry->b = 2; > + new_entry->c = 3; > + new_entry->d = 4; > + new_entry->e = 5; > + > + return; > +} > + > +/* { dg-final { scan-assembler "add\tx[0-9]+, x[0-9]+, :" {target lp64} } } */ > diff --git a/gcc/testsuite/gcc.target/aarch64/target_attr_18.c b/gcc/testsuite/gcc.target/aarch64/target_attr_18.c > new file mode 100644 > index 0000000..33b1d44 > --- /dev/null > +++ b/gcc/testsuite/gcc.target/aarch64/target_attr_18.c > @@ -0,0 +1,21 @@ > +/* This is a copy of target_attr_6.c to instead check no-strict-align. */ > +/* { dg-do compile } */ > +/* { dg-options "-O2 -save-temps -mstrict-align" } */ > + > +/* Inlining strict-align functions into non-strict align > + functions is not allowed. */ > + > +int > +bar (int a) > +{ > + return a - 6; > +} > + > +__attribute__ ((target ("no-strict-align"))) > +int > +bam (int a) > +{ > + return a - bar (a); > +} > + > +/* { dg-final { scan-assembler "bl.*bar" } } */ > OK with those changes. As Kyrill said, don't forget the PR number in the changelog. R.