From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-qv1-xf29.google.com (mail-qv1-xf29.google.com [IPv6:2607:f8b0:4864:20::f29]) by sourceware.org (Postfix) with ESMTPS id BF8843858D39 for ; Fri, 1 Jul 2022 07:51:58 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org BF8843858D39 Received: by mail-qv1-xf29.google.com with SMTP id i17so3337773qvo.13 for ; Fri, 01 Jul 2022 00:51:58 -0700 (PDT) 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=oyripwVa82wh2haGEHy6v6cMOyIONbNstvx+thg/gHY=; b=x5GwReN45fBbSUhECslkB8pXQaPooCRerci0IqOrHpG6ydCIo9q2e0Sj3mYOBNn+8Z N1iV0J6AGD1DlOlZOcaxI+S6p7CBG7vUwlu1+Q1jPNbEuH+NfyeKNC16gT9UaXlG25TN 42i9IChn784aH62DHsV3qQDOzGaRdePWWmbPZ7uz1l9RXfkCeaKKt/ADnx0GbEvNuyRa vsc1WIKdvo8NWn1BDBfjWC/fNgI/NZEoaTyHyVxmYYBc3SZYizauX8rR4L3uDVgQ6TNI cPOegugcCfUxlhtxnYVePcqeLaMyl/1YYOI1w2Ib5RpCwZ0jfB7OU98MR+vqRiI+aeaV 9MoA== X-Gm-Message-State: AJIora8LRjF1lKxRzubMqUqPLGcHEIovUWnfIPsRSjvsWzy7qNMQxNwb oQuPA+8jVVyv5+ZlxUVzvMgPECmJlyk4R2jm4N4= X-Google-Smtp-Source: AGRyM1udppOVsuiMtJ+fMpPnn70iD/RCQMXy3pZEiw4Dk9evY2aVlV1jj0fqHm2Lc8yDR6Oe4D0bvWkJUmSQtNPBG+8= X-Received: by 2002:a05:622a:4cd:b0:31d:26a1:2536 with SMTP id q13-20020a05622a04cd00b0031d26a12536mr10555164qtx.626.1656661918014; Fri, 01 Jul 2022 00:51:58 -0700 (PDT) MIME-Version: 1.0 References: <20220620154421.2411443-1-hjl.tools@gmail.com> In-Reply-To: <20220620154421.2411443-1-hjl.tools@gmail.com> From: Richard Biener Date: Fri, 1 Jul 2022 09:51:46 +0200 Message-ID: Subject: Re: [PATCH v2] Enable __memcmpeq after seeing __memcmpeq prototype To: "H.J. Lu" Cc: GCC Patches Content-Type: text/plain; charset="UTF-8" X-Spam-Status: No, score=-7.9 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, 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 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: Fri, 01 Jul 2022 07:52:01 -0000 On Mon, Jun 20, 2022 at 5:44 PM H.J. Lu wrote: > > extern int __memcmpeq (const void *, const void *, size_t); > > was was added to GLIBC 2.35. Expand BUILT_IN_MEMCMP_EQ to __memcmpeq > after seeing __memcmpeq prototype Can you instead use builtin_decl_declared_p (), see how frontends set that via set_builtin_decl_declared_p? > gcc/ > > * builtins.cc (have_memcmpeq_prototype): New. > (expand_builtin): Issue an error for BUILT_IN___MEMCMPEQ if > there is no __memcmpeq prototype. Expand BUILT_IN_MEMCMP_EQ > to BUILT_IN___MEMCMP_EQ if there is __memcmpeq prototype. > * builtins.def (BUILT_IN___MEMCMPEQ): New. > * builtins.h (have_memcmpeq_prototype): New. > > gcc/c/ > > * c-decl.cc (diagnose_mismatched_decls): Set > have_memcmpeq_prototype to true after seeing __memcmpeq prototype. > > gcc/cp/ > > * decl.cc (duplicate_decls): Set have_memcmpeq_prototype to true > after seeing __memcmpeq prototype. > > gcc/testsuite/ > > * c-c++-common/memcmpeq-1.c: New test. > * c-c++-common/memcmpeq-2.c: Likewise. > * c-c++-common/memcmpeq-3.c: Likewise. > * c-c++-common/memcmpeq-4.c: Likewise. > * c-c++-common/memcmpeq-5.c: Likewise. > * c-c++-common/memcmpeq-6.c: Likewise. > * c-c++-common/memcmpeq.h: Likewise. > --- > gcc/builtins.cc | 17 ++++++++++++++++- > gcc/builtins.def | 3 +++ > gcc/builtins.h | 3 +++ > gcc/c/c-decl.cc | 25 ++++++++++++++++++------- > gcc/cp/decl.cc | 5 +++++ > gcc/testsuite/c-c++-common/memcmpeq-1.c | 11 +++++++++++ > gcc/testsuite/c-c++-common/memcmpeq-2.c | 11 +++++++++++ > gcc/testsuite/c-c++-common/memcmpeq-3.c | 11 +++++++++++ > gcc/testsuite/c-c++-common/memcmpeq-4.c | 11 +++++++++++ > gcc/testsuite/c-c++-common/memcmpeq-5.c | 11 +++++++++++ > gcc/testsuite/c-c++-common/memcmpeq-6.c | 10 ++++++++++ > gcc/testsuite/c-c++-common/memcmpeq.h | 11 +++++++++++ > 12 files changed, 121 insertions(+), 8 deletions(-) > create mode 100644 gcc/testsuite/c-c++-common/memcmpeq-1.c > create mode 100644 gcc/testsuite/c-c++-common/memcmpeq-2.c > create mode 100644 gcc/testsuite/c-c++-common/memcmpeq-3.c > create mode 100644 gcc/testsuite/c-c++-common/memcmpeq-4.c > create mode 100644 gcc/testsuite/c-c++-common/memcmpeq-5.c > create mode 100644 gcc/testsuite/c-c++-common/memcmpeq-6.c > create mode 100644 gcc/testsuite/c-c++-common/memcmpeq.h > > diff --git a/gcc/builtins.cc b/gcc/builtins.cc > index 971b18c3745..96e283e5847 100644 > --- a/gcc/builtins.cc > +++ b/gcc/builtins.cc > @@ -104,6 +104,9 @@ builtin_info_type builtin_info[(int)END_BUILTINS]; > /* Non-zero if __builtin_constant_p should be folded right away. */ > bool force_folding_builtin_constant_p; > > +/* True if there is a __memcmpeq prototype. */ > +bool have_memcmpeq_prototype; > + > static int target_char_cast (tree, char *); > static int apply_args_size (void); > static int apply_result_size (void); > @@ -7392,6 +7395,15 @@ expand_builtin (tree exp, rtx target, rtx subtarget, machine_mode mode, > return target; > break; > > + case BUILT_IN___MEMCMPEQ: > + if (!have_memcmpeq_prototype) > + { > + error ("use of %<__builtin___memcmpeq ()%> without " > + "%<__memcmpeq%> prototype"); > + return const0_rtx; > + } > + break; > + > /* Expand it as BUILT_IN_MEMCMP_EQ first. If not successful, change it > back to a BUILT_IN_STRCMP. Remember to delete the 3rd parameter > when changing it to a strcmp call. */ > @@ -7445,7 +7457,10 @@ expand_builtin (tree exp, rtx target, rtx subtarget, machine_mode mode, > return target; > if (fcode == BUILT_IN_MEMCMP_EQ) > { > - tree newdecl = builtin_decl_explicit (BUILT_IN_MEMCMP); > + tree newdecl = builtin_decl_explicit > + (have_memcmpeq_prototype > + ? BUILT_IN___MEMCMPEQ > + : BUILT_IN_MEMCMP); > TREE_OPERAND (exp, 1) = build_fold_addr_expr (newdecl); > } > break; > diff --git a/gcc/builtins.def b/gcc/builtins.def > index 005976f34e9..95642c6acdf 100644 > --- a/gcc/builtins.def > +++ b/gcc/builtins.def > @@ -965,6 +965,9 @@ DEF_BUILTIN_STUB (BUILT_IN_ALLOCA_WITH_ALIGN_AND_MAX, "__builtin_alloca_with_ali > equality with zero. */ > DEF_BUILTIN_STUB (BUILT_IN_MEMCMP_EQ, "__builtin_memcmp_eq") > > +/* Similar to BUILT_IN_MEMCMP_EQ, but is mapped to __memcmpeq. */ > +DEF_EXT_LIB_BUILTIN (BUILT_IN___MEMCMPEQ, "__memcmpeq", BT_FN_INT_CONST_PTR_CONST_PTR_SIZE, ATTR_PURE_NOTHROW_NONNULL_LEAF) > + > /* An internal version of strcmp/strncmp, used when the result is only > tested for equality with zero. */ > DEF_BUILTIN_STUB (BUILT_IN_STRCMP_EQ, "__builtin_strcmp_eq") > diff --git a/gcc/builtins.h b/gcc/builtins.h > index 5ad830c9fbf..e3e80b33f6d 100644 > --- a/gcc/builtins.h > +++ b/gcc/builtins.h > @@ -49,6 +49,9 @@ extern struct target_builtins *this_target_builtins; > /* Non-zero if __builtin_constant_p should be folded right away. */ > extern bool force_folding_builtin_constant_p; > > +/* True if there is a __memcmpeq prototype. */ > +extern bool have_memcmpeq_prototype; > + > extern bool called_as_built_in (tree); > extern bool get_object_alignment_1 (tree, unsigned int *, > unsigned HOST_WIDE_INT *); > diff --git a/gcc/c/c-decl.cc b/gcc/c/c-decl.cc > index ae8990c138f..cc66d254017 100644 > --- a/gcc/c/c-decl.cc > +++ b/gcc/c/c-decl.cc > @@ -2140,13 +2140,24 @@ diagnose_mismatched_decls (tree newdecl, tree olddecl, > return false; > } > } > - /* Warn about enum/integer type mismatches. They are compatible types > - (C2X 6.7.2.2/5), but may pose portability problems. */ > - else if (enum_and_int_p && TREE_CODE (newdecl) != TYPE_DECL) > - warned = warning_at (DECL_SOURCE_LOCATION (newdecl), > - OPT_Wenum_int_mismatch, > - "conflicting types for %q+D due to enum/integer " > - "mismatch; have %qT", newdecl, newtype); > + else > + { > + /* Enable __memcmpeq after seeing its prototype. */ > + if (TREE_CODE (olddecl) == FUNCTION_DECL > + && fndecl_built_in_p (olddecl, BUILT_IN_NORMAL) > + && !C_DECL_DECLARED_BUILTIN (olddecl) > + && DECL_FUNCTION_CODE (olddecl) == BUILT_IN___MEMCMPEQ) > + have_memcmpeq_prototype = true; > + > + /* Warn about enum/integer type mismatches. They are compatible > + types (C2X 6.7.2.2/5), but may pose portability problems. */ > + if (enum_and_int_p && TREE_CODE (newdecl) != TYPE_DECL) > + warned = warning_at (DECL_SOURCE_LOCATION (newdecl), > + OPT_Wenum_int_mismatch, > + "conflicting types for %q+D due to " > + "enum/integer mismatch; have %qT", > + newdecl, newtype); > + } > > /* Redeclaration of a type is a constraint violation (6.7.2.3p1), > but silently ignore the redeclaration if either is in a system > diff --git a/gcc/cp/decl.cc b/gcc/cp/decl.cc > index 29fc36534c2..051e83e3540 100644 > --- a/gcc/cp/decl.cc > +++ b/gcc/cp/decl.cc > @@ -1719,6 +1719,11 @@ duplicate_decls (tree newdecl, tree olddecl, bool hiding, bool was_hidden) > > type = cp_build_type_attribute_variant (type, attribs); > TREE_TYPE (newdecl) = TREE_TYPE (olddecl) = type; > + > + /* Enable __memcmpeq after seeing its prototype. */ > + if (fndecl_built_in_p (olddecl, BUILT_IN_NORMAL) > + && DECL_FUNCTION_CODE (olddecl) == BUILT_IN___MEMCMPEQ) > + have_memcmpeq_prototype = true; > } > > /* If a function is explicitly declared "throw ()", propagate that to > diff --git a/gcc/testsuite/c-c++-common/memcmpeq-1.c b/gcc/testsuite/c-c++-common/memcmpeq-1.c > new file mode 100644 > index 00000000000..14622f0d765 > --- /dev/null > +++ b/gcc/testsuite/c-c++-common/memcmpeq-1.c > @@ -0,0 +1,11 @@ > +/* { dg-do compile } */ > +/* { dg-options "-O2" } */ > +/* { dg-final { scan-assembler "__memcmpeq" } } */ > + > +#include "memcmpeq.h" > + > +int > +foo (const char *s1, const char *s2, size_t len) > +{ > + return __builtin_memcmp (s1, s2, len) != 0; > +} > diff --git a/gcc/testsuite/c-c++-common/memcmpeq-2.c b/gcc/testsuite/c-c++-common/memcmpeq-2.c > new file mode 100644 > index 00000000000..f57f279f173 > --- /dev/null > +++ b/gcc/testsuite/c-c++-common/memcmpeq-2.c > @@ -0,0 +1,11 @@ > +/* { dg-do compile } */ > +/* { dg-options "-O2" } */ > +/* { dg-final { scan-assembler "__memcmpeq" } } */ > + > +#include "memcmpeq.h" > + > +int > +foo (const char *s1, const char *s2, size_t len) > +{ > + return memcmp (s1, s2, len) == 0; > +} > diff --git a/gcc/testsuite/c-c++-common/memcmpeq-3.c b/gcc/testsuite/c-c++-common/memcmpeq-3.c > new file mode 100644 > index 00000000000..2ca2131c23a > --- /dev/null > +++ b/gcc/testsuite/c-c++-common/memcmpeq-3.c > @@ -0,0 +1,11 @@ > +/* { dg-do compile } */ > +/* { dg-options "-O2" } */ > +/* { dg-final { scan-assembler-not "__memcmpeq" } } */ > + > +#include "memcmpeq.h" > + > +int > +foo (const char *s1, const char *s2, size_t len) > +{ > + return memcmp (s1, s2, len); > +} > diff --git a/gcc/testsuite/c-c++-common/memcmpeq-4.c b/gcc/testsuite/c-c++-common/memcmpeq-4.c > new file mode 100644 > index 00000000000..d59765894e7 > --- /dev/null > +++ b/gcc/testsuite/c-c++-common/memcmpeq-4.c > @@ -0,0 +1,11 @@ > +/* { dg-do compile } */ > +/* { dg-options "-O2" } */ > +/* { dg-final { scan-assembler-not "__memcmpeq" } } */ > + > +#include > + > +int > +foo (const char *s1, const char *s2, size_t len) > +{ > + return __builtin_memcmp_eq (s1, s2, len) != 0; > +} > diff --git a/gcc/testsuite/c-c++-common/memcmpeq-5.c b/gcc/testsuite/c-c++-common/memcmpeq-5.c > new file mode 100644 > index 00000000000..cb12358cd87 > --- /dev/null > +++ b/gcc/testsuite/c-c++-common/memcmpeq-5.c > @@ -0,0 +1,11 @@ > +/* { dg-do compile } */ > +/* { dg-options "-O2" } */ > +/* { dg-final { scan-assembler "__memcmpeq" } } */ > + > +#include "memcmpeq.h" > + > +int > +foo (const char *s1, const char *s2, size_t len) > +{ > + return __builtin___memcmpeq (s1, s2, len) != 0; > +} > diff --git a/gcc/testsuite/c-c++-common/memcmpeq-6.c b/gcc/testsuite/c-c++-common/memcmpeq-6.c > new file mode 100644 > index 00000000000..8f983c05a44 > --- /dev/null > +++ b/gcc/testsuite/c-c++-common/memcmpeq-6.c > @@ -0,0 +1,10 @@ > +/* { dg-do compile } */ > +/* { dg-options "-O2" } */ > + > +#include > + > +int > +foo (const char *s1, const char *s2, size_t len) > +{ > + return __builtin___memcmpeq (s1, s2, len) != 0; /* { dg-error "__builtin___memcmpeq" } */ > +} > diff --git a/gcc/testsuite/c-c++-common/memcmpeq.h b/gcc/testsuite/c-c++-common/memcmpeq.h > new file mode 100644 > index 00000000000..3f731a4806b > --- /dev/null > +++ b/gcc/testsuite/c-c++-common/memcmpeq.h > @@ -0,0 +1,11 @@ > +#include > + > +#if __cplusplus > +extern "C" { > +#endif > + > +extern int __memcmpeq (const void *, const void *, size_t); > + > +#if __cplusplus > +} > +#endif > -- > 2.36.1 >