From: "H.J. Lu" <hjl.tools@gmail.com>
To: gcc-patches@gcc.gnu.org
Subject: [PATCH v2] Enable __memcmpeq after seeing __memcmpeq prototype
Date: Mon, 20 Jun 2022 08:44:21 -0700 [thread overview]
Message-ID: <20220620154421.2411443-1-hjl.tools@gmail.com> (raw)
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
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 <stddef.h>
+
+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 <stddef.h>
+
+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 <string.h>
+
+#if __cplusplus
+extern "C" {
+#endif
+
+extern int __memcmpeq (const void *, const void *, size_t);
+
+#if __cplusplus
+}
+#endif
--
2.36.1
next reply other threads:[~2022-06-20 15:44 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-06-20 15:44 H.J. Lu [this message]
2022-07-01 7:51 ` Richard Biener
2022-07-05 16:28 ` H.J. Lu
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