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-rw-r--r--sysdeps/i386/multiarch/strlen.c58
1 files changed, 58 insertions, 0 deletions
diff --git a/sysdeps/i386/multiarch/strlen.c b/sysdeps/i386/multiarch/strlen.c
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index 0000000000..9e376a3cc3
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+++ b/sysdeps/i386/multiarch/strlen.c
@@ -0,0 +1,58 @@
+/* Multiple versions of strlen.
+   All versions must be listed in ifunc-impl-list.c.
+   Copyright (C) 2015 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+/* Define multiple versions only for the definition in libc.  */
+#if defined SHARED && IS_IN (libc)
+/* Redefine strlen so that the compiler won't complain about the type
+   mismatch with the IFUNC selector in strong_alias, below.  */
+# undef strlen
+# define strlen __redirect_strlen
+# include <string.h>
+# undef strlen
+
+# include <init-arch.h>
+
+extern __typeof (__redirect_strlen) __strlen_i386 attribute_hidden;
+extern __typeof (__redirect_strlen) __strlen_i586 attribute_hidden;
+extern __typeof (__redirect_strlen) __strlen_sse2 attribute_hidden;
+extern __typeof (__redirect_strlen) __strlen_sse2_bsf attribute_hidden;
+
+/* Avoid DWARF definition DIE on ifunc symbol so that GDB can handle
+   ifunc symbol properly.  */
+extern __typeof (__redirect_strlen) strlen;
+extern void *strlen_ifunc (void) __asm__ ("strlen");
+
+void *
+strlen_ifunc (void)
+{
+  if (HAS_CPU_FEATURE (SSE2))
+    {
+      if (HAS_ARCH_FEATURE (Slow_BSF))
+	return __strlen_sse2;
+      else
+	return __strlen_sse2_bsf;
+    }
+
+  if (USE_I586)
+    return __strlen_i586;
+  else
+    return __strlen_i386;
+}
+__asm__ (".type strlen, %gnu_indirect_function");
+#endif