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authorH.J. Lu <hjl.tools@gmail.com>2017-06-15 08:56:48 -0700
committerH.J. Lu <hjl.tools@gmail.com>2017-06-15 08:56:59 -0700
commit9ed0aa15d316fb30e056d3a2e8f3361460c67e78 (patch)
tree202758d5e45fbb9093bfbb3fbf442f25417f9da1 /sysdeps/x86_64/multiarch/strcat-sse2.S
parentb91a52d0d77d8c532d2cfa13be0db92faa397c4b (diff)
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x86-64: Implement strcat family IFUNC selectors in C
Implement strcat family IFUNC selectors in C.

All internal calls within libc.so can use IFUNC on x86-64 since unlike
x86, x86-64 supports PC-relative addressing to access the GOT entry so
that it can call via PLT without using an extra register.  For libc.a,
we can't use IFUNC for functions which are called before IFUNC has been
initialized.  Use IFUNC internally reduces the icache footprint since
libc.so and other codes in the process use the same implementations.
This patch uses IFUNC for strcat family functions within libc.

	* sysdeps/x86_64/multiarch/Makefile (sysdep_routines): Add
	strcat-sse2.
	* sysdeps/x86_64/multiarch/strcat-sse2.S: New file.
	* sysdeps/x86_64/multiarch/strcat.c: Likewise.
	* sysdeps/x86_64/multiarch/strncat.c: Likewise.
	* sysdeps/x86_64/multiarch/strcat.S: Removed.
	* sysdeps/x86_64/multiarch/strncat.S: Likewise.
Diffstat (limited to 'sysdeps/x86_64/multiarch/strcat-sse2.S')
-rw-r--r--sysdeps/x86_64/multiarch/strcat-sse2.S28
1 files changed, 28 insertions, 0 deletions
diff --git a/sysdeps/x86_64/multiarch/strcat-sse2.S b/sysdeps/x86_64/multiarch/strcat-sse2.S
new file mode 100644
index 0000000000..565ba30fc2
--- /dev/null
+++ b/sysdeps/x86_64/multiarch/strcat-sse2.S
@@ -0,0 +1,28 @@
+/* strcat optimized with SSE2.
+   Copyright (C) 2017 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/>.  */
+
+#if IS_IN (libc)
+
+# include <sysdep.h>
+# define strcat __strcat_sse2
+
+# undef libc_hidden_builtin_def
+# define libc_hidden_builtin_def(strcat)
+#endif
+
+#include <sysdeps/x86_64/strcat.S>