2009-06-05 18:32:00 +00:00
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/* strlen(str) -- determine the length of the string STR.
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2011-08-04 18:59:25 +00:00
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Copyright (C) 2009, 2010, 2011 Free Software Foundation, Inc.
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2009-06-05 18:32:00 +00:00
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Contributed by Ulrich Drepper <drepper@redhat.com>.
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This file is part of the GNU C Library.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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2012-02-09 23:18:22 +00:00
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License along with the GNU C Library; if not, see
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<http://www.gnu.org/licenses/>. */
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2009-06-05 18:32:00 +00:00
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#include <sysdep.h>
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2009-12-13 17:47:02 +00:00
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#include <init-arch.h>
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2009-06-05 18:32:00 +00:00
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/* Define multiple versions only for the definition in libc and for
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the DSO. In static binaries we need strlen before the initialization
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happened. */
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#if defined SHARED && !defined NOT_IN_libc
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.text
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ENTRY(strlen)
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.type strlen, @gnu_indirect_function
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cmpl $0, __cpu_features+KIND_OFFSET(%rip)
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jne 1f
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call __init_cpu_features
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2011-07-19 21:11:54 +00:00
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1: leaq __strlen_sse2_pminub(%rip), %rax
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testl $bit_Prefer_PMINUB_for_stringop, __cpu_features+FEATURE_OFFSET+index_Prefer_PMINUB_for_stringop(%rip)
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jnz 2f
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leaq __strlen_sse2(%rip), %rax
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2009-12-13 17:47:02 +00:00
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testl $bit_SSE4_2, __cpu_features+CPUID_OFFSET+index_SSE4_2(%rip)
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2009-06-05 18:32:00 +00:00
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jz 2f
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leaq __strlen_sse42(%rip), %rax
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2010-01-13 15:51:48 +00:00
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ret
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2010-08-27 05:09:34 +00:00
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2: testl $bit_Slow_BSF, __cpu_features+FEATURE_OFFSET+index_Slow_BSF(%rip)
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jz 3f
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2011-10-23 18:56:04 +00:00
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leaq __strlen_sse2_no_bsf(%rip), %rax
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2010-08-27 05:09:34 +00:00
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3: ret
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END(strlen)
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2009-06-05 18:32:00 +00:00
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# undef ENTRY
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# define ENTRY(name) \
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2009-06-05 18:51:59 +00:00
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.type __strlen_sse2, @function; \
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2009-07-03 10:01:57 +00:00
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.align 16; \
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2009-06-05 18:51:59 +00:00
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__strlen_sse2: cfi_startproc; \
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CALL_MCOUNT
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2009-06-05 18:32:00 +00:00
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# undef END
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# define END(name) \
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2009-06-05 18:51:59 +00:00
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cfi_endproc; .size __strlen_sse2, .-__strlen_sse2
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2009-06-05 18:32:00 +00:00
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# undef libc_hidden_builtin_def
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/* It doesn't make sense to send libc-internal strlen calls through a PLT.
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The speedup we get from using SSE4.2 instruction is likely eaten away
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by the indirect call in the PLT. */
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# define libc_hidden_builtin_def(name) \
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.globl __GI_strlen; __GI_strlen = __strlen_sse2
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#endif
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#include "../strlen.S"
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