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authorUlrich Drepper <drepper@redhat.com>1998-12-26 09:30:54 +0000
committerUlrich Drepper <drepper@redhat.com>1998-12-26 09:30:54 +0000
commit85f72e9c2a46601358e5e908053c13709b3003c3 (patch)
tree81d271ef44f1c5eeec78864acc54e471b13c9943 /sysdeps
parent65c64a0b4afc4814d11af5d185772eb48d72e6ce (diff)
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Update.
1998-12-25 Ulrich Drepper <drepper@cygnus.com> * elf/dl-hash.h: Move to... * sysdeps/generic/dl-hash.h: ...here. Correct parameter type (must be unsigned char). Remove conditional from inner loop and rearrange binary operations (12-22% performance increase). * sysdeps/i386/i686/dl-hash.h: New file. Yet 10% faster than optimized generic version.
Diffstat (limited to 'sysdeps')
-rw-r--r--sysdeps/generic/dl-hash.h74
-rw-r--r--sysdeps/i386/i686/dl-hash.h80
-rw-r--r--sysdeps/unix/sysv/linux/arm/Makefile2
3 files changed, 155 insertions, 1 deletions
diff --git a/sysdeps/generic/dl-hash.h b/sysdeps/generic/dl-hash.h
new file mode 100644
index 0000000..fc17793
--- /dev/null
+++ b/sysdeps/generic/dl-hash.h
@@ -0,0 +1,74 @@
+/* Compute hash alue for given string according to ELF standard.
+ Copyright (C) 1995, 1996, 1997, 1998 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 Library General Public License as
+ published by the Free Software Foundation; either version 2 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
+ Library General Public License for more details.
+
+ You should have received a copy of the GNU Library General Public
+ License along with the GNU C Library; see the file COPYING.LIB. If not,
+ write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ Boston, MA 02111-1307, USA. */
+
+#ifndef _DL_HASH_H
+#define _DL_HASH_H 1
+
+
+/* This is the hashing function specified by the ELF ABI. In the
+ first five operations no overflow is possible so we optimized it a
+ bit. */
+static inline unsigned int
+_dl_elf_hash (const unsigned char *name)
+{
+ unsigned long int hash = 0;
+ if (*name != '\0')
+ {
+ hash = *name++;
+ if (*name != '\0')
+ {
+ hash = (hash << 4) + *name++;
+ if (*name != '\0')
+ {
+ hash = (hash << 4) + *name++;
+ if (*name != '\0')
+ {
+ hash = (hash << 4) + *name++;
+ if (*name != '\0')
+ {
+ hash = (hash << 4) + *name++;
+ while (*name != '\0')
+ {
+ unsigned long int hi;
+ hash = (hash << 4) + *name++;
+ hi = hash & 0xf0000000;
+
+ /* The algorithm specified in the ELF ABI is as
+ follows:
+
+ if (hi != 0)
+ hash ^= hi >> 24;
+
+ hash &= ~hi;
+
+ But the following is equivalent and a lot
+ faster, especially on modern processors. */
+
+ hash ^= hi;
+ hash ^= hi >> 24;
+ }
+ }
+ }
+ }
+ }
+ }
+ return hash;
+}
+
+#endif /* dl-hash.h */
diff --git a/sysdeps/i386/i686/dl-hash.h b/sysdeps/i386/i686/dl-hash.h
new file mode 100644
index 0000000..809969c
--- /dev/null
+++ b/sysdeps/i386/i686/dl-hash.h
@@ -0,0 +1,80 @@
+/* Compute hash alue for given string according to ELF standard.
+ Copyright (C) 1998 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+ Contributed by Ulrich Drepper <drepper@cygnus.com>, 1998.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Library General Public License as
+ published by the Free Software Foundation; either version 2 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
+ Library General Public License for more details.
+
+ You should have received a copy of the GNU Library General Public
+ License along with the GNU C Library; see the file COPYING.LIB. If not,
+ write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ Boston, MA 02111-1307, USA. */
+
+#ifndef _DL_HASH_H
+#define _DL_HASH_H 1
+
+
+/* This is the hashing function specified by the ELF ABI. It is highly
+ optimized for the PII processors. Though it will run on i586 it
+ would be much slower than the generic C implementation. So don't
+ use it. */
+static inline unsigned int
+_dl_elf_hash (const unsigned char *name)
+{
+ unsigned int result;
+ unsigned int temp0;
+ unsigned int temp1;
+
+ __asm__ __volatile__
+ ("movzbl (%1),%2\n\t"
+ "testl %2, %2\n\t"
+ "jz 1f\n\t"
+ "movl %2, %0\n\t"
+ "movzbl 1(%1), %2\n\t"
+ "jecxz 1f\n\t"
+ "shll $4, %0\n\t"
+ "addl %2, %0\n\t"
+ "movzbl 2(%1), %2\n\t"
+ "jecxz 1f\n\t"
+ "shll $4, %0\n\t"
+ "addl %2, %0\n\t"
+ "movzbl 3(%1), %2\n\t"
+ "jecxz 1f\n\t"
+ "shll $4, %0\n\t"
+ "addl %2, %0\n\t"
+ "movzbl 4(%1), %2\n\t"
+ "jecxz 1f\n\t"
+ "shll $4, %0\n\t"
+ "addl $5, %1\n\t"
+ "addl %2, %0\n\t"
+ "movzbl (%1), %2\n\t"
+ "jecxz 1f\n"
+ "2:\t"
+ "shll $4, %0\n\t"
+ "movl $0xf0000000, %3\n\t"
+ "incl %1\n\t"
+ "addl %2, %0\n\t"
+ "andl %0, %3\n\t"
+ "andl $0x0fffffff, %0\n\t"
+ "shrl $24, %3\n\t"
+ "movzbl (%1), %2\n\t"
+ "xorl %3, %0\n\t"
+ "testl %2, %2\n\t"
+ "jnz 2b\n"
+ "1:\t"
+ : "=&r" (result), "=r" (name), "=&c" (temp0), "=&r" (temp1)
+ : "0" (0), "1" (name));
+
+ return result;
+}
+
+#endif /* dl-hash.h */
+
diff --git a/sysdeps/unix/sysv/linux/arm/Makefile b/sysdeps/unix/sysv/linux/arm/Makefile
index cebaa94..d76698b 100644
--- a/sysdeps/unix/sysv/linux/arm/Makefile
+++ b/sysdeps/unix/sysv/linux/arm/Makefile
@@ -1,5 +1,5 @@
ifeq ($(subdir),misc)
-sysdep_routines += setfsgid setfsuid setresgid setresuid
+sysdep_routines += setfsgid setfsuid setresgid setresuid ioperm
endif
ifeq ($(subdir),signal)