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-rw-r--r--sysdeps/alpha/ffs.S91
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diff --git a/sysdeps/alpha/ffs.S b/sysdeps/alpha/ffs.S
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+/* Copyright (C) 1996-2014 Free Software Foundation, Inc.
+ Contributed by David Mosberger (davidm@cs.arizona.edu).
+ 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/>. */
+
+/* Finds the first bit set in an integer. Optimized for the Alpha
+ architecture. */
+
+#include <sysdep.h>
+
+ .set noreorder
+ .set noat
+
+
+ENTRY(__ffs)
+#ifdef PROF
+ ldgp gp, 0(pv)
+ lda AT, _mcount
+ jsr AT, (AT), _mcount
+ .prologue 1
+ zap $16, 0xF0, $16
+ br $ffsl..ng
+#else
+ .prologue 0
+ zap $16, 0xF0, $16
+ # FALLTHRU
+#endif
+END(__ffs)
+
+ .align 4
+ENTRY(ffsl)
+#ifdef PROF
+ ldgp gp, 0(pv)
+ lda AT, _mcount
+ jsr AT, (AT), _mcount
+ .prologue 1
+$ffsl..ng:
+#else
+ .prologue 0
+#endif
+ not $16, $1 # e0 :
+ ldi $2, -1 # .. e1 :
+ cmpbge $1, $2, $3 # e0 : bit N == 1 for byte N == 0
+ clr $0 # .. e1 :
+ addq $3, 1, $4 # e0 :
+ bic $4, $3, $3 # e1 : bit N == 1 for first byte N != 0
+ and $3, 0xF0, $4 # e0 :
+ and $3, 0xCC, $5 # .. e1 :
+ and $3, 0xAA, $6 # e0 :
+ cmovne $4, 4, $0 # .. e1 :
+ cmovne $5, 2, $5 # e0 :
+ cmovne $6, 1, $6 # .. e1 :
+ addl $0, $5, $0 # e0 :
+ addl $0, $6, $0 # e1 : $0 == N
+ extbl $16, $0, $1 # e0 : $1 == byte N
+ ldi $2, 1 # .. e1 :
+ negq $1, $3 # e0 :
+ and $3, $1, $3 # e1 : bit N == least bit set of byte N
+ and $3, 0xF0, $4 # e0 :
+ and $3, 0xCC, $5 # .. e1 :
+ and $3, 0xAA, $6 # e0 :
+ cmovne $4, 5, $2 # .. e1 :
+ cmovne $5, 2, $5 # e0 :
+ cmovne $6, 1, $6 # .. e1 :
+ s8addl $0, $2, $0 # e0 : mult byte ofs by 8 and sum
+ addl $5, $6, $5 # .. e1 :
+ addl $0, $5, $0 # e0 :
+ nop # .. e1 :
+ cmoveq $16, 0, $0 # e0 : trap input == 0 case.
+ ret # .. e1 : 18
+
+END(ffsl)
+
+weak_alias (__ffs, ffs)
+libc_hidden_def (__ffs)
+libc_hidden_builtin_def (ffs)
+weak_extern (ffsl)
+weak_alias (ffsl, ffsll)