Linux-2.6.12-rc2v2.6.12-rc2

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!

1 files changed, 164 insertions, 0 deletions

diff --git a/arch/alpha/lib/memchr.S b/arch/alpha/lib/memchr.S
new file mode 100644
index 000000000000..14427eeb555e
--- /dev/null
+++ b/arch/alpha/lib/memchr.S
@@ -0,0 +1,164 @@
+/* Copyright (C) 1996 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+   Contributed by David Mosberger (davidm@cs.arizona.edu).
+
+   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.  */
+
+/* Finds characters in a memory area.  Optimized for the Alpha:
+
+      - memory accessed as aligned quadwords only
+      - uses cmpbge to compare 8 bytes in parallel
+      - does binary search to find 0 byte in last
+        quadword (HAKMEM needed 12 instructions to
+        do this instead of the 9 instructions that
+        binary search needs).
+
+For correctness consider that:
+
+      - only minimum number of quadwords may be accessed
+      - the third argument is an unsigned long
+*/
+
+        .set noreorder
+        .set noat
+
+        .globl memchr
+        .ent memchr
+memchr:
+        .frame $30,0,$26,0
+        .prologue 0
+
+        # Hack -- if someone passes in (size_t)-1, hoping to just
+        # search til the end of the address space, we will overflow
+        # below when we find the address of the last byte.  Given
+        # that we will never have a 56-bit address space, cropping
+        # the length is the easiest way to avoid trouble.
+        zap     $18, 0x80, $5   #-e0    :
+
+        beq     $18, $not_found # .. e1 :
+        ldq_u   $1, 0($16)      # e1    : load first quadword
+        insbl   $17, 1, $2      # .. e0 : $2 = 000000000000ch00
+        and     $17, 0xff, $17  #-e0    : $17 = 00000000000000ch
+        cmpult  $18, 9, $4      # .. e1 :
+        or      $2, $17, $17    # e0    : $17 = 000000000000chch
+        lda     $3, -1($31)     # .. e1 :
+        sll     $17, 16, $2     #-e0    : $2 = 00000000chch0000
+        addq    $16, $5, $5     # .. e1 :
+        or      $2, $17, $17    # e1    : $17 = 00000000chchchch
+        unop                    #       :
+        sll     $17, 32, $2     #-e0    : $2 = chchchch00000000
+        or      $2, $17, $17    # e1    : $17 = chchchchchchchch
+        extql   $1, $16, $7     # e0    : 
+        beq     $4, $first_quad # .. e1 :
+
+        ldq_u   $6, -1($5)      #-e1    : eight or less bytes to search
+        extqh   $6, $16, $6     # .. e0 :
+        mov     $16, $0         # e0    :
+        or      $7, $6, $1      # .. e1 : $1 = quadword starting at $16
+
+        # Deal with the case where at most 8 bytes remain to be searched
+        # in $1.  E.g.:
+        #       $18 = 6
+        #       $1 = ????c6c5c4c3c2c1
+$last_quad:
+        negq    $18, $6         #-e0    :
+        xor     $17, $1, $1     # .. e1 :
+        srl     $3, $6, $6      # e0    : $6 = mask of $18 bits set
+        cmpbge  $31, $1, $2     # .. e1 :
+        and     $2, $6, $2      #-e0    :
+        beq     $2, $not_found  # .. e1 :
+
+$found_it:
+        # Now, determine which byte matched:
+        negq    $2, $3          # e0    :
+        and     $2, $3, $2      # e1    :
+
+        and     $2, 0x0f, $1    #-e0    :
+        addq    $0, 4, $3       # .. e1 :
+        cmoveq  $1, $3, $0      # e0    :
+
+        addq    $0, 2, $3       # .. e1 :
+        and     $2, 0x33, $1    #-e0    :
+        cmoveq  $1, $3, $0      # .. e1 :
+
+        and     $2, 0x55, $1    # e0    :
+        addq    $0, 1, $3       # .. e1 :
+        cmoveq  $1, $3, $0      #-e0    :
+
+$done:  ret                     # .. e1 :
+
+        # Deal with the case where $18 > 8 bytes remain to be
+        # searched.  $16 may not be aligned.
+        .align 4
+$first_quad:
+        andnot  $16, 0x7, $0    #-e1    :
+        insqh   $3, $16, $2     # .. e0 : $2 = 0000ffffffffffff ($16<0:2> ff)
+        xor     $1, $17, $1     # e0    :
+        or      $1, $2, $1      # e1    : $1 = ====ffffffffffff
+        cmpbge  $31, $1, $2     #-e0    :
+        bne     $2, $found_it   # .. e1 :
+
+        # At least one byte left to process.
+
+        ldq     $1, 8($0)       # e0    :
+        subq    $5, 1, $18      # .. e1 :
+        addq    $0, 8, $0       #-e0    :
+
+        # Make $18 point to last quad to be accessed (the
+        # last quad may or may not be partial).
+
+        andnot  $18, 0x7, $18   # .. e1 :
+        cmpult  $0, $18, $2     # e0    :
+        beq     $2, $final      # .. e1 :
+
+        # At least two quads remain to be accessed.
+
+        subq    $18, $0, $4     #-e0    : $4 <- nr quads to be processed
+        and     $4, 8, $4       # e1    : odd number of quads?
+        bne     $4, $odd_quad_count # e1 :
+
+        # At least three quads remain to be accessed
+
+        mov     $1, $4          # e0    : move prefetched value to correct reg
+
+        .align  4
+$unrolled_loop:
+        ldq     $1, 8($0)       #-e0    : prefetch $1
+        xor     $17, $4, $2     # .. e1 :
+        cmpbge  $31, $2, $2     # e0    :
+        bne     $2, $found_it   # .. e1 :
+
+        addq    $0, 8, $0       #-e0    :
+$odd_quad_count:
+        xor     $17, $1, $2     # .. e1 :
+        ldq     $4, 8($0)       # e0    : prefetch $4
+        cmpbge  $31, $2, $2     # .. e1 :
+        addq    $0, 8, $6       #-e0    :
+        bne     $2, $found_it   # .. e1 :
+
+        cmpult  $6, $18, $6     # e0    :
+        addq    $0, 8, $0       # .. e1 :
+        bne     $6, $unrolled_loop #-e1 :
+
+        mov     $4, $1          # e0    : move prefetched value into $1
+$final: subq    $5, $0, $18     # .. e1 : $18 <- number of bytes left to do
+        bne     $18, $last_quad # e1    :
+
+$not_found:
+        mov     $31, $0         #-e0    :
+        ret                     # .. e1 :
+
+        .end memchr