glibc/sysdeps/alpha/strrchr.S
Paul Eggert 5a82c74822 Prefer https to http for gnu.org and fsf.org URLs
Also, change sources.redhat.com to sourceware.org.
This patch was automatically generated by running the following shell
script, which uses GNU sed, and which avoids modifying files imported
from upstream:

sed -ri '
  s,(http|ftp)(://(.*\.)?(gnu|fsf|sourceware)\.org($|[^.]|\.[^a-z])),https\2,g
  s,(http|ftp)(://(.*\.)?)sources\.redhat\.com($|[^.]|\.[^a-z]),https\2sourceware.org\4,g
' \
  $(find $(git ls-files) -prune -type f \
      ! -name '*.po' \
      ! -name 'ChangeLog*' \
      ! -path COPYING ! -path COPYING.LIB \
      ! -path manual/fdl-1.3.texi ! -path manual/lgpl-2.1.texi \
      ! -path manual/texinfo.tex ! -path scripts/config.guess \
      ! -path scripts/config.sub ! -path scripts/install-sh \
      ! -path scripts/mkinstalldirs ! -path scripts/move-if-change \
      ! -path INSTALL ! -path  locale/programs/charmap-kw.h \
      ! -path po/libc.pot ! -path sysdeps/gnu/errlist.c \
      ! '(' -name configure \
            -execdir test -f configure.ac -o -f configure.in ';' ')' \
      ! '(' -name preconfigure \
            -execdir test -f preconfigure.ac ';' ')' \
      -print)

and then by running 'make dist-prepare' to regenerate files built
from the altered files, and then executing the following to cleanup:

  chmod a+x sysdeps/unix/sysv/linux/riscv/configure
  # Omit irrelevant whitespace and comment-only changes,
  # perhaps from a slightly-different Autoconf version.
  git checkout -f \
    sysdeps/csky/configure \
    sysdeps/hppa/configure \
    sysdeps/riscv/configure \
    sysdeps/unix/sysv/linux/csky/configure
  # Omit changes that caused a pre-commit check to fail like this:
  # remote: *** error: sysdeps/powerpc/powerpc64/ppc-mcount.S: trailing lines
  git checkout -f \
    sysdeps/powerpc/powerpc64/ppc-mcount.S \
    sysdeps/unix/sysv/linux/s390/s390-64/syscall.S
  # Omit change that caused a pre-commit check to fail like this:
  # remote: *** error: sysdeps/sparc/sparc64/multiarch/memcpy-ultra3.S: last line does not end in newline
  git checkout -f sysdeps/sparc/sparc64/multiarch/memcpy-ultra3.S
2019-09-07 02:43:31 -07:00

111 lines
3.7 KiB
ArmAsm

/* Copyright (C) 1996-2019 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
<https://www.gnu.org/licenses/>. */
/* Return the address of the last occurrence of a given character
within a null-terminated string, or null if it is not found.
This is generally scheduled for the EV5 (got to look out for my own
interests :-), but with EV4 needs in mind. There are, in fact, fewer
stalls on the EV4 than there are on the EV5.
*/
#include <sysdep.h>
.set noreorder
.set noat
ENTRY(strrchr)
#ifdef PROF
ldgp gp, 0(pv)
lda AT, _mcount
jsr AT, (AT), _mcount
.prologue 1
#else
.prologue 0
#endif
and a1, 0xff, a1 # e0 : zero extend our test character
mov zero, t6 # .. e1 : t6 is last match aligned addr
sll a1, 8, t5 # e0 : replicate our test character
mov zero, t7 # .. e1 : t7 is last match byte compare mask
or t5, a1, a1 # e0 :
ldq_u t0, 0(a0) # .. e1 : load first quadword
sll a1, 16, t5 # e0 :
andnot a0, 7, v0 # .. e1 : align source addr
or t5, a1, a1 # e0 :
lda t4, -1 # .. e1 : build garbage mask
sll a1, 32, t5 # e0 :
cmpbge zero, t0, t1 # .. e1 : bits set iff byte == zero
mskqh t4, a0, t4 # e0 :
or t5, a1, a1 # .. e1 : character replication complete
xor t0, a1, t2 # e0 : make bytes == c zero
cmpbge zero, t4, t4 # .. e1 : bits set iff byte is garbage
cmpbge zero, t2, t3 # e0 : bits set iff byte == c
andnot t1, t4, t1 # .. e1 : clear garbage from null test
andnot t3, t4, t3 # e0 : clear garbage from char test
bne t1, $eos # .. e1 : did we already hit the terminator?
/* Character search main loop */
$loop:
ldq t0, 8(v0) # e0 : load next quadword
cmovne t3, v0, t6 # .. e1 : save previous comparisons match
cmovne t3, t3, t7 # e0 :
addq v0, 8, v0 # .. e1 :
xor t0, a1, t2 # e0 :
cmpbge zero, t0, t1 # .. e1 : bits set iff byte == zero
cmpbge zero, t2, t3 # e0 : bits set iff byte == c
beq t1, $loop # .. e1 : if we havnt seen a null, loop
/* Mask out character matches after terminator */
$eos:
negq t1, t4 # e0 : isolate first null byte match
and t1, t4, t4 # e1 :
subq t4, 1, t5 # e0 : build a mask of the bytes upto...
or t4, t5, t4 # e1 : ... and including the null
and t3, t4, t3 # e0 : mask out char matches after null
cmovne t3, t3, t7 # .. e1 : save it, if match found
cmovne t3, v0, t6 # e0 :
/* Locate the address of the last matched character */
/* Retain the early exit for the ev4 -- the ev5 mispredict penalty
is 5 cycles -- the same as just falling through. */
beq t7, $retnull # .. e1 :
and t7, 0xf0, t2 # e0 : binary search for the high bit set
cmovne t2, t2, t7 # .. e1 (zdb)
cmovne t2, 4, t2 # e0 :
and t7, 0xcc, t1 # .. e1 :
cmovne t1, t1, t7 # e0 :
cmovne t1, 2, t1 # .. e1 :
and t7, 0xaa, t0 # e0 :
cmovne t0, 1, t0 # .. e1 (zdb)
addq t2, t1, t1 # e0 :
addq t6, t0, v0 # .. e1 : add our aligned base ptr to the mix
addq v0, t1, v0 # e0 :
ret # .. e1 :
$retnull:
mov zero, v0 # e0 :
ret # .. e1 :
END(strrchr)
weak_alias (strrchr, rindex)
libc_hidden_builtin_def (strrchr)