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30891f35fa
We stopped adding "Contributed by" or similar lines in sources in 2012 in favour of git logs and keeping the Contributors section of the glibc manual up to date. Removing these lines makes the license header a bit more consistent across files and also removes the possibility of error in attribution when license blocks or files are copied across since the contributed-by lines don't actually reflect reality in those cases. Move all "Contributed by" and similar lines (Written by, Test by, etc.) into a new file CONTRIBUTED-BY to retain record of these contributions. These contributors are also mentioned in manual/contrib.texi, so we just maintain this additional record as a courtesy to the earlier developers. The following scripts were used to filter a list of files to edit in place and to clean up the CONTRIBUTED-BY file respectively. These were not added to the glibc sources because they're not expected to be of any use in future given that this is a one time task: https://gist.github.com/siddhesh/b5ecac94eabfd72ed2916d6d8157e7dc https://gist.github.com/siddhesh/15ea1f5e435ace9774f485030695ee02 Reviewed-by: Carlos O'Donell <carlos@redhat.com>
230 lines
5.8 KiB
ArmAsm
230 lines
5.8 KiB
ArmAsm
/* Optimized version of the standard strncpy() function.
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This file is part of the GNU C Library.
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Copyright (C) 2000-2021 Free Software Foundation, Inc.
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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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License along with the GNU C Library; if not, see
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<https://www.gnu.org/licenses/>. */
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/* Return: dest
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Inputs:
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in0: dest
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in1: src
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in2: len
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In this form, it assumes little endian mode.
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*/
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#include <sysdep.h>
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#undef ret
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#define saved_lc r15
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#define saved_pr r16
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#define thresh r17
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#define dest r18
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#define dest2 r19
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#define src r20
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#define len r21
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#define asrc r22
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#define tmp r23
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#define pos r24
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#define w0 r25
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#define w1 r26
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#define c r27
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#define sh2 r28
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#define sh1 r29
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#define loopcnt r30
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#define value r31
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ENTRY(strncpy)
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.prologue
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alloc r2 = ar.pfs, 3, 0, 29, 32
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#define MEMLAT 2
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.rotr r[MEMLAT + 2]
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.rotp p[MEMLAT + 1]
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mov ret0 = in0 // return value = dest
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.save pr, saved_pr
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mov saved_pr = pr // save the predicate registers
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.save ar.lc, saved_lc
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mov saved_lc = ar.lc // save the loop counter
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mov ar.ec = 0 // ec is not guaranteed to
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// be zero upon function entry
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.body
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cmp.geu p6, p5 = 24, in2
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(p6) br.cond.spnt .short_len
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sub tmp = r0, in0 ;; // tmp = -dest
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mov len = in2 // len
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mov dest = in0 // dest
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mov src = in1 // src
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and tmp = 7, tmp ;; // loopcnt = -dest % 8
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cmp.eq p6, p7 = tmp, r0
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adds loopcnt = -1, tmp // --loopcnt
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(p6) br.cond.sptk .dest_aligned ;;
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sub len = len, tmp // len -= -dest % 8
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mov ar.lc = loopcnt
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.l1: // copy -dest % 8 bytes
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(p5) ld1 c = [src], 1 // c = *src++
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;;
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st1 [dest] = c, 1 // *dest++ = c
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cmp.ne p5, p7 = c, r0
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br.cloop.dptk .l1 ;;
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(p7) br.cond.dpnt .found0_align
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.dest_aligned: // p7 should be cleared here
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shr.u c = len, 3 // c = len / 8
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and sh1 = 7, src // sh1 = src % 8
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and asrc = -8, src ;; // asrc = src & -OPSIZ -- align src
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adds c = (MEMLAT-1), c // c = (len / 8) + MEMLAT - 1
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sub thresh = 8, sh1
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mov pr.rot = 1 << 16 // set rotating predicates
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shl sh1 = sh1, 3 ;; // sh1 = 8 * (src % 8)
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mov ar.lc = c // "infinite" loop
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sub sh2 = 64, sh1 // sh2 = 64 - sh1
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cmp.eq p6, p0 = sh1, r0 // is the src aligned?
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(p6) br.cond.sptk .src_aligned
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adds c = -(MEMLAT-1), c ;; // c = (len / 8)
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ld8 r[1] = [asrc],8
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mov ar.lc = c ;;
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.align 32
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.l2:
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(p6) st8 [dest] = value, 8 // store val to dest
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ld8.s r[0] = [asrc], 8
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shr.u value = r[1], sh1 ;; // value = w0 >> sh1
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czx1.r pos = value ;; // do we have an "early" zero
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cmp.lt p7, p0 = pos, thresh // in w0 >> sh1?
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adds len = -8, len // len -= 8
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(p7) br.cond.dpnt .nonalign_found0
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chk.s r[0], .recovery2 // it is safe to do that only
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.back2: // after the previous test
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shl tmp = r[0], sh2 // tmp = w1 << sh2
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;;
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or value = value, tmp ;; // value |= tmp
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czx1.r pos = value ;;
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cmp.ne p7, p6 = 8, pos
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(p7) br.cond.dpnt .nonalign_found0
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br.ctop.dptk .l2 ;;
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adds len = 8, len
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br.cond.sptk .not_found0 ;;
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.nonalign_found0:
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cmp.gtu p6, p0 = -8, len
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(p6) br.cond.dptk .found0
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adds len = 8, len
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br.cond.sptk .not_found0 ;;
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.align 32
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.src_aligned:
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.l3:
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(p[0]) ld8.s r[0] = [src], 8
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(p[MEMLAT]) chk.s r[MEMLAT], .recovery3
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.back3:
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(p[MEMLAT]) mov value = r[MEMLAT]
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(p[MEMLAT]) czx1.r pos = r[MEMLAT] ;;
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(p[MEMLAT]) cmp.ne p7, p0 = 8, pos
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(p[MEMLAT]) adds len = -8, len // len -= 8
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(p7) br.cond.dpnt .found0
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(p[MEMLAT]) st8 [dest] = r[MEMLAT], 8
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br.ctop.dptk .l3 ;;
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chk.s r[MEMLAT-1], .recovery4
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.back4:
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mov value = r[MEMLAT-1]
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.not_found0:
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cmp.eq p5, p6 = len, r0
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adds len = -1, len
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(p5) br.cond.dptk .restore_and_exit ;;
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mov ar.lc = len
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.l4:
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(p6) extr.u c = value, 0, 8 // c = value & 0xff
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(p6) shr.u value = value, 8 ;;
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st1 [dest] = c, 1
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cmp.ne p6, p0 = c, r0
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br.cloop.dptk .l4
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br.cond.sptk .restore_and_exit
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.found0_align:
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mov pos = 0
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adds len = -8, len
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mov value = 0 ;;
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.found0:
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shl tmp = pos, 3
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shr.u loopcnt = len, 4 // loopcnt = len / 16
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mov c = -1 ;;
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cmp.eq p6, p0 = loopcnt, r0
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adds loopcnt = -1, loopcnt
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shl c = c, tmp ;;
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and len = 0xf, len
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andcm value = value, c
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mov ar.lc = loopcnt ;;
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cmp.le p7, p0 = 8, len
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adds dest2 = 16, dest
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st8 [dest] = value, 8
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and len = 0x7, len
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(p6) br.cond.dpnt .l6 ;;
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.l5:
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st8 [dest] = r0, 16
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st8 [dest2] = r0, 16
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br.cloop.dptk .l5 ;;
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.l6:
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(p7) st8 [dest] = r0, 8
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cmp.eq p5, p0 = len, r0
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adds len = -1, len
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(p5) br.cond.dptk .restore_and_exit ;;
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mov ar.lc = len ;;
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.l7:
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st1 [dest] = r0, 1
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br.cloop.dptk .l7 ;;
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.restore_and_exit:
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mov ar.lc = saved_lc // restore the loop counter
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mov pr = saved_pr, -1 // restore the predicate registers
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br.ret.sptk.many b0
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.short_len:
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cmp.eq p5, p0 = in2, r0
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adds loopcnt = -1, in2
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(p5) br.cond.spnt .restore_and_exit ;;
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mov ar.lc = loopcnt // p6 should be set when we get here
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.l8:
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(p6) ld1 c = [in1], 1 // c = *src++
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;;
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st1 [in0] = c, 1 // *dest++ = c
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(p6) cmp.ne p6, p0 = c, r0
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br.cloop.dptk .l8
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;;
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mov ar.lc = saved_lc // restore the loop counter
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mov pr = saved_pr, -1 // restore the predicate registers
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br.ret.sptk.many b0
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.recovery2:
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add c = 8, len
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add tmp = -8, asrc ;;
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cmp.gtu p8, p5 = c, thresh ;;
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(p8) ld8 r[0] = [tmp]
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(p5) mov r[0] = r0
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br.cond.sptk .back2
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.recovery3:
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add tmp = -(MEMLAT + 1) * 8, src ;;
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ld8 r[MEMLAT] = [tmp]
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br.cond.sptk .back3
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.recovery4:
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cmp.eq p5, p6 = len, r0
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add tmp = -MEMLAT * 8, src ;;
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(p6) ld8 r[MEMLAT - 1] = [tmp]
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(p5) mov r[MEMLAT - 1] = r0
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br.cond.sptk .back4
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END(strncpy)
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libc_hidden_builtin_def (strncpy)
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