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- /* Optimized version of the standard strncpy() function.
- This file is part of the GNU C Library.
- Copyright (C) 2000, 2001, 2002, 2003 Free Software Foundation, Inc.
- Contributed by Dan Pop <Dan.Pop@cern.ch>
- and Jakub Jelinek <jakub@redhat.com>.
- 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, write to the Free
- Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
- 02111-1307 USA. */
- /* Return: dest
- Inputs:
- in0: dest
- in1: src
- in2: len
- In this form, it assumes little endian mode.
- */
- #include "sysdep.h"
- #undef ret
- #define saved_lc r15
- #define saved_pr r16
- #define thresh r17
- #define dest r18
- #define dest2 r19
- #define src r20
- #define len r21
- #define asrc r22
- #define tmp r23
- #define pos r24
- #define w0 r25
- #define w1 r26
- #define c r27
- #define sh2 r28
- #define sh1 r29
- #define loopcnt r30
- #define value r31
- ENTRY(strncpy)
- .prologue
- alloc r2 = ar.pfs, 3, 0, 29, 32
- #define MEMLAT 2
- .rotr r[MEMLAT + 2]
- .rotp p[MEMLAT + 1]
- mov ret0 = in0 /* return value = dest */
- .save pr, saved_pr
- mov saved_pr = pr /* save the predicate registers */
- .save ar.lc, saved_lc
- mov saved_lc = ar.lc /* save the loop counter */
- mov ar.ec = 0 /* ec is not guaranteed to */
- /* be zero upon function entry */
- .body
- cmp.geu p6, p5 = 24, in2
- (p6) br.cond.spnt .short_len
- sub tmp = r0, in0 ;; /* tmp = -dest */
- mov len = in2 /* len */
- mov dest = in0 /* dest */
- mov src = in1 /* src */
- and tmp = 7, tmp ;; /* loopcnt = -dest % 8 */
- cmp.eq p6, p7 = tmp, r0
- adds loopcnt = -1, tmp /* --loopcnt */
- (p6) br.cond.sptk .dest_aligned ;;
- sub len = len, tmp /* len -= -dest % 8 */
- mov ar.lc = loopcnt
- .l1: /* copy -dest % 8 bytes */
- (p5) ld1 c = [src], 1 /* c = *src++ */
- ;;
- st1 [dest] = c, 1 /* *dest++ = c */
- cmp.ne p5, p7 = c, r0
- br.cloop.dptk .l1 ;;
- (p7) br.cond.dpnt .found0_align
- .dest_aligned: /* p7 should be cleared here */
- shr.u c = len, 3 /* c = len / 8 */
- and sh1 = 7, src /* sh1 = src % 8 */
- and asrc = -8, src ;; /* asrc = src & -OPSIZ -- align src */
- adds c = (MEMLAT-1), c /* c = (len / 8) + MEMLAT - 1 */
- sub thresh = 8, sh1
- mov pr.rot = 1 << 16 /* set rotating predicates */
- shl sh1 = sh1, 3 ;; /* sh1 = 8 * (src % 8) */
- mov ar.lc = c /* "infinite" loop */
- sub sh2 = 64, sh1 /* sh2 = 64 - sh1 */
- cmp.eq p6, p0 = sh1, r0 /* is the src aligned? */
- (p6) br.cond.sptk .src_aligned
- adds c = -(MEMLAT-1), c ;; /* c = (len / 8) */
- ld8 r[1] = [asrc],8
- mov ar.lc = c ;;
- .align 32
- .l2:
- (p6) st8 [dest] = value, 8 /* store val to dest */
- ld8.s r[0] = [asrc], 8
- shr.u value = r[1], sh1 ;; /* value = w0 >> sh1 */
- czx1.r pos = value ;; /* do we have an "early" zero */
- cmp.lt p7, p0 = pos, thresh /* in w0 >> sh1? */
- adds len = -8, len /* len -= 8 */
- (p7) br.cond.dpnt .nonalign_found0
- chk.s r[0], .recovery2 /* it is safe to do that only */
- .back2: /* after the previous test */
- shl tmp = r[0], sh2 /* tmp = w1 << sh2 */
- ;;
- or value = value, tmp ;; /* value |= tmp */
- czx1.r pos = value ;;
- cmp.ne p7, p6 = 8, pos
- (p7) br.cond.dpnt .nonalign_found0
- br.ctop.dptk .l2 ;;
- adds len = 8, len
- br.cond.sptk .not_found0 ;;
- .nonalign_found0:
- cmp.gtu p6, p0 = -8, len
- (p6) br.cond.dptk .found0
- adds len = 8, len
- br.cond.sptk .not_found0 ;;
- .align 32
- .src_aligned:
- .l3:
- (p[0]) ld8.s r[0] = [src], 8
- (p[MEMLAT]) chk.s r[MEMLAT], .recovery3
- .back3:
- (p[MEMLAT]) mov value = r[MEMLAT]
- (p[MEMLAT]) czx1.r pos = r[MEMLAT] ;;
- (p[MEMLAT]) cmp.ne p7, p0 = 8, pos
- (p[MEMLAT]) adds len = -8, len /* len -= 8 */
- (p7) br.cond.dpnt .found0
- (p[MEMLAT]) st8 [dest] = r[MEMLAT], 8
- br.ctop.dptk .l3 ;;
- chk.s r[MEMLAT-1], .recovery4
- .back4:
- mov value = r[MEMLAT-1]
- .not_found0:
- cmp.eq p5, p6 = len, r0
- adds len = -1, len
- (p5) br.cond.dptk .restore_and_exit ;;
- mov ar.lc = len
- .l4:
- (p6) extr.u c = value, 0, 8 /* c = value & 0xff */
- (p6) shr.u value = value, 8 ;;
- st1 [dest] = c, 1
- cmp.ne p6, p0 = c, r0
- br.cloop.dptk .l4
- br.cond.sptk .restore_and_exit
- .found0_align:
- mov pos = 0
- adds len = -8, len
- mov value = 0 ;;
- .found0:
- shl tmp = pos, 3
- shr.u loopcnt = len, 4 /* loopcnt = len / 16 */
- mov c = -1 ;;
- cmp.eq p6, p0 = loopcnt, r0
- adds loopcnt = -1, loopcnt
- shl c = c, tmp ;;
- and len = 0xf, len
- andcm value = value, c
- mov ar.lc = loopcnt ;;
- cmp.le p7, p0 = 8, len
- adds dest2 = 16, dest
- st8 [dest] = value, 8
- and len = 0x7, len
- (p6) br.cond.dpnt .l6 ;;
- .l5:
- st8 [dest] = r0, 16
- st8 [dest2] = r0, 16
- br.cloop.dptk .l5 ;;
- .l6:
- (p7) st8 [dest] = r0, 8
- cmp.eq p5, p0 = len, r0
- adds len = -1, len
- (p5) br.cond.dptk .restore_and_exit ;;
- mov ar.lc = len ;;
- .l7:
- st1 [dest] = r0, 1
- br.cloop.dptk .l7 ;;
- .restore_and_exit:
- mov ar.lc = saved_lc /* restore the loop counter */
- mov pr = saved_pr, -1 /* restore the predicate registers */
- br.ret.sptk.many b0
- .short_len:
- cmp.eq p5, p0 = in2, r0
- adds loopcnt = -1, in2
- (p5) br.cond.spnt .restore_and_exit ;;
- mov ar.lc = loopcnt /* p6 should be set when we get here */
- .l8:
- (p6) ld1 c = [in1], 1 /* c = *src++ */
- ;;
- st1 [in0] = c, 1 /* *dest++ = c */
- (p6) cmp.ne p6, p0 = c, r0
- br.cloop.dptk .l8
- ;;
- mov ar.lc = saved_lc /* restore the loop counter */
- mov pr = saved_pr, -1 /* restore the predicate registers */
- br.ret.sptk.many b0
- .recovery2:
- add c = 8, len
- add tmp = -8, asrc ;;
- cmp.gtu p8, p5 = c, thresh ;;
- (p8) ld8 r[0] = [tmp]
- (p5) mov r[0] = r0
- br.cond.sptk .back2
- .recovery3:
- add tmp = -(MEMLAT + 1) * 8, src ;;
- ld8 r[MEMLAT] = [tmp]
- br.cond.sptk .back3
- .recovery4:
- cmp.eq p5, p6 = len, r0
- add tmp = -MEMLAT * 8, src ;;
- (p6) ld8 r[MEMLAT - 1] = [tmp]
- (p5) mov r[MEMLAT - 1] = r0
- br.cond.sptk .back4
- END(strncpy)
- libc_hidden_def (strncpy)
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