/* 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 and Jakub Jelinek . 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)