/* Optimized version of the standard strcpy() function. This file is part of the GNU C Library. Copyright (C) 2000, 2001, 2003 Free Software Foundation, Inc. Contributed by Dan Pop <Dan.Pop@cern.ch>. 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 In this form, it assumes little endian mode. For big endian mode, the the two shifts in .l2 must be inverted: shl value = r[1], sh1 // value = w0 << sh1 shr.u tmp = r[0], sh2 // tmp = w1 >> sh2 */ #include "sysdep.h" #undef ret #define saved_lc r15 #define saved_pr r16 #define thresh r17 #define dest 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(strcpy) .prologue alloc r2 = ar.pfs, 2, 0, 30, 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 .body sub tmp = r0, in0 ;; // tmp = -dest mov dest = in0 // dest mov src = in1 // src and loopcnt = 7, tmp ;; // loopcnt = -dest % 8 cmp.eq p6, p0 = loopcnt, r0 adds loopcnt = -1, loopcnt // --loopcnt (p6) br.cond.sptk .dest_aligned ;; mov ar.lc = loopcnt .l1: // copy -dest % 8 bytes ld1 c = [src], 1 // c = *src++ ;; st1 [dest] = c, 1 // *dest++ = c cmp.eq p6, p0 = c, r0 (p6) br.cond.dpnt .restore_and_exit br.cloop.dptk .l1 ;; .dest_aligned: and sh1 = 7, src // sh1 = src % 8 mov ar.lc = -1 // "infinite" loop and asrc = -8, src ;; // asrc = src & -OPSIZ -- align src sub thresh = 8, sh1 mov pr.rot = 1 << 16 // set rotating predicates cmp.ne p7, p0 = r0, r0 // clear p7 shl sh1 = sh1, 3 ;; // sh1 = 8 * (src % 8) sub sh2 = 64, sh1 // sh2 = 64 - sh1 cmp.eq p6, p0 = sh1, r0 // is the src aligned? (p6) br.cond.sptk .src_aligned ;; ld8 r[1] = [asrc],8 ;; .align 32 .l2: 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? (p7) br.cond.dpnt .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, p0 = 8, pos (p7) br.cond.dpnt .found0 st8 [dest] = value, 8 // store val to dest br.ctop.dptk .l2 ;; .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 (p7) br.cond.dpnt .found0 (p[MEMLAT]) st8 [dest] = r[MEMLAT], 8 br.ctop.dptk .l3 ;; .found0: mov ar.lc = pos .l4: extr.u c = value, 0, 8 // c = value & 0xff shr.u value = value, 8 ;; st1 [dest] = c, 1 br.cloop.dptk .l4 ;; .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 .recovery2: add tmp = -8, asrc ;; ld8 r[0] = [tmp] br.cond.sptk .back2 .recovery3: add tmp = -(MEMLAT + 1) * 8, src ;; ld8 r[MEMLAT] = [tmp] br.cond.sptk .back3 END(strcpy) libc_hidden_def (strcpy)