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Diffstat (limited to 'ports/sysdeps/ia64/memcmp.S')
| -rw-r--r-- | ports/sysdeps/ia64/memcmp.S | 164 |
1 files changed, 164 insertions, 0 deletions
diff --git a/ports/sysdeps/ia64/memcmp.S b/ports/sysdeps/ia64/memcmp.S new file mode 100644 index 0000000000..ad7d4fb9e9 --- /dev/null +++ b/ports/sysdeps/ia64/memcmp.S @@ -0,0 +1,164 @@ +/* Optimized version of the standard memcmp() function. + This file is part of the GNU C Library. + Copyright (C) 2000, 2001, 2004, 2011 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, see + <http://www.gnu.org/licenses/>. */ + +/* Return: the result of the comparison + + Inputs: + in0: dest (aka s1) + in1: src (aka s2) + in2: byte count + + In this form, it assumes little endian mode. For big endian mode, + the two shifts in .l2 must be inverted: + + shl tmp1[0] = r[1 + MEMLAT], sh1 // tmp1 = w0 << sh1 + shr.u tmp2[0] = r[0 + MEMLAT], sh2 // tmp2 = w1 >> sh2 + + and all the mux1 instructions should be replaced by plain mov's. */ + +#include <sysdep.h> +#undef ret + +#define OP_T_THRES 16 +#define OPSIZ 8 +#define MEMLAT 2 + +#define start r15 +#define saved_pr r17 +#define saved_lc r18 +#define dest r19 +#define src r20 +#define len r21 +#define asrc r22 +#define tmp r23 +#define value1 r24 +#define value2 r25 +#define sh2 r28 +#define sh1 r29 +#define loopcnt r30 + +ENTRY(memcmp) + .prologue + alloc r2 = ar.pfs, 3, 37, 0, 40 + + .rotr r[MEMLAT + 2], q[MEMLAT + 5], tmp1[4], tmp2[4], val[2] + .rotp p[MEMLAT + 4 + 1] + + mov ret0 = r0 // by default return value = 0 + .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 + mov dest = in0 // dest + mov src = in1 // src + mov len = in2 // len + sub tmp = r0, in0 // tmp = -dest + ;; + and loopcnt = 7, tmp // loopcnt = -dest % 8 + cmp.ge p6, p0 = OP_T_THRES, len // is len <= OP_T_THRES +(p6) br.cond.spnt .cmpfew // compare byte by byte + ;; + cmp.eq p6, p0 = loopcnt, r0 +(p6) br.cond.sptk .dest_aligned + sub len = len, loopcnt // len -= -dest % 8 + adds loopcnt = -1, loopcnt // --loopcnt + ;; + mov ar.lc = loopcnt +.l1: // copy -dest % 8 bytes + ld1 value1 = [src], 1 // value = *src++ + ld1 value2 = [dest], 1 + ;; + cmp.ne p6, p0 = value1, value2 +(p6) br.cond.spnt .done + br.cloop.dptk .l1 +.dest_aligned: + and sh1 = 7, src // sh1 = src % 8 + and tmp = -8, len // tmp = len & -OPSIZ + and asrc = -8, src // asrc = src & -OPSIZ -- align src + shr.u loopcnt = len, 3 // loopcnt = len / 8 + and len = 7, len ;; // len = len % 8 + shl sh1 = sh1, 3 // sh1 = 8 * (src % 8) + adds loopcnt = -1, loopcnt // --loopcnt + mov pr.rot = 1 << 16 ;; // set rotating predicates + sub sh2 = 64, sh1 // sh2 = 64 - sh1 + mov ar.lc = loopcnt // set LC + cmp.eq p6, p0 = sh1, r0 // is the src aligned? +(p6) br.cond.sptk .src_aligned + add src = src, tmp // src += len & -OPSIZ + mov ar.ec = MEMLAT + 4 + 1 // four more passes needed + ld8 r[1] = [asrc], 8 ;; // r[1] = w0 + .align 32 + +// We enter this loop with p6 cleared by the above comparison + +.l2: +(p[0]) ld8 r[0] = [asrc], 8 // r[0] = w1 +(p[0]) ld8 q[0] = [dest], 8 +(p[MEMLAT]) shr.u tmp1[0] = r[1 + MEMLAT], sh1 // tmp1 = w0 >> sh1 +(p[MEMLAT]) shl tmp2[0] = r[0 + MEMLAT], sh2 // tmp2 = w1 << sh2 +(p[MEMLAT+4]) cmp.ne p6, p0 = q[MEMLAT + 4], val[1] +(p[MEMLAT+3]) or val[0] = tmp1[3], tmp2[3] // val = tmp1 | tmp2 +(p6) br.cond.spnt .l2exit + br.ctop.sptk .l2 + br.cond.sptk .cmpfew +.l3exit: + mux1 value1 = r[MEMLAT], @rev + mux1 value2 = q[MEMLAT], @rev + cmp.ne p6, p0 = r0, r0 ;; // clear p6 +.l2exit: +(p6) mux1 value1 = val[1], @rev +(p6) mux1 value2 = q[MEMLAT + 4], @rev ;; + cmp.ltu p6, p7 = value2, value1 ;; +(p6) mov ret0 = -1 +(p7) mov ret0 = 1 + mov pr = saved_pr, -1 // restore the predicate registers + mov ar.lc = saved_lc // restore the loop counter + br.ret.sptk.many b0 +.src_aligned: + cmp.ne p6, p0 = r0, r0 // clear p6 + mov ar.ec = MEMLAT + 1 ;; // set EC +.l3: +(p[0]) ld8 r[0] = [src], 8 +(p[0]) ld8 q[0] = [dest], 8 +(p[MEMLAT]) cmp.ne p6, p0 = r[MEMLAT], q[MEMLAT] +(p6) br.cond.spnt .l3exit + br.ctop.dptk .l3 ;; +.cmpfew: + cmp.eq p6, p0 = len, r0 // is len == 0 ? + adds len = -1, len // --len; +(p6) br.cond.spnt .restore_and_exit ;; + mov ar.lc = len +.l4: + ld1 value1 = [src], 1 + ld1 value2 = [dest], 1 + ;; + cmp.ne p6, p0 = value1, value2 +(p6) br.cond.spnt .done + br.cloop.dptk .l4 ;; +.done: +(p6) sub ret0 = value2, value1 // don't execute it if falling thru +.restore_and_exit: + mov pr = saved_pr, -1 // restore the predicate registers + mov ar.lc = saved_lc // restore the loop counter + br.ret.sptk.many b0 +END(memcmp) + +weak_alias (memcmp, bcmp) +libc_hidden_builtin_def (memcmp) |