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-rw-r--r--libc/string/ia64/memcmp.S165
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+/* Optimized version of the standard memcmp() function.
+ This file is part of the GNU C Library.
+ Copyright (C) 2000, 2001, 2004 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: 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
+ 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_def (memcmp)