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/* Optimized version of the standard memcpy() function.
This file is part of the GNU C Library.
Copyright (C) 2000 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 Library General Public License as
published by the Free Software Foundation; either version 2 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
Library General Public License for more details.
You should have received a copy of the GNU Library General Public
License along with the GNU C Library; see the file COPYING.LIB. 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: byte count
An assembly implementation of the algorithm used by the generic C
version from glibc. The case when all three arguments are multiples
of 8 is treated separatedly, for extra performance.
In this form, it assumes little endian mode. For big endian mode,
sh1 must be computed using an extra instruction: sub sh1 = 64, sh1
and the order of r[MEMLAT] and r[MEMLAT+1] must be reverted in the
shrp instruction. */
#include <sysdep.h>
#undef ret
#define OP_T_THRES 16
#define OPSIZ 8
#define saved_pfs r14
#define sf r15
#define rescnt r16
#define saved_pr r17
#define saved_lc r18
#define dest r19
#define src r20
#define len r21
#define asrc r22
#define tmp2 r23
#define tmp3 r24
#define tmp4 r25
#define ptable r26
#define ploop56 r27
#define loopaddr r28
#define sh1 r29
#define loopcnt r30
#define value r31
#define dl0 r22
#define dh0 r23
#define dl1 r24
#define dh1 r25
#define dl2 r26
#define dh2 r27
#define dl3 r28
#define dh3 r29
#define LOOP(shift) \
.align 32 ; \
.loop##shift##: \
(p[0]) ld8 r[0] = [asrc], 8 ; /* w1 */ \
(p[MEMLAT+1]) st8 [dest] = value, 8 ; \
(p[MEMLAT]) shrp value = r[MEMLAT], r[MEMLAT+1], shift ; \
nop.b 0 ; \
nop.b 0 ; \
br.ctop.sptk .loop##shift ; \
br.cond.sptk .cpyfew ; /* deal with the remaining bytes */
ENTRY(memcpy)
alloc saved_pfs = ar.pfs, 3, 40-3, 0, 40
#include "softpipe.h"
.rotr r[MEMLAT + 2], q[MEMLAT + 1], s0[2], s1[2], s2[2], s3[2]
.rotf tl0[5], th0[5], tl1[5], th1[5], tl2[5], th2[5], tl3[5], th3[5]
.rotp p[MEMLAT + 2]
mov ret0 = in0 // return value = dest
mov saved_pr = pr // save the predicate registers
brp.loop.many.tk.tk.imp .l0, .done - 16
mov saved_lc = ar.lc // save the loop counter
or tmp3 = in0, in1 ;; // tmp3 = dest | src
or tmp3 = tmp3, in2 // tmp3 = dest | src | len
mov dest = in0 // dest
mov src = in1 // src
mov len = in2 // len
sub tmp2 = r0, in0 // tmp2 = -dest
cmp.eq p6, p0 = in2, r0 // if (len == 0)
(p6) br.cond.spnt .restore_and_exit;;// return dest;
and tmp4 = 7, tmp3 // tmp4 = (dest | src | len) & 7
tbit.nz p8, p0 = src, 3 ;; // test for 16-byte boundary align
cmp.ne p6, p0 = tmp4, r0 // if ((dest | src | len) & 7 != 0)
(p6) br.cond.sptk .next // goto next;
// The optimal case, when dest, src and len are all multiples of 8
(p8) ld8 value = [src], 8 // align src if necessary
(p8) adds len = -8, len ;; // adjust len accordingly
shr.u loopcnt = len, 6 // loopcnt = len / 64
shr.u rescnt = len, 3 // rescnt = len / 8
mov pr.rot = 1 << 16 // set rotating predicates
mov ar.ec = 4 + 1 ;; // set the epilog counter
cmp.eq p6, p0 = loopcnt, r0
and rescnt = 7, rescnt // resnt = residual word count
adds loopcnt = -1, loopcnt // --loopcnt
(p8) st8 [dest] = value, 8 // copy one word if aligning
(p6) br.cond.spnt .epilog;; // there are < 8 words to copy
add sf = 64 * 4, src
mov ar.lc = loopcnt // set the loop counter
mov s0[1] = src
add s1[1] = 16*1, src
add s2[1] = 16*2, src
add s3[1] = 16*3, src
;;
mov dl0 = dest
add dh0 = 8 * 1, dest
add dl1 = 8 * 2, dest
add dh1 = 8 * 3, dest
add dl2 = 8 * 4, dest
add dh2 = 8 * 5, dest
add dl3 = 8 * 6, dest
add dh3 = 8 * 7, dest
;;
.l0:
(p[0]) lfetch.nta [sf], 64
(p[0]) ldfp8 tl0[0], th0[0] = [s0[1]]
(p[0]) ldfp8 tl1[0], th1[0] = [s1[1]]
(p[0]) ldfp8 tl2[0], th2[0] = [s2[1]]
(p[0]) ldfp8 tl3[0], th3[0] = [s3[1]]
(p[0]) add s0[0] = 64, s0[1]
(p[0]) add s1[0] = 64, s1[1]
(p[0]) add s2[0] = 64, s2[1]
(p[0]) add s3[0] = 64, s3[1]
(p[1]) mov src = s0[1] // for the epilog code
(p[4]) stf8 [dl0] = tl0[4], 64
(p[4]) stf8 [dh0] = th0[4], 64
(p[4]) stf8 [dl1] = tl1[4], 64
(p[4]) stf8 [dh1] = th1[4], 64
(p[4]) stf8 [dl2] = tl2[4], 64
(p[4]) stf8 [dh2] = th2[4], 64
(p[4]) stf8 [dl3] = tl3[4], 64
(p[4]) stf8 [dh3] = th3[4], 64
br.ctop.sptk.many .l0
.done:
mov dest = dl0
.epilog:
cmp.eq p6, p0 = rescnt, r0 // are there any words left to copy?
tbit.nz p10, p0 = rescnt, 0
(p6) br.cond.spnt .restore_and_exit ;;
(p10) ld8 r[0] = [src], 8
tbit.nz p11, p0 = rescnt, 1 ;;
(p11) ld8 r[1] = [src], 8
(p10) st8 [dest] = r[0], 8 ;;
(p11) ld8 r[2] = [src], 8
(p11) st8 [dest] = r[1], 8
tbit.nz p12, p0 = rescnt, 2 ;;
(p12) ld8 r[3] = [src], 8
(p11) st8 [dest] = r[2], 8 ;;
(p12) ld8 r[4] = [src], 8
(p12) st8 [dest] = r[3], 8 ;;
(p12) ld8 r[5] = [src], 8
(p12) st8 [dest] = r[4], 8
mov ar.lc = saved_lc ;; // restore the loop counter
(p12) ld8 r[6] = [src], 8
(p12) st8 [dest] = r[5], 8
mov ar.pfs = saved_pfs;; // restore the PFS
(p12) st8 [dest] = r[6]
mov pr = saved_pr, -1 // restore the predicate registers
br.ret.sptk.many b0
.next:
cmp.ge p6, p0 = OP_T_THRES, len // is len <= OP_T_THRES
and loopcnt = 7, tmp2 // loopcnt = -dest % 8
(p6) br.cond.spnt .cpyfew // copy 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 value = [src], 1 // value = *src++
;;
st1 [dest] = value, 1 // *dest++ = value
br.cloop.dptk .l1
.dest_aligned:
and sh1 = 7, src // sh1 = src % 8
and tmp2 = -8, len // tmp2 = 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
adds loopcnt = -1, loopcnt // --loopcnt
addl tmp4 = @ltoff(.table), gp
addl tmp3 = @ltoff(.loop56), gp
mov ar.ec = MEMLAT + 1 // set EC
mov pr.rot = 1 << 16;; // set rotating predicates
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, tmp2 // src += len & -OPSIZ
shl sh1 = sh1, 3 // sh1 = 8 * (src % 8)
ld8 ploop56 = [tmp3] // ploop56 = &loop56
ld8 ptable = [tmp4];; // ptable = &table
add tmp3 = ptable, sh1;; // tmp3 = &table + sh1
mov ar.ec = MEMLAT + 1 + 1 // one more pass needed
ld8 tmp4 = [tmp3];; // tmp4 = loop offset
sub loopaddr = ploop56,tmp4 // loopadd = &loop56 - loop offset
ld8 r[1] = [asrc], 8;; // w0
mov b6 = loopaddr;;
br b6 // jump to the appropriate loop
LOOP(8)
LOOP(16)
LOOP(24)
LOOP(32)
LOOP(40)
LOOP(48)
LOOP(56)
.src_aligned:
.l3:
(p[0]) ld8 r[0] = [src], 8
(p[MEMLAT]) st8 [dest] = r[MEMLAT], 8
br.ctop.dptk .l3
.cpyfew:
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 value = [src], 1
;;
st1 [dest] = value, 1
br.cloop.dptk .l4 ;;
.restore_and_exit:
mov ar.pfs = saved_pfs // restore the PFS
mov pr = saved_pr, -1 // restore the predicate registers
mov ar.lc = saved_lc // restore the loop counter
br.ret.sptk.many b0
.align 8
.table:
data8 0 // dummy entry
data8 .loop56 - .loop8
data8 .loop56 - .loop16
data8 .loop56 - .loop24
data8 .loop56 - .loop32
data8 .loop56 - .loop40
data8 .loop56 - .loop48
data8 .loop56 - .loop56
END(memcpy)
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