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+/* Optimized version of the standard memmove() 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
+ in2: byte count
+
+ The core of the function is the memcpy implementation used in memcpy.S.
+ When bytes have to be copied backwards, only the easy case, when
+ all arguments are multiples of 8, is optimised.
+
+ In this form, it assumes little endian mode. For big endian mode,
+ sh1 must be computed using an extra instruction: sub sh1 = 64, sh1
+ or the UM.be bit should be cleared at the beginning and set at the end. */
+
+#include <sysdep.h>
+#undef ret
+
+#define OP_T_THRES 16
+#define OPSIZ 8
+
+#define adest r15
+#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
+
+#ifdef GAS_ALIGN_BREAKS_UNWIND_INFO
+# define ALIGN(n) { nop 0 }
+#else
+# define ALIGN(n) .align n
+#endif
+
+#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 */
+
+#define MEMLAT 21
+#define Nrot (((2*MEMLAT+3) + 7) & ~7)
+
+ENTRY(memmove)
+ .prologue
+ alloc r2 = ar.pfs, 3, Nrot - 3, 0, Nrot
+ .rotr r[MEMLAT + 2], q[MEMLAT + 1]
+ .rotp p[MEMLAT + 2]
+ 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
+ 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
+ cmp.le p6, p0 = dest, src // if dest <= src it's always safe
+(p6) br.cond.spnt .forward // to copy forward
+ add tmp3 = src, len;;
+ cmp.lt p6, p0 = dest, tmp3 // if dest > src && dest < src + len
+(p6) br.cond.spnt .backward // we have to copy backward
+
+.forward:
+ shr.u loopcnt = len, 4 ;; // loopcnt = len / 16
+ 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
+
+ and tmp3 = 0xf, len
+ mov pr.rot = 1 << 16 // set rotating predicates
+ mov ar.ec = MEMLAT + 1 ;; // set the epilog counter
+ cmp.ne p6, p0 = tmp3, r0 // do we have to copy an extra word?
+ adds loopcnt = -1, loopcnt;; // --loopcnt
+(p6) ld8 value = [src], 8;;
+(p6) st8 [dest] = value, 8 // copy the "odd" word
+ mov ar.lc = loopcnt // set the loop counter
+ cmp.eq p6, p0 = 8, len
+(p6) br.cond.spnt .restore_and_exit;;// the one-word special case
+ adds adest = 8, dest // set adest one word ahead of dest
+ adds asrc = 8, src ;; // set asrc one word ahead of src
+ nop.b 0 // get the "golden" alignment for
+ nop.b 0 // the next loop
+.l0:
+(p[0]) ld8 r[0] = [src], 16
+(p[0]) ld8 q[0] = [asrc], 16
+(p[MEMLAT]) st8 [dest] = r[MEMLAT], 16
+(p[MEMLAT]) st8 [adest] = q[MEMLAT], 16
+ br.ctop.dptk .l0 ;;
+
+ mov pr = saved_pr, -1 // restore the predicate registers
+ mov ar.lc = saved_lc // restore the loop counter
+ 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 pr = saved_pr, -1 // restore the predicate registers
+ mov ar.lc = saved_lc // restore the loop counter
+ br.ret.sptk.many b0
+
+// In the case of a backward copy, optimise only the case when everything
+// is a multiple of 8, otherwise copy byte by byte. The backward copy is
+// used only when the blocks are overlapping and dest > src.
+
+.backward:
+ shr.u loopcnt = len, 3 // loopcnt = len / 8
+ add src = src, len // src points one byte past the end
+ add dest = dest, len ;; // dest points one byte past the end
+ mov ar.ec = MEMLAT + 1 // set the epilog counter
+ mov pr.rot = 1 << 16 // set rotating predicates
+ adds loopcnt = -1, loopcnt // --loopcnt
+ cmp.ne p6, p0 = tmp4, r0 // if ((dest | src | len) & 7 != 0)
+(p6) br.cond.sptk .bytecopy ;; // copy byte by byte backward
+ adds src = -8, src // src points to the last word
+ adds dest = -8, dest // dest points to the last word
+ mov ar.lc = loopcnt;; // set the loop counter
+.l5:
+(p[0]) ld8 r[0] = [src], -8
+(p[MEMLAT]) st8 [dest] = r[MEMLAT], -8
+ br.ctop.dptk .l5
+ br.cond.sptk .restore_and_exit
+.bytecopy:
+ adds src = -1, src // src points to the last byte
+ adds dest = -1, dest // dest points to the last byte
+ adds loopcnt = -1, len;; // loopcnt = len - 1
+ mov ar.lc = loopcnt;; // set the loop counter
+.l6:
+(p[0]) ld1 r[0] = [src], -1
+(p[MEMLAT]) st1 [dest] = r[MEMLAT], -1
+ br.ctop.dptk .l6
+ br.cond.sptk .restore_and_exit
+END(memmove)
+
+ .rodata
+ .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
+
+libc_hidden_def (memmove)