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Diffstat (limited to 'libc/string/ia64/memmove.S')
-rw-r--r-- | libc/string/ia64/memmove.S | 251 |
1 files changed, 251 insertions, 0 deletions
diff --git a/libc/string/ia64/memmove.S b/libc/string/ia64/memmove.S new file mode 100644 index 000000000..65f5b0383 --- /dev/null +++ b/libc/string/ia64/memmove.S @@ -0,0 +1,251 @@ +/* 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) |