| /* Optimized version of the standard memset() function. |
| This file is part of the GNU C Library. |
| Copyright (C) 2000, 2001, 2002, 2003 Free Software Foundation, Inc. |
| Contributed by Dan Pop for Itanium <Dan.Pop@cern.ch>. |
| Rewritten for McKinley by Sverre Jarp, HP Labs/CERN <Sverre.Jarp@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: value |
| in2: count |
| |
| The algorithm is fairly straightforward: set byte by byte until we |
| we get to a 16B-aligned address, then loop on 128 B chunks using an |
| early store as prefetching, then loop on 32B chucks, then clear remaining |
| words, finally clear remaining bytes. |
| Since a stf.spill f0 can store 16B in one go, we use this instruction |
| to get peak speed when value = 0. */ |
| |
| #include "sysdep.h" |
| #undef ret |
| |
| #define dest in0 |
| #define value in1 |
| #define cnt in2 |
| |
| #define tmp r31 |
| #define save_lc r30 |
| #define ptr0 r29 |
| #define ptr1 r28 |
| #define ptr2 r27 |
| #define ptr3 r26 |
| #define ptr9 r24 |
| #define loopcnt r23 |
| #define linecnt r22 |
| #define bytecnt r21 |
| |
| #define fvalue f6 |
| |
| /* This routine uses only scratch predicate registers (p6 - p15) */ |
| #define p_scr p6 /* default register for same-cycle branches */ |
| #define p_nz p7 |
| #define p_zr p8 |
| #define p_unalgn p9 |
| #define p_y p11 |
| #define p_n p12 |
| #define p_yy p13 |
| #define p_nn p14 |
| |
| #define movi0 mov |
| |
| #define MIN1 15 |
| #define MIN1P1HALF 8 |
| #define LINE_SIZE 128 |
| #define LSIZE_SH 7 /* shift amount */ |
| #define PREF_AHEAD 8 |
| |
| #define USE_FLP |
| #if defined(USE_INT) |
| #define store st8 |
| #define myval value |
| #elif defined(USE_FLP) |
| #define store stf8 |
| #define myval fvalue |
| #endif |
| |
| .align 64 |
| ENTRY(memset) |
| { .mmi |
| .prologue |
| alloc tmp = ar.pfs, 3, 0, 0, 0 |
| lfetch.nt1 [dest] |
| .save ar.lc, save_lc |
| movi0 save_lc = ar.lc |
| } { .mmi |
| .body |
| mov ret0 = dest /* return value */ |
| cmp.ne p_nz, p_zr = value, r0 /* use stf.spill if value is zero */ |
| cmp.eq p_scr, p0 = cnt, r0 |
| ;; } |
| { .mmi |
| and ptr2 = -(MIN1+1), dest /* aligned address */ |
| and tmp = MIN1, dest /* prepare to check for alignment */ |
| tbit.nz p_y, p_n = dest, 0 /* Do we have an odd address? (M_B_U) */ |
| } { .mib |
| mov ptr1 = dest |
| mux1 value = value, @brcst /* create 8 identical bytes in word */ |
| (p_scr) br.ret.dpnt.many rp /* return immediately if count = 0 */ |
| ;; } |
| { .mib |
| cmp.ne p_unalgn, p0 = tmp, r0 |
| } { .mib /* NB: # of bytes to move is 1 higher */ |
| sub bytecnt = (MIN1+1), tmp /* than loopcnt */ |
| cmp.gt p_scr, p0 = 16, cnt /* is it a minimalistic task? */ |
| (p_scr) br.cond.dptk.many .move_bytes_unaligned /* go move just a few (M_B_U) */ |
| ;; } |
| { .mmi |
| (p_unalgn) add ptr1 = (MIN1+1), ptr2 /* after alignment */ |
| (p_unalgn) add ptr2 = MIN1P1HALF, ptr2 /* after alignment */ |
| (p_unalgn) tbit.nz.unc p_y, p_n = bytecnt, 3 /* should we do a st8 ? */ |
| ;; } |
| { .mib |
| (p_y) add cnt = -8, cnt |
| (p_unalgn) tbit.nz.unc p_yy, p_nn = bytecnt, 2 /* should we do a st4 ? */ |
| } { .mib |
| (p_y) st8 [ptr2] = value, -4 |
| (p_n) add ptr2 = 4, ptr2 |
| ;; } |
| { .mib |
| (p_yy) add cnt = -4, cnt |
| (p_unalgn) tbit.nz.unc p_y, p_n = bytecnt, 1 /* should we do a st2 ? */ |
| } { .mib |
| (p_yy) st4 [ptr2] = value, -2 |
| (p_nn) add ptr2 = 2, ptr2 |
| ;; } |
| { .mmi |
| mov tmp = LINE_SIZE+1 /* for compare */ |
| (p_y) add cnt = -2, cnt |
| (p_unalgn) tbit.nz.unc p_yy, p_nn = bytecnt, 0 /* should we do a st1 ? */ |
| } { .mmi |
| setf.sig fvalue=value /* transfer value to FLP side */ |
| (p_y) st2 [ptr2] = value, -1 |
| (p_n) add ptr2 = 1, ptr2 |
| ;; } |
| |
| { .mmi |
| (p_yy) st1 [ptr2] = value |
| cmp.gt p_scr, p0 = tmp, cnt /* is it a minimalistic task? */ |
| } { .mbb |
| (p_yy) add cnt = -1, cnt |
| (p_scr) br.cond.dpnt.many .fraction_of_line /* go move just a few */ |
| ;; } |
| |
| { .mib |
| nop.m 0 |
| shr.u linecnt = cnt, LSIZE_SH |
| (p_zr) br.cond.dptk.many .l1b /* Jump to use stf.spill */ |
| ;; } |
| |
| #ifndef GAS_ALIGN_BREAKS_UNWIND_INFO |
| .align 32 /* -------- L1A: store ahead into cache lines; fill later */ |
| #endif |
| { .mmi |
| and tmp = -(LINE_SIZE), cnt /* compute end of range */ |
| mov ptr9 = ptr1 /* used for prefetching */ |
| and cnt = (LINE_SIZE-1), cnt /* remainder */ |
| } { .mmi |
| mov loopcnt = PREF_AHEAD-1 /* default prefetch loop */ |
| cmp.gt p_scr, p0 = PREF_AHEAD, linecnt /* check against actual value */ |
| ;; } |
| { .mmi |
| (p_scr) add loopcnt = -1, linecnt /* start of stores */ |
| add ptr2 = 8, ptr1 /* (beyond prefetch stores) */ |
| add ptr1 = tmp, ptr1 /* first address beyond total */ |
| ;; } /* range */ |
| { .mmi |
| add tmp = -1, linecnt /* next loop count */ |
| movi0 ar.lc = loopcnt |
| ;; } |
| .pref_l1a: |
| { .mib |
| store [ptr9] = myval, 128 /* Do stores one cache line apart */ |
| nop.i 0 |
| br.cloop.dptk.few .pref_l1a |
| ;; } |
| { .mmi |
| add ptr0 = 16, ptr2 /* Two stores in parallel */ |
| movi0 ar.lc = tmp |
| ;; } |
| .l1ax: |
| { .mmi |
| store [ptr2] = myval, 8 |
| store [ptr0] = myval, 8 |
| ;; } |
| { .mmi |
| store [ptr2] = myval, 24 |
| store [ptr0] = myval, 24 |
| ;; } |
| { .mmi |
| store [ptr2] = myval, 8 |
| store [ptr0] = myval, 8 |
| ;; } |
| { .mmi |
| store [ptr2] = myval, 24 |
| store [ptr0] = myval, 24 |
| ;; } |
| { .mmi |
| store [ptr2] = myval, 8 |
| store [ptr0] = myval, 8 |
| ;; } |
| { .mmi |
| store [ptr2] = myval, 24 |
| store [ptr0] = myval, 24 |
| ;; } |
| { .mmi |
| store [ptr2] = myval, 8 |
| store [ptr0] = myval, 32 |
| cmp.lt p_scr, p0 = ptr9, ptr1 /* do we need more prefetching? */ |
| ;; } |
| { .mmb |
| store [ptr2] = myval, 24 |
| (p_scr) store [ptr9] = myval, 128 |
| br.cloop.dptk.few .l1ax |
| ;; } |
| { .mbb |
| cmp.le p_scr, p0 = 8, cnt /* just a few bytes left ? */ |
| (p_scr) br.cond.dpnt.many .fraction_of_line /* Branch no. 2 */ |
| br.cond.dpnt.many .move_bytes_from_alignment /* Branch no. 3 */ |
| ;; } |
| |
| #ifdef GAS_ALIGN_BREAKS_UNWIND_INFO |
| { nop 0 } |
| #else |
| .align 32 |
| #endif |
| .l1b: /* ------------------ L1B: store ahead into cache lines; fill later */ |
| { .mmi |
| and tmp = -(LINE_SIZE), cnt /* compute end of range */ |
| mov ptr9 = ptr1 /* used for prefetching */ |
| and cnt = (LINE_SIZE-1), cnt /* remainder */ |
| } { .mmi |
| mov loopcnt = PREF_AHEAD-1 /* default prefetch loop */ |
| cmp.gt p_scr, p0 = PREF_AHEAD, linecnt /* check against actual value */ |
| ;; } |
| { .mmi |
| (p_scr) add loopcnt = -1, linecnt |
| add ptr2 = 16, ptr1 /* start of stores (beyond prefetch stores) */ |
| add ptr1 = tmp, ptr1 /* first address beyond total range */ |
| ;; } |
| { .mmi |
| add tmp = -1, linecnt /* next loop count */ |
| movi0 ar.lc = loopcnt |
| ;; } |
| .pref_l1b: |
| { .mib |
| stf.spill [ptr9] = f0, 128 /* Do stores one cache line apart */ |
| nop.i 0 |
| br.cloop.dptk.few .pref_l1b |
| ;; } |
| { .mmi |
| add ptr0 = 16, ptr2 /* Two stores in parallel */ |
| movi0 ar.lc = tmp |
| ;; } |
| .l1bx: |
| { .mmi |
| stf.spill [ptr2] = f0, 32 |
| stf.spill [ptr0] = f0, 32 |
| ;; } |
| { .mmi |
| stf.spill [ptr2] = f0, 32 |
| stf.spill [ptr0] = f0, 32 |
| ;; } |
| { .mmi |
| stf.spill [ptr2] = f0, 32 |
| stf.spill [ptr0] = f0, 64 |
| cmp.lt p_scr, p0 = ptr9, ptr1 /* do we need more prefetching? */ |
| ;; } |
| { .mmb |
| stf.spill [ptr2] = f0, 32 |
| (p_scr) stf.spill [ptr9] = f0, 128 |
| br.cloop.dptk.few .l1bx |
| ;; } |
| { .mib |
| cmp.gt p_scr, p0 = 8, cnt /* just a few bytes left ? */ |
| (p_scr) br.cond.dpnt.many .move_bytes_from_alignment |
| ;; } |
| |
| .fraction_of_line: |
| { .mib |
| add ptr2 = 16, ptr1 |
| shr.u loopcnt = cnt, 5 /* loopcnt = cnt / 32 */ |
| ;; } |
| { .mib |
| cmp.eq p_scr, p0 = loopcnt, r0 |
| add loopcnt = -1, loopcnt |
| (p_scr) br.cond.dpnt.many store_words |
| ;; } |
| { .mib |
| and cnt = 0x1f, cnt /* compute the remaining cnt */ |
| movi0 ar.lc = loopcnt |
| ;; } |
| #ifndef GAS_ALIGN_BREAKS_UNWIND_INFO |
| .align 32 |
| #endif |
| .l2: /* ---------------------------- L2A: store 32B in 2 cycles */ |
| { .mmb |
| store [ptr1] = myval, 8 |
| store [ptr2] = myval, 8 |
| ;; } { .mmb |
| store [ptr1] = myval, 24 |
| store [ptr2] = myval, 24 |
| br.cloop.dptk.many .l2 |
| ;; } |
| store_words: |
| { .mib |
| cmp.gt p_scr, p0 = 8, cnt /* just a few bytes left ? */ |
| (p_scr) br.cond.dpnt.many .move_bytes_from_alignment /* Branch */ |
| ;; } |
| |
| { .mmi |
| store [ptr1] = myval, 8 /* store */ |
| cmp.le p_y, p_n = 16, cnt /* */ |
| add cnt = -8, cnt /* subtract */ |
| ;; } |
| { .mmi |
| (p_y) store [ptr1] = myval, 8 /* store */ |
| (p_y) cmp.le.unc p_yy, p_nn = 16, cnt /* */ |
| (p_y) add cnt = -8, cnt /* subtract */ |
| ;; } |
| { .mmi /* store */ |
| (p_yy) store [ptr1] = myval, 8 /* */ |
| (p_yy) add cnt = -8, cnt /* subtract */ |
| ;; } |
| |
| .move_bytes_from_alignment: |
| { .mib |
| cmp.eq p_scr, p0 = cnt, r0 |
| tbit.nz.unc p_y, p0 = cnt, 2 /* should we terminate with a st4 ? */ |
| (p_scr) br.cond.dpnt.few .restore_and_exit |
| ;; } |
| { .mib |
| (p_y) st4 [ptr1] = value, 4 |
| tbit.nz.unc p_yy, p0 = cnt, 1 /* should we terminate with a st2 ? */ |
| ;; } |
| { .mib |
| (p_yy) st2 [ptr1] = value, 2 |
| tbit.nz.unc p_y, p0 = cnt, 0 |
| ;; } |
| |
| { .mib |
| (p_y) st1 [ptr1] = value |
| ;; } |
| .restore_and_exit: |
| { .mib |
| nop.m 0 |
| movi0 ar.lc = save_lc |
| br.ret.sptk.many rp |
| ;; } |
| |
| .move_bytes_unaligned: |
| { .mmi |
| .pred.rel "mutex",p_y, p_n |
| .pred.rel "mutex",p_yy, p_nn |
| (p_n) cmp.le p_yy, p_nn = 4, cnt |
| (p_y) cmp.le p_yy, p_nn = 5, cnt |
| (p_n) add ptr2 = 2, ptr1 |
| } { .mmi |
| (p_y) add ptr2 = 3, ptr1 |
| (p_y) st1 [ptr1] = value, 1 /* fill 1 (odd-aligned) byte */ |
| (p_y) add cnt = -1, cnt /* [15, 14 (or less) left] */ |
| ;; } |
| { .mmi |
| (p_yy) cmp.le.unc p_y, p0 = 8, cnt |
| add ptr3 = ptr1, cnt /* prepare last store */ |
| movi0 ar.lc = save_lc |
| } { .mmi |
| (p_yy) st2 [ptr1] = value, 4 /* fill 2 (aligned) bytes */ |
| (p_yy) st2 [ptr2] = value, 4 /* fill 2 (aligned) bytes */ |
| (p_yy) add cnt = -4, cnt /* [11, 10 (o less) left] */ |
| ;; } |
| { .mmi |
| (p_y) cmp.le.unc p_yy, p0 = 8, cnt |
| add ptr3 = -1, ptr3 /* last store */ |
| tbit.nz p_scr, p0 = cnt, 1 /* will there be a st2 at the end ? */ |
| } { .mmi |
| (p_y) st2 [ptr1] = value, 4 /* fill 2 (aligned) bytes */ |
| (p_y) st2 [ptr2] = value, 4 /* fill 2 (aligned) bytes */ |
| (p_y) add cnt = -4, cnt /* [7, 6 (or less) left] */ |
| ;; } |
| { .mmi |
| (p_yy) st2 [ptr1] = value, 4 /* fill 2 (aligned) bytes */ |
| (p_yy) st2 [ptr2] = value, 4 /* fill 2 (aligned) bytes */ |
| /* [3, 2 (or less) left] */ |
| tbit.nz p_y, p0 = cnt, 0 /* will there be a st1 at the end ? */ |
| } { .mmi |
| (p_yy) add cnt = -4, cnt |
| ;; } |
| { .mmb |
| (p_scr) st2 [ptr1] = value /* fill 2 (aligned) bytes */ |
| (p_y) st1 [ptr3] = value /* fill last byte (using ptr3) */ |
| br.ret.sptk.many rp |
| ;; } |
| END(memset) |
| libc_hidden_def (memset) |