1  /* Copyright (C) 1991-2023 Free Software Foundation, Inc.
       2     This file is part of the GNU C Library.
       3  
       4     The GNU C Library is free software; you can redistribute it and/or
       5     modify it under the terms of the GNU Lesser General Public
       6     License as published by the Free Software Foundation; either
       7     version 2.1 of the License, or (at your option) any later version.
       8  
       9     The GNU C Library is distributed in the hope that it will be useful,
      10     but WITHOUT ANY WARRANTY; without even the implied warranty of
      11     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
      12     Lesser General Public License for more details.
      13  
      14     You should have received a copy of the GNU Lesser General Public
      15     License along with the GNU C Library; if not, see
      16     <https://www.gnu.org/licenses/>.  */
      17  
      18  #include <string.h>
      19  #include <memcopy.h>
      20  
      21  #ifndef MEMSET
      22  # define MEMSET memset
      23  #endif
      24  
      25  void *
      26  inhibit_loop_to_libcall
      27  MEMSET (void *dstpp, int c, size_t len)
      28  {
      29    long int dstp = (long int) dstpp;
      30  
      31    if (len >= 8)
      32      {
      33        size_t xlen;
      34        op_t cccc;
      35  
      36        cccc = (unsigned char) c;
      37        cccc |= cccc << 8;
      38        cccc |= cccc << 16;
      39        if (OPSIZ > 4)
      40  	/* Do the shift in two steps to avoid warning if long has 32 bits.  */
      41  	cccc |= (cccc << 16) << 16;
      42  
      43        /* There are at least some bytes to set.
      44  	 No need to test for LEN == 0 in this alignment loop.  */
      45        while (dstp % OPSIZ != 0)
      46  	{
      47  	  ((byte *) dstp)[0] = c;
      48  	  dstp += 1;
      49  	  len -= 1;
      50  	}
      51  
      52        /* Write 8 `op_t' per iteration until less than 8 `op_t' remain.  */
      53        xlen = len / (OPSIZ * 8);
      54        while (xlen > 0)
      55  	{
      56  	  ((op_t *) dstp)[0] = cccc;
      57  	  ((op_t *) dstp)[1] = cccc;
      58  	  ((op_t *) dstp)[2] = cccc;
      59  	  ((op_t *) dstp)[3] = cccc;
      60  	  ((op_t *) dstp)[4] = cccc;
      61  	  ((op_t *) dstp)[5] = cccc;
      62  	  ((op_t *) dstp)[6] = cccc;
      63  	  ((op_t *) dstp)[7] = cccc;
      64  	  dstp += 8 * OPSIZ;
      65  	  xlen -= 1;
      66  	}
      67        len %= OPSIZ * 8;
      68  
      69        /* Write 1 `op_t' per iteration until less than OPSIZ bytes remain.  */
      70        xlen = len / OPSIZ;
      71        while (xlen > 0)
      72  	{
      73  	  ((op_t *) dstp)[0] = cccc;
      74  	  dstp += OPSIZ;
      75  	  xlen -= 1;
      76  	}
      77        len %= OPSIZ;
      78      }
      79  
      80    /* Write the last few bytes.  */
      81    while (len > 0)
      82      {
      83        ((byte *) dstp)[0] = c;
      84        dstp += 1;
      85        len -= 1;
      86      }
      87  
      88    return dstpp;
      89  }
      90  libc_hidden_builtin_def (MEMSET)