lib_mem.c

UCOS-III

    }


    data_align = 0u;
    for (i = 0u; i < sizeof(CPU_ALIGN); i++) {                  /* Fill each data_align octet with data val.            */
        data_align <<=  DEF_OCTET_NBR_BITS;
        data_align  |= (CPU_ALIGN)data_val;
    }

    size_rem      =  size;
    mem_align_mod = (CPU_INT08U)((CPU_ADDR)pmem % sizeof(CPU_ALIGN));   /* See Note #3.                                 */

    pmem_08 = (CPU_INT08U *)pmem;
    if (mem_align_mod != 0u) {                                  /* If leading octets avail,                   ...       */
        i = mem_align_mod;
        while ((size_rem > 0) &&                                /* ... start mem buf fill with leading octets ...       */
               (i        < sizeof(CPU_ALIGN ))) {               /* ... until next CPU_ALIGN word boundary.              */
           *pmem_08++ = data_val;
            size_rem -= sizeof(CPU_INT08U);
            i++;
        }
    }

    pmem_align = (CPU_ALIGN *)pmem_08;                          /* See Note #2a.                                        */
    while (size_rem >= sizeof(CPU_ALIGN)) {                     /* While mem buf aligned on CPU_ALIGN word boundaries,  */
       *pmem_align++ = data_align;                              /* ... fill mem buf with    CPU_ALIGN-sized data.       */
        size_rem    -= sizeof(CPU_ALIGN);
    }

    pmem_08 = (CPU_INT08U *)pmem_align;
    while (size_rem > 0) {                                      /* Finish mem buf fill with trailing octets.            */
       *pmem_08++   = data_val;
        size_rem   -= sizeof(CPU_INT08U);
    }
}


/*$PAGE*/
/*
*********************************************************************************************************
*                                             Mem_Copy()
*
* Description : Copy data octets from one memory buffer to another memory buffer.
*
* Argument(s) : pdest       Pointer to destination memory buffer.
*
*               psrc        Pointer to source      memory buffer.
*
*               size        Number of data buffer octets to copy (see Note #1).
*
* Return(s)   : none.
*
* Caller(s)   : Application.
*
* Note(s)     : (1) Null copies allowed (i.e. zero-length copies).
*
*               (2) Memory buffers NOT checked for overlapping.
*
*                   (a) IEEE Std 1003.1, 2004 Edition, Section 'memcpy() : DESCRIPTION' states that "if 
*                       copying takes place between objects that overlap, the behavior is undefined".
*
*                   (b) However, data octets from a source memory buffer at a higher address value SHOULD 
*                       successfully copy to a destination memory buffer at a lower  address value even 
*                       if any octets of the memory buffers overlap as long as no individual, atomic CPU 
*                       word copy overlaps.
*
*                       Since Mem_Copy() performs the data octet copy via 'CPU_ALIGN'-sized words &/or 
*                       octets; & since 'CPU_ALIGN'-sized words MUST be accessed on word-aligned addresses 
*                       (see Note #3b), neither 'CPU_ALIGN'-sized words nor octets at unique addresses can 
*                       ever overlap.
*
*                       Therefore, Mem_Copy() SHOULD be able to successfully copy overlapping memory 
*                       buffers as long as the source memory buffer is at a higher address value than the 
*                       destination memory buffer.
*
*               (3) For best CPU performance, optimized to copy data buffer using 'CPU_ALIGN'-sized data
*                   words.
*
*                   (a) Since many word-aligned processors REQUIRE that multi-octet words be accessed on
*                       word-aligned addresses, 'CPU_ALIGN'-sized words MUST be accessed on 'CPU_ALIGN'd
*                       addresses.
*
*               (4) Modulo arithmetic is used to determine whether a memory buffer starts on a 'CPU_ALIGN'
*                   address boundary.
*
*                   Modulo arithmetic in ANSI-C REQUIREs operations performed on integer values.  Thus,
*                   address values MUST be cast to an appropriately-sized integer value PRIOR to any
*                  'mem_align_mod' arithmetic operation.
*********************************************************************************************************
*/
/*$PAGE*/
#if (LIB_MEM_CFG_OPTIMIZE_ASM_EN != DEF_ENABLED)
void  Mem_Copy (       void        *pdest,
                const  void        *psrc,
                       CPU_SIZE_T   size)
{
           CPU_SIZE_T    size_rem;
           CPU_ALIGN    *pmem_align_dest;
    const  CPU_ALIGN    *pmem_align_src;
           CPU_INT08U   *pmem_08_dest;
    const  CPU_INT08U   *pmem_08_src;
           CPU_DATA      i;
           CPU_DATA      mem_align_mod_dest;
           CPU_DATA      mem_align_mod_src;
           CPU_BOOLEAN   mem_aligned;


    if (size < 1) {                                             /* See Note #1.                                         */
        return;
    }
    if (pdest == (void *)0) {
        return;
    }
    if (psrc  == (void *)0) {
        return;
    }


    size_rem           =  size;

    pmem_08_dest       = (      CPU_INT08U *)pdest;
    pmem_08_src        = (const CPU_INT08U *)psrc;
                                                                /* See Note #4.                                         */
    mem_align_mod_dest = (CPU_INT08U)((CPU_ADDR)pmem_08_dest % sizeof(CPU_ALIGN));
    mem_align_mod_src  = (CPU_INT08U)((CPU_ADDR)pmem_08_src  % sizeof(CPU_ALIGN));

    mem_aligned        = (mem_align_mod_dest == mem_align_mod_src) ? DEF_YES : DEF_NO;

    if (mem_aligned == DEF_YES) {                               /* If mem bufs' alignment offset equal, ...             */
                                                                /* ... optimize copy for mem buf alignment.             */
        if (mem_align_mod_dest != 0u) {                         /* If leading octets avail,                   ...       */
            i = mem_align_mod_dest;
            while ((size_rem   >  0) &&                         /* ... start mem buf copy with leading octets ...       */
                   (i          <  sizeof(CPU_ALIGN ))) {        /* ... until next CPU_ALIGN word boundary.              */
               *pmem_08_dest++ = *pmem_08_src++;
                size_rem      -=  sizeof(CPU_INT08U);
                i++;
            }
        }

        pmem_align_dest = (      CPU_ALIGN *)pmem_08_dest;      /* See Note #3a.                                        */
        pmem_align_src  = (const CPU_ALIGN *)pmem_08_src;
        while (size_rem      >=  sizeof(CPU_ALIGN)) {           /* While mem bufs aligned on CPU_ALIGN word boundaries, */
           *pmem_align_dest++ = *pmem_align_src++;              /* ... copy psrc to pdest with CPU_ALIGN-sized words.   */
            size_rem         -=  sizeof(CPU_ALIGN);
        }

        pmem_08_dest = (      CPU_INT08U *)pmem_align_dest;
        pmem_08_src  = (const CPU_INT08U *)pmem_align_src;
    }

    while (size_rem > 0) {                                      /* For unaligned mem bufs or trailing octets, ...       */
       *pmem_08_dest++ = *pmem_08_src++;                        /* ... copy psrc to pdest by octets.                    */
        size_rem      -=  sizeof(CPU_INT08U);
    }
}
#endif


/*$PAGE*/
/*
*********************************************************************************************************
*                                              Mem_Cmp()
*
* Description : Verify that ALL data octets in two memory buffers are identical in sequence.
*
* Argument(s) : p1_mem      Pointer to first  memory buffer.
*
*               p2_mem      Pointer to second memory buffer.
*
*               size        Number of data buffer octets to compare (see Note #1).
*
* Return(s)   : DEF_YES, if 'size' number of data octets are identical in both memory buffers.
*
*               DEF_NO,  otherwise.
*
* Caller(s)   : Application.
*
* Note(s)     : (1) Null compares allowed (i.e. zero-length compares); 'DEF_YES' returned to indicate 
*                   identical null compare.
*
*               (2) Many memory buffer comparisons vary ONLY in the least significant octets -- e.g.
*                   network address buffers.  Consequently, memory buffer comparison is more efficient
*                   if the comparison starts from the end of the memory buffers which will abort sooner
*                   on dissimilar memory buffers that vary only in the least significant octets.
*
*               (3) For best CPU performance, optimized to compare data buffers using 'CPU_ALIGN'-sized
*                   data words.
*
*                   (a) Since many word-aligned processors REQUIRE that multi-octet words be accessed on
*                       word-aligned addresses, 'CPU_ALIGN'-sized words MUST be accessed on 'CPU_ALIGN'd
*                       addresses.
*
*               (4) Modulo arithmetic is used to determine whether a memory buffer starts on a 'CPU_ALIGN'
*                   address boundary.
*
*                   Modulo arithmetic in ANSI-C REQUIREs operations performed on integer values.  Thus,
*                   address values MUST be cast to an appropriately-sized integer value PRIOR to any
*                  'mem_align_mod' arithmetic operation.
********************************************************************************************************
*/
/*$PAGE*/
CPU_BOOLEAN  Mem_Cmp (const  void        *p1_mem,
                      const  void        *p2_mem,
                             CPU_SIZE_T   size)
{
           CPU_SIZE_T    size_rem;
           CPU_ALIGN    *p1_mem_align;
           CPU_ALIGN    *p2_mem_align;
    const  CPU_INT08U   *p1_mem_08;
    const  CPU_INT08U   *p2_mem_08;
           CPU_DATA      i;
           CPU_DATA      mem_align_mod_1;
           CPU_DATA      mem_align_mod_2;
           CPU_BOOLEAN   mem_aligned;
           CPU_BOOLEAN   mem_cmp;


    if (size < 1) {                                             /* See Note #1.                                         */
        return (DEF_YES);
    }
    if (p1_mem == (void *)0) {
        return (DEF_NO);
    }
    if (p2_mem == (void *)0) {
        return (DEF_NO);
    }


    mem_cmp         =  DEF_YES;                                 /* Assume mem bufs are identical until cmp fails.       */
    size_rem        =  size;
                                                                /* Start @ end of mem bufs (see Note #2).               */
    p1_mem_08       = (const CPU_INT08U *)p1_mem + size;
    p2_mem_08       = (const CPU_INT08U *)p2_mem + size;
                                                                /* See Note #4.                                         */
    mem_align_mod_1 = (CPU_INT08U)((CPU_ADDR)p1_mem_08 % sizeof(CPU_ALIGN));
    mem_align_mod_2 = (CPU_INT08U)((CPU_ADDR)p2_mem_08 % sizeof(CPU_ALIGN));

    mem_aligned     = (mem_align_mod_1 == mem_align_mod_2) ? DEF_YES : DEF_NO;

    if (mem_aligned == DEF_YES) {                               /* If mem bufs' alignment offset equal, ...             */
                                                                /* ... optimize cmp for mem buf alignment.              */
        if (mem_align_mod_1 != 0u) {                            /* If trailing octets avail,                  ...       */
            i = mem_align_mod_1;
            while ((mem_cmp == DEF_YES) &&                      /* ... cmp mem bufs while identical &         ...       */
                   (size_rem > 0)       &&                      /* ... start mem buf cmp with trailing octets ...       */
                   (i        > 0)) {                            /* ... until next CPU_ALIGN word boundary.              */
                p1_mem_08--;
                p2_mem_08--;
                if (*p1_mem_08 != *p2_mem_08) {                 /* If ANY data octet(s) NOT identical, cmp fails.       */
                     mem_cmp = DEF_NO;
                }
                size_rem -= sizeof(CPU_INT08U);
                i--;
            }
        }

        if (mem_cmp == DEF_YES) {                               /* If cmp still identical, cmp aligned mem bufs.        */
            p1_mem_align = (CPU_ALIGN *)p1_mem_08;              /* See Note #3a.                                        */
            p2_mem_align = (CPU_ALIGN *)p2_mem_08;

            while ((mem_cmp  == DEF_YES) &&                     /* Cmp mem bufs while identical & ...                   */
                   (size_rem >= sizeof(CPU_ALIGN))) {           /* ... mem bufs aligned on CPU_ALIGN word boundaries.   */
                p1_mem_align--;
                p2_mem_align--;
                if (*p1_mem_align != *p2_mem_align) {           /* If ANY data octet(s) NOT identical, cmp fails.       */
                     mem_cmp = DEF_NO;
                }
                size_rem -= sizeof(CPU_ALIGN);
            }

            p1_mem_08 = (CPU_INT08U *)p1_mem_align;
            p2_mem_08 = (CPU_INT08U *)p2_mem_align;
        }
    }

    while ((mem_cmp == DEF_YES) &&                              /* Cmp mem bufs while identical ...                     */
           (size_rem > 0)) {                                    /* ... for unaligned mem bufs or trailing octets.       */