Illegal use of __byte() intrinsic.

Hi,

I have a problem with C2000 compiler, v6.4.x (tested with versions 6.4.4 and 6.4.6): the compiler issues the following error:

error: "src/ec1_lib_fwu_vrs00654/mcan/mcan_remote.c", line 113: Illegal use of intrinsic: __byte

The same project can be compiled with C2000 compiler v5.2.15 without problems.

It seems to me, that the problem is in compiler, because the problem is gone, when I comment out the line #122, but stays when I comment out the line #123 (notice, that both lines are far away from line #113 and they differ only in constants). The failure occures when -O2 (or higher) optimization is used, when -00 or -O1 is used, the code compiles correctly. I have been able to reproduce the problem on a different PC. Also, when I replace the body of function mcanRemoteFlagA() by { return 0; }, the code can be compiled.

My code look like this (with line numbers):

   110	
   111	    SETBYTE((void *) pBuffer, 0, (I16) GETBYTE((void *) aAuxBuffer, 0));        // FlagA1.Lo
   112	
   113	    nRemoteIdentStringAddr = ((U32) GETBYTE((void *) aAuxBuffer, 4) << 24u) | ((U32) GETBYTE((void *) aAuxBuffer, 3) << 16u) | ((U32) GETBYTE((void *) aAuxBuffer, 2) << 8u) | (U32) GETBYTE((void *) aAuxBuffer, 1);
   114	
   115	    // check whether remote node supports extended configuration (FlagA2):
   116	    if(tRemoteFlagA1.bit.fExtConfig == 1u)
   117	    {
   118	      if(mcanRemoteFlagA(nRemoteNodeNum, aAuxBuffer) == 0)
   119	      {
   120	        tRemoteFlagA2.all = 0u;                         // used to silence the compiler, which incorrectly thinks, that tRemoteFlagA2.all is used before setting its value at following two lines
   121	
   122	        SETBYTE((void *) &tRemoteFlagA2.all, 0, GETBYTE((void *) aAuxBuffer, 1));
   123	        SETBYTE((void *) &tRemoteFlagA2.all, 1, GETBYTE((void *) aAuxBuffer, 2));
   124	
   125	        retVal = LEN_IDENT_EX;
   126	      }
   127	      else
   128	      {
   129	        retVal = -1;
   130	      }
   131	
   132	      SETBYTE((void *) pBuffer, 1, (I16) GETBYTE((void *) aAuxBuffer, 1));
   133	      SETBYTE((void *) pBuffer, 2, (I16) GETBYTE((void *) aAuxBuffer, 2));
   134	    }
   135	    else
   136	    {
   137	      tRemoteFlagA2.all = 0;
   138	
   139	      retVal = LEN_IDENT;
   140	    }

The same code after preprocessing looks like this:

    __byte(((void *) pBuffer), (0)) = ((I16) __byte(((void *) aAuxBuffer), (0)));        // FlagA1.Lo

    nRemoteIdentStringAddr = ((U32) __byte(((void *) aAuxBuffer), (4)) << 24u) | ((U32) __byte(((void *) aAuxBuffer), (3)) << 16u) | ((U32) __byte(((void *) aAuxBuffer), (2)) << 8u) | (U32) __byte(((void *) aAuxBuffer), (1));

    // check whether remote node supports extended configuration (FlagA2):
    if(tRemoteFlagA1.bit.fExtConfig == 1u)
    {
      if(mcanRemoteFlagA(nRemoteNodeNum, aAuxBuffer) == 0)
      {
        tRemoteFlagA2.all = 0u;                         // used to silence the compiler, which incorrectly thinks, that tRemoteFlagA2.all is used before setting its value at following two lines

        __byte(((void *) &tRemoteFlagA2 . all), (0)) = (__byte(((void *) aAuxBuffer), (1)));
        __byte(((void *) &tRemoteFlagA2 . all), (1)) = (__byte(((void *) aAuxBuffer), (2)));

        retVal = 64;
      }
      else
      {
        retVal = -1;
      }

      __byte(((void *) pBuffer), (1)) = ((I16) __byte(((void *) aAuxBuffer), (1)));
      __byte(((void *) pBuffer), (2)) = ((I16) __byte(((void *) aAuxBuffer), (2)));
    }
    else
    {
      tRemoteFlagA2.all = 0;

      retVal = 20;
    }

typedef unsigned int U16; /**< Unsigned, 16-bits wide number */

/**
 * @brief Bit-field containing FlagA2 bits.
 */
typedef struct
{
  U16 fMapCommand       : 1;
  U16 fCPU28xx          : 1;
  U16 fReserved02       : 1;
  U16 fExtIdent         : 1;
  U16 fParType          : 1;
  U16 fFlagA3Supported  : 1;
  U16 fMultiNodeLoading : 1;
  U16 fIdentMessage     : 1;
  U16 fReserved08       : 1;
  U16 fReserved09       : 1;
  U16 fReserved10       : 1;
  U16 fReserved11       : 1;
  U16 fReserved12       : 1;
  U16 fReserved13       : 1;
  U16 fReserved14       : 1;
  U16 fReserved15       : 1;
} T_X_FLAGA2;

/**
 * Union for FlagA2
 */
typedef union
{
  T_X_FLAGA2 bit;               /**< This allows accessing individual bits of FlagA2 */
  U16 all;                      /**< This allows manipulation with whole FlagA2 */
} T_FLAGA2;

static U16 aAuxBuffer[5];

Any idea what is wrong?

Thanks,

  Jan