github.com/prattmic/llgo-embedded@v0.0.0-20150820070356-41cfecea0e1e/third_party/gofrontend/libffi/src/bfin/ffi.c (about)

     1  /* -----------------------------------------------------------------------
     2     ffi.c - Copyright (c) 2012  Alexandre K. I. de Mendonca <alexandre.keunecke@gmail.com>,
     3  							   Paulo Pizarro <paulo.pizarro@gmail.com>
     4  
     5     Blackfin Foreign Function Interface
     6  
     7     Permission is hereby granted, free of charge, to any person obtaining
     8     a copy of this software and associated documentation files (the
     9     ``Software''), to deal in the Software without restriction, including
    10     without limitation the rights to use, copy, modify, merge, publish,
    11     distribute, sublicense, and/or sell copies of the Software, and to
    12     permit persons to whom the Software is furnished to do so, subject to
    13     the following conditions:
    14  
    15     The above copyright notice and this permission notice shall be included
    16     in all copies or substantial portions of the Software.
    17  
    18     THE SOFTWARE IS PROVIDED ``AS IS'', WITHOUT WARRANTY OF ANY KIND,
    19     EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
    20     MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
    21     NONINFRINGEMENT.  IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
    22     HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
    23     WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
    24     OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
    25     DEALINGS IN THE SOFTWARE.
    26     ----------------------------------------------------------------------- */
    27  #include <ffi.h>
    28  #include <ffi_common.h>
    29  
    30  #include <stdlib.h>
    31  #include <stdio.h>
    32  
    33  /* Maximum number of GPRs available for argument passing.  */
    34  #define MAX_GPRARGS 3
    35  
    36  /*
    37   * Return types
    38   */
    39  #define FFIBFIN_RET_VOID 0
    40  #define FFIBFIN_RET_BYTE 1
    41  #define FFIBFIN_RET_HALFWORD 2
    42  #define FFIBFIN_RET_INT64 3
    43  #define FFIBFIN_RET_INT32 4
    44  
    45  /*====================================================================*/
    46  /*                          PROTOTYPE          *
    47   /*====================================================================*/
    48  void ffi_prep_args(unsigned char *, extended_cif *);
    49  
    50  /*====================================================================*/
    51  /*                          Externals                                 */
    52  /*                          (Assembly)                                */
    53  /*====================================================================*/
    54  
    55  extern void ffi_call_SYSV(unsigned, extended_cif *, void(*)(unsigned char *, extended_cif *), unsigned, void *, void(*fn)(void));
    56  
    57  /*====================================================================*/
    58  /*                          Implementation                            */
    59  /*                                                            */
    60  /*====================================================================*/
    61  
    62  
    63  /*
    64   * This function calculates the return type (size) based on type.
    65   */
    66  
    67  ffi_status ffi_prep_cif_machdep(ffi_cif *cif)
    68  {
    69     /* --------------------------------------*
    70      *   Return handling                *
    71      * --------------------------------------*/
    72     switch (cif->rtype->type) {
    73        case FFI_TYPE_VOID:
    74           cif->flags = FFIBFIN_RET_VOID;
    75           break;
    76        case FFI_TYPE_UINT16:
    77        case FFI_TYPE_SINT16:
    78           cif->flags = FFIBFIN_RET_HALFWORD;
    79           break;
    80        case FFI_TYPE_UINT8:
    81           cif->flags = FFIBFIN_RET_BYTE;
    82           break;
    83        case FFI_TYPE_INT:
    84        case FFI_TYPE_UINT32:
    85        case FFI_TYPE_SINT32:
    86        case FFI_TYPE_FLOAT:
    87        case FFI_TYPE_POINTER:
    88        case FFI_TYPE_SINT8:
    89           cif->flags = FFIBFIN_RET_INT32;
    90           break;
    91        case FFI_TYPE_SINT64:
    92        case FFI_TYPE_UINT64:
    93        case FFI_TYPE_DOUBLE:
    94            cif->flags = FFIBFIN_RET_INT64;
    95            break;
    96        case FFI_TYPE_STRUCT:
    97           if (cif->rtype->size <= 4){
    98          	 cif->flags = FFIBFIN_RET_INT32;
    99           }else if (cif->rtype->size == 8){
   100          	 cif->flags = FFIBFIN_RET_INT64;
   101           }else{
   102          	 //it will return via a hidden pointer in P0
   103          	 cif->flags = FFIBFIN_RET_VOID;
   104           }
   105           break;
   106        default:
   107           FFI_ASSERT(0);
   108           break;
   109     }
   110     return FFI_OK;
   111  }
   112  
   113  /*
   114   * This will prepare the arguments and will call the assembly routine
   115   * cif = the call interface
   116   * fn = the function to be called
   117   * rvalue = the return value
   118   * avalue = the arguments
   119   */
   120  void ffi_call(ffi_cif *cif, void(*fn)(void), void *rvalue, void **avalue)
   121  {
   122     int ret_type = cif->flags;
   123     extended_cif ecif;
   124     ecif.cif = cif;
   125     ecif.avalue = avalue;
   126     ecif.rvalue = rvalue;
   127  
   128     switch (cif->abi) {
   129        case FFI_SYSV:
   130           ffi_call_SYSV(cif->bytes, &ecif, ffi_prep_args, ret_type, ecif.rvalue, fn);
   131           break;
   132        default:
   133           FFI_ASSERT(0);
   134           break;
   135     }
   136  }
   137  
   138  
   139  /*
   140  * This function prepares the parameters (copies them from the ecif to the stack)
   141  *  to call the function (ffi_prep_args is called by the assembly routine in file
   142  *  sysv.S, which also calls the actual function)
   143  */
   144  void ffi_prep_args(unsigned char *stack, extended_cif *ecif)
   145  {
   146     register unsigned int i = 0;
   147     void **p_argv;
   148     unsigned char *argp;
   149     ffi_type **p_arg;
   150     argp = stack;
   151     p_argv = ecif->avalue;
   152     for (i = ecif->cif->nargs, p_arg = ecif->cif->arg_types;
   153          (i != 0);
   154          i--, p_arg++) {
   155        size_t z;
   156        z = (*p_arg)->size;
   157        if (z < sizeof(int)) {
   158           z = sizeof(int);
   159           switch ((*p_arg)->type) {
   160              case FFI_TYPE_SINT8: {
   161                    signed char v = *(SINT8 *)(* p_argv);
   162                    signed int t = v;
   163                    *(signed int *) argp = t;
   164                 }
   165                 break;
   166              case FFI_TYPE_UINT8: {
   167                    unsigned char v = *(UINT8 *)(* p_argv);
   168                    unsigned int t = v;
   169                    *(unsigned int *) argp = t;
   170                 }
   171                 break;
   172              case FFI_TYPE_SINT16:
   173                 *(signed int *) argp = (signed int) * (SINT16 *)(* p_argv);
   174                 break;
   175              case FFI_TYPE_UINT16:
   176                 *(unsigned int *) argp = (unsigned int) * (UINT16 *)(* p_argv);
   177                 break;
   178              case FFI_TYPE_STRUCT:
   179                 memcpy(argp, *p_argv, (*p_arg)->size);
   180                 break;
   181              default:
   182                 FFI_ASSERT(0);
   183                 break;
   184           }
   185        } else if (z == sizeof(int)) {
   186           *(unsigned int *) argp = (unsigned int) * (UINT32 *)(* p_argv);
   187        } else {
   188           memcpy(argp, *p_argv, z);
   189        }
   190        p_argv++;
   191        argp += z;
   192     }
   193  }
   194  
   195  
   196