Function EXPR

code_generators/interp_generator.py:521–575

`EXPR` is the core function use by the code generator to generate C-functions. It encapsulates the expression to execute by the virtual machine, for each block. Parameters ---------- opNum The index in the operation table, which is finalized as a C `switch-case`

(opNum: int, expr: str, retChar: str, 
         arg1Dchar: str=None, arg2Dchar: str=None, arg3Dchar: str=None, vecType: int=TYPE_LOOP)

TYPE_ALIGNED = 2
TYPE_STRIDED = 3
def EXPR(opNum: int, expr: str, retChar: str, 
         arg1Dchar: str=None, arg2Dchar: str=None, arg3Dchar: str=None, vecType: int=TYPE_LOOP) -> str:
    '''
    `EXPR` is the core function use by the code generator to generate C-functions.
    It encapsulates the expression to execute by the virtual machine, for each 
    block.

    Parameters
    ----------
    opNum
        The index in the operation table, which is finalized as a C `switch-case`
        statement block.
    expr
        A string expression with variables (all of which start with ``$``)

    vecType
        The vectorization enumerator (presently one of ``{TYPE_LOOP, TYPE_ALIGNED, TYPE_STRIDED}``).
    Returns
    -------
    expr

    '''
    argChars = [item for item in (arg1Dchar, arg2Dchar, arg3Dchar) if item != None]

    # STRING, and UNICODE have special operation syntax
    # Perhaps it would be easier to make string operations _all_ functions.
    if 'S' in argChars or 'U' in argChars:
        print( 'TODO: string: %s ' % expr )
        return 

    # Replace tokens
    # TODO: this should moreso be a C-define, but perhaps BLOCK_SIZE1/2/4/8/16?
    expr = expr.replace( '$BLOCKSIZE', str(BLOCKSIZE) )

    # Build loop structure
    # docString = '// {} ({}) :: {}'.format(retChar, argChars, expr)
    if vecType == TYPE_LOOP:
        expr = VEC_ARGN[len(argChars)](expr)
        #expr = 'case {0}: {2} {1}'.format( opNum, VEC_ARGN[len(argChars)](expr), docString )
    elif vecType == TYPE_ALIGNED:
        expr = VEC_ARGN_ALIGNED[len(argChars)](expr)
        #expr =  'case {0}: {2} {1}'.format( opNum, VEC_ARGN_ALIGNED[len(argChars)](expr), docString )
    elif vecType == TYPE_STRIDED:
        expr = VEC_ARGN_STRIDED[len(argChars)](expr)
        #expr = 'case {0}: {2} {1}'.format( opNum, VEC_ARGN_STRIDED[len(argChars)](expr), docString )
    else:
        raise ValueError( "Unknown vectorization type: {}".format(vecType) )
        
    expr = expr.replace( '$DEST', DEST() )
    expr = expr.replace( '$DTYPE0', DCHAR_TO_CTYPE[retChar] )
    for I, dchar in enumerate(argChars):
        #expr = expr.replace( '$ARG{}'.format(I+1), ARG( dchar, I+1 ) )
        expr = expr.replace( '$DTYPE{}'.format(I+1), DCHAR_TO_CTYPE[dchar]  )
        
    return expr