Пример #1
0
//------------------------------------------------------------------------
// LowerCast: Lower GT_CAST(srcType, DstType) nodes.
//
// Arguments:
//    tree - GT_CAST node to be lowered
//
// Return Value:
//    None.
//
// Notes:
//    Casts from float/double to a smaller int type are transformed as follows:
//    GT_CAST(float/double, byte)     =   GT_CAST(GT_CAST(float/double, int32), byte)
//    GT_CAST(float/double, sbyte)    =   GT_CAST(GT_CAST(float/double, int32), sbyte)
//    GT_CAST(float/double, int16)    =   GT_CAST(GT_CAST(double/double, int32), int16)
//    GT_CAST(float/double, uint16)   =   GT_CAST(GT_CAST(double/double, int32), uint16)
//
//    Note that for the overflow conversions we still depend on helper calls and
//    don't expect to see them here.
//    i) GT_CAST(float/double, int type with overflow detection)
//
void Lowering::LowerCast(GenTree* tree)
{
    assert(tree->OperGet() == GT_CAST);

    JITDUMP("LowerCast for: ");
    DISPNODE(tree);
    JITDUMP("\n");

    GenTree*  op1     = tree->gtOp.gtOp1;
    var_types dstType = tree->CastToType();
    var_types srcType = genActualType(op1->TypeGet());
    var_types tmpType = TYP_UNDEF;

    if (varTypeIsFloating(srcType))
    {
        noway_assert(!tree->gtOverflow());
        assert(!varTypeIsSmall(dstType)); // fgMorphCast creates intermediate casts when converting from float to small
                                          // int.
    }

    assert(!varTypeIsSmall(srcType));

    if (tmpType != TYP_UNDEF)
    {
        GenTree* tmp = comp->gtNewCastNode(tmpType, op1, tree->IsUnsigned(), tmpType);
        tmp->gtFlags |= (tree->gtFlags & (GTF_OVERFLOW | GTF_EXCEPT));

        tree->gtFlags &= ~GTF_UNSIGNED;
        tree->gtOp.gtOp1 = tmp;
        BlockRange().InsertAfter(op1, tmp);
    }

    // Now determine if we have operands that should be contained.
    ContainCheckCast(tree->AsCast());
}
Пример #2
0
//------------------------------------------------------------------------
// LowerCast: Lower GT_CAST(srcType, DstType) nodes.
//
// Arguments:
//    tree - GT_CAST node to be lowered
//
// Return Value:
//    None.
//
// Notes:
//    Casts from float/double to a smaller int type are transformed as follows:
//    GT_CAST(float/double, byte)     =   GT_CAST(GT_CAST(float/double, int32), byte)
//    GT_CAST(float/double, sbyte)    =   GT_CAST(GT_CAST(float/double, int32), sbyte)
//    GT_CAST(float/double, int16)    =   GT_CAST(GT_CAST(double/double, int32), int16)
//    GT_CAST(float/double, uint16)   =   GT_CAST(GT_CAST(double/double, int32), uint16)
//
//    Note that for the overflow conversions we still depend on helper calls and
//    don't expect to see them here.
//    i) GT_CAST(float/double, int type with overflow detection)
//
void Lowering::LowerCast(GenTree* tree)
{
    assert(tree->OperGet() == GT_CAST);

    JITDUMP("LowerCast for: ");
    DISPNODE(tree);
    JITDUMP("\n");

    GenTreePtr op1     = tree->gtOp.gtOp1;
    var_types  dstType = tree->CastToType();
    var_types  srcType = genActualType(op1->TypeGet());
    var_types  tmpType = TYP_UNDEF;

    if (varTypeIsFloating(srcType))
    {
        noway_assert(!tree->gtOverflow());
    }

    assert(!varTypeIsSmall(srcType));

    // case of src is a floating point type and dst is a small type.
    if (varTypeIsFloating(srcType) && varTypeIsSmall(dstType))
    {
        NYI_ARM("Lowering for cast from float to small type"); // Not tested yet.
        tmpType = TYP_INT;
    }

    if (tmpType != TYP_UNDEF)
    {
        GenTreePtr tmp = comp->gtNewCastNode(tmpType, op1, tmpType);
        tmp->gtFlags |= (tree->gtFlags & (GTF_UNSIGNED | GTF_OVERFLOW | GTF_EXCEPT));

        tree->gtFlags &= ~GTF_UNSIGNED;
        tree->gtOp.gtOp1 = tmp;
        BlockRange().InsertAfter(op1, tmp);
    }

    // Now determine if we have operands that should be contained.
    ContainCheckCast(tree->AsCast());
}