//------------------------------------------------------------------------
// 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());
}
//------------------------------------------------------------------------
// 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());
}