def slice_to_SLICE(sliceVals, width):
"""convert python slice to value of SLICE hdl type"""
if sliceVals.step is not None:
raise NotImplementedError()
start = sliceVals.start
stop = sliceVals.stop
if sliceVals.start is None:
start = INT.fromPy(width)
else:
start = toHVal(sliceVals.start)
if sliceVals.stop is None:
stop = INT.fromPy(0)
else:
stop = toHVal(sliceVals.stop)
startIsVal = isinstance(start, Value)
stopIsVal = isinstance(stop, Value)
indexesAreValues = startIsVal and stopIsVal
if indexesAreValues:
updateTime = max(start.updateTime, stop.updateTime)
else:
updateTime = -1
return Slice.getValueCls()((start, stop), SLICE, 1, updateTime)
def __getitem__(self, key):
iamVal = isinstance(self, HValue)
key = toHVal(key)
isSLICE = isinstance(key, Slice.getValueCls())
if isSLICE:
raise NotImplementedError()
elif isinstance(key, (HValue, RtlSignalBase)):
pass
else:
raise NotImplementedError(
f"Index operation not implemented for index {key}")
if iamVal and isinstance(key, HValue):
return self._getitem__val(key)
return Operator.withRes(AllOps.INDEX, [self, key],
self._dtype.element_t)
def __getitem__(self, key):
iamVal = isinstance(self, Value)
key = toHVal(key)
isSLICE = isinstance(key, Slice.getValueCls())
if isSLICE:
raise NotImplementedError()
elif isinstance(key, RtlSignalBase):
key = key._auto_cast(INT)
elif isinstance(key, Value):
pass
else:
raise NotImplementedError(
"Index operation not implemented for index %r" % (key))
if iamVal and isinstance(key, Value):
return self._getitem__val(key)
return Operator.withRes(AllOps.INDEX, [self, key], self._dtype.elmType)
"""
Definitions of most common types
"""
from hwt.hdl.types.bits import Bits
from hwt.hdl.types.slice import Slice
from hwt.hdl.types.string import String
from hwt.hdl.types.float import HFloat
BOOL = Bits(bit_length=1, name="bool")
INT = Bits(bit_length=32,
signed=True,
name="int",
strict_sign=False,
strict_width=False)
BIT = Bits(bit_length=1)
BIT_N = Bits(bit_length=1, negated=True)
STR = String()
SLICE = Slice()
FLOAT64 = HFloat(11, 52, name="float64")
def __getitem__(self, key):
"""
[] operator
:attention: Table below is for litle endian bit order (MSB:LSB)
which is default.
This is **reversed** as it is in pure python
where it is [0, len(self)].
:attention: slice on slice f signal is automatically reduced
to single slice
+-----------------------------+----------------------------------------------------------------------------------+
| a[up:low] | items low through up; a[16:8] selects upper byte from 16b vector a |
+-----------------------------+----------------------------------------------------------------------------------+
| a[up:] | low is automatically substituted with 0; a[8:] will select lower 8 bits |
+-----------------------------+----------------------------------------------------------------------------------+
| a[:end] | up is automatically substituted; a[:8] will select upper byte from 16b vector a |
+-----------------------------+----------------------------------------------------------------------------------+
| a[:], a[-1], a[-2:], a[:-2] | raises NotImplementedError (not implemented due to complicated support in hdl) |
+-----------+----------------------------------------------------------------------------------------------------+
"""
st = self._dtype
length = st.bit_length()
if length == 1 and not st.force_vector:
# assert not indexing on single bit
raise TypeError("indexing on single bit")
if isinstance(key, slice):
key = slice_to_SLICE(key, length)
isSLICE = True
else:
isSLICE = isinstance(key, Slice.getValueCls())
if isSLICE:
# :note: downto notation
start = key.val.start
stop = key.val.stop
if key.val.step != -1:
raise NotImplementedError()
startIsVal = isinstance(start, HValue)
stopIsVal = isinstance(stop, HValue)
indexesareHValues = startIsVal and stopIsVal
else:
key = toHVal(key, INT)
iamVal = isinstance(self, HValue)
iAmResultOfIndexing = (not iamVal and len(self.drivers) == 1
and isinstance(self.origin, Operator)
and self.origin.operator == AllOps.INDEX)
Bits = self._dtype.__class__
if isSLICE:
if indexesareHValues and start.val == length and stop.val == 0:
# selecting all bits no conversion needed
return self
if iAmResultOfIndexing:
# try reduce self and parent slice to one
original, parentIndex = self.origin.operands
if isinstance(parentIndex._dtype, Slice):
parentLower = parentIndex.val.stop
start = start + parentLower
stop = stop + parentLower
return original[start:stop]
# check start boundaries
if startIsVal:
_start = int(start)
if _start < 0 or _start > length:
raise IndexError(_start, length)
# check end boundaries
if stopIsVal:
_stop = int(stop)
if _stop < 0 or _stop > length:
raise IndexError(_stop, length)
# check width of selected range
if startIsVal and stopIsVal and _start - _stop <= 0:
raise IndexError(_start, _stop)
if iamVal:
if isinstance(key, SLICE.getValueCls()):
key = key.val
v = Bits3val.__getitem__(self, key)
if v._dtype.bit_length() == 1 and not v._dtype.force_vector:
assert v._dtype is not self._dtype
v._dtype.force_vector = True
return v
else:
key = SLICE.from_py(slice(start, stop, -1))
_resWidth = start - stop
resT = Bits(bit_length=_resWidth,
force_vector=True,
signed=st.signed,
negated=st.negated)
elif isinstance(key, Bits.getValueCls()):
if key._is_full_valid():
# check index range
_v = int(key)
if _v < 0 or _v > length - 1:
raise IndexError(_v)
if iAmResultOfIndexing:
original, parentIndex = self.origin.operands
if isinstance(parentIndex._dtype, Slice):
parentLower = parentIndex.val.stop
return original[parentLower + _v]
if iamVal:
return Bits3val.__getitem__(self, key)
resT = BIT
elif isinstance(key, RtlSignalBase):
t = key._dtype
if isinstance(t, Slice):
resT = Bits(bit_length=key.staticEval()._size(),
force_vector=True,
signed=st.signed,
negated=st.negated)
elif isinstance(t, Bits):
resT = BIT
else:
raise TypeError("Index operation not implemented"
" for index of type %r" % (t))
else:
raise TypeError("Index operation not implemented for index %r" %
(key))
if st.negated and resT is BIT:
resT = BIT_N
return Operator.withRes(AllOps.INDEX, [self, key], resT)
