from soc.decoder.orderedset import OrderedSet
from soc.decoder.selectable_int import (FieldSelectableInt, SelectableInt,
selectconcat)
-from soc.decoder.power_enums import spr_dict, XER_bits, insns, InternalOp
+from soc.decoder.power_enums import (spr_dict, spr_byname, XER_bits,
+ insns, InternalOp)
from soc.decoder.helpers import exts, trunc_div, trunc_rem
from collections import namedtuple
import math
def __init__(self, dec2, initial_sprs={}):
self.sd = dec2
dict.__init__(self)
- self.update(initial_sprs)
+ for key, v in initial_sprs.items():
+ if isinstance(key, SelectableInt):
+ key = key.value
+ key = special_sprs.get(key, key)
+ if isinstance(key, int):
+ info = spr_dict[key]
+ else:
+ info = spr_byname[key]
+ if not isinstance(v, SelectableInt):
+ v = SelectableInt(v, info.length)
+ self[key] = v
def __getitem__(self, key):
# if key in special_sprs get the special spr, otherwise return key
# "undefined", just set to variable-bit-width int (use exts "max")
self.undefined = SelectableInt(0, 256) # TODO, not hard-code 256!
- self.namespace = {'GPR': self.gpr,
+ self.namespace = {}
+ self.namespace.update(self.spr)
+ self.namespace.update({'GPR': self.gpr,
'MEM': self.mem,
'SPR': self.spr,
'memassign': self.memassign,
'undefined': self.undefined,
'mode_is_64bit': True,
'SO': XER_bits['SO']
- }
+ })
+
# field-selectable versions of Condition Register TODO check bitranges?
self.crl = []
if not (2 & already_done):
self.spr['XER'][XER_bits['CA32']] = cy32
- def handle_overflow(self, inputs, outputs):
+ def handle_overflow(self, inputs, outputs, div_overflow):
inv_a = yield self.dec2.e.invert_a
if inv_a:
inputs[0] = ~inputs[0]
imm = yield self.dec2.e.imm_data.data
inputs.append(SelectableInt(imm, 64))
assert len(outputs) >= 1
- print ("handle_overflow", inputs, outputs)
- if len(inputs) >= 2:
+ print ("handle_overflow", inputs, outputs, div_overflow)
+ if len(inputs) < 2 and div_overflow != 1:
+ return
+
+ # div overflow is different: it's returned by the pseudo-code
+ # because it's more complex than can be done by analysing the output
+ if div_overflow == 1:
+ ov, ov32 = 1, 1
+ # arithmetic overflow can be done by analysing the input and output
+ elif len(inputs) >= 2:
output = outputs[0]
# OV (64-bit)
ov32 = 1 if input32_sgn[0] == input32_sgn[1] and \
output32_sgn != input32_sgn[0] else 0
- self.spr['XER'][XER_bits['OV']] = ov
- self.spr['XER'][XER_bits['OV32']] = ov32
- so = self.spr['XER'][XER_bits['SO']]
- so = so | ov
- self.spr['XER'][XER_bits['SO']] = so
+ self.spr['XER'][XER_bits['OV']] = ov
+ self.spr['XER'][XER_bits['OV32']] = ov32
+ so = self.spr['XER'][XER_bits['SO']]
+ so = so | ov
+ self.spr['XER'][XER_bits['SO']] = so
def handle_comparison(self, outputs):
out = outputs[0]
carry_en = yield self.dec2.e.output_carry
if carry_en:
yield from self.handle_carry_(inputs, results, already_done)
+
+ # detect if overflow was in return result
+ overflow = None
+ if info.write_regs:
+ for name, output in zip(output_names, results):
+ if name == 'overflow':
+ overflow = output
+
ov_en = yield self.dec2.e.oe.oe
ov_ok = yield self.dec2.e.oe.ok
+ print ("internal overflow", overflow)
if ov_en & ov_ok:
- yield from self.handle_overflow(inputs, results)
+ yield from self.handle_overflow(inputs, results, overflow)
+
rc_en = yield self.dec2.e.rc.data
if rc_en:
self.handle_comparison(results)
# any modified return results?
if info.write_regs:
for name, output in zip(output_names, results):
+ if name == 'overflow': # ignore, done already (above)
+ continue
if isinstance(output, int):
output = SelectableInt(output, 256)
if name in ['CA', 'CA32']:
self.spr[name] = output
else:
self.namespace[name].eq(output)
+ if name == 'MSR':
+ print ('msr written', hex(self.msr.value))
else:
regnum = yield getattr(self.decoder, name)
print('writing reg %d %s' % (regnum, str(output)))