CRInSel, CROutSel,
LdstLen, In1Sel, In2Sel, In3Sel,
OutSel, SPRfull, SPRreduced,
- RC, SVP64LDSTmode, LDSTMode,
+ RCOE, SVP64LDSTmode, LDSTMode,
SVEXTRA, SVEtype, SVPtype)
from openpower.decoder.decode2execute1 import (Decode2ToExecute1Type, Data,
Decode2ToOperand)
def __init__(self, dec):
self.dec = dec
- self.sel_in = Signal(RC, reset_less=True)
+ self.sel_in = Signal(RCOE, reset_less=True)
self.insn_in = Signal(32, reset_less=True)
self.rc_out = Data(1, "rc")
# select Record bit out field
with m.Switch(self.sel_in):
- with m.Case(RC.RC):
+ with m.Case(RCOE.RC, RCOE.RC_ONLY):
comb += self.rc_out.data.eq(self.dec.Rc)
comb += self.rc_out.ok.eq(1)
- with m.Case(RC.ONE):
+ with m.Case(RCOE.ONE):
comb += self.rc_out.data.eq(1)
comb += self.rc_out.ok.eq(1)
- with m.Case(RC.NONE):
+ with m.Case(RCOE.NONE):
comb += self.rc_out.data.eq(0)
comb += self.rc_out.ok.eq(1)
class DecodeOE(Elaboratable):
"""DecodeOE from instruction
- decodes OE field: uses RC decode detection which might not be good
-
- -- For now, use "rc" in the decode table to decide whether oe exists.
- -- This is not entirely correct architecturally: For mulhd and
- -- mulhdu, the OE field is reserved. It remains to be seen what an
- -- actual POWER9 does if we set it on those instructions, for now we
- -- test that further down when assigning to the multiplier oe input.
+ decodes OE field: uses RC decode detection which has now been
+ updated to separate out RC_ONLY. all cases RC_ONLY are *NOT*
+ listening to the OE field, here.
"""
def __init__(self, dec, op):
self.dec = dec
self.op = op
- self.sel_in = Signal(RC, reset_less=True)
+ self.sel_in = Signal(RCOE, reset_less=True)
self.insn_in = Signal(32, reset_less=True)
self.oe_out = Data(1, "oe")
def elaborate(self, platform):
m = Module()
comb = m.d.comb
- op = self.op
- with m.Switch(op.internal_op):
-
- # mulhw, mulhwu, mulhd, mulhdu - these *ignore* OE
- # also rotate
- # XXX ARGH! ignoring OE causes incompatibility with microwatt
- # http://lists.libre-soc.org/pipermail/libre-soc-dev/2020-August/000302.html
- with m.Case(MicrOp.OP_MUL_H64, MicrOp.OP_MUL_H32,
- MicrOp.OP_EXTS, MicrOp.OP_CNTZ,
- MicrOp.OP_SHL, MicrOp.OP_SHR, MicrOp.OP_RLC,
- MicrOp.OP_LOAD, MicrOp.OP_STORE,
- MicrOp.OP_RLCL, MicrOp.OP_RLCR,
- MicrOp.OP_EXTSWSLI, MicrOp.OP_GREV, MicrOp.OP_TERNLOG):
- pass
-
- # all other ops decode OE field
+ with m.Switch(self.sel_in):
+ with m.Case(RCOE.RC):
+ comb += self.oe_out.data.eq(self.dec.OE)
+ comb += self.oe_out.ok.eq(1)
with m.Default():
- # select OE bit out field
- with m.Switch(self.sel_in):
- with m.Case(RC.RC):
- comb += self.oe_out.data.eq(self.dec.OE)
- comb += self.oe_out.ok.eq(1)
+ # default: clear OE.
+ comb += self.oe_out.data.eq(0)
+ comb += self.oe_out.ok.eq(0)
return m
# the alternative decoder, svdecldst. what a mess... *sigh*
sv_ptype = self.op_get("SV_Ptype")
fn = self.op_get("function_unit")
- # detect major opcode for LDs: include 58 here. from CSV files.
- # BLECH! TODO: these should be done using "mini decoders",
- # using row and column subsets
- is_major_ld = Signal()
- # bits... errr... MSB0 0..5 which is 26:32 python
- major = Signal(6)
- comb += major.eq(self.dec.opcode_in[26:32])
- comb += is_major_ld.eq((major == 34) | (major == 35) |
- (major == 50) | (major == 51) |
- (major == 48) | (major == 49) |
- (major == 42) | (major == 43) |
- (major == 40) | (major == 41) |
- (major == 32) | (major == 33) |
- (major == 58))
- with m.If(self.is_svp64_mode & is_major_ld):
- # straight-up: "it's a LD". this gives enough info
- # for SVP64 RM Mode decoding to detect LD/ST, and
- # consequently detect the SHIFT mode. sigh
- comb += rm_dec.fn_in.eq(Function.LDST)
- with m.Else():
- comb += rm_dec.fn_in.eq(fn) # decode needs to know Fn type
+ comb += rm_dec.fn_in.eq(fn) # decode needs to know Fn type
comb += rm_dec.ptype_in.eq(sv_ptype) # Single/Twin predicated
comb += rm_dec.rc_in.eq(rc_out) # Rc=1
comb += rm_dec.rm_in.eq(self.sv_rm) # SVP64 RM mode
# exclude fcfids and others
# XXX this is a REALLY bad hack, REALLY has to be done better.
# likely with a sub-decoder.
+ major = Signal(6)
+ comb += major.eq(self.dec.opcode_in[26:32])
xo5 = Signal(1) # 1 bit from Minor 59 XO field == 0b0XXXX
comb += xo5.eq(self.dec.opcode_in[5])
xo = Signal(5) # 5 bits from Minor 59 fcfids == 0b01110
projects / openpower-isa.git / blobdiff