from soc.decoder.decode2execute1 import (Decode2ToExecute1Type, Data,
Decode2ToOperand)
from soc.sv.svp64 import SVP64Rec
-from soc.consts import (MSR, sel, SPEC, EXTRA2, EXTRA3)
+from soc.consts import (MSR, sel, SPEC, EXTRA2, EXTRA3, SVP64P, field,
+ SPEC_SIZE, SPECb, SPEC_AUG_SIZE, SVP64CROffs)
from soc.regfile.regfiles import FastRegs
from soc.consts import TT
# which is zero which is ok.
spec = self.spec
- # now decode it. bit 2 is "scalar/vector". note that spec could be zero
+ # now decode it. bit 0 is "scalar/vector". note that spec could be zero
# from above, which (by design) has the effect of "no change", below.
# simple: isvec is top bit of spec
- comb += self.isvec.eq(spec[2])
+ comb += self.isvec.eq(spec[SPEC.VEC])
+ # extra bits for register number augmentation
+ spec_aug = Signal(SPEC_AUG_SIZE)
+ comb += spec_aug.eq(field(spec, SPECb.MSB, SPECb.LSB, SPEC_SIZE))
# decode vector differently from scalar
with m.If(self.isvec):
- # Vector: shifted up, extra in LSBs (RA << 2) | spec[0:1]
- comb += self.reg_out.eq(Cat(spec[:2], self.reg_in))
+ # Vector: shifted up, extra in LSBs (RA << 2) | spec[1:2]
+ comb += self.reg_out.eq(Cat(spec_aug, self.reg_in))
with m.Else():
- # Scalar: not shifted up, extra in MSBs RA | (spec[0:1] << 5)
- comb += self.reg_out.eq(Cat(self.reg_in, spec[:2]))
+ # Scalar: not shifted up, extra in MSBs RA | (spec[1:2] << 5)
+ comb += self.reg_out.eq(Cat(self.reg_in, spec_aug))
return m
"""
def __init__(self):
SVP64ExtraSpec.__init__(self)
- self.cr_in = Signal(3) # incoming CR number (3 bits, BA[2:5], BFA)
+ self.cr_in = Signal(3) # incoming CR number (3 bits, BA[0:2], BFA)
self.cr_out = Signal(7) # extra-augmented CR output (7 bits)
self.isvec = Signal(1) # reg is marked as vector if true
# which is zero which is ok.
spec = self.spec
- # now decode it. bit 2 is "scalar/vector". note that spec could be zero
+ # now decode it. bit 0 is "scalar/vector". note that spec could be zero
# from above, which (by design) has the effect of "no change", below.
# simple: isvec is top bit of spec
- comb += self.isvec.eq(spec[2])
+ comb += self.isvec.eq(spec[SPEC.VEC])
+ # extra bits for register number augmentation
+ spec_aug = Signal(SPEC_AUG_SIZE)
+ comb += spec_aug.eq(field(spec, SPECb.MSB, SPECb.LSB, SPEC_SIZE))
- # decode vector differently from scalar, insert bits 0 and 1 accordingly
+ # decode vector differently from scalar, insert bits 1 and 2 accordingly
with m.If(self.isvec):
- # Vector: shifted up, extra in LSBs (CR << 4) | (spec[0:1] << 2)
- comb += self.cr_out.eq(Cat(Const(0, 2), spec[:2], self.cr_in))
+ # Vector: shifted up, extra in LSBs (CR << 4) | (spec[1:2] << 2)
+ comb += self.cr_out.eq(Cat(Const(0, 2), spec_aug, self.cr_in))
with m.Else():
- # Scalar: not shifted up, extra in MSBs CR | (spec[0:1] << 3)
- comb += self.cr_out.eq(Cat(self.cr_in, spec[:2]))
+ # Scalar: not shifted up, extra in MSBs CR | (spec[1:2] << 3)
+ comb += self.cr_out.eq(Cat(self.cr_in, spec_aug))
return m
self.cr_bitfield_b = Data(3, "cr_bitfield_b")
self.cr_bitfield_o = Data(3, "cr_bitfield_o")
self.whole_reg = Data(8, "cr_fxm")
+ self.sv_override = Signal(2, reset_less=True) # do not do EXTRA spec
def elaborate(self, platform):
m = Module()
comb += self.cr_bitfield_b.ok.eq(0)
comb += self.cr_bitfield_o.ok.eq(0)
comb += self.whole_reg.ok.eq(0)
+ comb += self.sv_override.eq(0)
# select the relevant CR bitfields
with m.Switch(self.sel_in):
with m.Case(CRInSel.CR0):
comb += self.cr_bitfield.data.eq(0) # CR0 (MSB0 numbering)
comb += self.cr_bitfield.ok.eq(1)
+ comb += self.sv_override.eq(1)
+ with m.Case(CRInSel.CR1):
+ comb += self.cr_bitfield.data.eq(1) # CR1 (MSB0 numbering)
+ comb += self.cr_bitfield.ok.eq(1)
+ comb += self.sv_override.eq(2)
with m.Case(CRInSel.BI):
comb += self.cr_bitfield.data.eq(self.dec.BI[2:5])
comb += self.cr_bitfield.ok.eq(1)
self.insn_in = Signal(32, reset_less=True)
self.cr_bitfield = Data(3, "cr_bitfield")
self.whole_reg = Data(8, "cr_fxm")
+ self.sv_override = Signal(2, reset_less=True) # do not do EXTRA spec
def elaborate(self, platform):
m = Module()
comb += self.cr_bitfield.ok.eq(0)
comb += self.whole_reg.ok.eq(0)
+ comb += self.sv_override.eq(0)
with m.Switch(self.sel_in):
with m.Case(CROutSel.NONE):
with m.Case(CROutSel.CR0):
comb += self.cr_bitfield.data.eq(0) # CR0 (MSB0 numbering)
comb += self.cr_bitfield.ok.eq(self.rc_in) # only when RC=1
+ comb += self.sv_override.eq(1)
+ with m.Case(CROutSel.CR1):
+ comb += self.cr_bitfield.data.eq(1) # CR1 (MSB0 numbering)
+ comb += self.cr_bitfield.ok.eq(self.rc_in) # only when RC=1
+ comb += self.sv_override.eq(2)
with m.Case(CROutSel.BF):
comb += self.cr_bitfield.data.eq(self.dec.FormX.BF)
comb += self.cr_bitfield.ok.eq(1)
spr = Signal(10, reset_less=True)
comb += spr.eq(decode_spr_num(self.dec.SPR)) # from XFX
+ # XXX BUG - don't use hardcoded magic constants.
+ # also use ".value" otherwise the test fails. bit of a pain
+ # https://bugs.libre-soc.org/show_bug.cgi?id=603
+
SPR_PID = 48 # TODO read docs for POWER9
# Microwatt doesn't implement the partition table
# instead has PRTBL register (SPR) to point to process table
m.submodules.o_svdec = o_svdec = SVP64RegExtra()
m.submodules.o2_svdec = o2_svdec = SVP64RegExtra()
+ # debug access to crout_svdec (used in get_pdecode_cr_out)
+ self.crout_svdec = crout_svdec
+
# get the 5-bit reg data before svp64-munging it into 7-bit plus isvec
reg = Signal(5, reset_less=True)
comb += e.write_fast2.eq(dec_o2.fast_out)
# condition registers (CR)
- for to_reg, fromreg, svdec in (
- (e.read_cr1, self.dec_cr_in.cr_bitfield, crin_svdec),
- (e.read_cr2, self.dec_cr_in.cr_bitfield_b, crin_svdec_b),
- (e.read_cr3, self.dec_cr_in.cr_bitfield_o, crin_svdec_o),
- (e.write_cr, self.dec_cr_out.cr_bitfield, crout_svdec)):
+ for to_reg, cr, name, svdec in (
+ (e.read_cr1, self.dec_cr_in, "cr_bitfield", crin_svdec),
+ (e.read_cr2, self.dec_cr_in, "cr_bitfield_b", crin_svdec_b),
+ (e.read_cr3, self.dec_cr_in, "cr_bitfield_o", crin_svdec_o),
+ (e.write_cr, self.dec_cr_out, "cr_bitfield", crout_svdec)):
+ fromreg = getattr(cr, name)
comb += svdec.extra.eq(extra) # EXTRA field of SVP64 RM
comb += svdec.etype.eq(op.SV_Etype) # EXTRA2/3 for this insn
comb += svdec.cr_in.eq(fromreg.data) # 3-bit (CR0/BC/BFA)
- comb += to_reg.data.eq(svdec.cr_out) # 7-bit output
+ with m.If(svdec.isvec):
+ # check if this is CR0 or CR1: treated differently
+ # (does not "listen" to EXTRA2/3 spec for a start)
+ # also: the CRs start from completely different locations
+ with m.If(cr.sv_override == 1): # CR0
+ offs = SVP64CROffs.CR0
+ comb += to_reg.data.eq(srcstep+offs)
+ with m.Elif(cr.sv_override == 2): # CR1
+ offs = SVP64CROffs.CR1
+ comb += to_reg.data.eq(srcstep+1)
+ with m.Else():
+ comb += to_reg.data.eq(srcstep+svdec.cr_out) # 7-bit output
+ with m.Else():
+ comb += to_reg.data.eq(svdec.cr_out) # 7-bit output
comb += to_reg.ok.eq(fromreg.ok)
# sigh this is exactly the sort of thing for which the
def elaborate(self, platform):
m = Module()
+ opcode_in = self.opcode_in
comb = m.d.comb
# sigh copied this from TopPowerDecoder
# raw opcode in assumed to be in LE order: byte-reverse it to get BE
l.append(raw_le[i:i+8])
l.reverse()
raw_be = Cat(*l)
- comb += self.opcode_in.eq(Mux(self.bigendian, raw_be, raw_le))
+ comb += opcode_in.eq(Mux(self.bigendian, raw_be, raw_le))
# start identifying if the incoming opcode is SVP64 prefix)
major = Signal(6, reset_less=True)
+ ident = Signal(2, reset_less=True)
- comb += major.eq(self.opcode_in[26:32])
- comb += self.is_svp64_mode.eq((major == Const(1, 6)) & # EXT01
- self.opcode_in[31-7] & # identifier
- self.opcode_in[31-9]) # bits
+ comb += major.eq(sel(opcode_in, SVP64P.OPC))
+ comb += ident.eq(sel(opcode_in, SVP64P.SVP64_7_9))
+
+ comb += self.is_svp64_mode.eq(
+ (major == Const(1, 6)) & # EXT01
+ (ident == Const(0b11, 2)) # identifier bits
+ )
- # now grab the 24-bit ReMap context bits,
- rmfields = [6, 8] + list(range(10,32)) # SVP64 24-bit RM
- l = []
- for idx in rmfields:
- l.append(self.opcode_in[31-idx])
- # in nMigen, Cat begins at the LSB and proceeds upwards
- l.reverse() # put the LSB at the start of the list
with m.If(self.is_svp64_mode):
- comb += self.svp64_rm.eq(Cat(*l))
+ # now grab the 24-bit ReMap context bits,
+ comb += self.svp64_rm.eq(sel(opcode_in, SVP64P.RM))
return m
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