It is very simple and straightforward, the only weirdness being the
extraction of the register information and conversion to v3.0B numbering.
+
+Encoding format of svp64: https://libre-soc.org/openpower/sv/svp64/
+Bugtracker: https://bugs.libre-soc.org/show_bug.cgi?id=578
"""
+
import os, sys
+from collections import OrderedDict
from soc.decoder.pseudo.pagereader import ISA
from soc.decoder.power_enums import get_csv, find_wiki_dir
+# identifies register by type
def is_CR_3bit(regname):
return regname in ['BF', 'BFA']
def is_GPR(regname):
return regname in ['RA', 'RB', 'RC', 'RS', 'RT']
-
+def get_regtype(regname):
+ if is_CR_3bit(regname):
+ return "CR_3bit"
+ if is_CR_5bit(regname):
+ return "CR_5bit"
+ if is_GPR(regname):
+ return "GPR"
+
+# decode GPR into sv extra
+def get_extra_gpr(etype, regmode, field):
+ if regmode == 'scalar':
+ # cut into 2-bits 5-bits SS FFFFF
+ sv_extra = field >> 5
+ field = field & 0b11111
+ else:
+ # cut into 5-bits 2-bits FFFFF SS
+ sv_extra = field & 0b11
+ field = field >> 2
+ return sv_extra, field
+
+
+# decode 3-bit CR into sv extra
+def get_extra_cr_3bit(etype, regmode, field):
+ if regmode == 'scalar':
+ # cut into 2-bits 3-bits SS FFF
+ sv_extra = field >> 3
+ field = field & 0b111
+ else:
+ # cut into 3-bits 4-bits FFF SSSS but will cut 2 zeros off later
+ sv_extra = field & 0b1111
+ field = field >> 4
+ return sv_extra, field
+
+
+# gets SVP64 ReMap information
class SVP64RM:
def __init__(self):
self.instrs = {}
pth = find_wiki_dir()
- print (pth)
for fname in os.listdir(pth):
- print (fname)
if fname.startswith("RM"):
- entries = get_csv(fname)
- print (entries)
+ for entry in get_csv(fname):
+ self.instrs[entry['insn']] = entry
+# decodes svp64 assembly listings and creates EXT001 svp64 prefixes
class SVP64:
def __init__(self, lst):
self.lst = lst
def translate(self, lst):
isa = ISA() # reads the v3.0B pseudo-code markdown files
+ svp64 = SVP64RM() # reads the svp64 Remap entries for registers
res = []
for insn in lst:
# find first space, to get opcode
if v30b_op not in isa.instr:
raise Exception("opcode %s of '%s' not supported" % \
(v30b_op, insn))
+ if v30b_op not in svp64.instrs:
+ raise Exception("opcode %s of '%s' not an svp64 instruction" % \
+ (v30b_op, insn))
+ isa.instr[v30b_op].regs[0]
+ v30b_regs = isa.instr[v30b_op].regs[0]
+ rm = svp64.instrs[v30b_op]
+ print ("v3.0B regs", opcode, v30b_regs)
+ print (rm)
+
+ # right. the first thing to do is identify the ordering of
+ # the registers, by name. the EXTRA2/3 ordering is in
+ # rm['0']..rm['3'] but those fields contain the names RA, BB
+ # etc. we have to read the pseudocode to understand which
+ # reg is which in our instruction. sigh.
+
+ # first turn the svp64 rm into a "by name" dict, recording
+ # which position in the RM EXTRA it goes into
+ svp64_reg_byname = {}
+ for i in range(4):
+ rfield = rm[str(i)]
+ if not rfield or rfield == '0':
+ continue
+ print ("EXTRA field", i, rfield)
+ rfield = rfield.split(";") # s:RA;d:CR1 etc.
+ for r in rfield:
+ r = r[2:] # ignore s: and d:
+ svp64_reg_byname[r] = i # this reg in EXTRA position 0-3
+ print ("EXTRA field index, by regname", svp64_reg_byname)
+
+ # okaaay now we identify the field value (opcode N,N,N) with
+ # the pseudo-code info (opcode RT, RA, RB)
+ opregfields = zip(fields, v30b_regs) # err that was easy
+
+ # now for each of those find its place in the EXTRA encoding
+ extras = OrderedDict()
+ for idx, (field, regname) in enumerate(opregfields):
+ extra = svp64_reg_byname.get(regname, None)
+ regtype = get_regtype(regname)
+ extras[extra] = (idx, field, regname, regtype)
+ print (" ", extra, extras[extra])
+
+ # great! got the extra fields in their associated positions:
+ # also we know the register type. now to create the EXTRA encodings
+ etype = rm['Etype'] # Extra type: EXTRA3/EXTRA2
+ extra_bits = 0
+ v30b_newfields = []
+ for extra_idx, (idx, field, regname, regtype) in extras.items():
+ # is it a field we don't alter/examine? if so just put it
+ # into newfields
+ if regtype is None:
+ v30b_newfields.append(field)
+
+ # first, decode the field number. "5.v" or "3.s" or "9"
+ field = field.split(".")
+ regmode = 'scalar' # default
+ if len(field) == 2:
+ if field[1] == 's':
+ regmode = 'scalar'
+ elif field[1] == 'v':
+ regmode = 'vector'
+ field = int(field[0]) # actual register number
+ print (" ", regmode, field, end=" ")
+
+ # XXX TODO: the following is a bit of a laborious repeated
+ # mess, which could (and should) easily be parameterised.
+
+ # encode SV-GPR field into extra, v3.0field
+ if regtype == 'GPR':
+ sv_extra, field = get_extra_gpr(etype, regmode, field)
+ # now sanity-check. EXTRA3 is ok, EXTRA2 has limits
+ # (and shrink to a single bit if ok)
+ if etype == 'EXTRA2':
+ if regmode == 'scalar':
+ # range is r0-r63 in increments of 1
+ assert (sv_extra >> 1) == 0, \
+ "scalar GPR %s cannot fit into EXTRA2 %s" % \
+ (regname, str(extras[extra_idx]))
+ # all good: encode as scalar
+ sv_extra = sv_extra & 0b01
+ else:
+ # range is r0-r127 in increments of 4
+ assert sv_extra & 0b01 == 0, \
+ "vector field %s cannot fit into EXTRA2 %s" % \
+ (regname, str(extras[extra_idx]))
+ # all good: encode as vector (bit 2 set)
+ sv_extra = 0b10 | (sv_extra >> 1)
+ elif regmode == 'vector':
+ # EXTRA3 vector bit needs marking
+ sv_extra |= 0b100
+
+ # encode SV-CR 3-bit field into extra, v3.0field
+ elif regtype == 'CR_3bit':
+ sv_extra, field = get_extra_cr_3bit(etype, regmode, field)
+ # now sanity-check (and shrink afterwards)
+ if etype == 'EXTRA2':
+ if regmode == 'scalar':
+ # range is CR0-CR15 in increments of 1
+ assert (sv_extra >> 1) == 0, \
+ "scalar CR %s cannot fit into EXTRA2 %s" % \
+ (regname, str(extras[extra_idx]))
+ # all good: encode as scalar
+ sv_extra = sv_extra & 0b01
+ else:
+ # range is CR0-CR127 in increments of 16
+ assert sv_extra & 0b111 == 0, \
+ "vector CR %s cannot fit into EXTRA2 %s" % \
+ (regname, str(extras[extra_idx]))
+ # all good: encode as vector (bit 2 set)
+ sv_extra = 0b10 | (sv_extra >> 3)
+ else:
+ if regmode == 'scalar':
+ # range is CR0-CR31 in increments of 1
+ assert (sv_extra >> 2) == 0, \
+ "scalar CR %s cannot fit into EXTRA2 %s" % \
+ (regname, str(extras[extra_idx]))
+ # all good: encode as scalar
+ sv_extra = sv_extra & 0b11
+ else:
+ # range is CR0-CR127 in increments of 8
+ assert sv_extra & 0b11 == 0, \
+ "vector CR %s cannot fit into EXTRA2 %s" % \
+ (regname, str(extras[extra_idx]))
+ # all good: encode as vector (bit 3 set)
+ sv_extra = 0b100 | (sv_extra >> 2)
+
+ # encode SV-CR 5-bit field into extra, v3.0field
+ # *sigh* this is the same as 3-bit except the 2 LSBs are
+ # passed through
+ elif regtype == 'CR_5bit':
+ cr_subfield = field & 0b11
+ field = field >> 2 # strip bottom 2 bits
+ sv_extra, field = get_extra_cr_3bit(etype, regmode, field)
+ # now sanity-check (and shrink afterwards)
+ if etype == 'EXTRA2':
+ if regmode == 'scalar':
+ # range is CR0-CR15 in increments of 1
+ assert (sv_extra >> 1) == 0, \
+ "scalar CR %s cannot fit into EXTRA2 %s" % \
+ (regname, str(extras[extra_idx]))
+ # all good: encode as scalar
+ sv_extra = sv_extra & 0b01
+ else:
+ # range is CR0-CR127 in increments of 16
+ assert sv_extra & 0b111 == 0, \
+ "vector CR %s cannot fit into EXTRA2 %s" % \
+ (regname, str(extras[extra_idx]))
+ # all good: encode as vector (bit 2 set)
+ sv_extra = 0b10 | (sv_extra >> 3)
+ else:
+ if regmode == 'scalar':
+ # range is CR0-CR31 in increments of 1
+ assert (sv_extra >> 2) == 0, \
+ "scalar CR %s cannot fit into EXTRA2 %s" % \
+ (regname, str(extras[extra_idx]))
+ # all good: encode as scalar
+ sv_extra = sv_extra & 0b11
+ else:
+ # range is CR0-CR127 in increments of 8
+ assert sv_extra & 0b11 == 0, \
+ "vector CR %s cannot fit into EXTRA2 %s" % \
+ (regname, str(extras[extra_idx]))
+ # all good: encode as vector (bit 3 set)
+ sv_extra = 0b100 | (sv_extra >> 2)
+
+ # reconstruct the actual 5-bit CR field
+ field = (field << 2) | cr_subfield
+
+ # capture the extra field info
+ print ("=>", "%5s" % bin(sv_extra), field)
+ extras[extra_idx] = sv_extra
+
+ # append altered field value to v3.0b
+ v30b_newfields.append(str(field))
+
+ print ("new v3.0B fields", v30b_op, v30b_newfields)
+ print ("extras", extras)
+ print ()
return res
if __name__ == '__main__':
isa = SVP64(['slw 3, 1, 4',
'extsw 5, 3',
- 'sv.extsw 5, 3'])
+ 'sv.extsw 5, 3',
+ 'sv.cmpi 5, 1, 3, 2',
+ 'sv.setb 5, 31',
+ 'sv.isel 64.v, 3, 2, 65.v'
+ ])
csvs = SVP64RM()
projects / soc.git / blobdiff