src/soc/decoder/power_svp64.py

   1 # SPDX-License-Identifier: LGPLv3+
   2 # Copyright (C) 2021 Luke Kenneth Casson Leighton <lkcl@lkcl.net>
   3 # Funded by NLnet http://nlnet.nl
   4
   5 from soc.decoder.power_enums import get_csv, find_wiki_dir
   6 import os
   7
   8 # identifies register by type
   9 def is_CR_3bit(regname):
  10     return regname in ['BF', 'BFA']
  11
  12 def is_CR_5bit(regname):
  13     return regname in ['BA', 'BB', 'BC', 'BI', 'BT']
  14
  15 def is_GPR(regname):
  16     return regname in ['RA', 'RB', 'RC', 'RS', 'RT']
  17
  18 def get_regtype(regname):
  19     if is_CR_3bit(regname):
  20         return "CR_3bit"
  21     if is_CR_5bit(regname):
  22         return "CR_5bit"
  23     if is_GPR(regname):
  24         return "GPR"
  25
  26
  27 def decode_extra(rm, prefix=''):
  28     # first turn the svp64 rm into a "by name" dict, recording
  29     # which position in the RM EXTRA it goes into
  30     # also: record if the src or dest was a CR, for sanity-checking
  31     # (elwidth overrides on CRs are banned)
  32     dest_reg_cr, src_reg_cr = False, False
  33     svp64_srcreg_byname = {}
  34     svp64_destreg_byname = {}
  35     for i in range(4):
  36         print (rm)
  37         rfield = rm[prefix+str(i)]
  38         if not rfield or rfield == '0':
  39             continue
  40         print ("EXTRA field", i, rfield)
  41         rfield = rfield.split(";") # s:RA;d:CR1 etc.
  42         for r in rfield:
  43             rtype = r[0]
  44             # TODO: ignoring s/d makes it impossible to do
  45             # LD/ST-with-update.
  46             r = r[2:] # ignore s: and d:
  47             if rtype == 'd':
  48                 svp64_destreg_byname[r] = i # dest reg in EXTRA position 0-3
  49             else:
  50                 svp64_srcreg_byname[r] = i # src reg in EXTRA position 0-3
  51             # check the regtype (if CR, record that)
  52             regtype = get_regtype(r)
  53             if regtype in ['CR_3bit', 'CR_5bit']:
  54                 if rtype == 'd':
  55                     dest_reg_cr = True
  56                 if rtype == 's':
  57                     src_reg_cr = True
  58
  59     return dest_reg_cr, src_reg_cr, svp64_srcreg_byname, svp64_destreg_byname
  60
  61
  62 # gets SVP64 ReMap information
  63 class SVP64RM:
  64     def __init__(self, microwatt_format=False):
  65         """SVP64RM: gets micro-opcode information
  66
  67         microwatt_format: moves RS to in1 (to match decode1.vhdl)
  68         """
  69         self.instrs = {}
  70         self.svp64_instrs = {}
  71         pth = find_wiki_dir()
  72         for fname in os.listdir(pth):
  73             if fname.startswith("RM") or fname.startswith("LDSTRM"):
  74                 for entry in get_csv(fname):
  75                     if microwatt_format:
  76                         # move RS from position 1 to position 3, to match
  77                         # microwatt decode1.vhdl format
  78                         if entry['in1'] == 'RS' and entry['in3'] == 'NONE':
  79                             entry['in1'] = 'NONE'
  80                             entry['in3'] = 'RS'
  81                     self.instrs[entry['insn']] = entry
  82
  83
  84     def get_svp64_csv(self, fname):
  85         # first get the v3.0B entries
  86         v30b = get_csv(fname)
  87
  88         # now add the RM fields (for each instruction)
  89         for entry in v30b:
  90             # dummy (blank) fields, first
  91             entry.update({'EXTRA0': '0', 'EXTRA1': '0', 'EXTRA2': '0',
  92                           'EXTRA3': '0',
  93                           'SV_Ptype': 'NONE', 'SV_Etype': 'NONE',
  94                           'sv_cr_in': 'NONE', 'sv_cr_out': 'NONE'})
  95             for fname in ['in1', 'in2', 'in3', 'out']:
  96                 entry['sv_%s' % fname] = 'NONE'
  97
  98             # is this SVP64-augmented?
  99             asmcode = entry['comment']
 100             if asmcode not in self.instrs:
 101                 continue
 102
 103             # start updating the fields, merge relevant info
 104             svp64 = self.instrs[asmcode]
 105             for k, v in {'EXTRA0': '0', 'EXTRA1': '1', 'EXTRA2': '2',
 106                           'EXTRA3': '3',
 107                           'SV_Ptype': 'Ptype', 'SV_Etype': 'Etype'}.items():
 108                 entry[k] = svp64[v]
 109
 110             # hmm, we need something more useful: a cross-association
 111             # of the in1/2/3 and CR in/out with the EXTRA0-3 fields
 112             decode = decode_extra(entry, "EXTRA")
 113             dest_reg_cr, src_reg_cr, svp64_src, svp64_dest = decode
 114
 115             # now examine in1/2/3/out, create sv_in1/2/3/out
 116             for fname in ['in1', 'in2', 'in3', 'out']:
 117                 regfield = entry[fname]
 118                 extra_index = None
 119                 if regfield == 'RA_OR_ZERO':
 120                     regfield = 'RA'
 121                 print (asmcode, regfield, fname, svp64_dest, svp64_src)
 122                 # find the reg in the SVP64 extra map
 123                 if (fname == 'out' and regfield in svp64_dest):
 124                     extra_index = svp64_dest[regfield]
 125                 if (fname != 'out' and regfield in svp64_src):
 126                     extra_index = svp64_src[regfield]
 127                 # ta-daa, we know in1/2/3/out's bit-offset
 128                 if extra_index is not None:
 129                     entry['sv_%s' % fname] = "Idx"+str(extra_index)
 130
 131             # TODO: CRs a little tricky, the power_enums.CRInSel is a bit odd.
 132             # ignore WHOLE_REG for now
 133             cr_in = entry['CR in']
 134             extra_index = 'NONE'
 135             if cr_in in svp64_src:
 136                 entry['sv_cr_in'] = "Idx"+str(svp64_src[cr_in])
 137             elif cr_in == 'BA_BB':
 138                 index1 = svp64_src.get('BA', None)
 139                 index2 = svp64_src.get('BB', None)
 140                 entry['sv_cr_in'] = "Idx_%d_%d" % (index1, index2)
 141
 142             # CRout a lot easier.  ignore WHOLE_REG for now
 143             cr_out = entry['CR out']
 144             extra_index = svp64_dest.get(cr_out, None)
 145             if extra_index is not None:
 146                 entry['sv_cr_out'] = 'Idx%d' % extra_index
 147
 148             # more enum-friendly Ptype names.  should have done this in
 149             # sv_analysis.py, oh well
 150             if entry['SV_Ptype'] == '1P':
 151                 entry['SV_Ptype'] = 'P1'
 152             if entry['SV_Ptype'] == '2P':
 153                 entry['SV_Ptype'] = 'P2'
 154             self.svp64_instrs[asmcode] = entry
 155
 156         return v30b
 157
 158 if __name__ == '__main__':
 159     isa = SVP64RM()
 160     minor_30 = isa.get_svp64_csv("minor_30.csv")
 161     for entry in minor_30:
 162         print (entry)
 163     minor_19 = isa.get_svp64_csv("minor_19.csv")
 164     for entry in minor_19:
 165         if entry['comment'].startswith('cr'):
 166             print (entry)
 167     minor_31 = isa.get_svp64_csv("minor_31.csv")
 168     for entry in minor_31:
 169         print (entry)