Hexagon (target/hexagon) generater phase 4 - decode tree

Python script that emits the decode tree in dectree_generated.h.

Signed-off-by: Taylor Simpson <tsimpson@quicinc.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <1612763186-18161-23-git-send-email-tsimpson@quicinc.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
This commit is contained in:
Taylor Simpson 2021-02-07 23:46:12 -06:00 committed by Richard Henderson
parent ece6cd1e42
commit 469c2cbbbc
1 changed files with 351 additions and 0 deletions

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target/hexagon/dectree.py Executable file
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#!/usr/bin/env python3
##
## Copyright(c) 2019-2021 Qualcomm Innovation Center, Inc. All Rights Reserved.
##
## This program is free software; you can redistribute it and/or modify
## it under the terms of the GNU General Public License as published by
## the Free Software Foundation; either version 2 of the License, or
## (at your option) any later version.
##
## This program is distributed in the hope that it will be useful,
## but WITHOUT ANY WARRANTY; without even the implied warranty of
## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
## GNU General Public License for more details.
##
## You should have received a copy of the GNU General Public License
## along with this program; if not, see <http://www.gnu.org/licenses/>.
##
import io
import re
import sys
import iset
encs = {tag : ''.join(reversed(iset.iset[tag]['enc'].replace(' ', '')))
for tag in iset.tags if iset.iset[tag]['enc'] != 'MISSING ENCODING'}
enc_classes = set([iset.iset[tag]['enc_class'] for tag in encs.keys()])
subinsn_enc_classes = \
set([enc_class for enc_class in enc_classes \
if enc_class.startswith('SUBINSN_')])
ext_enc_classes = \
set([enc_class for enc_class in enc_classes \
if enc_class not in ('NORMAL', '16BIT') and \
not enc_class.startswith('SUBINSN_')])
try:
subinsn_groupings = iset.subinsn_groupings
except AttributeError:
subinsn_groupings = {}
for (tag, subinsn_grouping) in subinsn_groupings.items():
encs[tag] = ''.join(reversed(subinsn_grouping['enc'].replace(' ', '')))
dectree_normal = {'leaves' : set()}
dectree_16bit = {'leaves' : set()}
dectree_subinsn_groupings = {'leaves' : set()}
dectree_subinsns = {name : {'leaves' : set()} for name in subinsn_enc_classes}
dectree_extensions = {name : {'leaves' : set()} for name in ext_enc_classes}
for tag in encs.keys():
if tag in subinsn_groupings:
dectree_subinsn_groupings['leaves'].add(tag)
continue
enc_class = iset.iset[tag]['enc_class']
if enc_class.startswith('SUBINSN_'):
if len(encs[tag]) != 32:
encs[tag] = encs[tag] + '0' * (32 - len(encs[tag]))
dectree_subinsns[enc_class]['leaves'].add(tag)
elif enc_class == '16BIT':
if len(encs[tag]) != 16:
raise Exception('Tag "{}" has enc_class "{}" and not an encoding ' +
'width of 16 bits!'.format(tag, enc_class))
dectree_16bit['leaves'].add(tag)
else:
if len(encs[tag]) != 32:
raise Exception('Tag "{}" has enc_class "{}" and not an encoding ' +
'width of 32 bits!'.format(tag, enc_class))
if enc_class == 'NORMAL':
dectree_normal['leaves'].add(tag)
else:
dectree_extensions[enc_class]['leaves'].add(tag)
faketags = set()
for (tag, enc) in iset.enc_ext_spaces.items():
faketags.add(tag)
encs[tag] = ''.join(reversed(enc.replace(' ', '')))
dectree_normal['leaves'].add(tag)
faketags |= set(subinsn_groupings.keys())
def every_bit_counts(bitset):
for i in range(1, len(next(iter(bitset)))):
if len(set([bits[:i] + bits[i+1:] for bits in bitset])) == len(bitset):
return False
return True
def auto_separate(node):
tags = node['leaves']
if len(tags) <= 1:
return
enc_width = len(encs[next(iter(tags))])
opcode_bit_for_all = \
[all([encs[tag][i] in '01' \
for tag in tags]) for i in range(enc_width)]
opcode_bit_is_0_for_all = \
[opcode_bit_for_all[i] and all([encs[tag][i] == '0' \
for tag in tags]) for i in range(enc_width)]
opcode_bit_is_1_for_all = \
[opcode_bit_for_all[i] and all([encs[tag][i] == '1' \
for tag in tags]) for i in range(enc_width)]
differentiator_opcode_bit = \
[opcode_bit_for_all[i] and \
not (opcode_bit_is_0_for_all[i] or \
opcode_bit_is_1_for_all[i]) \
for i in range(enc_width)]
best_width = 0
for width in range(4, 0, -1):
for lsb in range(enc_width - width, -1, -1):
bitset = set([encs[tag][lsb:lsb+width] for tag in tags])
if all(differentiator_opcode_bit[lsb:lsb+width]) and \
(len(bitset) == len(tags) or every_bit_counts(bitset)):
best_width = width
best_lsb = lsb
caught_all_tags = len(bitset) == len(tags)
break
if best_width != 0:
break
if best_width == 0:
raise Exception('Could not find a way to differentiate the encodings ' +
'of the following tags:\n{}'.format('\n'.join(tags)))
if caught_all_tags:
for width in range(1, best_width):
for lsb in range(enc_width - width, -1, -1):
bitset = set([encs[tag][lsb:lsb+width] for tag in tags])
if all(differentiator_opcode_bit[lsb:lsb+width]) and \
len(bitset) == len(tags):
best_width = width
best_lsb = lsb
break
else:
continue
break
node['separator_lsb'] = best_lsb
node['separator_width'] = best_width
node['children'] = []
for value in range(2 ** best_width):
child = {}
bits = ''.join(reversed('{:0{}b}'.format(value, best_width)))
child['leaves'] = \
set([tag for tag in tags \
if encs[tag][best_lsb:best_lsb+best_width] == bits])
node['children'].append(child)
for child in node['children']:
auto_separate(child)
auto_separate(dectree_normal)
auto_separate(dectree_16bit)
if subinsn_groupings:
auto_separate(dectree_subinsn_groupings)
for dectree_subinsn in dectree_subinsns.values():
auto_separate(dectree_subinsn)
for dectree_ext in dectree_extensions.values():
auto_separate(dectree_ext)
for tag in faketags:
del encs[tag]
def table_name(parents, node):
path = parents + [node]
root = path[0]
tag = next(iter(node['leaves']))
if tag in subinsn_groupings:
enc_width = len(subinsn_groupings[tag]['enc'].replace(' ', ''))
else:
tag = next(iter(node['leaves'] - faketags))
enc_width = len(encs[tag])
determining_bits = ['_'] * enc_width
for (parent, child) in zip(path[:-1], path[1:]):
lsb = parent['separator_lsb']
width = parent['separator_width']
value = parent['children'].index(child)
determining_bits[lsb:lsb+width] = \
list(reversed('{:0{}b}'.format(value, width)))
if tag in subinsn_groupings:
name = 'DECODE_ROOT_EE'
else:
enc_class = iset.iset[tag]['enc_class']
if enc_class in ext_enc_classes:
name = 'DECODE_EXT_{}'.format(enc_class)
elif enc_class in subinsn_enc_classes:
name = 'DECODE_SUBINSN_{}'.format(enc_class)
else:
name = 'DECODE_ROOT_{}'.format(enc_width)
if node != root:
name += '_' + ''.join(reversed(determining_bits))
return name
def print_node(f, node, parents):
if len(node['leaves']) <= 1:
return
name = table_name(parents, node)
lsb = node['separator_lsb']
width = node['separator_width']
print('DECODE_NEW_TABLE({},{},DECODE_SEPARATOR_BITS({},{}))'.\
format(name, 2 ** width, lsb, width), file=f)
for child in node['children']:
if len(child['leaves']) == 0:
print('INVALID()', file=f)
elif len(child['leaves']) == 1:
(tag,) = child['leaves']
if tag in subinsn_groupings:
class_a = subinsn_groupings[tag]['class_a']
class_b = subinsn_groupings[tag]['class_b']
enc = subinsn_groupings[tag]['enc'].replace(' ', '')
if 'RESERVED' in tag:
print('INVALID()', file=f)
else:
print('SUBINSNS({},{},{},"{}")'.\
format(tag, class_a, class_b, enc), file=f)
elif tag in iset.enc_ext_spaces:
enc = iset.enc_ext_spaces[tag].replace(' ', '')
print('EXTSPACE({},"{}")'.format(tag, enc), file=f)
else:
enc = ''.join(reversed(encs[tag]))
print('TERMINAL({},"{}")'.format(tag, enc), file=f)
else:
print('TABLE_LINK({})'.format(table_name(parents + [node], child)),
file=f)
print('DECODE_END_TABLE({},{},DECODE_SEPARATOR_BITS({},{}))'.\
format(name, 2 ** width, lsb, width), file=f)
print(file=f)
parents.append(node)
for child in node['children']:
print_node(f, child, parents)
parents.pop()
def print_tree(f, tree):
print_node(f, tree, [])
def print_match_info(f):
for tag in sorted(encs.keys(), key=iset.tags.index):
enc = ''.join(reversed(encs[tag]))
mask = int(re.sub(r'[^1]', r'0', enc.replace('0', '1')), 2)
match = int(re.sub(r'[^01]', r'0', enc), 2)
suffix = ''
print('DECODE{}_MATCH_INFO({},0x{:x}U,0x{:x}U)'.\
format(suffix, tag, mask, match), file=f)
regre = re.compile(
r'((?<!DUP)[MNORCPQXSGVZA])([stuvwxyzdefg]+)([.]?[LlHh]?)(\d+S?)')
immre = re.compile(r'[#]([rRsSuUm])(\d+)(?:[:](\d+))?')
def ordered_unique(l):
return sorted(set(l), key=l.index)
implicit_registers = {
'SP' : 29,
'FP' : 30,
'LR' : 31
}
num_registers = {
'R' : 32,
'V' : 32
}
def print_op_info(f):
for tag in sorted(encs.keys(), key=iset.tags.index):
enc = encs[tag]
print(file=f)
print('DECODE_OPINFO({},'.format(tag), file=f)
regs = ordered_unique(regre.findall(iset.iset[tag]['syntax']))
imms = ordered_unique(immre.findall(iset.iset[tag]['syntax']))
regno = 0
for reg in regs:
reg_type = reg[0]
reg_letter = reg[1][0]
reg_num_choices = int(reg[3].rstrip('S'))
reg_mapping = reg[0] + ''.join(['_' for letter in reg[1]]) + reg[3]
reg_enc_fields = re.findall(reg_letter + '+', enc)
if len(reg_enc_fields) == 0:
raise Exception('Tag "{}" missing register field!'.format(tag))
if len(reg_enc_fields) > 1:
raise Exception('Tag "{}" has split register field!'.\
format(tag))
reg_enc_field = reg_enc_fields[0]
if 2 ** len(reg_enc_field) != reg_num_choices:
raise Exception('Tag "{}" has incorrect register field width!'.\
format(tag))
print(' DECODE_REG({},{},{})'.\
format(regno, len(reg_enc_field), enc.index(reg_enc_field)),
file=f)
if reg_type in num_registers and \
reg_num_choices != num_registers[reg_type]:
print(' DECODE_MAPPED_REG({},{})'.\
format(regno, reg_mapping), file=f)
regno += 1
def implicit_register_key(reg):
return implicit_registers[reg]
for reg in sorted(
set([r for r in (iset.iset[tag]['rregs'].split(',') + \
iset.iset[tag]['wregs'].split(',')) \
if r in implicit_registers]), key=implicit_register_key):
print(' DECODE_IMPL_REG({},{})'.\
format(regno, implicit_registers[reg]), file=f)
regno += 1
if imms and imms[0][0].isupper():
imms = reversed(imms)
for imm in imms:
if imm[0].isupper():
immno = 1
else:
immno = 0
imm_type = imm[0]
imm_width = int(imm[1])
imm_shift = imm[2]
if imm_shift:
imm_shift = int(imm_shift)
else:
imm_shift = 0
if imm_type.islower():
imm_letter = 'i'
else:
imm_letter = 'I'
remainder = imm_width
for m in reversed(list(re.finditer(imm_letter + '+', enc))):
remainder -= m.end() - m.start()
print(' DECODE_IMM({},{},{},{})'.\
format(immno, m.end() - m.start(), m.start(), remainder),
file=f)
if remainder != 0:
if imm[2]:
imm[2] = ':' + imm[2]
raise Exception('Tag "{}" has an incorrect number of ' + \
'encoding bits for immediate "{}"'.\
format(tag, ''.join(imm)))
if imm_type.lower() in 'sr':
print(' DECODE_IMM_SXT({},{})'.\
format(immno, imm_width), file=f)
if imm_type.lower() == 'n':
print(' DECODE_IMM_NEG({},{})'.\
format(immno, imm_width), file=f)
if imm_shift:
print(' DECODE_IMM_SHIFT({},{})'.\
format(immno, imm_shift), file=f)
print(')', file=f)
if __name__ == '__main__':
with open(sys.argv[1], 'w') as f:
print_tree(f, dectree_normal)
print_tree(f, dectree_16bit)
if subinsn_groupings:
print_tree(f, dectree_subinsn_groupings)
for (name, dectree_subinsn) in sorted(dectree_subinsns.items()):
print_tree(f, dectree_subinsn)
for (name, dectree_ext) in sorted(dectree_extensions.items()):
print_tree(f, dectree_ext)
print_match_info(f)
print_op_info(f)