From b45a02e2f79ff3030d0013d375b02ed18a2303b7 Mon Sep 17 00:00:00 2001 From: Richard Henderson Date: Mon, 15 Jun 2020 12:48:47 -0400 Subject: [PATCH] decodetree: Multi-cleanup Includes multiple changes by Richard Henderson as follows: - Use proper varargs to print the arguments. (2fd51b19c9) - Rename MultiPattern to IncMultiPattern (040145c4f8) - Split out MultiPattern from IncMultiPattern (df63044d02) - Allow group covering the entire insn space (b44b3449a0) - Move semantic propagation into classes (08561fc128) - Implement non-overlapping groups (067e8b0f45) - Drop check for less than 2 patterns in a group (fe079aa13d) --- qemu/scripts/decodetree.py | 675 +++++++++++++++++-------------------- 1 file changed, 305 insertions(+), 370 deletions(-) diff --git a/qemu/scripts/decodetree.py b/qemu/scripts/decodetree.py index 02fe4560..530d41ca 100644 --- a/qemu/scripts/decodetree.py +++ b/qemu/scripts/decodetree.py @@ -1,4 +1,4 @@ -#!/usr/bin/env python +#!/usr/bin/env python3 # Copyright (c) 2018 Linaro Limited # # This library is free software; you can redistribute it and/or @@ -17,139 +17,7 @@ # # Generate a decoding tree from a specification file. -# -# The tree is built from instruction "patterns". A pattern may represent -# a single architectural instruction or a group of same, depending on what -# is convenient for further processing. -# -# Each pattern has "fixedbits" & "fixedmask", the combination of which -# describes the condition under which the pattern is matched: -# -# (insn & fixedmask) == fixedbits -# -# Each pattern may have "fields", which are extracted from the insn and -# passed along to the translator. Examples of such are registers, -# immediates, and sub-opcodes. -# -# In support of patterns, one may declare fields, argument sets, and -# formats, each of which may be re-used to simplify further definitions. -# -# *** Field syntax: -# -# field_def := '%' identifier ( unnamed_field )+ ( !function=identifier )? -# unnamed_field := number ':' ( 's' ) number -# -# For unnamed_field, the first number is the least-significant bit position of -# the field and the second number is the length of the field. If the 's' is -# present, the field is considered signed. If multiple unnamed_fields are -# present, they are concatenated. In this way one can define disjoint fields. -# -# If !function is specified, the concatenated result is passed through the -# named function, taking and returning an integral value. -# -# FIXME: the fields of the structure into which this result will be stored -# is restricted to "int". Which means that we cannot expand 64-bit items. -# -# Field examples: -# -# %disp 0:s16 -- sextract(i, 0, 16) -# %imm9 16:6 10:3 -- extract(i, 16, 6) << 3 | extract(i, 10, 3) -# %disp12 0:s1 1:1 2:10 -- sextract(i, 0, 1) << 11 -# | extract(i, 1, 1) << 10 -# | extract(i, 2, 10) -# %shimm8 5:s8 13:1 !function=expand_shimm8 -# -- expand_shimm8(sextract(i, 5, 8) << 1 -# | extract(i, 13, 1)) -# -# *** Argument set syntax: -# -# args_def := '&' identifier ( args_elt )+ ( !extern )? -# args_elt := identifier -# -# Each args_elt defines an argument within the argument set. -# Each argument set will be rendered as a C structure "arg_$name" -# with each of the fields being one of the member arguments. -# -# If !extern is specified, the backing structure is assumed to -# have been already declared, typically via a second decoder. -# -# Argument set examples: -# -# ®3 ra rb rc -# &loadstore reg base offset -# -# *** Format syntax: -# -# fmt_def := '@' identifier ( fmt_elt )+ -# fmt_elt := fixedbit_elt | field_elt | field_ref | args_ref -# fixedbit_elt := [01.-]+ -# field_elt := identifier ':' 's'? number -# field_ref := '%' identifier | identifier '=' '%' identifier -# args_ref := '&' identifier -# -# Defining a format is a handy way to avoid replicating groups of fields -# across many instruction patterns. -# -# A fixedbit_elt describes a contiguous sequence of bits that must -# be 1, 0, [.-] for don't care. The difference between '.' and '-' -# is that '.' means that the bit will be covered with a field or a -# final [01] from the pattern, and '-' means that the bit is really -# ignored by the cpu and will not be specified. -# -# A field_elt describes a simple field only given a width; the position of -# the field is implied by its position with respect to other fixedbit_elt -# and field_elt. -# -# If any fixedbit_elt or field_elt appear then all bits must be defined. -# Padding with a fixedbit_elt of all '.' is an easy way to accomplish that. -# -# A field_ref incorporates a field by reference. This is the only way to -# add a complex field to a format. A field may be renamed in the process -# via assignment to another identifier. This is intended to allow the -# same argument set be used with disjoint named fields. -# -# A single args_ref may specify an argument set to use for the format. -# The set of fields in the format must be a subset of the arguments in -# the argument set. If an argument set is not specified, one will be -# inferred from the set of fields. -# -# It is recommended, but not required, that all field_ref and args_ref -# appear at the end of the line, not interleaving with fixedbit_elf or -# field_elt. -# -# Format examples: -# -# @opr ...... ra:5 rb:5 ... 0 ....... rc:5 -# @opi ...... ra:5 lit:8 1 ....... rc:5 -# -# *** Pattern syntax: -# -# pat_def := identifier ( pat_elt )+ -# pat_elt := fixedbit_elt | field_elt | field_ref -# | args_ref | fmt_ref | const_elt -# fmt_ref := '@' identifier -# const_elt := identifier '=' number -# -# The fixedbit_elt and field_elt specifiers are unchanged from formats. -# A pattern that does not specify a named format will have one inferred -# from a referenced argument set (if present) and the set of fields. -# -# A const_elt allows a argument to be set to a constant value. This may -# come in handy when fields overlap between patterns and one has to -# include the values in the fixedbit_elt instead. -# -# The decoder will call a translator function for each pattern matched. -# -# Pattern examples: -# -# addl_r 010000 ..... ..... .... 0000000 ..... @opr -# addl_i 010000 ..... ..... .... 0000000 ..... @opi -# -# which will, in part, invoke -# -# trans_addl_r(ctx, &arg_opr, insn) -# and -# trans_addl_i(ctx, &arg_opi, insn) +# See the syntax and semantics in docs/devel/decodetree.rst. # import os @@ -163,7 +31,6 @@ variablewidth = False fields = {} arguments = {} formats = {} -patterns = [] allpatterns = [] anyextern = False @@ -183,24 +50,26 @@ def error_with_file(file, lineno, *args): global output_file global output_fd + prefix = '' + if file: + prefix += '{0}:'.format(file) if lineno: - r = '{0}:{1}: error:'.format(file, lineno) - elif input_file: - r = '{0}: error:'.format(file) - else: - r = 'error:' - for a in args: - r += ' ' + str(a) - r += '\n' - sys.stderr.write(r) + prefix += '{0}:'.format(lineno) + if prefix: + prefix += ' ' + print(prefix, end='error: ', file=sys.stderr) + print(*args, file=sys.stderr) + if output_file and output_fd: output_fd.close() os.remove(output_file) exit(1) +# end error_with_file def error(lineno, *args): - error_with_file(input_file, lineno, args) + error_with_file(input_file, lineno, *args) +# end error def output(*args): @@ -209,13 +78,6 @@ def output(*args): output_fd.write(a) -if sys.version_info >= (3, 4): - re_fullmatch = re.fullmatch -else: - def re_fullmatch(pat, str): - return re.match('^' + pat + '$', str) - - def output_autogen(): output('/* This file is autogenerated by scripts/decodetree.py. */\n\n') @@ -261,6 +123,7 @@ def is_pow2(x): def ctz(x): """Return the number of times 2 factors into X.""" + assert x != 0 r = 0 while ((x >> r) & 1) == 0: r += 1 @@ -268,6 +131,8 @@ def ctz(x): def is_contiguous(bits): + if bits == 0: + return -1 shift = ctz(bits) if is_pow2((bits >> shift) + 1): return shift @@ -505,32 +370,99 @@ class Pattern(General): output(ind, 'u.f_', arg, '.', n, ' = ', f.str_extract(), ';\n') output(ind, 'if (', translate_prefix, '_', self.name, '(ctx, &u.f_', arg, ')) return true;\n') + + # Normal patterns do not have children. + def build_tree(self): + return + def prop_masks(self): + return + def prop_format(self): + return + def prop_width(self): + return + # end Pattern class MultiPattern(General): - """Class representing an overlapping set of instruction patterns""" + """Class representing a set of instruction patterns""" - def __init__(self, lineno, pats, fixb, fixm, udfm, w): + def __init__(self, lineno): self.file = input_file self.lineno = lineno - self.pats = pats + self.pats = [] self.base = None - self.fixedbits = fixb - self.fixedmask = fixm - self.undefmask = udfm - self.width = w + self.fixedbits = 0 + self.fixedmask = 0 + self.undefmask = 0 + self.width = None def __str__(self): - r = "{" - for p in self.pats: - r = r + ' ' + str(p) - return r + "}" + r = 'group' + if self.fixedbits is not None: + r += ' ' + str_match_bits(self.fixedbits, self.fixedmask) + return r def output_decl(self): for p in self.pats: p.output_decl() + def prop_masks(self): + global insnmask + + fixedmask = insnmask + undefmask = insnmask + + # Collect fixedmask/undefmask for all of the children. + for p in self.pats: + p.prop_masks() + fixedmask &= p.fixedmask + undefmask &= p.undefmask + + # Widen fixedmask until all fixedbits match + repeat = True + fixedbits = 0 + while repeat and fixedmask != 0: + fixedbits = None + for p in self.pats: + thisbits = p.fixedbits & fixedmask + if fixedbits is None: + fixedbits = thisbits + elif fixedbits != thisbits: + fixedmask &= ~(fixedbits ^ thisbits) + break + else: + repeat = False + + self.fixedbits = fixedbits + self.fixedmask = fixedmask + self.undefmask = undefmask + + def build_tree(self): + for p in self.pats: + p.build_tree() + + def prop_format(self): + for p in self.pats: + p.build_tree() + + def prop_width(self): + width = None + for p in self.pats: + p.prop_width() + if width is None: + width = p.width + elif width != p.width: + error_with_file(self.file, self.lineno, + 'width mismatch in patterns within braces') + self.width = width + +# end MultiPattern + + +class IncMultiPattern(MultiPattern): + """Class representing an overlapping set of instruction patterns""" + def output_code(self, i, extracted, outerbits, outermask): global translate_prefix ind = str_indent(i) @@ -547,7 +479,154 @@ class MultiPattern(General): output(ind, '}\n') else: p.output_code(i, extracted, p.fixedbits, p.fixedmask) -#end MultiPattern +#end IncMultiPattern + + +class Tree: + """Class representing a node in a decode tree""" + + def __init__(self, fm, tm): + self.fixedmask = fm + self.thismask = tm + self.subs = [] + self.base = None + + def str1(self, i): + ind = str_indent(i) + r = '{0}{1:08x}'.format(ind, self.fixedmask) + if self.format: + r += ' ' + self.format.name + r += ' [\n' + for (b, s) in self.subs: + r += '{0} {1:08x}:\n'.format(ind, b) + r += s.str1(i + 4) + '\n' + r += ind + ']' + return r + + def __str__(self): + return self.str1(0) + + def output_code(self, i, extracted, outerbits, outermask): + ind = str_indent(i) + + # If we identified all nodes below have the same format, + # extract the fields now. + if not extracted and self.base: + output(ind, self.base.extract_name(), + '(ctx, &u.f_', self.base.base.name, ', insn);\n') + extracted = True + + # Attempt to aid the compiler in producing compact switch statements. + # If the bits in the mask are contiguous, extract them. + sh = is_contiguous(self.thismask) + if sh > 0: + # Propagate SH down into the local functions. + def str_switch(b, sh=sh): + return '(insn >> {0}) & 0x{1:x}'.format(sh, b >> sh) + + def str_case(b, sh=sh): + return '0x{0:x}'.format(b >> sh) + else: + def str_switch(b): + return 'insn & 0x{0:08x}'.format(b) + + def str_case(b): + return '0x{0:08x}'.format(b) + + output(ind, 'switch (', str_switch(self.thismask), ') {\n') + for b, s in sorted(self.subs): + assert (self.thismask & ~s.fixedmask) == 0 + innermask = outermask | self.thismask + innerbits = outerbits | b + output(ind, 'case ', str_case(b), ':\n') + output(ind, ' /* ', + str_match_bits(innerbits, innermask), ' */\n') + s.output_code(i + 4, extracted, innerbits, innermask) + output(ind, ' return false;\n') + output(ind, '}\n') +# end Tree + + +class ExcMultiPattern(MultiPattern): + """Class representing a non-overlapping set of instruction patterns""" + + def output_code(self, i, extracted, outerbits, outermask): + # Defer everything to our decomposed Tree node + self.tree.output_code(i, extracted, outerbits, outermask) + + @staticmethod + def __build_tree(pats, outerbits, outermask): + # Find the intersection of all remaining fixedmask. + innermask = ~outermask & insnmask + for i in pats: + innermask &= i.fixedmask + + if innermask == 0: + # Edge condition: One pattern covers the entire insnmask + if len(pats) == 1: + t = Tree(outermask, innermask) + t.subs.append((0, pats[0])) + return t + + text = 'overlapping patterns:' + for p in pats: + text += '\n' + p.file + ':' + str(p.lineno) + ': ' + str(p) + error_with_file(pats[0].file, pats[0].lineno, text) + + fullmask = outermask | innermask + + # Sort each element of pats into the bin selected by the mask. + bins = {} + for i in pats: + fb = i.fixedbits & innermask + if fb in bins: + bins[fb].append(i) + else: + bins[fb] = [i] + + # We must recurse if any bin has more than one element or if + # the single element in the bin has not been fully matched. + t = Tree(fullmask, innermask) + + for b, l in bins.items(): + s = l[0] + if len(l) > 1 or s.fixedmask & ~fullmask != 0: + s = ExcMultiPattern.__build_tree(l, b | outerbits, fullmask) + t.subs.append((b, s)) + + return t + + def build_tree(self): + super().prop_format() + self.tree = self.__build_tree(self.pats, self.fixedbits, + self.fixedmask) + + @staticmethod + def __prop_format(tree): + """Propagate Format objects into the decode tree""" + + # Depth first search. + for (b, s) in tree.subs: + if isinstance(s, Tree): + ExcMultiPattern.__prop_format(s) + + # If all entries in SUBS have the same format, then + # propagate that into the tree. + f = None + for (b, s) in tree.subs: + if f is None: + f = s.base + if f is None: + return + if f is not s.base: + return + tree.base = f + + def prop_format(self): + super().prop_format() + self.__prop_format(self.tree) + +# end ExcMultiPattern def parse_field(lineno, name, toks): @@ -562,18 +641,18 @@ def parse_field(lineno, name, toks): width = 0 func = None for t in toks: - if re_fullmatch('!function=' + re_ident, t): + if re.fullmatch('!function=' + re_ident, t): if func: error(lineno, 'duplicate function') func = t.split('=') func = func[1] continue - if re_fullmatch('[0-9]+:s[0-9]+', t): + if re.fullmatch('[0-9]+:s[0-9]+', t): # Signed field extract subtoks = t.split(':s') sign = True - elif re_fullmatch('[0-9]+:[0-9]+', t): + elif re.fullmatch('[0-9]+:[0-9]+', t): # Unsigned field extract subtoks = t.split(':') sign = False @@ -622,11 +701,11 @@ def parse_arguments(lineno, name, toks): flds = [] extern = False for t in toks: - if re_fullmatch('!extern', t): + if re.fullmatch('!extern', t): extern = True anyextern = True continue - if not re_fullmatch(re_ident, t): + if not re.fullmatch(re_ident, t): error(lineno, 'invalid argument set token "{0}"'.format(t)) if t in flds: error(lineno, 'duplicate argument "{0}"'.format(t)) @@ -706,18 +785,19 @@ def infer_format(arg, fieldmask, flds, width): # end infer_format -def parse_generic(lineno, is_format, name, toks): +def parse_generic(lineno, parent_pat, name, toks): """Parse one instruction format from TOKS at LINENO""" global fields global arguments global formats - global patterns global allpatterns global re_ident global insnwidth global insnmask global variablewidth + is_format = parent_pat is None + fixedmask = 0 fixedbits = 0 undefmask = 0 @@ -755,13 +835,13 @@ def parse_generic(lineno, is_format, name, toks): continue # 'Foo=%Bar' imports a field with a different name. - if re_fullmatch(re_ident + '=%' + re_ident, t): + if re.fullmatch(re_ident + '=%' + re_ident, t): (fname, iname) = t.split('=%') flds = add_field_byname(lineno, flds, fname, iname) continue # 'Foo=number' sets an argument field to a constant value - if re_fullmatch(re_ident + '=[+-]?[0-9]+', t): + if re.fullmatch(re_ident + '=[+-]?[0-9]+', t): (fname, value) = t.split('=') value = int(value) flds = add_field(lineno, flds, fname, ConstField(value)) @@ -769,7 +849,7 @@ def parse_generic(lineno, is_format, name, toks): # Pattern of 0s, 1s, dots and dashes indicate required zeros, # required ones, or dont-cares. - if re_fullmatch('[01.-]+', t): + if re.fullmatch('[01.-]+', t): shift = len(t) fms = t.replace('0', '1') fms = fms.replace('.', '0') @@ -786,7 +866,7 @@ def parse_generic(lineno, is_format, name, toks): fixedmask = (fixedmask << shift) | fms undefmask = (undefmask << shift) | ubm # Otherwise, fieldname:fieldwidth - elif re_fullmatch(re_ident + ':s?[0-9]+', t): + elif re.fullmatch(re_ident + ':s?[0-9]+', t): (fname, flen) = t.split(':') sign = False if flen[0] == 's': @@ -868,7 +948,7 @@ def parse_generic(lineno, is_format, name, toks): error(lineno, 'field {0} not initialized'.format(f)) pat = Pattern(name, lineno, fmt, fixedbits, fixedmask, undefmask, fieldmask, flds, width) - patterns.append(pat) + parent_pat.pats.append(pat) allpatterns.append(pat) # Validate the masks that we have assembled. @@ -889,63 +969,15 @@ def parse_generic(lineno, is_format, name, toks): # end parse_general -def build_multi_pattern(lineno, pats): - """Validate the Patterns going into a MultiPattern.""" - global patterns - global insnmask - - if len(pats) < 2: - error(lineno, 'less than two patterns within braces') - - fixedmask = insnmask - undefmask = insnmask - - # Collect fixed/undefmask for all of the children. - # Move the defining lineno back to that of the first child. - for p in pats: - fixedmask &= p.fixedmask - undefmask &= p.undefmask - if p.lineno < lineno: - lineno = p.lineno - - width = None - for p in pats: - if width is None: - width = p.width - elif width != p.width: - error(lineno, 'width mismatch in patterns within braces') - - repeat = True - while repeat: - if fixedmask == 0: - error(lineno, 'no overlap in patterns within braces') - fixedbits = None - for p in pats: - thisbits = p.fixedbits & fixedmask - if fixedbits is None: - fixedbits = thisbits - elif fixedbits != thisbits: - fixedmask &= ~(fixedbits ^ thisbits) - break - else: - repeat = False - - mp = MultiPattern(lineno, pats, fixedbits, fixedmask, undefmask, width) - patterns.append(mp) -# end build_multi_pattern - - -def parse_file(f): +def parse_file(f, parent_pat): """Parse all of the patterns within a file""" - global patterns - # Read all of the lines of the file. Concatenate lines # ending in backslash; discard empty lines and comments. toks = [] lineno = 0 nesting = 0 - saved_pats = [] + nesting_pats = [] for line in f: lineno += 1 @@ -989,17 +1021,23 @@ def parse_file(f): del toks[0] # End nesting? - if name == '}': - if nesting == 0: - error(start_lineno, 'mismatched close brace') + if name == '}' or name == ']': if len(toks) != 0: error(start_lineno, 'extra tokens after close brace') + + # Make sure { } and [ ] nest properly. + if (name == '}') != isinstance(parent_pat, IncMultiPattern): + error(lineno, 'mismatched close brace') + + try: + parent_pat = nesting_pats.pop() + except: + error(lineno, 'extra close brace') + nesting -= 2 if indent != nesting: - error(start_lineno, 'indentation ', indent, ' != ', nesting) - pats = patterns - patterns = saved_pats.pop() - build_multi_pattern(lineno, pats) + error(lineno, 'indentation ', indent, ' != ', nesting) + toks = [] continue @@ -1008,11 +1046,18 @@ def parse_file(f): error(start_lineno, 'indentation ', indent, ' != ', nesting) # Start nesting? - if name == '{': + if name == '{' or name == '[': if len(toks) != 0: error(start_lineno, 'extra tokens after open brace') - saved_pats.append(patterns) - patterns = [] + + if name == '{': + nested_pat = IncMultiPattern(start_lineno) + else: + nested_pat = ExcMultiPattern(start_lineno) + parent_pat.pats.append(nested_pat) + nesting_pats.append(parent_pat) + parent_pat = nested_pat + nesting += 2 toks = [] continue @@ -1023,115 +1068,16 @@ def parse_file(f): elif name[0] == '&': parse_arguments(start_lineno, name[1:], toks) elif name[0] == '@': - parse_generic(start_lineno, True, name[1:], toks) + parse_generic(start_lineno, None, name[1:], toks) else: - parse_generic(start_lineno, False, name, toks) + parse_generic(start_lineno, parent_pat, name, toks) toks = [] + + if nesting != 0: + error(lineno, 'missing close brace') # end parse_file -class Tree: - """Class representing a node in a decode tree""" - - def __init__(self, fm, tm): - self.fixedmask = fm - self.thismask = tm - self.subs = [] - self.base = None - - def str1(self, i): - ind = str_indent(i) - r = '{0}{1:08x}'.format(ind, self.fixedmask) - if self.format: - r += ' ' + self.format.name - r += ' [\n' - for (b, s) in self.subs: - r += '{0} {1:08x}:\n'.format(ind, b) - r += s.str1(i + 4) + '\n' - r += ind + ']' - return r - - def __str__(self): - return self.str1(0) - - def output_code(self, i, extracted, outerbits, outermask): - ind = str_indent(i) - - # If we identified all nodes below have the same format, - # extract the fields now. - if not extracted and self.base: - output(ind, self.base.extract_name(), - '(ctx, &u.f_', self.base.base.name, ', insn);\n') - extracted = True - - # Attempt to aid the compiler in producing compact switch statements. - # If the bits in the mask are contiguous, extract them. - sh = is_contiguous(self.thismask) - if sh > 0: - # Propagate SH down into the local functions. - def str_switch(b, sh=sh): - return '(insn >> {0}) & 0x{1:x}'.format(sh, b >> sh) - - def str_case(b, sh=sh): - return '0x{0:x}'.format(b >> sh) - else: - def str_switch(b): - return 'insn & 0x{0:08x}'.format(b) - - def str_case(b): - return '0x{0:08x}'.format(b) - - output(ind, 'switch (', str_switch(self.thismask), ') {\n') - for b, s in sorted(self.subs): - assert (self.thismask & ~s.fixedmask) == 0 - innermask = outermask | self.thismask - innerbits = outerbits | b - output(ind, 'case ', str_case(b), ':\n') - output(ind, ' /* ', - str_match_bits(innerbits, innermask), ' */\n') - s.output_code(i + 4, extracted, innerbits, innermask) - output(ind, ' return false;\n') - output(ind, '}\n') -# end Tree - - -def build_tree(pats, outerbits, outermask): - # Find the intersection of all remaining fixedmask. - innermask = ~outermask & insnmask - for i in pats: - innermask &= i.fixedmask - - if innermask == 0: - text = 'overlapping patterns:' - for p in pats: - text += '\n' + p.file + ':' + str(p.lineno) + ': ' + str(p) - error_with_file(pats[0].file, pats[0].lineno, text) - - fullmask = outermask | innermask - - # Sort each element of pats into the bin selected by the mask. - bins = {} - for i in pats: - fb = i.fixedbits & innermask - if fb in bins: - bins[fb].append(i) - else: - bins[fb] = [i] - - # We must recurse if any bin has more than one element or if - # the single element in the bin has not been fully matched. - t = Tree(fullmask, innermask) - - for b, l in bins.items(): - s = l[0] - if len(l) > 1 or s.fixedmask & ~fullmask != 0: - s = build_tree(l, b | outerbits, fullmask) - t.subs.append((b, s)) - - return t -# end build_tree - - class SizeTree: """Class representing a node in a size decode tree""" @@ -1273,28 +1219,6 @@ def build_size_tree(pats, width, outerbits, outermask): # end build_size_tree -def prop_format(tree): - """Propagate Format objects into the decode tree""" - - # Depth first search. - for (b, s) in tree.subs: - if isinstance(s, Tree): - prop_format(s) - - # If all entries in SUBS have the same format, then - # propagate that into the tree. - f = None - for (b, s) in tree.subs: - if f is None: - f = s.base - if f is None: - return - if f is not s.base: - return - tree.base = f -# end prop_format - - def prop_size(tree): """Propagate minimum widths up the decode size tree""" @@ -1315,7 +1239,6 @@ def prop_size(tree): def main(): global arguments global formats - global patterns global allpatterns global translate_scope global translate_prefix @@ -1362,18 +1285,29 @@ def main(): if len(args) < 1: error(0, 'missing input file') + + toppat = ExcMultiPattern(0) + for filename in args: input_file = filename f = open(filename, 'r') - parse_file(f) + parse_file(f, toppat) f.close() - if variablewidth: - stree = build_size_tree(patterns, 8, 0, 0) - prop_size(stree) + # We do not want to compute masks for toppat, because those masks + # are used as a starting point for build_tree. For toppat, we must + # insist that decode begins from naught. + for i in toppat.pats: + i.prop_masks() - dtree = build_tree(patterns, 0, 0) - prop_format(dtree) + toppat.build_tree() + toppat.prop_format() + + if variablewidth: + for i in toppat.pats: + i.prop_width() + stree = build_size_tree(toppat.pats, 8, 0, 0) + prop_size(stree) if output_file: output_fd = open(output_file, 'w') @@ -1425,13 +1359,14 @@ def main(): '(DisasContext *ctx, ', insntype, ' insn)\n{\n') i4 = str_indent(4) + if len(allpatterns) != 0: output(i4, 'union {\n') for n in sorted(arguments.keys()): f = arguments[n] output(i4, i4, f.struct_name(), ' f_', f.name, ';\n') output(i4, '} u;\n\n') - dtree.output_code(4, False, 0, 0) + toppat.output_code(4, False, 0, 0) output(i4, 'return false;\n') output('}\n')