@@ -965,6 +965,147 @@ def build_tree(pats, outerbits, outermask):
# end build_tree
+class SizeTree:
+ """Class representing a node in a size decode tree"""
+
+ def __init__(self, m, w):
+ self.mask = m
+ self.subs = []
+ self.base = None
+ self.width = w
+
+ def str1(self, i):
+ ind = str_indent(i)
+ r = '{0}{1:08x}'.format(ind, self.mask)
+ 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 need to load more bytes to test, do so now.
+ if extracted < self.width:
+ output(ind, 'insn = ', decode_function,
+ '_load_bytes(ctx, insn, {0}, {1});\n'
+ .format(extracted / 8, self.width / 8));
+ extracted = self.width
+
+ # Attempt to aid the compiler in producing compact switch statements.
+ # If the bits in the mask are contiguous, extract them.
+ sh = is_contiguous(self.mask)
+ 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.mask), ') {\n')
+ for b, s in sorted(self.subs):
+ innermask = outermask | self.mask
+ 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, '}\n')
+ output(ind, 'return insn;\n')
+# end SizeTree
+
+class SizeLeaf:
+ """Class representing a leaf node in a size decode tree"""
+
+ def __init__(self, m, w):
+ self.mask = m
+ self.width = w
+
+ def str1(self, i):
+ ind = str_indent(i)
+ return '{0}{1:08x}'.format(ind, self.mask)
+
+ def __str__(self):
+ return self.str1(0)
+
+ def output_code(self, i, extracted, outerbits, outermask):
+ global decode_function
+ ind = str_indent(i)
+
+ # If we need to load more bytes, do so now.
+ if extracted < self.width:
+ output(ind, 'insn = ', decode_function,
+ '_load_bytes(ctx, insn, {0}, {1});\n'
+ .format(extracted / 8, self.width / 8));
+ extracted = self.width
+ output(ind, 'return insn;\n')
+# end SizeLeaf
+
+
+def build_size_tree(pats, width, outerbits, outermask):
+ global insnwidth
+
+ # Collect the mask of bits that are fixed in this width
+ innermask = 0xff << (insnwidth - width)
+ innermask &= ~outermask
+ minwidth = None
+ onewidth = True
+ for i in pats:
+ innermask &= i.fixedmask
+ if minwidth is None:
+ minwidth = i.width
+ elif minwidth != i.width:
+ onewidth = False;
+ if minwidth < i.width:
+ minwidth = i.width
+
+ if onewidth:
+ return SizeLeaf(innermask, minwidth)
+
+ if innermask == 0:
+ if width < minwidth:
+ return build_size_tree(pats, width + 8, outerbits, outermask)
+
+ pnames = []
+ for p in pats:
+ pnames.append(p.name + ':' + p.file + ':' + str(p.lineno))
+ error_with_file(pats[0].file, pats[0].lineno,
+ 'overlapping patterns size {0}:'.format(width), pnames)
+
+ bins = {}
+ for i in pats:
+ fb = i.fixedbits & innermask
+ if fb in bins:
+ bins[fb].append(i)
+ else:
+ bins[fb] = [i]
+
+ fullmask = outermask | innermask
+ lens = sorted(bins.keys())
+ if len(lens) == 1:
+ b = lens[0]
+ return build_size_tree(bins[b], width + 8, b | outerbits, fullmask)
+
+ r = SizeTree(innermask, width)
+ for b, l in bins.items():
+ s = build_size_tree(l, width, b | outerbits, fullmask)
+ r.subs.append((b, s))
+ return r
+# end build_size_tree
+
+
def prop_format(tree):
"""Propagate Format objects into the decode tree"""
@@ -987,6 +1128,23 @@ def prop_format(tree):
# end prop_format
+def prop_size(tree):
+ """Propagate minimum widths up the decode size tree"""
+
+ if isinstance(tree, SizeTree):
+ min = None
+ for (b, s) in tree.subs:
+ width = prop_size(s)
+ if min is None or min > width:
+ min = width
+ assert min >= tree.width
+ tree.width = min
+ else:
+ min = tree.width
+ return min
+# end prop_size
+
+
def main():
global arguments
global formats
@@ -1042,8 +1200,12 @@ def main():
parse_file(f)
f.close()
- t = build_tree(patterns, 0, 0)
- prop_format(t)
+ if variablewidth:
+ stree = build_size_tree(patterns, 8, 0, 0)
+ prop_size(stree)
+
+ dtree = build_tree(patterns, 0, 0)
+ prop_format(dtree)
if output_file:
output_fd = open(output_file, 'w')
@@ -1084,11 +1246,18 @@ def main():
f = arguments[n]
output(i4, i4, f.struct_name(), ' f_', f.name, ';\n')
output(i4, '} u;\n\n')
- t.output_code(4, False, 0, 0)
+ dtree.output_code(4, False, 0, 0)
output(i4, 'return false;\n')
output('}\n')
+ if variablewidth:
+ output('\n', decode_scope, insntype, ' ', decode_function,
+ '_load(DisasContext *ctx)\n{\n',
+ ' ', insntype, ' insn = 0;\n\n')
+ stree.output_code(4, 0, 0, 0)
+ output('}\n')
+
if output_file:
output_fd.close()
# end main
Read the instruction, loading no more bytes than necessary. Signed-off-by: Richard Henderson <richard.henderson@linaro.org> --- scripts/decodetree.py | 175 +++++++++++++++++++++++++++++++++++++++++- 1 file changed, 172 insertions(+), 3 deletions(-) -- 2.17.1