mirror of
https://github.com/libretro/scummvm.git
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138 lines
3.1 KiB
Python
138 lines
3.1 KiB
Python
import re
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import op
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class proc:
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last_addr = 0xc000
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def __init__(self, name):
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self.name = name
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self.calls = []
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self.stmts = []
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self.labels = set()
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self.__label_re = re.compile(r'^(\S+):(.*)$')
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self.offset = proc.last_addr
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proc.last_addr += 4
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def add_label(self, label):
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self.stmts.append(op.label(label))
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self.labels.add(label)
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def remove_label(self, label):
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try:
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self.labels.remove(label)
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except:
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pass
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for l in self.stmts:
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if isinstance(l, op.label) and l.name == label:
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self.stmts.remove(l)
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return
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def optimize_sequence(self, cls):
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i = 0
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stmts = self.stmts
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while i < len(stmts):
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if not isinstance(stmts[i], cls):
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i += 1
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continue
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j = i + 1
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while j < len(stmts):
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if not isinstance(stmts[j], cls):
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break
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j = j + 1
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n = j - i
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if n > 1:
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print "Eliminate consequtive storage instructions at %u-%u" %(i, j)
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del stmts[i + 1:j]
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stmts[i].repeat = n
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else:
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i = j
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return
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def optimize(self):
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print "optimizing..."
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#trivial simplifications, removing last ret
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while len(self.stmts) and isinstance(self.stmts[-1], op.label):
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print "stripping last label"
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self.stmts.pop()
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if isinstance(self.stmts[-1], op._ret) and (len(self.stmts) < 2 or not isinstance(self.stmts[-2], op.label)):
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print "stripping last ret"
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self.stmts.pop()
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#merging push ax pop bx constructs
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i = 0
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while i + 1 < len(self.stmts):
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a, b = self.stmts[i], self.stmts[i + 1]
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if isinstance(a, op._push) and isinstance(b, op._pop):
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ar, br = a.regs, b.regs
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movs = []
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while len(ar) and len(br):
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src = ar.pop()
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dst = br.pop(0)
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movs.append(op._mov2(dst, src))
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if len(br) == 0:
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self.stmts.pop(i + 1)
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print "merging %d push-pops into movs" %(len(movs))
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for m in movs:
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print "\t%s <- %s" %(m.dst, m.src)
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self.stmts[i + 1:i + 1] = movs
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if len(ar) == 0:
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self.stmts.pop(i)
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else:
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i += 1
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#eliminating unused labels
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for s in list(self.stmts):
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if not isinstance(s, op.label):
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continue
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print "checking label %s..." %s.name
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used = False
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for j in self.stmts:
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if isinstance(j, op.basejmp) and j.label == s.name:
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print "used"
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used = True
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break
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if not used:
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print self.labels
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self.remove_label(s.name)
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self.optimize_sequence(op._stosb);
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self.optimize_sequence(op._stosw);
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self.optimize_sequence(op._movsb);
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self.optimize_sequence(op._movsw);
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def add(self, stmt):
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#print stmt
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comment = stmt.rfind(';')
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if comment >= 0:
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stmt = stmt[:comment]
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stmt = stmt.strip()
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r = self.__label_re.search(stmt)
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if r is not None:
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#label
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self.add_label(r.group(1).lower())
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#print "remains: %s" %r.group(2)
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stmt = r.group(2).strip()
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if len(stmt) == 0:
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return
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s = stmt.split(None)
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cmd = s[0]
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cl = getattr(op, '_' + cmd)
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arg = " ".join(s[1:]) if len(s) > 1 else str()
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o = cl(arg)
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self.stmts.append(o)
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def __str__(self):
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r = []
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for i in self.stmts:
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r.append(i.__str__())
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return "\n".join(r)
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def visit(self, visitor, skip = 0):
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for i in xrange(skip, len(self.stmts)):
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self.stmts[i].visit(visitor)
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