def remove_label(self, label): try: self.labels.remove(label) except: pass for i in xrange(len(self.stmts)): if isinstance(self.stmts[i], op.label) and self.stmts[i].name == label: self.stmts[i] = op._nop(None) return
def remove_label(self, label): try: self.labels.remove(label) except: pass for i in xrange(len(self.stmts)): if isinstance(self.stmts[i], op.label) and self.stmts[i].name == label: self.stmts[i] = op._nop(None) return
def optimize_sequence(self, cls):
i = 0
stmts = self.stmts
while i < len(stmts):
if not isinstance(stmts[i], cls):
i += 1
continue
if i > 0 and isinstance(
stmts[i - 1],
op._rep): #skip rep prefixed instructions for now
i += 1
continue
j = i + 1
while j < len(stmts):
if not isinstance(stmts[j], cls):
break
j = j + 1
n = j - i
if n > 1:
print "Eliminate consequtive storage instructions at %u-%u" % (
i, j)
for k in range(i + 1, j):
stmts[k] = op._nop(None)
stmts[i].repeat = n
else:
i = j
i = 0
while i < len(stmts):
if not isinstance(stmts[i], op._rep):
i += 1
continue
if i + 1 >= len(stmts):
break
if isinstance(stmts[i + 1], cls):
stmts[i + 1].repeat = 'cx'
stmts[i + 1].clear_cx = True
stmts[i] = op._nop(None)
i += 1
return
def optimize_sequence(self, cls): i = 0 stmts = self.stmts while i < len(stmts): if not isinstance(stmts[i], cls): i += 1 continue if i > 0 and isinstance(stmts[i - 1], op._rep): #skip rep prefixed instructions for now i += 1 continue j = i + 1 while j < len(stmts): if not isinstance(stmts[j], cls): break j = j + 1 n = j - i if n > 1: print "Eliminate consequtive storage instructions at %u-%u" %(i, j) for k in range(i+1,j): stmts[k] = op._nop(None) stmts[i].repeat = n else: i = j i = 0 while i < len(stmts): if not isinstance(stmts[i], op._rep): i += 1 continue if i + 1 >= len(stmts): break if isinstance(stmts[i + 1], cls): stmts[i + 1].repeat = 'cx' stmts[i + 1].clear_cx = True stmts[i] = op._nop(None) i += 1 return
def optimize(self, keep_labels=[]):
print "optimizing..."
#trivial simplifications
while len(self.stmts) and isinstance(self.stmts[-1], op.label):
print "stripping last label"
self.stmts.pop()
#mark labels that directly precede a ret
for i in range(len(self.stmts)):
if not isinstance(self.stmts[i], op.label):
continue
j = i
while j < len(self.stmts) and isinstance(self.stmts[j],
(op.label, op._nop)):
j += 1
if j == len(self.stmts) or isinstance(self.stmts[j], op._ret):
print "Return label: %s" % (self.stmts[i].name, )
self.retlabels.add(self.stmts[i].name)
#merging push ax pop bx constructs
i = 0
while i + 1 < len(self.stmts):
a, b = self.stmts[i], self.stmts[i + 1]
if isinstance(a, op._push) and isinstance(b, op._pop):
ar, br = a.regs, b.regs
movs = []
while len(ar) and len(br):
src = ar.pop()
dst = br.pop(0)
movs.append(op._mov2(dst, src))
if len(br) == 0:
self.stmts.pop(i + 1)
print "merging %d push-pops into movs" % (len(movs))
for m in movs:
print "\t%s <- %s" % (m.dst, m.src)
self.stmts[i + 1:i + 1] = movs
if len(ar) == 0:
self.stmts.pop(i)
else:
i += 1
#eliminating unused labels
for s in list(self.stmts):
if not isinstance(s, op.label):
continue
print "checking label %s..." % s.name
used = s.name in keep_labels
if s.name not in self.retlabels:
for j in self.stmts:
if isinstance(j, op.basejmp) and j.label == s.name:
print "used"
used = True
break
if not used:
print self.labels
self.remove_label(s.name)
#removing duplicate rets and rets at end
for i in xrange(len(self.stmts)):
if isinstance(self.stmts[i], op._ret):
j = i + 1
while j < len(self.stmts) and isinstance(
self.stmts[j], op._nop):
j += 1
if j == len(self.stmts) or isinstance(self.stmts[j], op._ret):
self.stmts[i] = op._nop(None)
self.optimize_sequence(op._stosb)
self.optimize_sequence(op._stosw)
self.optimize_sequence(op._movsb)
self.optimize_sequence(op._movsw)
def optimize(self, keep_labels=[]): print "optimizing..." #trivial simplifications while len(self.stmts) and isinstance(self.stmts[-1], op.label): print "stripping last label" self.stmts.pop() #mark labels that directly precede a ret for i in range(len(self.stmts)): if not isinstance(self.stmts[i], op.label): continue j = i while j < len(self.stmts) and isinstance(self.stmts[j], (op.label, op._nop)): j += 1 if j == len(self.stmts) or isinstance(self.stmts[j], op._ret): print "Return label: %s" % (self.stmts[i].name,) self.retlabels.add(self.stmts[i].name) #merging push ax pop bx constructs i = 0 while i + 1 < len(self.stmts): a, b = self.stmts[i], self.stmts[i + 1] if isinstance(a, op._push) and isinstance(b, op._pop): ar, br = a.regs, b.regs movs = [] while len(ar) and len(br): src = ar.pop() dst = br.pop(0) movs.append(op._mov2(dst, src)) if len(br) == 0: self.stmts.pop(i + 1) print "merging %d push-pops into movs" %(len(movs)) for m in movs: print "\t%s <- %s" %(m.dst, m.src) self.stmts[i + 1:i + 1] = movs if len(ar) == 0: self.stmts.pop(i) else: i += 1 #eliminating unused labels for s in list(self.stmts): if not isinstance(s, op.label): continue print "checking label %s..." %s.name used = s.name in keep_labels if s.name not in self.retlabels: for j in self.stmts: if isinstance(j, op.basejmp) and j.label == s.name: print "used" used = True break if not used: print self.labels self.remove_label(s.name) #removing duplicate rets and rets at end for i in xrange(len(self.stmts)): if isinstance(self.stmts[i], op._ret): j = i+1 while j < len(self.stmts) and isinstance(self.stmts[j], op._nop): j += 1 if j == len(self.stmts) or isinstance(self.stmts[j], op._ret): self.stmts[i] = op._nop(None) self.optimize_sequence(op._stosb); self.optimize_sequence(op._stosw); self.optimize_sequence(op._movsb); self.optimize_sequence(op._movsw);
