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GP-4859 RuleOrCompare
This commit is contained in:
caheckman
parent
2ef83410be
commit
a31c4033a8
8 changed files with 141 additions and 234 deletions
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@ -4,9 +4,9 @@
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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@ -1124,9 +1124,6 @@ int4 SplitVarnode::applyRuleIn(SplitVarnode &in,Funcdata &data)
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break;
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case CPUI_INT_OR:
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{
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Equal2Form equal2form;
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if (equal2form.applyRule(in,workop,workishi,data))
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return 1;
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LogicalForm logicalform;
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if (logicalform.applyRule(in,workop,workishi,data))
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return 1;
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@ -1134,9 +1131,6 @@ int4 SplitVarnode::applyRuleIn(SplitVarnode &in,Funcdata &data)
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break;
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case CPUI_INT_XOR:
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{
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Equal2Form equal2form;
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if (equal2form.applyRule(in,workop,workishi,data))
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return 1;
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LogicalForm logicalform;
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if (logicalform.applyRule(in,workop,workishi,data))
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return 1;
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@ -1151,6 +1145,9 @@ int4 SplitVarnode::applyRuleIn(SplitVarnode &in,Funcdata &data)
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Equal1Form equal1form;
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if (equal1form.applyRule(in,workop,workishi,data))
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return 1;
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Equal2Form equal2form;
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if (equal2form.applyRule(in,workop,workishi,data))
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return 1;
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}
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break;
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case CPUI_INT_LESS:
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@ -1870,95 +1867,30 @@ bool Equal1Form::applyRule(SplitVarnode &i,PcodeOp *hop,bool workishi,Funcdata &
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return false;
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}
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bool Equal2Form::checkLoForm(void)
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{ // Assuming we have equal <- or <- xor <- hi1, verify if we have the full equal form
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Varnode *orvnin = orop->getIn(1-orhislot);
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if (orvnin == lo1) { // lo2 is an implied 0
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loxor = (PcodeOp *)0;
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lo2 = (Varnode *)0;
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return true;
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}
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if (!orvnin->isWritten()) return false;
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loxor = orvnin->getDef();
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if (loxor->code() != CPUI_INT_XOR) return false;
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if (loxor->getIn(0) == lo1) {
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lo2 = loxor->getIn(1);
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return true;
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}
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else if (loxor->getIn(1) == lo1) {
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lo2 = loxor->getIn(0);
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return true;
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}
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return false;
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}
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bool Equal2Form::fillOutFromOr(Funcdata &data)
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{ // We have filled in either or <- xor <- hi1, OR, or <- hi1
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// Now try to fill in the rest of the form
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Varnode *outvn = orop->getOut();
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list<PcodeOp *>::const_iterator iter,enditer;
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iter = outvn->beginDescend();
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enditer = outvn->endDescend();
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while(iter != enditer) {
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equalop = *iter;
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++iter;
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if ((equalop->code() != CPUI_INT_EQUAL)&&(equalop->code() != CPUI_INT_NOTEQUAL)) continue;
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if (!equalop->getIn(1)->isConstant()) continue;
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if (equalop->getIn(1)->getOffset() != 0) continue;
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if (!checkLoForm()) continue;
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if (!replace(data)) continue;
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return true;
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}
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return false;
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}
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bool Equal2Form::replace(Funcdata &data)
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{
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if ((hi2==(Varnode *)0)&&(lo2==(Varnode *)0)) {
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param2.initPartial(in.getSize(),0); // Double precis zero constant
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return SplitVarnode::prepareBoolOp(in,param2,equalop);
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}
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if ((hi2==(Varnode *)0)&&(lo2->isConstant())) {
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param2.initPartial(in.getSize(),lo2->getOffset());
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return SplitVarnode::prepareBoolOp(in,param2,equalop);
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}
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if ((lo2==(Varnode *)0)&&(hi2->isConstant())) {
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param2.initPartial(in.getSize(),hi2->getOffset() << 8*lo1->getSize());
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return SplitVarnode::prepareBoolOp(in,param2,equalop);
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}
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if (lo2 == (Varnode *)0) {
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// Equal to a zero extended and shifted var
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return false;
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}
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if (hi2 == (Varnode *)0) {
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// Equal to a zero extended var
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return false;
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}
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if (hi2->isConstant()&&lo2->isConstant()) {
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uintb val = hi2->getOffset();
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val <<= 8*lo1->getSize();
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val |= lo2->getOffset();
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param2.initPartial(in.getSize(),val);
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return SplitVarnode::prepareBoolOp(in,param2,equalop);
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return SplitVarnode::prepareBoolOp(in,param2,boolAndOr);
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}
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if (hi2->isConstant()||lo2->isConstant()) {
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// Some kind of mixed form
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return false;
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}
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param2.initPartial(in.getSize(),lo2,hi2);
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return SplitVarnode::prepareBoolOp(in,param2,equalop);
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return SplitVarnode::prepareBoolOp(in,param2,boolAndOr);
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}
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// Given a known double precis input, look for double precision compares of the form
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// a == b, a != b
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//
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// We look for
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// res = ((hi1 ^ hi2) | (lo1 ^ lo2) == 0)
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// where hi2 or lo2 may be zero, and optimized out
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// res = (hi1 == hi2) && (lo1 == lo2) or
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// res = (hi1 != hi2) || (lo1 != lo2)
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bool Equal2Form::applyRule(SplitVarnode &i,PcodeOp *op,bool workishi,Funcdata &data)
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{
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@ -1967,41 +1899,37 @@ bool Equal2Form::applyRule(SplitVarnode &i,PcodeOp *op,bool workishi,Funcdata &d
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in = i;
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hi1 = in.getHi();
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lo1 = in.getLo();
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if (op->code() == CPUI_INT_OR) {
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orop = op;
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orhislot = op->getSlot(hi1);
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hixor = (PcodeOp *)0;
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hi2 = (Varnode *)0;
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if (fillOutFromOr(data)) {
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if (!param2.exceedsConstPrecision()) {
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SplitVarnode::replaceBoolOp(data,equalop,in,param2,equalop->code());
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return true;
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}
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OpCode eqCode = op->code();
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int4 hi1slot = op->getSlot(hi1);
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hi2 = op->getIn(1-hi1slot);
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Varnode *outvn = op->getOut();
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list<PcodeOp *>::const_iterator iter,enditer;
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iter = outvn->beginDescend();
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enditer = outvn->endDescend();
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while(iter != enditer) {
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boolAndOr = *iter;
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++iter;
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if (eqCode == CPUI_INT_EQUAL && boolAndOr->code() != CPUI_BOOL_AND) continue;
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if (eqCode == CPUI_INT_NOTEQUAL && boolAndOr->code() != CPUI_BOOL_OR) continue;
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int4 slot = boolAndOr->getSlot(outvn);
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Varnode *othervn = boolAndOr->getIn(1-slot);
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if (!othervn->isWritten()) continue;
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PcodeOp *equalLo = othervn->getDef();
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if (equalLo->code() != eqCode) continue;
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if (equalLo->getIn(0) == lo1) {
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lo2 = equalLo->getIn(1);
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}
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}
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else { // We see an XOR
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hixor = op;
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xorhislot = hixor->getSlot(hi1);
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hi2 = hixor->getIn(1-xorhislot);
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Varnode *vn = op->getOut();
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list<PcodeOp *>::const_iterator iter,enditer;
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iter = vn->beginDescend();
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enditer = vn->endDescend();
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while(iter != enditer) {
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orop = *iter;
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++iter;
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if (orop->code() != CPUI_INT_OR) continue;
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orhislot = orop->getSlot(vn);
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if (fillOutFromOr(data)) {
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if (!param2.exceedsConstPrecision()) {
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SplitVarnode::replaceBoolOp(data,equalop,in,param2,equalop->code());
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return true;
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}
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}
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else if (equalLo->getIn(1) == lo1) {
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lo2 = equalLo->getIn(0);
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}
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else {
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continue;
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}
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if (!replace(data)) continue;
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if (param2.exceedsConstPrecision()) continue;
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SplitVarnode::replaceBoolOp(data,boolAndOr,in,param2,eqCode);
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return true;
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}
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return false;
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}
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