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GP-4715 SSA revisit MemRange

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caheckman 2024-09-30 22:36:53 +00:00
parent a3d0b40f36
commit 23d43b8167
11 changed files with 229 additions and 113 deletions
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25
Ghidra/Features/Decompiler/src/decompile/cpp/funcdata_varnode.cc
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@ -397,36 +397,45 @@ void Funcdata::combineInputVarnodes(Varnode *vnHi,Varnode *vnLo)
if (!isContiguous)
throw LowlevelError("Input varnodes being combined are not contiguous");
vector<PcodeOp *> pieceList;
bool otherOps = false;
bool otherOpsHi = false;
bool otherOpsLo = false;
list<PcodeOp *>::const_iterator iter;
for(iter=vnHi->beginDescend();iter!=vnHi->endDescend();++iter) {
PcodeOp *op = *iter;
if (op->code() == CPUI_PIECE && op->getIn(0) == vnHi && op->getIn(1) == vnLo)
pieceList.push_back(op);
else
otherOps = true;
otherOpsHi = true;
}
for(iter=vnLo->beginDescend();iter!=vnLo->endDescend();++iter) {
PcodeOp *op = *iter;
if (op->code() != CPUI_PIECE || op->getIn(0) != vnHi || op->getIn(1) != vnLo)
otherOpsLo = true;
}
for(int4 i=0;i<pieceList.size();++i) {
opRemoveInput(pieceList[i], 1);
opUnsetInput(pieceList[i], 0);
}
// If there are other PcodeOps besides PIECEs that are directly combining vnHi and vnLo
// create replacement Varnodes constructed as SUBPIECEs of the new combined Varnode
PcodeOp *subHi = (PcodeOp *)0;
PcodeOp *subLo = (PcodeOp *)0;
if (otherOps) {
// If there are other PcodeOps besides PIECEs that are directly combining vnHi and vnLo
// create replacement Varnodes constructed as SUBPIECEs of the new combined Varnode
if (otherOpsHi) {
BlockBasic *bb = (BlockBasic *)bblocks.getBlock(0);
subHi = newOp(2,bb->getStart());
opSetOpcode(subHi, CPUI_SUBPIECE);
opSetInput(subHi,newConstant(4, vnLo->getSize()),1);
Varnode *newHi = newVarnodeOut(vnHi->getSize(),vnHi->getAddr(),subHi);
opInsertBegin(subHi, bb);
totalReplace(vnHi, newHi);
}
if (otherOpsLo) {
BlockBasic *bb = (BlockBasic *)bblocks.getBlock(0);
subLo = newOp(2,bb->getStart());
opSetOpcode(subLo, CPUI_SUBPIECE);
opSetInput(subLo,newConstant(4, 0),1);
Varnode *newLo = newVarnodeOut(vnLo->getSize(),vnLo->getAddr(),subLo);
opInsertBegin(subLo, bb);
totalReplace(vnHi, newHi);
totalReplace(vnLo, newLo);
}
int4 outSize = vnHi->getSize() + vnLo->getSize();
@ -438,10 +447,10 @@ void Funcdata::combineInputVarnodes(Varnode *vnHi,Varnode *vnLo)
opSetInput(pieceList[i],inVn,0);
opSetOpcode(pieceList[i], CPUI_COPY);
}
if (otherOps) {
if (otherOpsHi)
opSetInput(subHi,inVn,0);
if (otherOpsLo)
opSetInput(subLo,inVn,0);
}
}
/// Construct a constant Varnode up to 128 bits, using INT_ZEXT and PIECE if necessary.