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[SelectionDAGBuilder] Use address width when lowering ptrtoaddr #139423

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[SelectionDAGBuilder] Use address width when lowering ptrtoaddr #139423

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3c8c76e
[𝘀𝗽𝗿] initial version
arichardson May 11, 2025
d4520dc
remove unused variable
arichardson May 11, 2025
1222b60
rebase
arichardson Jun 11, 2025
8afae27
rebase, no more test diff due to semantics change
arichardson Aug 11, 2025
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12 changes: 10 additions & 2 deletions llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -3980,8 +3980,16 @@ void SelectionDAGBuilder::visitSIToFP(const User &I) {
}

void SelectionDAGBuilder::visitPtrToAddr(const User &I) {
// FIXME: this is not correct for pointers with addr width != pointer width
visitPtrToInt(I);
const auto &TLI = DAG.getTargetLoweringInfo();
const DataLayout &DL = DAG.getDataLayout();
// ptrtoaddr is equivalent to a truncate of ptrtoint to address/index width
auto Op0 = I.getOperand(0);
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Suggested change
auto Op0 = I.getOperand(0);
const Value *Op0 = I.getOperand(0);

No auto

SDValue N = getValue(Op0);
// By definition the type of the ptrtoaddr must be equal to the address type.
assert(I.getType() == DL.getAddressType(Op0->getType()));
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Don't need to assert things enforced by the verifier

EVT AddrVT = TLI.getValueType(DL, I.getType());
N = DAG.getNode(ISD::TRUNCATE, getCurSDLoc(), AddrVT, N);
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If these are the same type, why do you need the truncate?

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While most targets will have them be the same, the Op0 type can be wider. This is the case e.g. for the AMD GPU buffer pointers.

setValue(&I, N);
}

void SelectionDAGBuilder::visitPtrToInt(const User &I) {
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