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[CHERI] Update CallSiteInfo handling in RISCVExpandPseudoInsts for improved assertions in upstream #260

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Merged
merged 1 commit into from
Oct 13, 2025
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[CHERI] Update CallSiteInfo handling in RISCVExpandPseudoInsts for improved assertions in upstream #260

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56 changes: 33 additions & 23 deletions llvm/lib/Target/RISCV/RISCVExpandPseudoInsts.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -111,24 +111,23 @@ class RISCVExpandPseudo : public MachineFunctionPass {
* function is / may be exported from this compartment but, at this call site,
* should be treated as a library call.
*/
MachineBasicBlock *insertLoadOfImportTable(MachineBasicBlock &MBB,
MachineBasicBlock::iterator MBBI,
const Function *Fn,
Register DestReg,
bool TreatAsLibrary = false,
bool CallImportTarget = false);
MachineBasicBlock *
insertLoadOfImportTable(MachineBasicBlock &MBB,
MachineBasicBlock::iterator MBBI, const Function *Fn,
Register DestReg, bool TreatAsLibrary = false,
bool CallImportTarget = false,
const MachineInstr *OriginalCall = nullptr);
/**
* Helper that inserts a load from the import table identified by an import
* and export table entry symbol.
*
* Calls the result if `CallImportTarget` is true.
*/
MachineBasicBlock *
insertLoadOfImportTable(MachineBasicBlock &MBB,
MachineBasicBlock::iterator MBBI,
MCSymbol *ImportSymbol, MCSymbol *ExportSymbol,
const StringRef ImportName, Register DestReg,
bool IsLibrary, bool IsPublic, bool CallImportTarget);
MachineBasicBlock *insertLoadOfImportTable(
MachineBasicBlock &MBB, MachineBasicBlock::iterator MBBI,
MCSymbol *ImportSymbol, MCSymbol *ExportSymbol,
const StringRef ImportName, Register DestReg, bool IsLibrary,
bool IsPublic, bool CallImportTarget, const MachineInstr *OriginalCall);

#ifndef NDEBUG
unsigned getInstSizeInBytes(const MachineFunction &MF) const {
Expand Down Expand Up @@ -268,7 +267,7 @@ bool RISCVExpandPseudo::expandMI(MachineBasicBlock &MBB,
MachineBasicBlock *RISCVExpandPseudo::insertLoadOfImportTable(
MachineBasicBlock &MBB, MachineBasicBlock::iterator MBBI,
const Function *Fn, Register DestReg, bool TreatAsLibrary,
bool CallImportTarget) {
bool CallImportTarget, const MachineInstr *OriginalCall) {
auto *MF = MBB.getParent();
const StringRef ImportName = Fn->getName();
// We can hit this code path if we need to do a library-style import
Expand Down Expand Up @@ -296,7 +295,8 @@ MachineBasicBlock *RISCVExpandPseudo::insertLoadOfImportTable(
MCSymbol *ExportSymbol = MF->getContext().getOrCreateSymbol(ExportEntryName);
return insertLoadOfImportTable(
MBB, MBBI, ImportSymbol, ExportSymbol, ImportName, DestReg,
IsLibrary || TreatAsLibrary, Fn->hasExternalLinkage(), CallImportTarget);
IsLibrary || TreatAsLibrary, Fn->hasExternalLinkage(), CallImportTarget,
OriginalCall);
}

static const GlobalValue *resolveGlobalAlias(const GlobalValue *GV) {
Expand All @@ -309,7 +309,8 @@ static const GlobalValue *resolveGlobalAlias(const GlobalValue *GV) {
MachineBasicBlock *RISCVExpandPseudo::insertLoadOfImportTable(
MachineBasicBlock &MBB, MachineBasicBlock::iterator MBBI,
MCSymbol *ImportSymbol, MCSymbol *ExportSymbol, const StringRef ImportName,
Register DestReg, bool IsLibrary, bool IsPublic, bool CallImportTarget) {
Register DestReg, bool IsLibrary, bool IsPublic, bool CallImportTarget,
const MachineInstr *OriginalCall) {
auto *MF = MBB.getParent();
const DebugLoc DL = MBBI->getDebugLoc();
MachineBasicBlock *NewMBB =
Expand All @@ -328,9 +329,12 @@ MachineBasicBlock *RISCVExpandPseudo::insertLoadOfImportTable(
.addReg(DestReg, RegState::Kill)
.addMBB(NewMBB, RISCVII::MO_CHERIOT_COMPARTMENT_LO_I);

if (CallImportTarget)
BuildMI(NewMBB, DL, TII->get(RISCV::C_CJALR))
.addReg(DestReg, RegState::Kill);
if (CallImportTarget) {
auto NewCallMI = BuildMI(NewMBB, DL, TII->get(RISCV::C_CJALR))
.addReg(DestReg, RegState::Kill);
if (OriginalCall && OriginalCall->shouldUpdateAdditionalCallInfo())
MF->moveAdditionalCallInfo(OriginalCall, NewCallMI);
}

NewMBB->splice(NewMBB->end(), &MBB, std::next(MBBI), MBB.end());
// Update machine-CFG edges.
Expand Down Expand Up @@ -408,8 +412,10 @@ bool RISCVExpandPseudo::expandCompartmentCall(MachineBasicBlock &MBB,
BuildMI(NewMBB, DL, TII->get(RISCV::CLC_64), RISCV::X7_Y)
.addReg(RISCV::X7_Y, RegState::Kill)
.addMBB(NewMBB, RISCVII::MO_CHERIOT_COMPARTMENT_LO_I);
BuildMI(NewMBB, DL, TII->get(RISCV::C_CJALR))
.addReg(RISCV::X7_Y, RegState::Kill);
auto NewCallMI = BuildMI(NewMBB, DL, TII->get(RISCV::C_CJALR))
.addReg(RISCV::X7_Y, RegState::Kill);
if (MI.shouldUpdateAdditionalCallInfo())
MF->moveAdditionalCallInfo(&MI, NewCallMI);

// Move all the rest of the instructions to NewMBB.
NewMBB->splice(NewMBB->end(), &MBB, std::next(MBBI), MBB.end());
Expand Down Expand Up @@ -455,7 +461,7 @@ bool RISCVExpandPseudo::expandLibraryCall(
MI.setDesc(TII->get(RISCV::PseudoCCALL));
return true;
}
insertLoadOfImportTable(MBB, MBBI, Fn, RISCV::X7_Y, true, true);
insertLoadOfImportTable(MBB, MBBI, Fn, RISCV::X7_Y, true, true, &MI);

NextMBBI = MBB.end();
} else if (Callee.isSymbol()) {
Expand Down Expand Up @@ -486,14 +492,18 @@ bool RISCVExpandPseudo::expandLibraryCall(
MF->getContext().getOrCreateSymbol(ExportEntryName);
insertLoadOfImportTable(MBB, MBBI, ImportSymbol, ExportSymbol,
Callee.getSymbolName(), RISCV::X7_Y, true, true,
true);
true, &MI);

NextMBBI = MBB.end();
} else {
assert(Callee.isReg() && "Expected register operand");
// Indirect library calls are just cjalr instructions.
BuildMI(&MBB, MI.getDebugLoc(), TII->get(RISCV::C_CJALR)).add(Callee);
auto NewCallMI =
BuildMI(&MBB, MI.getDebugLoc(), TII->get(RISCV::C_CJALR)).add(Callee);
if (MI.shouldUpdateAdditionalCallInfo())
MF->moveAdditionalCallInfo(NewCallMI, &MI);
}

MI.eraseFromParent();
return true;
}
Expand Down