[RISCV][CodeGen] Support multiple save locations for the same callee-saved register #168159
+230
−147
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You can test this locally with the following command:git-clang-format --diff origin/main HEAD --extensions cpp -- llvm/lib/CodeGen/CFIInstrInserter.cpp --diff_from_common_commit
View the diff from clang-format here.diff --git a/llvm/lib/CodeGen/CFIInstrInserter.cpp b/llvm/lib/CodeGen/CFIInstrInserter.cpp
index 667928304..20fe26afe 100644
--- a/llvm/lib/CodeGen/CFIInstrInserter.cpp
+++ b/llvm/lib/CodeGen/CFIInstrInserter.cpp
@@ -65,104 +65,104 @@ class CFIInstrInserter : public MachineFunctionPass {
return insertedCFI;
}
- private:
+private:
#define INVALID_REG UINT_MAX
#define INVALID_OFFSET INT_MAX
- /// contains the location where CSR register is saved.
- struct CSRSavedLocation {
- enum Kind { INVALID, REGISTER, CFA_OFFSET };
- CSRSavedLocation() {
- K = Kind::INVALID;
- Reg = 0;
- Offset = 0;
- }
- Kind K;
- // Dwarf register number
- unsigned Reg;
- // CFA offset
- int64_t Offset;
- bool isValid() const { return K != Kind::INVALID; }
- bool operator==(const CSRSavedLocation &RHS) const {
- switch (K) {
- case Kind::INVALID:
- return !RHS.isValid();
- case Kind::REGISTER:
- return Reg == RHS.Reg;
- case Kind::CFA_OFFSET:
- return Offset == RHS.Offset;
- }
- llvm_unreachable("Unknown CSRSavedLocation Kind!");
- }
- void dump(raw_ostream &OS) const {
- switch (K) {
- case Kind::INVALID:
- OS << "INVALID";
- break;
- case Kind::REGISTER:
- OS << "In Dwarf register: " << Reg;
- break;
- case Kind::CFA_OFFSET:
- OS << "At CFA offset: " << Offset;
- break;
- }
- }
- };
-
- struct MBBCFAInfo {
- MachineBasicBlock *MBB;
- /// Value of cfa offset valid at basic block entry.
- int64_t IncomingCFAOffset = -1;
- /// Value of cfa offset valid at basic block exit.
- int64_t OutgoingCFAOffset = -1;
- /// Value of cfa register valid at basic block entry.
- unsigned IncomingCFARegister = 0;
- /// Value of cfa register valid at basic block exit.
- unsigned OutgoingCFARegister = 0;
- /// Set of locations where the callee saved registers are at basic block
- /// entry.
- SmallVector<CSRSavedLocation> IncomingCSRLocations;
- /// Set of locations where the callee saved registers are at basic block
- /// exit.
- SmallVector<CSRSavedLocation> OutgoingCSRLocations;
- /// If in/out cfa offset and register values for this block have already
- /// been set or not.
- bool Processed = false;
- };
-
- /// Contains cfa offset and register values valid at entry and exit of basic
- /// blocks.
- std::vector<MBBCFAInfo> MBBVector;
-
- /// Calculate cfa offset and register values valid at entry and exit for all
- /// basic blocks in a function.
- void calculateCFAInfo(MachineFunction &MF);
- /// Calculate cfa offset and register values valid at basic block exit by
- /// checking the block for CFI instructions. Block's incoming CFA info
- /// remains the same.
- void calculateOutgoingCFAInfo(MBBCFAInfo &MBBInfo);
- /// Update in/out cfa offset and register values for successors of the basic
- /// block.
- void updateSuccCFAInfo(MBBCFAInfo &MBBInfo);
-
- /// Check if incoming CFA information of a basic block matches outgoing CFA
- /// information of the previous block. If it doesn't, insert CFI instruction
- /// at the beginning of the block that corrects the CFA calculation rule for
- /// that block.
- bool insertCFIInstrs(MachineFunction &MF);
- /// Return the cfa offset value that should be set at the beginning of a MBB
- /// if needed. The negated value is needed when creating CFI instructions
- /// that set absolute offset.
- int64_t getCorrectCFAOffset(MachineBasicBlock *MBB) {
- return MBBVector[MBB->getNumber()].IncomingCFAOffset;
- }
-
- void reportCFAError(const MBBCFAInfo &Pred, const MBBCFAInfo &Succ);
- void reportCSRError(const MBBCFAInfo &Pred, const MBBCFAInfo &Succ);
- /// Go through each MBB in a function and check that outgoing offset and
- /// register of its predecessors match incoming offset and register of that
- /// MBB, as well as that incoming offset and register of its successors match
- /// outgoing offset and register of the MBB.
- unsigned verify(MachineFunction &MF);
+ /// contains the location where CSR register is saved.
+ struct CSRSavedLocation {
+ enum Kind { INVALID, REGISTER, CFA_OFFSET };
+ CSRSavedLocation() {
+ K = Kind::INVALID;
+ Reg = 0;
+ Offset = 0;
+ }
+ Kind K;
+ // Dwarf register number
+ unsigned Reg;
+ // CFA offset
+ int64_t Offset;
+ bool isValid() const { return K != Kind::INVALID; }
+ bool operator==(const CSRSavedLocation &RHS) const {
+ switch (K) {
+ case Kind::INVALID:
+ return !RHS.isValid();
+ case Kind::REGISTER:
+ return Reg == RHS.Reg;
+ case Kind::CFA_OFFSET:
+ return Offset == RHS.Offset;
+ }
+ llvm_unreachable("Unknown CSRSavedLocation Kind!");
+ }
+ void dump(raw_ostream &OS) const {
+ switch (K) {
+ case Kind::INVALID:
+ OS << "INVALID";
+ break;
+ case Kind::REGISTER:
+ OS << "In Dwarf register: " << Reg;
+ break;
+ case Kind::CFA_OFFSET:
+ OS << "At CFA offset: " << Offset;
+ break;
+ }
+ }
+ };
+
+ struct MBBCFAInfo {
+ MachineBasicBlock *MBB;
+ /// Value of cfa offset valid at basic block entry.
+ int64_t IncomingCFAOffset = -1;
+ /// Value of cfa offset valid at basic block exit.
+ int64_t OutgoingCFAOffset = -1;
+ /// Value of cfa register valid at basic block entry.
+ unsigned IncomingCFARegister = 0;
+ /// Value of cfa register valid at basic block exit.
+ unsigned OutgoingCFARegister = 0;
+ /// Set of locations where the callee saved registers are at basic block
+ /// entry.
+ SmallVector<CSRSavedLocation> IncomingCSRLocations;
+ /// Set of locations where the callee saved registers are at basic block
+ /// exit.
+ SmallVector<CSRSavedLocation> OutgoingCSRLocations;
+ /// If in/out cfa offset and register values for this block have already
+ /// been set or not.
+ bool Processed = false;
+ };
+
+ /// Contains cfa offset and register values valid at entry and exit of basic
+ /// blocks.
+ std::vector<MBBCFAInfo> MBBVector;
+
+ /// Calculate cfa offset and register values valid at entry and exit for all
+ /// basic blocks in a function.
+ void calculateCFAInfo(MachineFunction &MF);
+ /// Calculate cfa offset and register values valid at basic block exit by
+ /// checking the block for CFI instructions. Block's incoming CFA info
+ /// remains the same.
+ void calculateOutgoingCFAInfo(MBBCFAInfo &MBBInfo);
+ /// Update in/out cfa offset and register values for successors of the basic
+ /// block.
+ void updateSuccCFAInfo(MBBCFAInfo &MBBInfo);
+
+ /// Check if incoming CFA information of a basic block matches outgoing CFA
+ /// information of the previous block. If it doesn't, insert CFI instruction
+ /// at the beginning of the block that corrects the CFA calculation rule for
+ /// that block.
+ bool insertCFIInstrs(MachineFunction &MF);
+ /// Return the cfa offset value that should be set at the beginning of a MBB
+ /// if needed. The negated value is needed when creating CFI instructions
+ /// that set absolute offset.
+ int64_t getCorrectCFAOffset(MachineBasicBlock *MBB) {
+ return MBBVector[MBB->getNumber()].IncomingCFAOffset;
+ }
+
+ void reportCFAError(const MBBCFAInfo &Pred, const MBBCFAInfo &Succ);
+ void reportCSRError(const MBBCFAInfo &Pred, const MBBCFAInfo &Succ);
+ /// Go through each MBB in a function and check that outgoing offset and
+ /// register of its predecessors match incoming offset and register of that
+ /// MBB, as well as that incoming offset and register of its successors match
+ /// outgoing offset and register of the MBB.
+ unsigned verify(MachineFunction &MF);
};
} // namespace
|
ppenzin
changed the title
Contributor
Author
Previously there was an implicit assumption in the code that a CSR can only be saved in one location. There can be scenarious where CSR is saved in different locations.
ppenzin
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🐧 Linux x64 Test Results
Failed Tests(click on a test name to see its output) LLVMLLVM.CodeGen/X86/cfi-inserter-callee-save-register-2.mirLLVM.CodeGen/X86/cfi-inserter-callee-save-register.mirLLVM.CodeGen/X86/cfi-inserter-verify-inconsistent-loc.mirLLVM.CodeGen/X86/segmented-stacks-dynamic.llLLVM.CodeGen/X86/segmented-stacks.llLLVM.DebugInfo/MIR/X86/no-cfi-loc.mirIf these failures are unrelated to your changes (for example tests are broken or flaky at HEAD), please open an issue at https://github.com/llvm/llvm-project/issues and add the |
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Record callee-saved register locations instead of which register. Use SmallVector of
CSRSavedLocationin MBBCFAInfo indexed by the register index. Reorder the declarations to make full type of CSRSavedLocation available.