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-rw-r--r--backend/lib/CodeGen/GlobalISel/LegalizerHelper.cpp153
1 files changed, 153 insertions, 0 deletions
diff --git a/backend/lib/CodeGen/GlobalISel/LegalizerHelper.cpp b/backend/lib/CodeGen/GlobalISel/LegalizerHelper.cpp
index 33ec1ce..b169c55 100644
--- a/backend/lib/CodeGen/GlobalISel/LegalizerHelper.cpp
+++ b/backend/lib/CodeGen/GlobalISel/LegalizerHelper.cpp
@@ -3345,6 +3345,12 @@ Expected<void> LegalizerHelper::lower(MachineInstr &Instruction,
case GenericOpcode::G_ROTL:
case GenericOpcode::G_ROTR:
return lowerRotate(Instruction);
+ case GenericOpcode::G_DYN_STACKALLOC:
+ return lowerDynStackAlloc(Instruction);
+ case GenericOpcode::G_STACKSAVE:
+ return lowerStackSave(Instruction);
+ case GenericOpcode::G_STACKRESTORE:
+ return lowerStackRestore(Instruction);
case GenericOpcode::G_ABDS:
case GenericOpcode::G_ABDU: {
const bool IsSigned = Instruction.opcode() == opcode(GenericOpcode::G_ABDS);
@@ -3649,6 +3655,153 @@ Expected<void> LegalizerHelper::lower(MachineInstr &Instruction,
}
}
+Expected<void> LegalizerHelper::lowerDynStackAlloc(MachineInstr &Instruction) {
+ if (Instruction.operandCount() != 3)
+ return makeUnexpected(ErrorCode::VerificationError,
+ "G_DYN_STACKALLOC requires destination, size, and alignment operands");
+ if (MIRBuilder.target().stackGrowthDirection() != StackGrowthDirection::Down)
+ return makeUnexpected(ErrorCode::Unsupported,
+ "dynamic stack allocation requires a downward-growing stack");
+
+ const PhysicalRegister StackPointer = MIRBuilder.target().stackPointerRegisterToSaveRestore();
+ if (!StackPointer.isValid())
+ return makeUnexpected(ErrorCode::Unsupported,
+ "target does not define a stack pointer for dynamic allocation");
+
+ const MachineOperand *DestinationOperand = Instruction.operandAt(0);
+ const MachineOperand *SizeOperand = Instruction.operandAt(1);
+ const MachineOperand *AlignmentOperand = Instruction.operandAt(2);
+ const Register *Destination =
+ DestinationOperand == nullptr ? nullptr : DestinationOperand->getIf<Register>();
+ const Register *AllocationSize =
+ SizeOperand == nullptr ? nullptr : SizeOperand->getIf<Register>();
+ if (Destination == nullptr || AllocationSize == nullptr || AlignmentOperand == nullptr)
+ return makeUnexpected(ErrorCode::VerificationError, "G_DYN_STACKALLOC has invalid operands");
+
+ auto PointerType = MRI.getType(*Destination);
+ auto AllocationSizeType = MRI.getType(*AllocationSize);
+ auto AlignmentValue = signedImmediate(*AlignmentOperand);
+ if (!PointerType)
+ return std::unexpected(PointerType.error());
+ if (!AllocationSizeType)
+ return std::unexpected(AllocationSizeType.error());
+ if (!AlignmentValue)
+ return std::unexpected(AlignmentValue.error());
+ if (!PointerType->isPointer() || !AllocationSizeType->isCategoryNeutralScalar() ||
+ PointerType->scalarBitWidth() != AllocationSizeType->scalarBitWidth()) {
+ return makeUnexpected(ErrorCode::VerificationError,
+ "G_DYN_STACKALLOC requires pointer-width integer allocation size");
+ }
+ if (*AlignmentValue <= 0 || !std::has_single_bit(static_cast<std::uint64_t>(*AlignmentValue))) {
+ return makeUnexpected(ErrorCode::VerificationError,
+ "G_DYN_STACKALLOC alignment must be a positive power of two");
+ }
+
+ auto StackPointerCopy = MRI.createVirtualRegister(*PointerType);
+ auto IntegerStackPointer = MRI.createVirtualRegister(*AllocationSizeType);
+ auto Allocation = MRI.createVirtualRegister(*AllocationSizeType);
+ if (!StackPointerCopy)
+ return std::unexpected(StackPointerCopy.error());
+ if (!IntegerStackPointer)
+ return std::unexpected(IntegerStackPointer.error());
+ if (!Allocation)
+ return std::unexpected(Allocation.error());
+
+ if (auto Point = MIRBuilder.setInsertPointBefore(Instruction); !Point)
+ return std::unexpected(Point.error());
+ if (auto Built = MIRBuilder.buildCopy(*StackPointerCopy, Register::fromPhysical(StackPointer));
+ !Built) {
+ return std::unexpected(Built.error());
+ }
+ if (auto Built = MIRBuilder.buildPtrToInt(*IntegerStackPointer, *StackPointerCopy); !Built)
+ return std::unexpected(Built.error());
+ if (auto Built = MIRBuilder.buildSub(*Allocation, *IntegerStackPointer, *AllocationSize); !Built)
+ return std::unexpected(Built.error());
+
+ Register AlignedAllocation = *Allocation;
+ if (*AlignmentValue > 1) {
+ auto LowBits = APInt::fromUnsigned(AllocationSizeType->scalarBitWidth(),
+ static_cast<std::uint64_t>(*AlignmentValue) - 1U);
+ if (!LowBits)
+ return std::unexpected(LowBits.error());
+ auto AlignmentMask = LowBits->bitwiseNot();
+ if (!AlignmentMask)
+ return std::unexpected(AlignmentMask.error());
+ auto Mask = buildConstantRegister(MIRBuilder, *AllocationSizeType, std::move(*AlignmentMask));
+ if (!Mask)
+ return std::unexpected(Mask.error());
+ auto MaskedAllocation = MRI.createVirtualRegister(*AllocationSizeType);
+ if (!MaskedAllocation)
+ return std::unexpected(MaskedAllocation.error());
+ if (auto Built = MIRBuilder.buildAnd(*MaskedAllocation, *Allocation, *Mask); !Built)
+ return std::unexpected(Built.error());
+ AlignedAllocation = *MaskedAllocation;
+ }
+
+ auto TargetPointer = MRI.createVirtualRegister(*PointerType);
+ if (!TargetPointer)
+ return std::unexpected(TargetPointer.error());
+ if (auto Built = MIRBuilder.buildIntToPtr(*TargetPointer, AlignedAllocation); !Built)
+ return std::unexpected(Built.error());
+ if (auto Built = MIRBuilder.buildCopy(Register::fromPhysical(StackPointer), *TargetPointer);
+ !Built) {
+ return std::unexpected(Built.error());
+ }
+ if (auto Built = MIRBuilder.buildCopy(*Destination, *TargetPointer); !Built)
+ return std::unexpected(Built.error());
+
+ MachineBasicBlock *Block = Instruction.parent();
+ if (Block == nullptr)
+ return makeUnexpected(ErrorCode::InternalError,
+ "G_DYN_STACKALLOC became detached during lowering");
+ return Block->removeInstruction(Instruction);
+}
+
+Expected<void> LegalizerHelper::lowerStackSave(MachineInstr &Instruction) {
+ const PhysicalRegister StackPointer = MIRBuilder.target().stackPointerRegisterToSaveRestore();
+ if (!StackPointer.isValid())
+ return makeUnexpected(ErrorCode::Unsupported,
+ "target does not define a stack pointer for stack save");
+ const MachineOperand *DestinationOperand = Instruction.operandAt(0);
+ const Register *Destination =
+ DestinationOperand == nullptr ? nullptr : DestinationOperand->getIf<Register>();
+ if (Instruction.operandCount() != 1 || Destination == nullptr)
+ return makeUnexpected(ErrorCode::VerificationError,
+ "G_STACKSAVE requires one register destination");
+ if (auto Point = MIRBuilder.setInsertPointBefore(Instruction); !Point)
+ return std::unexpected(Point.error());
+ if (auto Built = MIRBuilder.buildCopy(*Destination, Register::fromPhysical(StackPointer));
+ !Built) {
+ return std::unexpected(Built.error());
+ }
+ MachineBasicBlock *Block = Instruction.parent();
+ if (Block == nullptr)
+ return makeUnexpected(ErrorCode::InternalError, "G_STACKSAVE became detached during lowering");
+ return Block->removeInstruction(Instruction);
+}
+
+Expected<void> LegalizerHelper::lowerStackRestore(MachineInstr &Instruction) {
+ const PhysicalRegister StackPointer = MIRBuilder.target().stackPointerRegisterToSaveRestore();
+ if (!StackPointer.isValid())
+ return makeUnexpected(ErrorCode::Unsupported,
+ "target does not define a stack pointer for stack restore");
+ const MachineOperand *SourceOperand = Instruction.operandAt(0);
+ const Register *Source = SourceOperand == nullptr ? nullptr : SourceOperand->getIf<Register>();
+ if (Instruction.operandCount() != 1 || Source == nullptr)
+ return makeUnexpected(ErrorCode::VerificationError,
+ "G_STACKRESTORE requires one register source");
+ if (auto Point = MIRBuilder.setInsertPointBefore(Instruction); !Point)
+ return std::unexpected(Point.error());
+ if (auto Built = MIRBuilder.buildCopy(Register::fromPhysical(StackPointer), *Source); !Built)
+ return std::unexpected(Built.error());
+ MachineBasicBlock *Block = Instruction.parent();
+ if (Block == nullptr) {
+ return makeUnexpected(ErrorCode::InternalError,
+ "G_STACKRESTORE became detached during lowering");
+ }
+ return Block->removeInstruction(Instruction);
+}
+
Expected<void> LegalizerHelper::lowerAbsToAddXor(MachineInstr &Instruction) {
const Register Destination = *Instruction.operandAt(0)->getIf<Register>();
const Register Source = *Instruction.operandAt(1)->getIf<Register>();
generated by cgit v1.2.3 (git 2.46.0) at 2026-10-29 10:04:36 +0000