2 files changed, 42 insertions, 0 deletions
diff --git a/llvm/lib/Target/RISCV/RISCVISelLowering.cpp b/llvm/lib/Target/RISCV/RISCVISelLowering.cpp
index 2da0e319ddd..eef7af53fae 100644
--- a/llvm/lib/Target/RISCV/RISCVISelLowering.cpp
+++ b/llvm/lib/Target/RISCV/RISCVISelLowering.cpp
@@ -2151,6 +2151,44 @@ RISCVTargetLowering::getRegForInlineAsmConstraint(const TargetRegisterInfo *TRI,
   return TargetLowering::getRegForInlineAsmConstraint(TRI, Constraint, VT);
 }
 
+void RISCVTargetLowering::LowerAsmOperandForConstraint(
+    SDValue Op, std::string &Constraint, std::vector<SDValue> &Ops,
+    SelectionDAG &DAG) const {
+  // Currently only support length 1 constraints.
+  if (Constraint.length() == 1) {
+    switch (Constraint[0]) {
+    case 'I':
+      // Validate & create a 12-bit signed immediate operand.
+      if (auto *C = dyn_cast<ConstantSDNode>(Op)) {
+        uint64_t CVal = C->getSExtValue();
+        if (isInt<12>(CVal))
+          Ops.push_back(
+              DAG.getTargetConstant(CVal, SDLoc(Op), Subtarget.getXLenVT()));
+      }
+      return;
+    case 'J':
+      // Validate & create an integer zero operand.
+      if (auto *C = dyn_cast<ConstantSDNode>(Op))
+        if (C->getZExtValue() == 0)
+          Ops.push_back(
+              DAG.getTargetConstant(0, SDLoc(Op), Subtarget.getXLenVT()));
+      return;
+    case 'K':
+      // Validate & create a 5-bit unsigned immediate operand.
+      if (auto *C = dyn_cast<ConstantSDNode>(Op)) {
+        uint64_t CVal = C->getZExtValue();
+        if (isUInt<5>(CVal))
+          Ops.push_back(
+              DAG.getTargetConstant(CVal, SDLoc(Op), Subtarget.getXLenVT()));
+      }
+      return;
+    default:
+      break;
+    }
+  }
+  TargetLowering::LowerAsmOperandForConstraint(Op, Constraint, Ops, DAG);
+}
+
 Instruction *RISCVTargetLowering::emitLeadingFence(IRBuilder<> &Builder,
                                                    Instruction *Inst,
                                                    AtomicOrdering Ord) const {
diff --git a/llvm/lib/Target/RISCV/RISCVISelLowering.h b/llvm/lib/Target/RISCV/RISCVISelLowering.h
index 8e756a1c522..f3bf4410686 100644
--- a/llvm/lib/Target/RISCV/RISCVISelLowering.h
+++ b/llvm/lib/Target/RISCV/RISCVISelLowering.h
@@ -93,6 +93,10 @@ public:
   getRegForInlineAsmConstraint(const TargetRegisterInfo *TRI,
                                StringRef Constraint, MVT VT) const override;
 
+  void LowerAsmOperandForConstraint(SDValue Op, std::string &Constraint,
+                                    std::vector<SDValue> &Ops,
+                                    SelectionDAG &DAG) const override;
+
   MachineBasicBlock *
   EmitInstrWithCustomInserter(MachineInstr &MI,
                               MachineBasicBlock *BB) const override;