diff --git a/llvm/lib/Target/LoongArch/LoongArchISelLowering.h b/llvm/lib/Target/LoongArch/LoongArchISelLowering.h
--- a/llvm/lib/Target/LoongArch/LoongArchISelLowering.h
+++ b/llvm/lib/Target/LoongArch/LoongArchISelLowering.h
@@ -202,6 +202,8 @@
                              unsigned AS,
                              Instruction *I = nullptr) const override;
 
+  bool isLegalAddImmediate(int64_t Imm) const override;
+
   bool hasAndNotCompare(SDValue Y) const override;
 
   bool convertSelectOfConstantsToMath(EVT VT) const override { return true; }
diff --git a/llvm/lib/Target/LoongArch/LoongArchISelLowering.cpp b/llvm/lib/Target/LoongArch/LoongArchISelLowering.cpp
--- a/llvm/lib/Target/LoongArch/LoongArchISelLowering.cpp
+++ b/llvm/lib/Target/LoongArch/LoongArchISelLowering.cpp
@@ -3243,6 +3243,10 @@
   return true;
 }
 
+bool LoongArchTargetLowering::isLegalAddImmediate(int64_t Imm) const {
+  return isInt<12>(Imm);
+}
+
 bool LoongArchTargetLowering::hasAndNotCompare(SDValue Y) const {
   // TODO: Support vectors.
   if (Y.getValueType().isVector())
diff --git a/llvm/test/CodeGen/LoongArch/lsr-legaladdimm.ll b/llvm/test/CodeGen/LoongArch/lsr-legaladdimm.ll
new file mode 100644
--- /dev/null
+++ b/llvm/test/CodeGen/LoongArch/lsr-legaladdimm.ll
@@ -0,0 +1,15 @@
+; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
+; RUN: llc --mtriple=loongarch64 < %s | FileCheck %s
+
+define i32 @lsr_addimm(i32 %x, i32 %y) {
+; CHECK-LABEL: lsr_addimm:
+; CHECK:       # %bb.0:
+; CHECK-NEXT:    addi.d	$a0, $a0, -1
+; CHECK-NEXT:    bstrpick.d	$a1, $a1, 31, 20
+; CHECK-NEXT:    and $a0, $a1, $a0
+; CHECK-NEXT:    ret
+  %1 = add i32 %x, 4095
+  %2 = lshr i32 %y, 20
+  %r = and i32 %2, %1
+  ret i32 %r
+}