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
@@ -61,6 +61,7 @@
   }
 
   setOperationAction(ISD::SELECT_CC, GRLenVT, Expand);
+  setOperationAction(ISD::SIGN_EXTEND_INREG, MVT::i1, Expand);
 
   // Compute derived properties from the register classes.
   computeRegisterProperties(STI.getRegisterInfo());
diff --git a/llvm/test/CodeGen/LoongArch/ir-instruction/sext-zext-trunc.ll b/llvm/test/CodeGen/LoongArch/ir-instruction/sext-zext-trunc.ll
new file mode 100644
--- /dev/null
+++ b/llvm/test/CodeGen/LoongArch/ir-instruction/sext-zext-trunc.ll
@@ -0,0 +1,436 @@
+; RUN: llc --mtriple=loongarch32 < %s | FileCheck %s --check-prefix=LA32
+; RUN: llc --mtriple=loongarch64 < %s | FileCheck %s --check-prefix=LA64
+
+; Test sext/zext/trunc
+
+define i8 @sext_i1_to_i8(i1 %a) {
+; LA32-LABEL: sext_i1_to_i8:
+; LA32:       # %bb.0:
+; LA32-NEXT:    andi $a0, $a0, 1
+; LA32-NEXT:    ori $a1, $zero, 0
+; LA32-NEXT:    sub.w $a0, $a1, $a0
+; LA32-NEXT:    jirl $zero, $ra, 0
+;
+; LA64-LABEL: sext_i1_to_i8:
+; LA64:       # %bb.0:
+; LA64-NEXT:    andi $a0, $a0, 1
+; LA64-NEXT:    ori $a1, $zero, 0
+; LA64-NEXT:    sub.d $a0, $a1, $a0
+; LA64-NEXT:    jirl $zero, $ra, 0
+  %1 = sext i1 %a to i8
+  ret i8 %1
+}
+
+define i16 @sext_i1_to_i16(i1 %a) {
+; LA32-LABEL: sext_i1_to_i16:
+; LA32:       # %bb.0:
+; LA32-NEXT:    andi $a0, $a0, 1
+; LA32-NEXT:    ori $a1, $zero, 0
+; LA32-NEXT:    sub.w $a0, $a1, $a0
+; LA32-NEXT:    jirl $zero, $ra, 0
+;
+; LA64-LABEL: sext_i1_to_i16:
+; LA64:       # %bb.0:
+; LA64-NEXT:    andi $a0, $a0, 1
+; LA64-NEXT:    ori $a1, $zero, 0
+; LA64-NEXT:    sub.d $a0, $a1, $a0
+; LA64-NEXT:    jirl $zero, $ra, 0
+  %1 = sext i1 %a to i16
+  ret i16 %1
+}
+
+define i32 @sext_i1_to_i32(i1 %a) {
+; LA32-LABEL: sext_i1_to_i32:
+; LA32:       # %bb.0:
+; LA32-NEXT:    andi $a0, $a0, 1
+; LA32-NEXT:    ori $a1, $zero, 0
+; LA32-NEXT:    sub.w $a0, $a1, $a0
+; LA32-NEXT:    jirl $zero, $ra, 0
+;
+; LA64-LABEL: sext_i1_to_i32:
+; LA64:       # %bb.0:
+; LA64-NEXT:    andi $a0, $a0, 1
+; LA64-NEXT:    ori $a1, $zero, 0
+; LA64-NEXT:    sub.d $a0, $a1, $a0
+; LA64-NEXT:    jirl $zero, $ra, 0
+  %1 = sext i1 %a to i32
+  ret i32 %1
+}
+
+define i64 @sext_i1_to_i64(i1 %a) {
+; LA32-LABEL: sext_i1_to_i64:
+; LA32:       # %bb.0:
+; LA32-NEXT:    andi $a0, $a0, 1
+; LA32-NEXT:    ori $a1, $zero, 0
+; LA32-NEXT:    sub.w $a0, $a1, $a0
+; LA32-NEXT:    move $a1, $a0
+; LA32-NEXT:    jirl $zero, $ra, 0
+;
+; LA64-LABEL: sext_i1_to_i64:
+; LA64:       # %bb.0:
+; LA64-NEXT:    andi $a0, $a0, 1
+; LA64-NEXT:    ori $a1, $zero, 0
+; LA64-NEXT:    sub.d $a0, $a1, $a0
+; LA64-NEXT:    jirl $zero, $ra, 0
+  %1 = sext i1 %a to i64
+  ret i64 %1
+}
+
+define i16 @sext_i8_to_i16(i8 %a) {
+; LA32-LABEL: sext_i8_to_i16:
+; LA32:       # %bb.0:
+; LA32-NEXT:    ext.w.b $a0, $a0
+; LA32-NEXT:    jirl $zero, $ra, 0
+;
+; LA64-LABEL: sext_i8_to_i16:
+; LA64:       # %bb.0:
+; LA64-NEXT:    ext.w.b $a0, $a0
+; LA64-NEXT:    jirl $zero, $ra, 0
+  %1 = sext i8 %a to i16
+  ret i16 %1
+}
+
+define i32 @sext_i8_to_i32(i8 %a) {
+; LA32-LABEL: sext_i8_to_i32:
+; LA32:       # %bb.0:
+; LA32-NEXT:    ext.w.b $a0, $a0
+; LA32-NEXT:    jirl $zero, $ra, 0
+;
+; LA64-LABEL: sext_i8_to_i32:
+; LA64:       # %bb.0:
+; LA64-NEXT:    ext.w.b $a0, $a0
+; LA64-NEXT:    jirl $zero, $ra, 0
+  %1 = sext i8 %a to i32
+  ret i32 %1
+}
+
+define i64 @sext_i8_to_i64(i8 %a) {
+; LA32-LABEL: sext_i8_to_i64:
+; LA32:       # %bb.0:
+; LA32-NEXT:    ext.w.b $a0, $a0
+; LA32-NEXT:    srai.w $a1, $a0, 31
+; LA32-NEXT:    jirl $zero, $ra, 0
+;
+; LA64-LABEL: sext_i8_to_i64:
+; LA64:       # %bb.0:
+; LA64-NEXT:    ext.w.b $a0, $a0
+; LA64-NEXT:    jirl $zero, $ra, 0
+  %1 = sext i8 %a to i64
+  ret i64 %1
+}
+
+define i32 @sext_i16_to_i32(i16 %a) {
+; LA32-LABEL: sext_i16_to_i32:
+; LA32:       # %bb.0:
+; LA32-NEXT:    ext.w.h $a0, $a0
+; LA32-NEXT:    jirl $zero, $ra, 0
+;
+; LA64-LABEL: sext_i16_to_i32:
+; LA64:       # %bb.0:
+; LA64-NEXT:    ext.w.h $a0, $a0
+; LA64-NEXT:    jirl $zero, $ra, 0
+  %1 = sext i16 %a to i32
+  ret i32 %1
+}
+
+define i64 @sext_i16_to_i64(i16 %a) {
+; LA32-LABEL: sext_i16_to_i64:
+; LA32:       # %bb.0:
+; LA32-NEXT:    ext.w.h $a0, $a0
+; LA32-NEXT:    srai.w $a1, $a0, 31
+; LA32-NEXT:    jirl $zero, $ra, 0
+;
+; LA64-LABEL: sext_i16_to_i64:
+; LA64:       # %bb.0:
+; LA64-NEXT:    ext.w.h $a0, $a0
+; LA64-NEXT:    jirl $zero, $ra, 0
+  %1 = sext i16 %a to i64
+  ret i64 %1
+}
+
+define i64 @sext_i32_to_i64(i32 %a) {
+; LA32-LABEL: sext_i32_to_i64:
+; LA32:       # %bb.0:
+; LA32-NEXT:    srai.w $a1, $a0, 31
+; LA32-NEXT:    jirl $zero, $ra, 0
+;
+; LA64-LABEL: sext_i32_to_i64:
+; LA64:       # %bb.0:
+; LA64-NEXT:    addi.w $a0, $a0, 0
+; LA64-NEXT:    jirl $zero, $ra, 0
+  %1 = sext i32 %a to i64
+  ret i64 %1
+}
+
+define i8 @zext_i1_to_i8(i1 %a) {
+; LA32-LABEL: zext_i1_to_i8:
+; LA32:       # %bb.0:
+; LA32-NEXT:    andi $a0, $a0, 1
+; LA32-NEXT:    jirl $zero, $ra, 0
+;
+; LA64-LABEL: zext_i1_to_i8:
+; LA64:       # %bb.0:
+; LA64-NEXT:    andi $a0, $a0, 1
+; LA64-NEXT:    jirl $zero, $ra, 0
+  %1 = zext i1 %a to i8
+  ret i8 %1
+}
+
+define i16 @zext_i1_to_i16(i1 %a) {
+; LA32-LABEL: zext_i1_to_i16:
+; LA32:       # %bb.0:
+; LA32-NEXT:    andi $a0, $a0, 1
+; LA32-NEXT:    jirl $zero, $ra, 0
+;
+; LA64-LABEL: zext_i1_to_i16:
+; LA64:       # %bb.0:
+; LA64-NEXT:    andi $a0, $a0, 1
+; LA64-NEXT:    jirl $zero, $ra, 0
+  %1 = zext i1 %a to i16
+  ret i16 %1
+}
+
+define i32 @zext_i1_to_i32(i1 %a) {
+; LA32-LABEL: zext_i1_to_i32:
+; LA32:       # %bb.0:
+; LA32-NEXT:    andi $a0, $a0, 1
+; LA32-NEXT:    jirl $zero, $ra, 0
+;
+; LA64-LABEL: zext_i1_to_i32:
+; LA64:       # %bb.0:
+; LA64-NEXT:    andi $a0, $a0, 1
+; LA64-NEXT:    jirl $zero, $ra, 0
+  %1 = zext i1 %a to i32
+  ret i32 %1
+}
+
+define i64 @zext_i1_to_i64(i1 %a) {
+; LA32-LABEL: zext_i1_to_i64:
+; LA32:       # %bb.0:
+; LA32-NEXT:    andi $a0, $a0, 1
+; LA32-NEXT:    ori $a1, $zero, 0
+; LA32-NEXT:    jirl $zero, $ra, 0
+;
+; LA64-LABEL: zext_i1_to_i64:
+; LA64:       # %bb.0:
+; LA64-NEXT:    andi $a0, $a0, 1
+; LA64-NEXT:    jirl $zero, $ra, 0
+  %1 = zext i1 %a to i64
+  ret i64 %1
+}
+
+define i16 @zext_i8_to_i16(i8 %a) {
+; LA32-LABEL: zext_i8_to_i16:
+; LA32:       # %bb.0:
+; LA32-NEXT:    andi $a0, $a0, 255
+; LA32-NEXT:    jirl $zero, $ra, 0
+;
+; LA64-LABEL: zext_i8_to_i16:
+; LA64:       # %bb.0:
+; LA64-NEXT:    andi $a0, $a0, 255
+; LA64-NEXT:    jirl $zero, $ra, 0
+  %1 = zext i8 %a to i16
+  ret i16 %1
+}
+
+define i32 @zext_i8_to_i32(i8 %a) {
+; LA32-LABEL: zext_i8_to_i32:
+; LA32:       # %bb.0:
+; LA32-NEXT:    andi $a0, $a0, 255
+; LA32-NEXT:    jirl $zero, $ra, 0
+;
+; LA64-LABEL: zext_i8_to_i32:
+; LA64:       # %bb.0:
+; LA64-NEXT:    andi $a0, $a0, 255
+; LA64-NEXT:    jirl $zero, $ra, 0
+  %1 = zext i8 %a to i32
+  ret i32 %1
+}
+
+define i64 @zext_i8_to_i64(i8 %a) {
+; LA32-LABEL: zext_i8_to_i64:
+; LA32:       # %bb.0:
+; LA32-NEXT:    andi $a0, $a0, 255
+; LA32-NEXT:    ori $a1, $zero, 0
+; LA32-NEXT:    jirl $zero, $ra, 0
+;
+; LA64-LABEL: zext_i8_to_i64:
+; LA64:       # %bb.0:
+; LA64-NEXT:    andi $a0, $a0, 255
+; LA64-NEXT:    jirl $zero, $ra, 0
+  %1 = zext i8 %a to i64
+  ret i64 %1
+}
+
+define i32 @zext_i16_to_i32(i16 %a) {
+; LA32-LABEL: zext_i16_to_i32:
+; LA32:       # %bb.0:
+; LA32-NEXT:    lu12i.w $a1, 15
+; LA32-NEXT:    ori $a1, $a1, 4095
+; LA32-NEXT:    and $a0, $a0, $a1
+; LA32-NEXT:    jirl $zero, $ra, 0
+;
+; LA64-LABEL: zext_i16_to_i32:
+; LA64:       # %bb.0:
+; LA64-NEXT:    lu12i.w $a1, 15
+; LA64-NEXT:    ori $a1, $a1, 4095
+; LA64-NEXT:    and $a0, $a0, $a1
+; LA64-NEXT:    jirl $zero, $ra, 0
+  %1 = zext i16 %a to i32
+  ret i32 %1
+}
+
+define i64 @zext_i16_to_i64(i16 %a) {
+; LA32-LABEL: zext_i16_to_i64:
+; LA32:       # %bb.0:
+; LA32-NEXT:    lu12i.w $a1, 15
+; LA32-NEXT:    ori $a1, $a1, 4095
+; LA32-NEXT:    and $a0, $a0, $a1
+; LA32-NEXT:    ori $a1, $zero, 0
+; LA32-NEXT:    jirl $zero, $ra, 0
+;
+; LA64-LABEL: zext_i16_to_i64:
+; LA64:       # %bb.0:
+; LA64-NEXT:    lu12i.w $a1, 15
+; LA64-NEXT:    ori $a1, $a1, 4095
+; LA64-NEXT:    and $a0, $a0, $a1
+; LA64-NEXT:    jirl $zero, $ra, 0
+  %1 = zext i16 %a to i64
+  ret i64 %1
+}
+
+define i64 @zext_i32_to_i64(i32 %a) {
+; LA32-LABEL: zext_i32_to_i64:
+; LA32:       # %bb.0:
+; LA32-NEXT:    ori $a1, $zero, 0
+; LA32-NEXT:    jirl $zero, $ra, 0
+;
+; LA64-LABEL: zext_i32_to_i64:
+; LA64:       # %bb.0:
+; LA64-NEXT:    addi.w $a1, $zero, -1
+; LA64-NEXT:    lu32i.d $a1, 0
+; LA64-NEXT:    and $a0, $a0, $a1
+; LA64-NEXT:    jirl $zero, $ra, 0
+  %1 = zext i32 %a to i64
+  ret i64 %1
+}
+
+define i1 @trunc_i8_to_i1(i8 %a) {
+; LA32-LABEL: trunc_i8_to_i1:
+; LA32:       # %bb.0:
+; LA32-NEXT:    jirl $zero, $ra, 0
+;
+; LA64-LABEL: trunc_i8_to_i1:
+; LA64:       # %bb.0:
+; LA64-NEXT:    jirl $zero, $ra, 0
+  %1 = trunc i8 %a to i1
+  ret i1 %1
+}
+
+define i1 @trunc_i16_to_i1(i16 %a) {
+; LA32-LABEL: trunc_i16_to_i1:
+; LA32:       # %bb.0:
+; LA32-NEXT:    jirl $zero, $ra, 0
+;
+; LA64-LABEL: trunc_i16_to_i1:
+; LA64:       # %bb.0:
+; LA64-NEXT:    jirl $zero, $ra, 0
+  %1 = trunc i16 %a to i1
+  ret i1 %1
+}
+
+define i1 @trunc_i32_to_i1(i32 %a) {
+; LA32-LABEL: trunc_i32_to_i1:
+; LA32:       # %bb.0:
+; LA32-NEXT:    jirl $zero, $ra, 0
+;
+; LA64-LABEL: trunc_i32_to_i1:
+; LA64:       # %bb.0:
+; LA64-NEXT:    jirl $zero, $ra, 0
+  %1 = trunc i32 %a to i1
+  ret i1 %1
+}
+
+define i1 @trunc_i64_to_i1(i64 %a) {
+; LA32-LABEL: trunc_i64_to_i1:
+; LA32:       # %bb.0:
+; LA32-NEXT:    jirl $zero, $ra, 0
+;
+; LA64-LABEL: trunc_i64_to_i1:
+; LA64:       # %bb.0:
+; LA64-NEXT:    jirl $zero, $ra, 0
+  %1 = trunc i64 %a to i1
+  ret i1 %1
+}
+
+define i8 @trunc_i16_to_i8(i16 %a) {
+; LA32-LABEL: trunc_i16_to_i8:
+; LA32:       # %bb.0:
+; LA32-NEXT:    jirl $zero, $ra, 0
+;
+; LA64-LABEL: trunc_i16_to_i8:
+; LA64:       # %bb.0:
+; LA64-NEXT:    jirl $zero, $ra, 0
+  %1 = trunc i16 %a to i8
+  ret i8 %1
+}
+
+define i8 @trunc_i32_to_i8(i32 %a) {
+; LA32-LABEL: trunc_i32_to_i8:
+; LA32:       # %bb.0:
+; LA32-NEXT:    jirl $zero, $ra, 0
+;
+; LA64-LABEL: trunc_i32_to_i8:
+; LA64:       # %bb.0:
+; LA64-NEXT:    jirl $zero, $ra, 0
+  %1 = trunc i32 %a to i8
+  ret i8 %1
+}
+
+define i8 @trunc_i64_to_i8(i64 %a) {
+; LA32-LABEL: trunc_i64_to_i8:
+; LA32:       # %bb.0:
+; LA32-NEXT:    jirl $zero, $ra, 0
+;
+; LA64-LABEL: trunc_i64_to_i8:
+; LA64:       # %bb.0:
+; LA64-NEXT:    jirl $zero, $ra, 0
+  %1 = trunc i64 %a to i8
+  ret i8 %1
+}
+
+define i16 @trunc_i32_to_i16(i32 %a) {
+; LA32-LABEL: trunc_i32_to_i16:
+; LA32:       # %bb.0:
+; LA32-NEXT:    jirl $zero, $ra, 0
+;
+; LA64-LABEL: trunc_i32_to_i16:
+; LA64:       # %bb.0:
+; LA64-NEXT:    jirl $zero, $ra, 0
+  %1 = trunc i32 %a to i16
+  ret i16 %1
+}
+
+define i16 @trunc_i64_to_i16(i64 %a) {
+; LA32-LABEL: trunc_i64_to_i16:
+; LA32:       # %bb.0:
+; LA32-NEXT:    jirl $zero, $ra, 0
+;
+; LA64-LABEL: trunc_i64_to_i16:
+; LA64:       # %bb.0:
+; LA64-NEXT:    jirl $zero, $ra, 0
+  %1 = trunc i64 %a to i16
+  ret i16 %1
+}
+
+define i32 @trunc_i64_to_i32(i64 %a) {
+; LA32-LABEL: trunc_i64_to_i32:
+; LA32:       # %bb.0:
+; LA32-NEXT:    jirl $zero, $ra, 0
+;
+; LA64-LABEL: trunc_i64_to_i32:
+; LA64:       # %bb.0:
+; LA64-NEXT:    jirl $zero, $ra, 0
+  %1 = trunc i64 %a to i32
+  ret i32 %1
+}