diff --git a/clang/include/clang/Basic/BuiltinsLoongArchLASX.def b/clang/include/clang/Basic/BuiltinsLoongArchLASX.def
diff --git a/clang/include/clang/Basic/BuiltinsLoongArchLSX.def b/clang/include/clang/Basic/BuiltinsLoongArchLSX.def
diff --git a/clang/include/clang/Basic/DiagnosticDriverKinds.td b/clang/include/clang/Basic/DiagnosticDriverKinds.td
@@ -765,6 +765,12 @@ def warn_drv_loongarch_conflicting_implied_val : Warning<
   InGroup<OptionIgnored>;
 def err_drv_loongarch_invalid_mfpu_EQ : Error<
   "invalid argument '%0' to -mfpu=; must be one of: 64, 32, none, 0 (alias for none)">;
+def err_drv_loongarch_wrong_fpu_width_for_lsx : Error<
+  "wrong fpu width; LSX depends on 64-bit FPU.">;
+def err_drv_loongarch_wrong_fpu_width_for_lasx : Error<
+  "wrong fpu width; LASX depends on 64-bit FPU.">;
+def err_drv_loongarch_invalid_simd_option_combination : Error<
+  "invalid option combination; LASX depends on LSX.">;
 
 def err_drv_expand_response_file : Error<
   "failed to expand response file: %0">;

diff --git a/clang/include/clang/Driver/Options.td b/clang/include/clang/Driver/Options.td
@@ -208,6 +208,8 @@ def m_riscv_Features_Group : OptionGroup<"<riscv features group>">,
                              Group<m_Group>, DocName<"RISC-V">;
 def m_ve_Features_Group : OptionGroup<"<ve features group>">,
                           Group<m_Group>, DocName<"VE">;
+def m_loongarch_Features_Group : OptionGroup<"<loongarch features group>">,
+                                 Group<m_Group>, DocName<"LoongArch">;
 
 def m_libc_Group : OptionGroup<"<m libc group>">, Group<m_mips_Features_Group>,
                    Flags<[HelpHidden]>;
@@ -4886,6 +4888,14 @@ def mstack_protector_guard_reg_EQ : Joined<["-"], "mstack-protector-guard-reg=">
 def mfentry : Flag<["-"], "mfentry">, HelpText<"Insert calls to fentry at function entry (x86/SystemZ only)">,
   Visibility<[ClangOption, CC1Option]>, Group<m_Group>,
   MarshallingInfoFlag<CodeGenOpts<"CallFEntry">>;
+def mlsx : Flag<["-"], "mlsx">, Group<m_loongarch_Features_Group>,
+  HelpText<"Enable Loongson SIMD Extension (LSX).">;
+def mno_lsx : Flag<["-"], "mno-lsx">, Group<m_loongarch_Features_Group>,
+  HelpText<"Disable Loongson SIMD Extension (LSX).">;
+def mlasx : Flag<["-"], "mlasx">, Group<m_loongarch_Features_Group>,
+  HelpText<"Enable Loongson Advanced SIMD Extension (LASX).">;
+def mno_lasx : Flag<["-"], "mno-lasx">, Group<m_loongarch_Features_Group>,
+  HelpText<"Disable Loongson Advanced SIMD Extension (LASX).">;
 def mnop_mcount : Flag<["-"], "mnop-mcount">, HelpText<"Generate mcount/__fentry__ calls as nops. To activate they need to be patched in.">,
   Visibility<[ClangOption, CC1Option]>, Group<m_Group>,
   MarshallingInfoFlag<CodeGenOpts<"MNopMCount">>;

diff --git a/clang/lib/Basic/Targets/LoongArch.cpp b/clang/lib/Basic/Targets/LoongArch.cpp
@@ -208,6 +208,11 @@ void LoongArchTargetInfo::getTargetDefines(const LangOptions &Opts,
     TuneCPU = ArchName;
   Builder.defineMacro("__loongarch_tune", Twine('"') + TuneCPU + Twine('"'));
 
+  if (HasFeatureLSX)
+    Builder.defineMacro("__loongarch_sx", Twine(1));
+  if (HasFeatureLASX)
+    Builder.defineMacro("__loongarch_asx", Twine(1));
+
   StringRef ABI = getABI();
   if (ABI == "lp64d" || ABI == "lp64f" || ABI == "lp64s")
     Builder.defineMacro("__loongarch_lp64");
@@ -257,6 +262,8 @@ bool LoongArchTargetInfo::hasFeature(StringRef Feature) const {
       .Case("loongarch64", Is64Bit)
       .Case("32bit", !Is64Bit)
       .Case("64bit", Is64Bit)
+      .Case("lsx", HasFeatureLSX)
+      .Case("lasx", HasFeatureLASX)
       .Default(false);
 }
 
@@ -274,7 +281,10 @@ bool LoongArchTargetInfo::handleTargetFeatures(
       if (Feature == "+d") {
         HasFeatureD = true;
       }
-    }
+    } else if (Feature == "+lsx")
+      HasFeatureLSX = true;
+    else if (Feature == "+lasx")
+      HasFeatureLASX = true;
   }
   return true;
 }

diff --git a/clang/lib/Basic/Targets/LoongArch.h b/clang/lib/Basic/Targets/LoongArch.h
@@ -27,12 +27,16 @@ class LLVM_LIBRARY_VISIBILITY LoongArchTargetInfo : public TargetInfo {
   std::string CPU;
   bool HasFeatureD;
   bool HasFeatureF;
+  bool HasFeatureLSX;
+  bool HasFeatureLASX;
 
 public:
   LoongArchTargetInfo(const llvm::Triple &Triple, const TargetOptions &)
       : TargetInfo(Triple) {
     HasFeatureD = false;
     HasFeatureF = false;
+    HasFeatureLSX = false;
+    HasFeatureLASX = false;
     LongDoubleWidth = 128;
     LongDoubleAlign = 128;
     LongDoubleFormat = &llvm::APFloat::IEEEquad();

diff --git a/clang/lib/CodeGen/Targets/LoongArch.cpp b/clang/lib/CodeGen/Targets/LoongArch.cpp
@@ -321,6 +321,13 @@ ABIArgInfo LoongArchABIInfo::classifyArgumentType(QualType Ty, bool IsFixed,
     return ABIArgInfo::getDirect();
   }
 
+  // Pass 128-bit/256-bit vector values via vector registers directly.
+  if (Ty->isVectorType() && (((getContext().getTypeSize(Ty) == 128) &&
+                              (getTarget().hasFeature("lsx"))) ||
+                             ((getContext().getTypeSize(Ty) == 256) &&
+                              getTarget().hasFeature("lasx"))))
+    return ABIArgInfo::getDirect();
+
   // Complex types for the *f or *d ABI must be passed directly rather than
   // using CoerceAndExpand.
   if (IsFixed && Ty->isComplexType() && FRLen && FARsLeft >= 2) {

diff --git a/clang/lib/Driver/ToolChains/Arch/LoongArch.cpp b/clang/lib/Driver/ToolChains/Arch/LoongArch.cpp
@@ -175,6 +175,38 @@ void loongarch::getLoongArchTargetFeatures(const Driver &D,
     A->ignoreTargetSpecific();
   if (Arg *A = Args.getLastArgNoClaim(options::OPT_mfpu_EQ))
     A->ignoreTargetSpecific();
+
+  // Select lsx feature determined by -m[no-]lsx.
+  if (const Arg *A = Args.getLastArg(options::OPT_mlsx, options::OPT_mno_lsx)) {
+    // LSX depends on 64-bit FPU.
+    // -m*-float and -mfpu=none/0/32 conflict with -mlsx.
+    if (A->getOption().matches(options::OPT_mlsx)) {
+      if (llvm::find(Features, "-d") != Features.end())
+        D.Diag(diag::err_drv_loongarch_wrong_fpu_width_for_lsx);
+      else /*-mlsx*/
+        Features.push_back("+lsx");
+    } else /*-mno-lsx*/ {
+      Features.push_back("-lsx");
+    }
+  }
+
+  // Select lasx feature determined by -m[no-]lasx.
+  if (const Arg *A =
+          Args.getLastArg(options::OPT_mlasx, options::OPT_mno_lasx)) {
+    // LASX depends on 64-bit FPU and LSX.
+    // -mno-lsx conflicts with -mlasx.
+    if (A->getOption().matches(options::OPT_mlasx)) {
+      if (llvm::find(Features, "-d") != Features.end())
+        D.Diag(diag::err_drv_loongarch_wrong_fpu_width_for_lasx);
+      else if (llvm::find(Features, "-lsx") != Features.end())
+        D.Diag(diag::err_drv_loongarch_invalid_simd_option_combination);
+      else { /*-mlasx*/
+        Features.push_back("+lsx");
+        Features.push_back("+lasx");
+      }
+    } else /*-mno-lasx*/
+      Features.push_back("-lasx");
+  }
 }
 
 std::string loongarch::postProcessTargetCPUString(const std::string &CPU,

diff --git a/clang/lib/Headers/CMakeLists.txt b/clang/lib/Headers/CMakeLists.txt
@@ -93,6 +93,8 @@ set(hlsl_files
 
 set(loongarch_files
   larchintrin.h
+  lasxintrin.h
+  lsxintrin.h
   )
 
 set(mips_msa_files

diff --git a/clang/lib/Headers/lasxintrin.h b/clang/lib/Headers/lasxintrin.h
diff --git a/clang/lib/Headers/lsxintrin.h b/clang/lib/Headers/lsxintrin.h
diff --git a/clang/lib/Sema/SemaChecking.cpp b/clang/lib/Sema/SemaChecking.cpp
diff --git a/clang/test/CodeGen/LoongArch/lasx/builtin-alias-error.c b/clang/test/CodeGen/LoongArch/lasx/builtin-alias-error.c
diff --git a/clang/test/CodeGen/LoongArch/lasx/builtin-alias.c b/clang/test/CodeGen/LoongArch/lasx/builtin-alias.c
diff --git a/clang/test/CodeGen/LoongArch/lasx/builtin-error.c b/clang/test/CodeGen/LoongArch/lasx/builtin-error.c
diff --git a/clang/test/CodeGen/LoongArch/lasx/builtin.c b/clang/test/CodeGen/LoongArch/lasx/builtin.c
diff --git a/clang/test/CodeGen/LoongArch/lsx/builtin-alias-error.c b/clang/test/CodeGen/LoongArch/lsx/builtin-alias-error.c
diff --git a/clang/test/CodeGen/LoongArch/lsx/builtin-alias.c b/clang/test/CodeGen/LoongArch/lsx/builtin-alias.c
diff --git a/clang/test/CodeGen/LoongArch/lsx/builtin-error.c b/clang/test/CodeGen/LoongArch/lsx/builtin-error.c
diff --git a/clang/test/CodeGen/LoongArch/lsx/builtin.c b/clang/test/CodeGen/LoongArch/lsx/builtin.c
diff --git a/clang/test/Driver/loongarch-mlasx-error.c b/clang/test/Driver/loongarch-mlasx-error.c
@@ -0,0 +1,15 @@
+// RUN: not %clang --target=loongarch64 %s -fsyntax-only -mlasx -msingle-float 2>&1 \
+// RUN:   FileCheck --check-prefix=ERROR_LASX_FPU64 %s
+// RUN: not %clang --target=loongarch64 %s -fsyntax-only -mlasx -msoft-float 2>&1 \
+// RUN:   FileCheck --check-prefix=ERROR_LASX_FPU64 %s
+// RUN: not %clang --target=loongarch64 %s -fsyntax-only -mlasx -mfpu=32 2>&1 \
+// RUN:   FileCheck --check-prefix=ERROR_LASX_FPU64 %s
+// RUN: not %clang --target=loongarch64 %s -fsyntax-only -mlasx -mfpu=0 2>&1 \
+// RUN:   FileCheck --check-prefix=ERROR_LASX_FPU64 %s
+// RUN: not %clang --target=loongarch64 %s -fsyntax-only -mlasx -mfpu=none 2>&1 \
+// RUN:   FileCheck --check-prefix=ERROR_LASX_FPU64 %s
+// RUN: not %clang --target=loongarch64 %s -fsyntax-only -mlasx -mno-lsx 2>&1 \
+// RUN:   FileCheck --check-prefix=ERROR_LASX_FPU128 %s
+
+// ERROR_LASX_FPU64: error: wrong fpu width; LASX depends on 64-bit FPU.
+// ERROR_LASX_FPU128: error: invalid option combination; LASX depends on LSX.
diff --git a/clang/test/Driver/loongarch-mlasx.c b/clang/test/Driver/loongarch-mlasx.c
@@ -0,0 +1,37 @@
+/// Test -m[no-]lasx options.
+
+// RUN: %clang --target=loongarch64 -mlasx -fsyntax-only %s -### 2>&1 | \
+// RUN:   FileCheck %s --check-prefix=CC1-LASX
+// RUN: %clang --target=loongarch64 -mno-lasx -fsyntax-only %s -### 2>&1 | \
+// RUN:   FileCheck %s --check-prefix=CC1-NOLASX
+// RUN: %clang --target=loongarch64 -mlasx -mno-lasx -fsyntax-only %s -### 2>&1 | \
+// RUN:   FileCheck %s --check-prefix=CC1-NOLASX
+// RUN: %clang --target=loongarch64 -mno-lasx -mlasx -fsyntax-only %s -### 2>&1 | \
+// RUN:   FileCheck %s --check-prefix=CC1-LASX
+// RUN: %clang --target=loongarch64 -mlsx -mlasx -fsyntax-only %s -### 2>&1 | \
+// RUN:   FileCheck %s --check-prefix=CC1-LASX
+// RUN: %clang --target=loongarch64 -mlasx -mlsx -fsyntax-only %s -### 2>&1 | \
+// RUN:   FileCheck %s --check-prefix=CC1-LASX
+
+// RUN: %clang --target=loongarch64 -mlasx -S -emit-llvm %s -o - | \
+// RUN:   FileCheck %s --check-prefix=IR-LASX
+// RUN: %clang --target=loongarch64 -mno-lasx -S -emit-llvm %s -o - | \
+// RUN:   FileCheck %s --check-prefix=IR-NOLASX
+// RUN: %clang --target=loongarch64 -mlasx -mno-lasx -S -emit-llvm %s -o - | \
+// RUN:   FileCheck %s --check-prefix=IR-NOLASX
+// RUN: %clang --target=loongarch64 -mno-lasx -mlasx -S -emit-llvm %s -o - | \
+// RUN:   FileCheck %s --check-prefix=IR-LASX
+// RUN: %clang --target=loongarch64 -mlsx -mlasx -S -emit-llvm %s -o - | \
+// RUN:   FileCheck %s --check-prefix=IR-LASX
+// RUN: %clang --target=loongarch64 -mlasx -mlsx -S -emit-llvm %s -o - | \
+// RUN:   FileCheck %s --check-prefix=IR-LASX
+
+// CC1-LASX: "-target-feature" "+lsx" "-target-feature" "+lasx"
+// CC1-NOLASX: "-target-feature" "-lasx"
+
+// IR-LASX: attributes #[[#]] ={{.*}}"target-features"="{{(.*,)?}}+lasx{{(,.*)?}}"
+// IR-NOLASX: attributes #[[#]] ={{.*}}"target-features"="{{(.*,)?}}-lasx{{(,.*)?}}"
+
+int foo(void){
+  return 3;
+}
diff --git a/clang/test/Driver/loongarch-mlsx-error.c b/clang/test/Driver/loongarch-mlsx-error.c
@@ -0,0 +1,12 @@
+// RUN: not %clang --target=loongarch64 %s -fsyntax-only -mlsx -msingle-float 2>&1 \
+// RUN:   FileCheck --check-prefix=ERROR_LSX_FPU64 %s
+// RUN: not %clang --target=loongarch64 %s -fsyntax-only -mlsx -msoft-float 2>&1 \
+// RUN:   FileCheck --check-prefix=ERROR_LSX_FPU64 %s
+// RUN: not %clang --target=loongarch64 %s -fsyntax-only -mlsx -mfpu=32 2>&1 \
+// RUN:   FileCheck --check-prefix=ERROR_LSX_FPU64 %s
+// RUN: not %clang --target=loongarch64 %s -fsyntax-only -mlsx -mfpu=0 2>&1 \
+// RUN:   FileCheck --check-prefix=ERROR_LSX_FPU64 %s
+// RUN: not %clang --target=loongarch64 %s -fsyntax-only -mlsx -mfpu=none 2>&1 \
+// RUN:   FileCheck --check-prefix=ERROR_LSX_FPU64 %s
+
+// ERROR_LSX_FPU64: error: wrong fpu width; LSX depends on 64-bit FPU.
diff --git a/clang/test/Driver/loongarch-mlsx.c b/clang/test/Driver/loongarch-mlsx.c
@@ -0,0 +1,41 @@
+/// Test -m[no-]lsx options.
+
+// RUN: %clang --target=loongarch64 -mlsx -fsyntax-only %s -### 2>&1 | \
+// RUN:   FileCheck %s --check-prefix=CC1-LSX
+// RUN: %clang --target=loongarch64 -mno-lsx -fsyntax-only %s -### 2>&1 | \
+// RUN:   FileCheck %s --check-prefix=CC1-NOLSX
+// RUN: %clang --target=loongarch64 -mlsx -mno-lsx -fsyntax-only %s -### 2>&1 | \
+// RUN:   FileCheck %s --check-prefix=CC1-NOLSX
+// RUN: %clang --target=loongarch64 -mno-lsx -mlsx -fsyntax-only %s -### 2>&1 | \
+// RUN:   FileCheck %s --check-prefix=CC1-LSX
+// RUN: %clang --target=loongarch64 -mlsx -mno-lasx -fsyntax-only %s -### 2>&1 | \
+// RUN:   FileCheck %s --check-prefix=CC1-LSX
+// RUN: %clang --target=loongarch64 -mno-lasx -mlsx -fsyntax-only %s -### 2>&1 | \
+// RUN:   FileCheck %s --check-prefix=CC1-LSX
+// RUN: %clang --target=loongarch64 -mno-lsx -mno-lasx -fsyntax-only %s -### 2>&1 | \
+// RUN:   FileCheck %s --check-prefix=CC1-NOLSX
+
+// RUN: %clang --target=loongarch64 -mlsx -S -emit-llvm %s -o - | \
+// RUN:   FileCheck %s --check-prefix=IR-LSX
+// RUN: %clang --target=loongarch64 -mno-lsx -S -emit-llvm %s -o - | \
+// RUN:   FileCheck %s --check-prefix=IR-NOLSX
+// RUN: %clang --target=loongarch64 -mlsx -mno-lsx -S -emit-llvm %s -o - | \
+// RUN:   FileCheck %s --check-prefix=IR-NOLSX
+// RUN: %clang --target=loongarch64 -mno-lsx -mlsx -S -emit-llvm %s -o - | \
+// RUN:   FileCheck %s --check-prefix=IR-LSX
+// RUN: %clang --target=loongarch64 -mlsx -mno-lasx -S -emit-llvm %s -o - | \
+// RUN:   FileCheck %s --check-prefix=IR-LSX
+// RUN: %clang --target=loongarch64 -mno-lasx -mlsx -S -emit-llvm %s -o - | \
+// RUN:   FileCheck %s --check-prefix=IR-LSX
+// RUN: %clang --target=loongarch64 -mno-lsx -mno-lasx -S -emit-llvm %s -o - | \
+// RUN:   FileCheck %s --check-prefix=IR-NOLSX
+
+// CC1-LSX: "-target-feature" "+lsx"
+// CC1-NOLSX: "-target-feature" "-lsx"
+
+// IR-LSX: attributes #[[#]] ={{.*}}"target-features"="{{(.*,)?}}+lsx{{(,.*)?}}"
+// IR-NOLSX: attributes #[[#]] ={{.*}}"target-features"="{{(.*,)?}}-lsx{{(,.*)?}}"
+
+int foo(void){
+  return 3;
+}
diff --git a/clang/test/Preprocessor/init-loongarch.c b/clang/test/Preprocessor/init-loongarch.c
@@ -807,3 +807,38 @@
 
 // ARCH-TUNE: #define __loongarch_arch "[[ARCH]]"
 // ARCH-TUNE: #define __loongarch_tune "[[TUNE]]"
+
+// RUN: %clang --target=loongarch64 -mlsx -x c -E -dM %s -o - \
+// RUN:   | FileCheck --match-full-lines --check-prefix=MLSX %s
+// RUN: %clang --target=loongarch64 -mno-lsx -mlsx -x c -E -dM %s -o - \
+// RUN:   | FileCheck --match-full-lines --check-prefix=MLSX %s
+// RUN: %clang --target=loongarch64 -mlsx -mno-lasx -x c -E -dM %s -o - \
+// RUN:   | FileCheck --match-full-lines --check-prefix=MLSX %s
+// RUN: %clang --target=loongarch64 -mno-lasx -mlsx -x c -E -dM %s -o - \
+// RUN:   | FileCheck --match-full-lines --check-prefix=MLSX %s
+// MLSX-NOT: #define __loongarch_asx
+// MLSX: #define __loongarch_sx 1
+
+// RUN: %clang --target=loongarch64 -mlasx -x c -E -dM %s -o - \
+// RUN:   | FileCheck --match-full-lines --check-prefix=MLASX %s
+// RUN: %clang --target=loongarch64 -mno-lasx -mlasx -x c -E -dM %s -o - \
+// RUN:   | FileCheck --match-full-lines --check-prefix=MLASX %s
+// RUN: %clang --target=loongarch64 -mlsx -mlasx -x c -E -dM %s -o - \
+// RUN:   | FileCheck --match-full-lines --check-prefix=MLASX %s
+// RUN: %clang --target=loongarch64 -mlasx -mlsx -x c -E -dM %s -o - \
+// RUN:   | FileCheck --match-full-lines --check-prefix=MLASX %s
+// MLASX: #define __loongarch_asx 1
+// MLASX: #define __loongarch_sx 1
+
+// RUN: %clang --target=loongarch64 -mno-lsx -x c -E -dM %s -o - \
+// RUN:   | FileCheck --match-full-lines --check-prefix=MNO-LSX %s
+// RUN: %clang --target=loongarch64 -mlsx -mno-lsx -x c -E -dM %s -o - \
+// RUN:   | FileCheck --match-full-lines --check-prefix=MNO-LSX %s
+// RUN: %clang --target=loongarch64 -mno-lsx -mno-lasx -x c -E -dM %s -o - \
+// RUN:   | FileCheck --match-full-lines --check-prefix=MNO-LSX %s
+// RUN: %clang --target=loongarch64 -mno-lasx -mno-lsx -x c -E -dM %s -o - \
+// RUN:   | FileCheck --match-full-lines --check-prefix=MNO-LSX %s
+// RUN: %clang --target=loongarch64 -mno-lasx -x c -E -dM %s -o - \
+// RUN:   | FileCheck --match-full-lines --check-prefix=MNO-LSX %s
+// MNO-LSX-NOT: #define __loongarch_asx
+// MNO-LSX-NOT: #define __loongarch_sx