diff --git a/llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp b/llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp
--- a/llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp
+++ b/llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp
@@ -106,6 +106,7 @@
 static const uint64_t kMIPS32_ShadowOffset32 = 0x0aaa0000;
 static const uint64_t kMIPS64_ShadowOffset64 = 1ULL << 37;
 static const uint64_t kAArch64_ShadowOffset64 = 1ULL << 36;
+static const uint64_t kLoongArch64_ShadowOffset64 = 1ULL << 46;
 static const uint64_t kRISCV64_ShadowOffset64 = 0xd55550000;
 static const uint64_t kFreeBSD_ShadowOffset32 = 1ULL << 30;
 static const uint64_t kFreeBSD_ShadowOffset64 = 1ULL << 46;
@@ -484,6 +485,7 @@
   bool IsMIPS64 = TargetTriple.isMIPS64();
   bool IsArmOrThumb = TargetTriple.isARM() || TargetTriple.isThumb();
   bool IsAArch64 = TargetTriple.getArch() == Triple::aarch64;
+  bool IsLoongArch64 = TargetTriple.getArch() == Triple::loongarch64;
   bool IsRISCV64 = TargetTriple.getArch() == Triple::riscv64;
   bool IsWindows = TargetTriple.isOSWindows();
   bool IsFuchsia = TargetTriple.isOSFuchsia();
@@ -555,6 +557,8 @@
       Mapping.Offset = kDynamicShadowSentinel;
     else if (IsAArch64)
       Mapping.Offset = kAArch64_ShadowOffset64;
+    else if (IsLoongArch64)
+      Mapping.Offset = kLoongArch64_ShadowOffset64;
     else if (IsRISCV64)
       Mapping.Offset = kRISCV64_ShadowOffset64;
     else if (IsAMDGPU)
@@ -573,12 +577,12 @@
   }
 
   // OR-ing shadow offset if more efficient (at least on x86) if the offset
-  // is a power of two, but on ppc64 we have to use add since the shadow
-  // offset is not necessary 1/8-th of the address space.  On SystemZ,
-  // we could OR the constant in a single instruction, but it's more
+  // is a power of two, but on ppc64 and loongarch64 we have to use add since
+  // the shadow offset is not necessarily 1/8-th of the address space.  On
+  // SystemZ, we could OR the constant in a single instruction, but it's more
   // efficient to load it once and use indexed addressing.
   Mapping.OrShadowOffset = !IsAArch64 && !IsPPC64 && !IsSystemZ && !IsPS &&
-                           !IsRISCV64 &&
+                           !IsRISCV64 && !IsLoongArch64 &&
                            !(Mapping.Offset & (Mapping.Offset - 1)) &&
                            Mapping.Offset != kDynamicShadowSentinel;
   bool IsAndroidWithIfuncSupport =