diff --git a/CMakeLists.txt b/CMakeLists.txt
index 7e6c6e989..6c4fed042 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -90,6 +90,8 @@ elseif (LOWERCASE_CMAKE_SYSTEM_PROCESSOR MATCHES "s390x")
     set(WTF_CPU_S390X 1)
 elseif (LOWERCASE_CMAKE_SYSTEM_PROCESSOR MATCHES "riscv64")
     set(WTF_CPU_RISCV64 1)
+elseif (LOWERCASE_CMAKE_SYSTEM_PROCESSOR MATCHES "loongarch64")
+    set(WTF_CPU_LOONGARCH64 1)
 else ()
     message(FATAL_ERROR "Unknown CPU '${LOWERCASE_CMAKE_SYSTEM_PROCESSOR}'")
 endif ()
diff --git a/Source/JavaScriptCore/CMakeLists.txt b/Source/JavaScriptCore/CMakeLists.txt
index 83b0f399c..a439444ef 100644
--- a/Source/JavaScriptCore/CMakeLists.txt
+++ b/Source/JavaScriptCore/CMakeLists.txt
@@ -1280,6 +1280,7 @@ if (WTF_CPU_ARM)
 elseif (WTF_CPU_ARM64)
 elseif (WTF_CPU_ALPHA)
 elseif (WTF_CPU_HPPA)
+elseif (WTF_CPU_LOONGARCH64)
 elseif (WTF_CPU_PPC)
 elseif (WTF_CPU_PPC64)
 elseif (WTF_CPU_PPC64LE)
diff --git a/Source/ThirdParty/ANGLE/src/common/mathutil.h b/Source/ThirdParty/ANGLE/src/common/mathutil.h
index 7959da8bd..c86afd61e 100644
--- a/Source/ThirdParty/ANGLE/src/common/mathutil.h
+++ b/Source/ThirdParty/ANGLE/src/common/mathutil.h
@@ -16,6 +16,7 @@
 #include <algorithm>
 #include <string.h>
 #include <stdlib.h>
+#include <cstdint>
 
 namespace gl
 {
diff --git a/Source/ThirdParty/brotli/dec/port.h b/Source/ThirdParty/brotli/dec/port.h
index 54f51b010..e6da12d35 100644
--- a/Source/ThirdParty/brotli/dec/port.h
+++ b/Source/ThirdParty/brotli/dec/port.h
@@ -60,6 +60,10 @@
 #define BROTLI_TARGET_RISCV64
 #endif
 
+#if defined(__loongarch64)
+#define BROTLI_TARGET_LOONGARCH64
+#endif
+
 #ifdef BROTLI_BUILD_PORTABLE
 #define BROTLI_ALIGNED_READ (!!1)
 #elif defined(BROTLI_TARGET_X86) || defined(BROTLI_TARGET_X64) || \
@@ -100,6 +104,7 @@ static BROTLI_INLINE void BrotliDump(const char* f, int l, const char* fn) {
 #elif defined(BROTLI_BUILD_32_BIT)
 #define BROTLI_64_BITS 0
 #elif defined(BROTLI_TARGET_X64) || defined(BROTLI_TARGET_ARMV8) || \
+    defined(BROTLI_TARGET_LOONGARCH64) || \
     defined(BROTLI_TARGET_POWERPC64) || defined(BROTLI_TARGET_RISCV64)
 #define BROTLI_64_BITS 1
 #else
diff --git a/Source/WTF/wtf/Platform.h b/Source/WTF/wtf/Platform.h
index 7aefa1bab..224bd5ac7 100644
--- a/Source/WTF/wtf/Platform.h
+++ b/Source/WTF/wtf/Platform.h
@@ -176,6 +176,11 @@
 #define WTF_CPU_X86_SSE2 1
 #endif
 
+/* CPU(LOONGARCH64) - LoongArch */
+#if defined(__loongarch64)
+#define WTF_CPU_LOONGARCH64 1
+#endif
+
 /* CPU(RISCV64) - RISCV64 */
 #if defined(__riscv) && defined(__riscv_xlen) && __riscv_xlen == 64
 #define WTF_CPU_RISCV64 1
@@ -710,6 +715,7 @@
     || CPU(ALPHA) \
     || CPU(ARM64) \
     || CPU(S390X) \
+    || CPU(LOONGARCH64) \
     || CPU(MIPS64) \
     || CPU(PPC64) \
     || CPU(PPC64LE) \
diff --git a/Source/WTF/wtf/dtoa/utils.h b/Source/WTF/wtf/dtoa/utils.h
index 176d5909f..b13616295 100644
--- a/Source/WTF/wtf/dtoa/utils.h
+++ b/Source/WTF/wtf/dtoa/utils.h
@@ -49,7 +49,7 @@
 defined(__ARMEL__) || \
 defined(_MIPS_ARCH_MIPS32R2)
 #define DOUBLE_CONVERSION_CORRECT_DOUBLE_OPERATIONS 1
-#elif CPU(MIPS) || CPU(MIPS64) || CPU(PPC) || CPU(PPC64) || CPU(PPC64LE) || CPU(SH4) || CPU(S390) || CPU(S390X) || CPU(IA64) || CPU(ALPHA) || CPU(ARM64) || CPU(HPPA) || CPU(RISCV64)
+#elif CPU(MIPS) || CPU(MIPS64) || CPU(PPC) || CPU(PPC64) || CPU(PPC64LE) || CPU(SH4) || CPU(S390) || CPU(S390X) || CPU(IA64) || CPU(ALPHA) || CPU(ARM64) || CPU(HPPA) || CPU(LOONGARCH64) || CPU(RISCV64)
 #define DOUBLE_CONVERSION_CORRECT_DOUBLE_OPERATIONS 1
 #elif defined(_M_IX86) || defined(__i386__)
 #if defined(_WIN32)
diff --git a/Tools/Scripts/webkitdirs.pm b/Tools/Scripts/webkitdirs.pm
index 4a075d41c..5932fed69 100755
--- a/Tools/Scripts/webkitdirs.pm
+++ b/Tools/Scripts/webkitdirs.pm
@@ -1264,6 +1264,11 @@ sub isARM()
     return ($Config{archname} =~ /^arm[v\-]/) || ($Config{archname} =~ /^aarch64[v\-]/);
 }
 
+sub isLOONGARCH()
+{
+    return ($Config{archname} =~ /^loongarch64\-/);
+}
+
 sub isRISCV()
 {
     return ($Config{archname} =~ /^riscv(|32|64)\-/);