diff --git a/llvm/lib/Support/ARMBuildAttrs.cpp b/llvm/lib/Support/ARMBuildAttrs.cpp
index 6ff74e02820da..815cfc62a4b0e 100644
--- a/llvm/lib/Support/ARMBuildAttrs.cpp
+++ b/llvm/lib/Support/ARMBuildAttrs.cpp
@@ -7,10 +7,6 @@
 //===----------------------------------------------------------------------===//
 
 #include "llvm/Support/ARMBuildAttributes.h"
-#include "llvm/ADT/Twine.h"
-#include "llvm/Support/LEB128.h"
-#include <iomanip>
-#include <sstream>
 
 using namespace llvm;
 
diff --git a/llvm/lib/Support/ConvertUTFWrapper.cpp b/llvm/lib/Support/ConvertUTFWrapper.cpp
index 3fa7365e72d34..4952fe65d7767 100644
--- a/llvm/lib/Support/ConvertUTFWrapper.cpp
+++ b/llvm/lib/Support/ConvertUTFWrapper.cpp
@@ -10,7 +10,6 @@
 #include "llvm/ADT/StringRef.h"
 #include "llvm/Support/ConvertUTF.h"
 #include "llvm/Support/ErrorHandling.h"
-#include "llvm/Support/SwapByteOrder.h"
 #include <string>
 #include <vector>
 
diff --git a/llvm/lib/Support/DAGDeltaAlgorithm.cpp b/llvm/lib/Support/DAGDeltaAlgorithm.cpp
index f1b730e2b58c4..8b23b05913291 100644
--- a/llvm/lib/Support/DAGDeltaAlgorithm.cpp
+++ b/llvm/lib/Support/DAGDeltaAlgorithm.cpp
@@ -35,7 +35,6 @@
 #include "llvm/Support/Debug.h"
 #include "llvm/Support/Format.h"
 #include "llvm/Support/raw_ostream.h"
-#include <algorithm>
 #include <cassert>
 #include <map>
 using namespace llvm;
diff --git a/llvm/lib/Support/InitLLVM.cpp b/llvm/lib/Support/InitLLVM.cpp
index 2b3ddd39b0879..eb89f6f8915cb 100644
--- a/llvm/lib/Support/InitLLVM.cpp
+++ b/llvm/lib/Support/InitLLVM.cpp
@@ -8,13 +8,10 @@
 
 #include "llvm/Support/InitLLVM.h"
 #include "llvm/ADT/StringRef.h"
-#include "llvm/Support/AutoConvert.h"
 #include "llvm/Support/Error.h"
 #include "llvm/Support/ErrorHandling.h"
 #include "llvm/Support/ManagedStatic.h"
-#include "llvm/Support/PrettyStackTrace.h"
 #include "llvm/Support/Signals.h"
-#include "llvm/Support/SwapByteOrder.h"
 
 #ifdef _WIN32
 #include "llvm/Support/Windows/WindowsSupport.h"
diff --git a/llvm/lib/Support/LockFileManager.cpp b/llvm/lib/Support/LockFileManager.cpp
index 4a8dd89b7619b..9a45a9966458e 100644
--- a/llvm/lib/Support/LockFileManager.cpp
+++ b/llvm/lib/Support/LockFileManager.cpp
@@ -25,7 +25,6 @@
 #include <sys/stat.h>
 #include <sys/types.h>
 #include <system_error>
-#include <thread>
 #include <tuple>
 
 #ifdef _WIN32
diff --git a/llvm/lib/Support/MSP430AttributeParser.cpp b/llvm/lib/Support/MSP430AttributeParser.cpp
index 27694b8f60f36..bfc69cb2bb3ce 100644
--- a/llvm/lib/Support/MSP430AttributeParser.cpp
+++ b/llvm/lib/Support/MSP430AttributeParser.cpp
@@ -8,7 +8,6 @@
 
 #include "llvm/Support/MSP430AttributeParser.h"
 #include "llvm/ADT/ArrayRef.h"
-#include "llvm/Support/ErrorHandling.h"
 
 using namespace llvm;
 using namespace llvm::MSP430Attrs;
diff --git a/llvm/lib/Support/MemoryBuffer.cpp b/llvm/lib/Support/MemoryBuffer.cpp
index aea81964ba9fd..7ea68ee4cafd7 100644
--- a/llvm/lib/Support/MemoryBuffer.cpp
+++ b/llvm/lib/Support/MemoryBuffer.cpp
@@ -19,7 +19,6 @@
 #include "llvm/Support/Error.h"
 #include "llvm/Support/ErrorHandling.h"
 #include "llvm/Support/FileSystem.h"
-#include "llvm/Support/MathExtras.h"
 #include "llvm/Support/Process.h"
 #include "llvm/Support/Program.h"
 #include "llvm/Support/SmallVectorMemoryBuffer.h"
diff --git a/llvm/lib/Support/NativeFormatting.cpp b/llvm/lib/Support/NativeFormatting.cpp
index 3b9273e1eaadb..7a64730434193 100644
--- a/llvm/lib/Support/NativeFormatting.cpp
+++ b/llvm/lib/Support/NativeFormatting.cpp
@@ -11,7 +11,6 @@
 #include "llvm/ADT/SmallString.h"
 #include "llvm/ADT/StringExtras.h"
 #include "llvm/Support/Format.h"
-#include "llvm/Support/MathExtras.h"
 #include "llvm/Support/raw_ostream.h"
 
 #include <cmath>
diff --git a/llvm/lib/Support/Path.cpp b/llvm/lib/Support/Path.cpp
index 4db9bc80b415b..d775285197103 100644
--- a/llvm/lib/Support/Path.cpp
+++ b/llvm/lib/Support/Path.cpp
@@ -16,7 +16,6 @@
 #include "llvm/ADT/StringExtras.h"
 #include "llvm/Config/config.h"
 #include "llvm/Config/llvm-config.h"
-#include "llvm/Support/Endian.h"
 #include "llvm/Support/Errc.h"
 #include "llvm/Support/ErrorHandling.h"
 #include "llvm/Support/FileSystem.h"
diff --git a/llvm/lib/Support/Process.cpp b/llvm/lib/Support/Process.cpp
index 54462f23c8424..57bcc2d116dad 100644
--- a/llvm/lib/Support/Process.cpp
+++ b/llvm/lib/Support/Process.cpp
@@ -18,7 +18,6 @@
 #include "llvm/Support/CrashRecoveryContext.h"
 #include "llvm/Support/FileSystem.h"
 #include "llvm/Support/Path.h"
-#include "llvm/Support/Program.h"
 
 #include <optional>
 #include <stdlib.h> // for _Exit
diff --git a/llvm/lib/Support/RWMutex.cpp b/llvm/lib/Support/RWMutex.cpp
index 4294c4356f476..83adef5bcd97d 100644
--- a/llvm/lib/Support/RWMutex.cpp
+++ b/llvm/lib/Support/RWMutex.cpp
@@ -13,7 +13,6 @@
 #include "llvm/Support/RWMutex.h"
 #include "llvm/Config/config.h"
 #include "llvm/Config/llvm-config.h" // for LLVM_ENABLE_THREADS
-#include "llvm/Support/Allocator.h"
 
 #if defined(LLVM_USE_RW_MUTEX_IMPL)
 using namespace llvm;
diff --git a/llvm/lib/Support/SuffixTreeNode.cpp b/llvm/lib/Support/SuffixTreeNode.cpp
index 9f1f94a39895e..dee8c5816b8bb 100644
--- a/llvm/lib/Support/SuffixTreeNode.cpp
+++ b/llvm/lib/Support/SuffixTreeNode.cpp
@@ -12,7 +12,6 @@
 //===----------------------------------------------------------------------===//
 
 #include "llvm/Support/SuffixTreeNode.h"
-#include "llvm/Support/Casting.h"
 
 using namespace llvm;
 
diff --git a/llvm/lib/Support/Threading.cpp b/llvm/lib/Support/Threading.cpp
index 7cc7ba44cc72d..693de0e6400fb 100644
--- a/llvm/lib/Support/Threading.cpp
+++ b/llvm/lib/Support/Threading.cpp
@@ -16,10 +16,8 @@
 #include "llvm/Config/llvm-config.h"
 
 #include <cassert>
-#include <errno.h>
 #include <optional>
 #include <stdlib.h>
-#include <string.h>
 
 using namespace llvm;
 
diff --git a/llvm/lib/Support/VirtualFileSystem.cpp b/llvm/lib/Support/VirtualFileSystem.cpp
index b3cdaa3eefc90..5febdf992fbfe 100644
--- a/llvm/lib/Support/VirtualFileSystem.cpp
+++ b/llvm/lib/Support/VirtualFileSystem.cpp
@@ -37,7 +37,6 @@
 #include "llvm/Support/SourceMgr.h"
 #include "llvm/Support/YAMLParser.h"
 #include "llvm/Support/raw_ostream.h"
-#include <algorithm>
 #include <atomic>
 #include <cassert>
 #include <cstdint>
diff --git a/llvm/lib/Support/YAMLTraits.cpp b/llvm/lib/Support/YAMLTraits.cpp
index 56b557646100b..d259da65c5cf7 100644
--- a/llvm/lib/Support/YAMLTraits.cpp
+++ b/llvm/lib/Support/YAMLTraits.cpp
@@ -21,7 +21,6 @@
 #include "llvm/Support/VersionTuple.h"
 #include "llvm/Support/YAMLParser.h"
 #include "llvm/Support/raw_ostream.h"
-#include <algorithm>
 #include <cassert>
 #include <cstdint>
 #include <cstring>
diff --git a/llvm/lib/Support/raw_ostream.cpp b/llvm/lib/Support/raw_ostream.cpp
index 5d30c797ebf5b..91fb4dbf16720 100644
--- a/llvm/lib/Support/raw_ostream.cpp
+++ b/llvm/lib/Support/raw_ostream.cpp
@@ -13,7 +13,6 @@
 #include "llvm/Support/raw_ostream.h"
 #include "llvm/ADT/StringExtras.h"
 #include "llvm/Config/config.h"
-#include "llvm/Support/AutoConvert.h"
 #include "llvm/Support/Compiler.h"
 #include "llvm/Support/Duration.h"
 #include "llvm/Support/ErrorHandling.h"
diff --git a/llvm/lib/Support/raw_socket_stream.cpp b/llvm/lib/Support/raw_socket_stream.cpp
index 04b3233084a41..7a4be5759f900 100644
--- a/llvm/lib/Support/raw_socket_stream.cpp
+++ b/llvm/lib/Support/raw_socket_stream.cpp
@@ -19,7 +19,6 @@
 #include <atomic>
 #include <fcntl.h>
 #include <functional>
-#include <thread>
 
 #ifndef _WIN32
 #include <poll.h>