--- /dev/null
+++ dyld/dyld-1330/mach_o_writer/LinkerOptimizationHintsWriter.cpp
@@ -0,0 +1,82 @@
+/*
+ * Copyright (c) 2022 Apple Inc. All rights reserved.
+ *
+ * @APPLE_LICENSE_HEADER_START@
+ *
+ * This file contains Original Code and/or Modifications of Original Code
+ * as defined in and that are subject to the Apple Public Source License
+ * Version 2.0 (the 'License'). You may not use this file except in
+ * compliance with the License. Please obtain a copy of the License at
+ * http://www.opensource.apple.com/apsl/ and read it before using this
+ * file.
+ *
+ * The Original Code and all software distributed under the License are
+ * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
+ * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
+ * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
+ * Please see the License for the specific language governing rights and
+ * limitations under the License.
+ *
+ * @APPLE_LICENSE_HEADER_END@
+ */
+
+// mach_o
+#include "Fixups.h"
+#include "Misc.h"
+
+// mach_o_writer
+#include "LinkerOptimizationHintsWriter.h"
+
+namespace mach_o {
+
+//
+// MARK: --- LinkerOptimizationHints::Location methods ---
+//
+
+LinkerOptimizationHintsWriter::Location::Location(Kind kind, std::vector<uint64_t> addrs)
+: kind(kind), addrs(addrs)
+{
+}
+
+LinkerOptimizationHintsWriter::Location::Location(Kind kind, std::span<uint64_t> addrs)
+: kind(kind), addrs(addrs.begin(), addrs.end())
+{
+}
+
+void LinkerOptimizationHintsWriter::append_uleb128(uint64_t value)
+{
+    uint8_t byte;
+    do {
+        byte = value & 0x7F;
+        value &= ~0x7F;
+        if ( value != 0 )
+            byte |= 0x80;
+        _bytes.push_back(byte);
+        value = value >> 7;
+    } while( byte >= 0x80 );
+}
+
+LinkerOptimizationHintsWriter::LinkerOptimizationHintsWriter(std::span<const Location> sortedLocs, bool is64)
+    : LinkerOptimizationHints()
+{
+    if ( sortedLocs.empty() )
+        return;
+
+    _bytes.reserve(256);
+    for ( const Location& loc : sortedLocs ) {
+        append_uleb128((uint64_t)loc.kind);
+        append_uleb128((uint64_t)loc.addrs.size());
+        for ( uint64_t addr : loc.addrs )
+            append_uleb128(addr);
+    }
+
+    // align to pointer size
+    uint32_t pointerSize = is64 ? 8 : 4;
+    while ( (_bytes.size() % pointerSize) != 0 )
+        _bytes.push_back(0);
+
+    _buffer = _bytes;
+}
+
+} // namespace mach_o