Index: COFF/Chunks.h
===================================================================
--- COFF/Chunks.h
+++ COFF/Chunks.h
@@ -151,6 +151,8 @@
                    uint64_t P) const;
   void applyRelARM(uint8_t *Off, uint16_t Type, OutputSection *OS, uint64_t S,
                    uint64_t P) const;
+  void applyRelARM64(uint8_t *Off, uint16_t Type, OutputSection *OS, uint64_t S,
+                     uint64_t P) const;
 
   // Called if the garbage collector decides to not include this chunk
   // in a final output. It's supposed to print out a log message to stdout.
@@ -264,6 +266,12 @@
     0xdc, 0xf8, 0x00, 0xf0, // ldr.w pc, [ip]
 };
 
+static const uint8_t ImportThunkARM64[] = {
+    0x10, 0x00, 0x00, 0x90, // adrp x16, #0
+    0x10, 0x02, 0x40, 0xf9, // ldr  x16, [x16]
+    0x00, 0x02, 0x1f, 0xd6, // br   x16
+};
+
 // Windows-specific.
 // A chunk for DLL import jump table entry. In a final output, it's
 // contents will be a JMP instruction to some __imp_ symbol.
@@ -299,6 +307,17 @@
   Defined *ImpSymbol;
 };
 
+class ImportThunkChunkARM64 : public Chunk {
+public:
+  explicit ImportThunkChunkARM64(Defined *S) : ImpSymbol(S) {}
+  size_t getSize() const override { return sizeof(ImportThunkARM64); }
+  void getBaserels(std::vector<Baserel> *Res) override;
+  void writeTo(uint8_t *Buf) const override;
+
+private:
+  Defined *ImpSymbol;
+};
+
 // Windows-specific.
 // See comments for DefinedLocalImport class.
 class LocalImportChunk : public Chunk {
Index: COFF/Chunks.cpp
===================================================================
--- COFF/Chunks.cpp
+++ COFF/Chunks.cpp
@@ -52,6 +52,7 @@
 static void add32(uint8_t *P, int32_t V) { write32le(P, read32le(P) + V); }
 static void add64(uint8_t *P, int64_t V) { write64le(P, read64le(P) + V); }
 static void or16(uint8_t *P, uint16_t V) { write16le(P, read16le(P) | V); }
+static void or32(uint8_t *P, uint32_t V) { write32le(P, read32le(P) | V); }
 
 static void applySecRel(const SectionChunk *Sec, uint8_t *Off,
                         OutputSection *OS, uint64_t S) {
@@ -166,6 +167,41 @@
   }
 }
 
+static void applyArm64Addr(uint8_t *Off, uint64_t Imm) {
+  uint32_t ImmLo = (Imm & 0x3) << 29;
+  uint32_t ImmHi = (Imm & 0x1FFFFC) << 3;
+  uint64_t Mask = (0x3 << 29) | (0x1FFFFC << 3);
+  write32le(Off, (read32le(Off) & ~Mask) | ImmLo | ImmHi);
+}
+
+// Update the immediate field in a AARCH64 ldr, str, and add instruction.
+static void applyArm64Imm(uint8_t *Off, uint64_t Imm) {
+  uint32_t Orig = read32le(Off);
+  Imm += (Orig >> 10) & 0xFFF;
+  Orig &= ~(0xFFF << 10);
+  write32le(Off, Orig | ((Imm & 0xFFF) << 10));
+}
+
+static void applyArm64Ldr(uint8_t *Off, uint64_t Imm) {
+  int Size = read32le(Off) >> 30;
+  Imm >>= Size;
+  applyArm64Imm(Off, Imm);
+}
+
+void SectionChunk::applyRelARM64(uint8_t *Off, uint16_t Type, OutputSection *OS,
+                                 uint64_t S, uint64_t P) const {
+  switch (Type) {
+  case IMAGE_REL_ARM64_PAGEBASE_REL21: applyArm64Addr(Off, (S >> 12) - (P >> 12)); break;
+  case IMAGE_REL_ARM64_PAGEOFFSET_12A: applyArm64Imm(Off, S & 0xfff); break;
+  case IMAGE_REL_ARM64_PAGEOFFSET_12L: applyArm64Ldr(Off, S & 0xfff); break;
+  case IMAGE_REL_ARM64_BRANCH26:       or32(Off, ((S - P) & 0x0FFFFFFC) >> 2); break;
+  case IMAGE_REL_ARM64_ADDR32:         add32(Off, S + Config->ImageBase); break;
+  case IMAGE_REL_ARM64_ADDR64:         add64(Off, S + Config->ImageBase); break;
+  default:
+    fatal("unsupported relocation type 0x" + Twine::utohexstr(Type));
+  }
+}
+
 void SectionChunk::writeTo(uint8_t *Buf) const {
   if (!hasData())
     return;
@@ -210,6 +246,9 @@
     case ARMNT:
       applyRelARM(Off, Rel.Type, OS, S, P);
       break;
+    case ARM64:
+      applyRelARM64(Off, Rel.Type, OS, S, P);
+      break;
     default:
       llvm_unreachable("unknown machine type");
     }
@@ -236,6 +275,10 @@
     if (Rel.Type == IMAGE_REL_ARM_MOV32T)
       return IMAGE_REL_BASED_ARM_MOV32T;
     return IMAGE_REL_BASED_ABSOLUTE;
+  case ARM64:
+    if (Rel.Type == IMAGE_REL_ARM64_ADDR64)
+      return IMAGE_REL_BASED_DIR64;
+    return IMAGE_REL_BASED_ABSOLUTE;
   default:
     llvm_unreachable("unknown machine type");
   }
@@ -345,6 +388,17 @@
   applyMOV32T(Buf + OutputSectionOff, ImpSymbol->getRVA() + Config->ImageBase);
 }
 
+void ImportThunkChunkARM64::getBaserels(std::vector<Baserel> *Res) {
+}
+
+void ImportThunkChunkARM64::writeTo(uint8_t *Buf) const {
+  int64_t PageOff = (ImpSymbol->getRVA() >> 12) - (RVA >> 12);
+  int64_t Off = ImpSymbol->getRVA() & 0xfff;
+  memcpy(Buf + OutputSectionOff, ImportThunkARM64, sizeof(ImportThunkARM64));
+  applyArm64Addr(Buf + OutputSectionOff, PageOff);
+  applyArm64Ldr(Buf + OutputSectionOff + 4, Off);
+}
+
 void LocalImportChunk::getBaserels(std::vector<Baserel> *Res) {
   Res->emplace_back(getRVA());
 }
Index: COFF/Symbols.cpp
===================================================================
--- COFF/Symbols.cpp
+++ COFF/Symbols.cpp
@@ -68,6 +68,8 @@
     return make<ImportThunkChunkX64>(S);
   if (Machine == I386)
     return make<ImportThunkChunkX86>(S);
+  if (Machine == ARM64)
+    return make<ImportThunkChunkARM64>(S);
   assert(Machine == ARMNT);
   return make<ImportThunkChunkARM>(S);
 }
Index: test/COFF/arm64-relocs-imports.test
===================================================================
--- /dev/null
+++ test/COFF/arm64-relocs-imports.test
@@ -0,0 +1,136 @@
+# REQUIRES: aarch64
+
+# RUN: yaml2obj < %s > %t.obj
+# RUN: llvm-objdump -d %t.obj | FileCheck %s -check-prefix BEFORE
+# RUN: lld-link /entry:main /subsystem:console /out:%t.exe %t.obj %p/Inputs/library-arm64.lib
+# RUN: llvm-objdump -d %t.exe | FileCheck %s -check-prefix AFTER
+
+# BEFORE: Disassembly of section .text:
+# BEFORE:        0:       fe 0f 1f f8     str     x30, [sp, #-16]!
+# BEFORE:        4:       00 00 00 90     adrp    x0, #0
+# BEFORE:        8:       00 08 00 91     add     x0, x0, #2
+# BEFORE:        c:       00 00 00 94     bl      #0
+# BEFORE:       10:       00 01 40 39     ldrb    w0, [x8]
+# BEFORE:       14:       00 01 40 79     ldrh    w0, [x8]
+# BEFORE:       18:       00 01 40 b9     ldr     w0, [x8]
+# BEFORE:       1c:       00 01 40 f9     ldr     x0, [x8]
+# BEFORE:       20:       e0 03 1f 2a     mov      w0, wzr
+# BEFORE:       24:       fe 07 41 f8     ldr     x30, [sp], #16
+# BEFORE:       28:       c0 03 5f d6     ret
+# BEFORE:       2c:       08 00 00 00     <unknown>
+# BEFORE:       30:       00 00 00 00     <unknown>
+
+# AFTER: Disassembly of section .text:
+# AFTER:  140002000:      fe 0f 1f f8     str     x30, [sp, #-16]!
+# AFTER:  140002004:      e0 ff ff f0     adrp    x0, #-4096
+# AFTER:  140002008:      00 18 00 91     add     x0, x0, #6
+# AFTER:  14000200c:      0a 00 00 94     bl      #40
+# AFTER:  140002010:      00 21 40 39     ldrb    w0, [x8, #8]
+# AFTER:  140002014:      00 11 40 79     ldrh    w0, [x8, #8]
+# AFTER:  140002018:      00 09 40 b9     ldr     w0, [x8, #8]
+# AFTER:  14000201c:      00 05 40 f9     ldr     x0, [x8, #8]
+# AFTER:  140002020:      e0 03 1f 2a     mov      w0, wzr
+# AFTER:  140002024:      fe 07 41 f8     ldr     x30, [sp], #16
+# AFTER:  140002028:      c0 03 5f d6     ret
+# AFTER:  14000202c:      10 10 00 40     <unknown>
+# AFTER:  140002030:      01 00 00 00     <unknown>
+# AFTER:  140002034:      10 00 00 b0     adrp    x16, #4096
+# AFTER:  140002038:      10 1e 40 f9     ldr     x16, [x16, #56]
+# AFTER:  14000203c:      00 02 1f d6     br      x16
+
+--- !COFF
+header:
+  Machine:         IMAGE_FILE_MACHINE_ARM64
+  Characteristics: [  ]
+sections:
+  - Name:            .text
+    Characteristics: [ IMAGE_SCN_CNT_CODE, IMAGE_SCN_MEM_EXECUTE, IMAGE_SCN_MEM_READ ]
+    Alignment:       4
+    SectionData:     FE0F1FF80000009000080091000000940001403900014079000140B9000140F9E0031F2AFE0741F8C0035FD60800000000000000
+    Relocations:
+      - VirtualAddress:  4
+        SymbolName:      .Lstr
+        Type:            4
+      - VirtualAddress:  8
+        SymbolName:      .Lstr
+        Type:            6
+      - VirtualAddress:  12
+        SymbolName:      function
+        Type:            3
+      - VirtualAddress:  16
+        SymbolName:      .Lglobal
+        Type:            7
+      - VirtualAddress:  20
+        SymbolName:      .Lglobal
+        Type:            7
+      - VirtualAddress:  24
+        SymbolName:      .Lglobal
+        Type:            7
+      - VirtualAddress:  28
+        SymbolName:      .Lglobal
+        Type:            7
+      - VirtualAddress:  44
+        SymbolName:      .Lglobal
+        Type:            14
+  - Name:            .data
+    Characteristics: [ IMAGE_SCN_CNT_INITIALIZED_DATA, IMAGE_SCN_MEM_READ, IMAGE_SCN_MEM_WRITE ]
+    Alignment:       4
+    SectionData:     ''
+  - Name:            .bss
+    Characteristics: [ IMAGE_SCN_CNT_UNINITIALIZED_DATA, IMAGE_SCN_MEM_READ, IMAGE_SCN_MEM_WRITE ]
+    Alignment:       4
+    SectionData:     ''
+  - Name:            .rdata
+    Characteristics: [ IMAGE_SCN_CNT_INITIALIZED_DATA, IMAGE_SCN_MEM_READ ]
+    Alignment:       1
+    SectionData:     00000000202068656C6C6F20776F726C6400
+symbols:
+  - Name:            .text
+    Value:           0
+    SectionNumber:   1
+    SimpleType:      IMAGE_SYM_TYPE_NULL
+    ComplexType:     IMAGE_SYM_DTYPE_NULL
+    StorageClass:    IMAGE_SYM_CLASS_STATIC
+    SectionDefinition:
+      Length:          28
+      NumberOfRelocations: 3
+      NumberOfLinenumbers: 0
+      CheckSum:        1438860354
+      Number:          1
+  - Name:            .rdata
+    Value:           0
+    SectionNumber:   4
+    SimpleType:      IMAGE_SYM_TYPE_NULL
+    ComplexType:     IMAGE_SYM_DTYPE_NULL
+    StorageClass:    IMAGE_SYM_CLASS_STATIC
+    SectionDefinition:
+      Length:          12
+      NumberOfRelocations: 0
+      NumberOfLinenumbers: 0
+      CheckSum:        872944732
+      Number:          4
+  - Name:            main
+    Value:           0
+    SectionNumber:   1
+    SimpleType:      IMAGE_SYM_TYPE_NULL
+    ComplexType:     IMAGE_SYM_DTYPE_NULL
+    StorageClass:    IMAGE_SYM_CLASS_EXTERNAL
+  - Name:            .Lstr
+    Value:           4
+    SectionNumber:   4
+    SimpleType:      IMAGE_SYM_TYPE_NULL
+    ComplexType:     IMAGE_SYM_DTYPE_NULL
+    StorageClass:    IMAGE_SYM_CLASS_STATIC
+  - Name:            .Lglobal
+    Value:           8
+    SectionNumber:   4
+    SimpleType:      IMAGE_SYM_TYPE_NULL
+    ComplexType:     IMAGE_SYM_DTYPE_NULL
+    StorageClass:    IMAGE_SYM_CLASS_STATIC
+  - Name:            function
+    Value:           0
+    SectionNumber:   0
+    SimpleType:      IMAGE_SYM_TYPE_NULL
+    ComplexType:     IMAGE_SYM_DTYPE_NULL
+    StorageClass:    IMAGE_SYM_CLASS_EXTERNAL
+...