Index: include/llvm/BinaryFormat/ELFRelocs/AArch64.def
===================================================================
--- include/llvm/BinaryFormat/ELFRelocs/AArch64.def
+++ include/llvm/BinaryFormat/ELFRelocs/AArch64.def
@@ -124,8 +124,11 @@
 ELF_RELOC(R_AARCH64_GLOB_DAT,                        0x401)
 ELF_RELOC(R_AARCH64_JUMP_SLOT,                       0x402)
 ELF_RELOC(R_AARCH64_RELATIVE,                        0x403)
-ELF_RELOC(R_AARCH64_TLS_DTPREL64,                    0x404)
-ELF_RELOC(R_AARCH64_TLS_DTPMOD64,                    0x405)
+// 0x404 and 0x405 are now R_AARCH64_TLS_IMPDEF1 and R_AARCH64_TLS_IMPDEF2
+// We follow GNU and define TLS_IMPDEF1 as TLS_DTPMOD64 and TLS_IMPDEF2 as
+// TLS_DTPREL64
+ELF_RELOC(R_AARCH64_TLS_DTPMOD64,                    0x404)
+ELF_RELOC(R_AARCH64_TLS_DTPREL64,                    0x405)
 ELF_RELOC(R_AARCH64_TLS_TPREL64,                     0x406)
 ELF_RELOC(R_AARCH64_TLSDESC,                         0x407)
 ELF_RELOC(R_AARCH64_IRELATIVE,                       0x408)
Index: test/tools/llvm-readobj/Inputs/relocs.py
===================================================================
--- test/tools/llvm-readobj/Inputs/relocs.py
+++ test/tools/llvm-readobj/Inputs/relocs.py
@@ -710,8 +710,8 @@
   R_AARCH64_GLOB_DAT                    = 0x401
   R_AARCH64_JUMP_SLOT                   = 0x402
   R_AARCH64_RELATIVE                    = 0x403
-  R_AARCH64_TLS_DTPREL64                = 0x404
-  R_AARCH64_TLS_DTPMOD64                = 0x405
+  R_AARCH64_TLS_DTPMOD64                = 0x404
+  R_AARCH64_TLS_DTPREL64                = 0x405
   R_AARCH64_TLS_TPREL64                 = 0x406
   R_AARCH64_TLSDESC                     = 0x407
   R_AARCH64_IRELATIVE                   = 0x408
Index: test/tools/llvm-readobj/reloc-types-elf-aarch64.test
===================================================================
--- test/tools/llvm-readobj/reloc-types-elf-aarch64.test
+++ test/tools/llvm-readobj/reloc-types-elf-aarch64.test
@@ -122,8 +122,8 @@
 # CHECK: Type: R_AARCH64_GLOB_DAT (1025)
 # CHECK: Type: R_AARCH64_JUMP_SLOT (1026)
 # CHECK: Type: R_AARCH64_RELATIVE (1027)
-# CHECK: Type: R_AARCH64_TLS_DTPREL64 (1028)
-# CHECK: Type: R_AARCH64_TLS_DTPMOD64 (1029)
+# CHECK: Type: R_AARCH64_TLS_DTPMOD64 (1028)
+# CHECK: Type: R_AARCH64_TLS_DTPREL64 (1029)
 # CHECK: Type: R_AARCH64_TLS_TPREL64 (1030)
 # CHECK: Type: R_AARCH64_TLSDESC (1031)
 # CHECK: Type: R_AARCH64_IRELATIVE (1032)
@@ -382,9 +382,9 @@
       - Offset: 0x00000000000001D4
         Type:   R_AARCH64_RELATIVE
       - Offset: 0x00000000000001D8
-        Type:   R_AARCH64_TLS_DTPREL64
-      - Offset: 0x00000000000001DC
         Type:   R_AARCH64_TLS_DTPMOD64
+      - Offset: 0x00000000000001DC
+        Type:   R_AARCH64_TLS_DTPREL64
       - Offset: 0x00000000000001E0
         Type:   R_AARCH64_TLS_TPREL64
       - Offset: 0x00000000000001E4