Index: ELF/Target.cpp
===================================================================
--- ELF/Target.cpp
+++ ELF/Target.cpp
@@ -200,6 +200,8 @@
 private:
   void relocateTlsGdToLe(uint32_t Type, uint8_t *Loc, uint8_t *BufEnd,
                          uint64_t P, uint64_t SA) const;
+  void relocateTlsGdToIe(uint32_t Type, uint8_t *Loc, uint8_t *BufEnd,
+                         uint64_t P, uint64_t SA) const;
   void relocateTlsIeToLe(uint32_t Type, uint8_t *Loc, uint8_t *BufEnd,
                          uint64_t P, uint64_t SA) const;
 
@@ -1362,6 +1364,8 @@
   if (Type == R_AARCH64_TLSIE_LD64_GOTTPREL_LO12_NC ||
       Type == R_AARCH64_TLSIE_ADR_GOTTPREL_PAGE21)
     return true;
+  if (isTlsDescRel(Type, S))
+    return canBePreempted(&S);
   return refersToGotEntry(Type) || needsPlt<ELF64LE>(Type, S);
 }
 
@@ -1517,13 +1521,12 @@
   case R_AARCH64_TLSDESC_ADR_PAGE21:
   case R_AARCH64_TLSDESC_LD64_LO12_NC:
   case R_AARCH64_TLSDESC_ADD_LO12_NC:
-  case R_AARCH64_TLSDESC_CALL: {
+  case R_AARCH64_TLSDESC_CALL:
     if (canBePreempted(S))
-      fatal("Unsupported TLS optimization");
-    uint64_t X = S ? S->getVA<ELF64LE>() : SA;
-    relocateTlsGdToLe(Type, Loc, BufEnd, P, X);
+      relocateTlsGdToIe(Type, Loc, BufEnd, P, SA);
+    else
+      relocateTlsGdToLe(Type, Loc, BufEnd, P, SA);
     return 0;
-  }
   case R_AARCH64_TLSIE_ADR_GOTTPREL_PAGE21:
   case R_AARCH64_TLSIE_LD64_GOTTPREL_LO12_NC:
     relocateTlsIeToLe(Type, Loc, BufEnd, P, S->getVA<ELF64LE>());
@@ -1576,6 +1579,51 @@
   write32le(Loc, NewInst);
 }
 
+// Global-Dynamic relocations can be relaxed to Initial-Exec if both binary is
+// an executable and target is not final (can be preempted).
+void AArch64TargetInfo::relocateTlsGdToIe(uint32_t Type, uint8_t *Loc,
+                                          uint8_t *BufEnd, uint64_t P,
+                                          uint64_t SA) const {
+  // TLSDESC Global-Dynamic relocation are in the form:
+  //   adrp    x0, :tlsdesc:v             [R_AARCH64_TLSDESC_ADR_PAGE21]
+  //   ldr     x1, [x0, #:tlsdesc_lo12:v] [R_AARCH64_TLSDESC_LD64_LO12_NC]
+  //   add     x0, x0, :tlsdesc_los:v     [R_AARCH64_TLSDESC_ADD_LO12_NC]
+  //   .tlsdesccall                       [R_AARCH64_TLSDESC_CALL]
+  // And it can optimized to:
+  //   adrp    x0, :tlsie:v
+  //   ldr     x0, [x0, :tlsie_lo12:v]
+  //   nop
+  //   nop
+
+  // For Initial-Exec from Global-Dynamic TLS relax the idea is to emit
+  // a R_AARCH64_TLS_TPREL64 dynamic relocation and thus adjust the
+  // tlsdesc call to access the GOT slot adjusted by dynamic linker.
+  checkUInt<32>(SA, Type);
+
+  switch (Type) {
+  case R_AARCH64_TLSDESC_ADD_LO12_NC:
+  case R_AARCH64_TLSDESC_CALL:
+    // nop
+    write32le(Loc, 0xD503201F);
+    break;
+  case R_AARCH64_TLSDESC_ADR_PAGE21: {
+    // adrp
+    uint64_t X = getAArch64Page(SA) - getAArch64Page(P);
+    updateAArch64Addr(Loc, (X >> 12) & 0x1FFFFF); // X[32:12]
+    return;
+  }
+  case R_AARCH64_TLSDESC_LD64_LO12_NC: {
+    // ldr with target register being 'x0'
+    uint32_t NewInst = read32le(Loc) & 0xFFFFFFE0;
+    NewInst |= (SA & 0xFF8) << 7;
+    write32le(Loc, NewInst);
+    break;
+  }
+  default:
+    llvm_unreachable("Unsupported relocation for TLS GD to IE relaxation");
+  }
+}
+
 // Initial-Exec relocations can be relaxed to Local-Exec if symbol is final
 // (can not be preempted).
 void AArch64TargetInfo::relocateTlsIeToLe(uint32_t Type, uint8_t *Loc,
Index: test/ELF/Inputs/aarch64-tls-ie.s
===================================================================
--- test/ELF/Inputs/aarch64-tls-ie.s
+++ test/ELF/Inputs/aarch64-tls-ie.s
@@ -1,4 +1,3 @@
-.text
  .global foo
  .section .tdata,"awT",%progbits
  .align 2
@@ -8,7 +7,6 @@
  .word 5
  .text
 
-.text
  .global bar
  .section .tdata,"awT",%progbits
  .align 2
Index: test/ELF/aarch64-tls-gdie.s
===================================================================
--- /dev/null
+++ test/ELF/aarch64-tls-gdie.s
@@ -0,0 +1,30 @@
+# REQUIRES: aarch64
+# RUN: llvm-mc -filetype=obj -triple=aarch64-unknown-linux %p/Inputs/aarch64-tls-ie.s -o %ttlsie.o
+# RUN: llvm-mc -filetype=obj -triple=aarch64-unknown-linux %s -o %tmain.o
+# RUN: ld.lld -shared %ttlsie.o -o %t.so
+# RUN: ld.lld %tmain.o -o %tout %t.so
+# RUN: llvm-objdump -d %tout | FileCheck %s
+# RUN: llvm-readobj -s -r %tout | FileCheck -check-prefix=RELOC %s
+
+# Global-Dynamic to Initial-Exec relax creates a R_AARCH64_TPREL64
+# RELOC:      Relocations [
+# RELOC-NEXT:   Section ({{.*}}) .rela.dyn {
+# RELOC-NEXT:    {{.*}} R_AARCH64_TLS_TPREL64 foo 0x0
+# RELOC-NEXT:   }
+# RELOC-NEXT: ]
+
+# CHECK: Disassembly of section .text:
+# CHECK: _start:
+# CHECK:  11000:	00 00 00 b0	adrp    x0, #4096
+# CHECK:  11004:	00 58 40 f9 	ldr     x0, [x0, #176]
+# CHECK:  11008:	1f 20 03 d5 	nop
+# CHECK:  1100c:	1f 20 03 d5 	nop
+
+.text
+.globl _start
+_start:
+ adrp    x0, :tlsdesc:foo
+ ldr     x1, [x0, :tlsdesc_lo12:foo]
+ add     x0, x0, :tlsdesc_lo12:foo
+ .tlsdesccall foo
+ blr     x1