diff --git a/llvm/test/tools/llvm-objdump/ELF/AMDGPU/subtarget.ll b/llvm/test/tools/llvm-objdump/ELF/AMDGPU/subtarget.ll
new file mode 100644
--- /dev/null
+++ b/llvm/test/tools/llvm-objdump/ELF/AMDGPU/subtarget.ll
@@ -0,0 +1,83 @@
+define amdgpu_kernel void @test_kernel() {
+  ret void
+}
+
+; Test subtarget detection.
+;
+; ----------------------------------GFX10--------------------------------------
+;
+; RUN: llc -mtriple=amdgcn-amd-amdhsa -mcpu=gfx1030 -filetype=obj -O0 -o %t.o %s
+; RUN: llvm-objdump -D --arch-name=amdgcn --mcpu=gfx1030 %t.o > specify.txt
+; RUN: llvm-objdump -D %t.o > detect.txt
+; RUN: diff specify.txt detect.txt
+
+; RUN: llc -mtriple=amdgcn-amd-amdhsa -mcpu=gfx1012 -filetype=obj -O0 -o %t.o %s
+; RUN: llvm-objdump -D --arch-name=amdgcn --mcpu=gfx1012 %t.o > specify.txt
+; RUN: llvm-objdump -D %t.o > detect.txt
+; RUN: diff specify.txt detect.txt
+
+; RUN: llc -mtriple=amdgcn-amd-amdhsa -mcpu=gfx1011 -filetype=obj -O0 -o %t.o %s
+; RUN: llvm-objdump -D --arch-name=amdgcn --mcpu=gfx1011 %t.o > specify.txt
+; RUN: llvm-objdump -D %t.o > detect.txt
+; RUN: diff specify.txt detect.txt
+
+; RUN: llc -mtriple=amdgcn-amd-amdhsa -mcpu=gfx1010 -filetype=obj -O0 -o %t.o %s
+; RUN: llvm-objdump -D --arch-name=amdgcn --mcpu=gfx1010 %t.o > specify.txt
+; RUN: llvm-objdump -D %t.o > detect.txt
+; RUN: diff specify.txt detect.txt
+
+
+; ----------------------------------GFX9---------------------------------------
+;
+; RUN: llc -mtriple=amdgcn-amd-amdhsa -mcpu=gfx909 -filetype=obj -O0 -o %t.o %s
+; RUN: llvm-objdump -D --arch-name=amdgcn --mcpu=gfx909 %t.o > specify.txt
+; RUN: llvm-objdump -D %t.o > detect.txt
+; RUN: diff specify.txt detect.txt
+
+; RUN: llc -mtriple=amdgcn-amd-amdhsa -mcpu=gfx908 -filetype=obj -O0 -o %t.o %s
+; RUN: llvm-objdump -D --arch-name=amdgcn --mcpu=gfx908 %t.o > specify.txt
+; RUN: llvm-objdump -D %t.o > detect.txt
+; RUN: diff specify.txt detect.txt
+
+; RUN: llc -mtriple=amdgcn-amd-amdhsa -mcpu=gfx906 -filetype=obj -O0 -o %t.o %s
+; RUN: llvm-objdump -D --arch-name=amdgcn --mcpu=gfx906 %t.o > specify.txt
+; RUN: llvm-objdump -D %t.o > detect.txt
+; RUN: diff specify.txt detect.txt
+
+; RUN: llc -mtriple=amdgcn-amd-amdhsa -mcpu=gfx904 -filetype=obj -O0 -o %t.o %s
+; RUN: llvm-objdump -D --arch-name=amdgcn --mcpu=gfx904 %t.o > specify.txt
+; RUN: llvm-objdump -D %t.o > detect.txt
+; RUN: diff specify.txt detect.txt
+
+; RUN: llc -mtriple=amdgcn-amd-amdhsa -mcpu=gfx902 -filetype=obj -O0 -o %t.o %s
+; RUN: llvm-objdump -D --arch-name=amdgcn --mcpu=gfx902 %t.o > specify.txt
+; RUN: llvm-objdump -D %t.o > detect.txt
+; RUN: diff specify.txt detect.txt
+
+; RUN: llc -mtriple=amdgcn-amd-amdhsa -mcpu=gfx900 -filetype=obj -O0 -o %t.o %s
+; RUN: llvm-objdump -D --arch-name=amdgcn --mcpu=gfx900 %t.o > specify.txt
+; RUN: llvm-objdump -D %t.o > detect.txt
+; RUN: diff specify.txt detect.txt
+
+
+; ----------------------------------GFX8---------------------------------------
+;
+; RUN: llc -mtriple=amdgcn-amd-amdhsa -mcpu=gfx810 -filetype=obj -O0 -o %t.o %s
+; RUN: llvm-objdump -D --arch-name=amdgcn --mcpu=gfx810 %t.o > specify.txt
+; RUN: llvm-objdump -D %t.o > detect.txt
+; RUN: diff specify.txt detect.txt
+
+; RUN: llc -mtriple=amdgcn-amd-amdhsa -mcpu=gfx803 -filetype=obj -O0 -o %t.o %s
+; RUN: llvm-objdump -D --arch-name=amdgcn --mcpu=gfx803 %t.o > specify.txt
+; RUN: llvm-objdump -D %t.o > detect.txt
+; RUN: diff specify.txt detect.txt
+
+; RUN: llc -mtriple=amdgcn-amd-amdhsa -mcpu=gfx802 -filetype=obj -O0 -o %t.o %s
+; RUN: llvm-objdump -D --arch-name=amdgcn --mcpu=gfx802 %t.o > specify.txt
+; RUN: llvm-objdump -D %t.o > detect.txt
+; RUN: diff specify.txt detect.txt
+
+; RUN: llc -mtriple=amdgcn-amd-amdhsa -mcpu=gfx801 -filetype=obj -O0 -o %t.o %s
+; RUN: llvm-objdump -D --arch-name=amdgcn --mcpu=gfx801 %t.o > specify.txt
+; RUN: llvm-objdump -D %t.o > detect.txt
+; RUN: diff specify.txt detect.txt
diff --git a/llvm/tools/llvm-objdump/llvm-objdump.cpp b/llvm/tools/llvm-objdump/llvm-objdump.cpp
--- a/llvm/tools/llvm-objdump/llvm-objdump.cpp
+++ b/llvm/tools/llvm-objdump/llvm-objdump.cpp
@@ -2067,6 +2067,61 @@
     reportWarning("failed to disassemble missing symbol " + Sym, FileName);
 }
 
+static Optional<StringRef> getAMDGPUCPU(const ObjectFile *Obj) {
+  using namespace llvm::ELF;
+#define IS_AMDGPU_CPU(CPU_FLAG) ((Flags) & (CPU_FLAG)) == (CPU_FLAG)
+
+  const ELF64LEFile *EF = cast<ELFObjectFile<ELF64LE>>(Obj)->getELFFile();
+  auto *TheElfHeader = EF->getHeader();
+  assert(TheElfHeader->e_machine == ELF::EM_AMDGPU);
+  uint64_t Flags = TheElfHeader->e_flags;
+
+  // Compare codes in descending order.
+  if (IS_AMDGPU_CPU(EF_AMDGPU_MACH_AMDGCN_GFX1030))
+    return StringRef("gfx1030");
+  if (IS_AMDGPU_CPU(EF_AMDGPU_MACH_AMDGCN_GFX1012))
+    return StringRef("gfx1012");
+  if (IS_AMDGPU_CPU(EF_AMDGPU_MACH_AMDGCN_GFX1011))
+    return StringRef("gfx1011");
+  if (IS_AMDGPU_CPU(EF_AMDGPU_MACH_AMDGCN_GFX1010))
+    return StringRef("gfx1010");
+
+  if (IS_AMDGPU_CPU(EF_AMDGPU_MACH_AMDGCN_GFX909))
+    return StringRef("gfx909");
+  if (IS_AMDGPU_CPU(EF_AMDGPU_MACH_AMDGCN_GFX908))
+    return StringRef("gfx908");
+  if (IS_AMDGPU_CPU(EF_AMDGPU_MACH_AMDGCN_GFX906))
+    return StringRef("gfx906");
+  if (IS_AMDGPU_CPU(EF_AMDGPU_MACH_AMDGCN_GFX904))
+    return StringRef("gfx904");
+  if (IS_AMDGPU_CPU(EF_AMDGPU_MACH_AMDGCN_GFX902))
+    return StringRef("gfx902");
+  if (IS_AMDGPU_CPU(EF_AMDGPU_MACH_AMDGCN_GFX900))
+    return StringRef("gfx900");
+
+  if (IS_AMDGPU_CPU(EF_AMDGPU_MACH_AMDGCN_GFX810))
+    return StringRef("gfx810");
+  if (IS_AMDGPU_CPU(EF_AMDGPU_MACH_AMDGCN_GFX803))
+    return StringRef("gfx803");
+  if (IS_AMDGPU_CPU(EF_AMDGPU_MACH_AMDGCN_GFX802))
+    return StringRef("gfx802");
+  if (IS_AMDGPU_CPU(EF_AMDGPU_MACH_AMDGCN_GFX801))
+    return StringRef("gfx801");
+
+#undef IS_AMDGPU_CPU
+
+  return None;
+}
+
+static Optional<StringRef> getTargetCPUIfPossible(const ObjectFile *Obj) {
+  switch (Obj->getArch()) {
+  case Triple::amdgcn:
+    return getAMDGPUCPU(Obj);
+  default:
+    return None;
+  }
+}
+
 static void disassembleObject(const ObjectFile *Obj, bool InlineRelocs) {
   const Target *TheTarget = getTarget(Obj);
 
@@ -2089,6 +2144,11 @@
   if (!AsmInfo)
     reportError(Obj->getFileName(),
                 "no assembly info for target " + TripleName);
+
+  auto TargetCPUString = getTargetCPUIfPossible(Obj);
+  if (MCPU.empty() && TargetCPUString)
+    MCPU = TargetCPUString.getValue().str();
+
   std::unique_ptr<const MCSubtargetInfo> STI(
       TheTarget->createMCSubtargetInfo(TripleName, MCPU, Features.getString()));
   if (!STI)