diff --git a/llvm/include/llvm/Object/ELFObjectFile.h b/llvm/include/llvm/Object/ELFObjectFile.h
--- a/llvm/include/llvm/Object/ELFObjectFile.h
+++ b/llvm/include/llvm/Object/ELFObjectFile.h
@@ -86,6 +86,10 @@
 
   SubtargetFeatures getRISCVFeatures() const;
 
+  StringRef getTargetCPUName() const override;
+
+  StringRef getAMDGPUCPUName() const;
+
   void setARMSubArch(Triple &TheTriple) const override;
 
   virtual uint16_t getEType() const = 0;
diff --git a/llvm/include/llvm/Object/ObjectFile.h b/llvm/include/llvm/Object/ObjectFile.h
--- a/llvm/include/llvm/Object/ObjectFile.h
+++ b/llvm/include/llvm/Object/ObjectFile.h
@@ -327,6 +327,7 @@
   virtual StringRef getFileFormatName() const = 0;
   virtual Triple::ArchType getArch() const = 0;
   virtual SubtargetFeatures getFeatures() const = 0;
+  virtual StringRef getTargetCPUName() const { return StringRef(""); };
   virtual void setARMSubArch(Triple &TheTriple) const { }
   virtual Expected<uint64_t> getStartAddress() const {
     return errorCodeToError(object_error::parse_failed);
diff --git a/llvm/lib/Object/ELFObjectFile.cpp b/llvm/lib/Object/ELFObjectFile.cpp
--- a/llvm/lib/Object/ELFObjectFile.cpp
+++ b/llvm/lib/Object/ELFObjectFile.cpp
@@ -355,6 +355,116 @@
   }
 }
 
+StringRef ELFObjectFileBase::getTargetCPUName() const {
+  switch (getEMachine()) {
+  case ELF::EM_AMDGPU:
+    return getAMDGPUCPUName();
+  default:
+    return StringRef("");
+  }
+}
+
+StringRef ELFObjectFileBase::getAMDGPUCPUName() const {
+  using namespace ELF;
+  unsigned EF_CPU = getPlatformFlags() & EF_AMDGPU_MACH;
+  switch (EF_CPU) {
+    // Radeon HD 2000/3000 Series (R600).
+  case EF_AMDGPU_MACH_R600_R600:
+    return StringRef("r600");
+  case EF_AMDGPU_MACH_R600_R630:
+    return StringRef("r630");
+  case EF_AMDGPU_MACH_R600_RS880:
+    return StringRef("rs880");
+  case EF_AMDGPU_MACH_R600_RV670:
+    return StringRef("rv670");
+
+    // Radeon HD 4000 Series (R700).
+  case EF_AMDGPU_MACH_R600_RV710:
+    return StringRef("rv710");
+  case EF_AMDGPU_MACH_R600_RV730:
+    return StringRef("rv730");
+  case EF_AMDGPU_MACH_R600_RV770:
+    return StringRef("rv770");
+
+    // Radeon HD 5000 Series (Evergreen).
+  case EF_AMDGPU_MACH_R600_CEDAR:
+    return StringRef("cedar");
+  case EF_AMDGPU_MACH_R600_CYPRESS:
+    return StringRef("cypress");
+  case EF_AMDGPU_MACH_R600_JUNIPER:
+    return StringRef("juniper");
+  case EF_AMDGPU_MACH_R600_REDWOOD:
+    return StringRef("redwood");
+  case EF_AMDGPU_MACH_R600_SUMO:
+    return StringRef("sumo");
+
+    // Radeon HD 6000 Series (Northern Islands).
+  case EF_AMDGPU_MACH_R600_BARTS:
+    return StringRef("barts");
+  case EF_AMDGPU_MACH_R600_CAICOS:
+    return StringRef("caicos");
+  case EF_AMDGPU_MACH_R600_CAYMAN:
+    return StringRef("cayman");
+  case EF_AMDGPU_MACH_R600_TURKS:
+    return StringRef("turks");
+
+    // AMDGCN GFX6.
+  case EF_AMDGPU_MACH_AMDGCN_GFX600:
+    return StringRef("gfx600");
+  case EF_AMDGPU_MACH_AMDGCN_GFX601:
+    return StringRef("gfx601");
+
+    // AMDGCN GFX7.
+  case EF_AMDGPU_MACH_AMDGCN_GFX700:
+    return StringRef("gfx700");
+  case EF_AMDGPU_MACH_AMDGCN_GFX701:
+    return StringRef("gfx701");
+  case EF_AMDGPU_MACH_AMDGCN_GFX702:
+    return StringRef("gfx702");
+  case EF_AMDGPU_MACH_AMDGCN_GFX703:
+    return StringRef("gfx703");
+  case EF_AMDGPU_MACH_AMDGCN_GFX704:
+    return StringRef("gfx704");
+
+    // AMDGCN GFX8.
+  case EF_AMDGPU_MACH_AMDGCN_GFX801:
+    return StringRef("gfx801");
+  case EF_AMDGPU_MACH_AMDGCN_GFX802:
+    return StringRef("gfx802");
+  case EF_AMDGPU_MACH_AMDGCN_GFX803:
+    return StringRef("gfx803");
+  case EF_AMDGPU_MACH_AMDGCN_GFX810:
+    return StringRef("gfx810");
+
+    // AMDGCN GFX9.
+  case EF_AMDGPU_MACH_AMDGCN_GFX900:
+    return StringRef("gfx900");
+  case EF_AMDGPU_MACH_AMDGCN_GFX902:
+    return StringRef("gfx902");
+  case EF_AMDGPU_MACH_AMDGCN_GFX904:
+    return StringRef("gfx904");
+  case EF_AMDGPU_MACH_AMDGCN_GFX906:
+    return StringRef("gfx906");
+  case EF_AMDGPU_MACH_AMDGCN_GFX908:
+    return StringRef("gfx908");
+  case EF_AMDGPU_MACH_AMDGCN_GFX909:
+    return StringRef("gfx909");
+
+    // AMDGCN GFX10.
+  case EF_AMDGPU_MACH_AMDGCN_GFX1010:
+    return StringRef("gfx1010");
+  case EF_AMDGPU_MACH_AMDGCN_GFX1011:
+    return StringRef("gfx1011");
+  case EF_AMDGPU_MACH_AMDGCN_GFX1012:
+    return StringRef("gfx1012");
+  case EF_AMDGPU_MACH_AMDGCN_GFX1030:
+    return StringRef("gfx1030");
+
+  default:
+    return StringRef("");
+  }
+}
+
 // FIXME Encode from a tablegen description or target parser.
 void ELFObjectFileBase::setARMSubArch(Triple &TheTriple) const {
   if (TheTriple.getSubArch() != Triple::NoSubArch)
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. Disassembly is only supported for GFX8 and beyond.
+;
+; ----------------------------------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
@@ -2089,6 +2089,11 @@
   if (!AsmInfo)
     reportError(Obj->getFileName(),
                 "no assembly info for target " + TripleName);
+
+  // If MCPU isn't specified, detect it. Right now only AMDGPU implements the
+  // detection. In other cases, an empty string is returned.
+  MCPU = MCPU.empty() ? Obj->getTargetCPUName().str() : MCPU;
+
   std::unique_ptr<const MCSubtargetInfo> STI(
       TheTarget->createMCSubtargetInfo(TripleName, MCPU, Features.getString()));
   if (!STI)