https://www.graalvm.org/ 
class org.graalvm.compiler.asm.amd64.test.BitOpsTest$5 implements org.graalvm.compiler.asm.test.AssemblerTest$CodeGenTest
  minor version: 0
  major version: 59
  flags: flags: (0x0020) ACC_SUPER
  this_class: org.graalvm.compiler.asm.amd64.test.BitOpsTest$5
  super_class: java.lang.Object
{
  final org.graalvm.compiler.asm.amd64.test.BitOpsTest this$0;
    descriptor: Lorg/graalvm/compiler/asm/amd64/test/BitOpsTest;
    flags: (0x1010) ACC_FINAL, ACC_SYNTHETIC

  void <init>(org.graalvm.compiler.asm.amd64.test.BitOpsTest);
    descriptor: (Lorg/graalvm/compiler/asm/amd64/test/BitOpsTest;)V
    flags: (0x0000) 
    Code:
      stack=2, locals=2, args_size=2
        start local 0 // org.graalvm.compiler.asm.amd64.test.BitOpsTest$5 this
         0: .line 154
            aload 0 /* this */
            aload 1
            putfield org.graalvm.compiler.asm.amd64.test.BitOpsTest$5.this$0:Lorg/graalvm/compiler/asm/amd64/test/BitOpsTest;
            aload 0 /* this */
            invokespecial java.lang.Object.<init>:()V
            return
        end local 0 // org.graalvm.compiler.asm.amd64.test.BitOpsTest$5 this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    1     0  this  Lorg/graalvm/compiler/asm/amd64/test/BitOpsTest$5;
    MethodParameters:
        Name  Flags
      this$0  final

  public byte[] generateCode(org.graalvm.compiler.code.CompilationResult, jdk.vm.ci.code.TargetDescription, jdk.vm.ci.code.RegisterConfig, jdk.vm.ci.code.CallingConvention);
    descriptor: (Lorg/graalvm/compiler/code/CompilationResult;Ljdk/vm/ci/code/TargetDescription;Ljdk/vm/ci/code/RegisterConfig;Ljdk/vm/ci/code/CallingConvention;)[B
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=5, locals=8, args_size=5
        start local 0 // org.graalvm.compiler.asm.amd64.test.BitOpsTest$5 this
        start local 1 // org.graalvm.compiler.code.CompilationResult compResult
        start local 2 // jdk.vm.ci.code.TargetDescription target
        start local 3 // jdk.vm.ci.code.RegisterConfig registerConfig
        start local 4 // jdk.vm.ci.code.CallingConvention cc
         0: .line 158
            new org.graalvm.compiler.asm.amd64.AMD64Assembler
            dup
            aload 2 /* target */
            invokespecial org.graalvm.compiler.asm.amd64.AMD64Assembler.<init>:(Ljdk/vm/ci/code/TargetDescription;)V
            astore 5 /* asm */
        start local 5 // org.graalvm.compiler.asm.amd64.AMD64Assembler asm
         1: .line 159
            aload 3 /* registerConfig */
            getstatic jdk.vm.ci.meta.JavaKind.Int:Ljdk/vm/ci/meta/JavaKind;
            invokeinterface jdk.vm.ci.code.RegisterConfig.getReturnRegister:(Ljdk/vm/ci/meta/JavaKind;)Ljdk/vm/ci/code/Register;
            astore 6 /* ret */
        start local 6 // jdk.vm.ci.code.Register ret
         2: .line 160
            aload 4 /* cc */
            iconst_0
            invokevirtual jdk.vm.ci.code.CallingConvention.getArgument:(I)Ljdk/vm/ci/meta/AllocatableValue;
            invokestatic jdk.vm.ci.code.ValueUtil.asRegister:(Ljdk/vm/ci/meta/Value;)Ljdk/vm/ci/code/Register;
            astore 7 /* arg */
        start local 7 // jdk.vm.ci.code.Register arg
         3: .line 161
            getstatic org.graalvm.compiler.asm.amd64.AMD64Assembler$AMD64RMOp.TZCNT:Lorg/graalvm/compiler/asm/amd64/AMD64Assembler$AMD64RMOp;
            aload 5 /* asm */
            getstatic org.graalvm.compiler.asm.amd64.AMD64BaseAssembler$OperandSize.DWORD:Lorg/graalvm/compiler/asm/amd64/AMD64BaseAssembler$OperandSize;
            aload 6 /* ret */
            aload 7 /* arg */
            invokevirtual org.graalvm.compiler.asm.amd64.AMD64Assembler$AMD64RMOp.emit:(Lorg/graalvm/compiler/asm/amd64/AMD64Assembler;Lorg/graalvm/compiler/asm/amd64/AMD64BaseAssembler$OperandSize;Ljdk/vm/ci/code/Register;Ljdk/vm/ci/code/Register;)V
         4: .line 162
            aload 5 /* asm */
            iconst_0
            invokevirtual org.graalvm.compiler.asm.amd64.AMD64Assembler.ret:(I)V
         5: .line 163
            aload 5 /* asm */
            iconst_1
            invokevirtual org.graalvm.compiler.asm.amd64.AMD64Assembler.close:(Z)[B
            areturn
        end local 7 // jdk.vm.ci.code.Register arg
        end local 6 // jdk.vm.ci.code.Register ret
        end local 5 // org.graalvm.compiler.asm.amd64.AMD64Assembler asm
        end local 4 // jdk.vm.ci.code.CallingConvention cc
        end local 3 // jdk.vm.ci.code.RegisterConfig registerConfig
        end local 2 // jdk.vm.ci.code.TargetDescription target
        end local 1 // org.graalvm.compiler.code.CompilationResult compResult
        end local 0 // org.graalvm.compiler.asm.amd64.test.BitOpsTest$5 this
      LocalVariableTable:
        Start  End  Slot            Name  Signature
            0    6     0            this  Lorg/graalvm/compiler/asm/amd64/test/BitOpsTest$5;
            0    6     1      compResult  Lorg/graalvm/compiler/code/CompilationResult;
            0    6     2          target  Ljdk/vm/ci/code/TargetDescription;
            0    6     3  registerConfig  Ljdk/vm/ci/code/RegisterConfig;
            0    6     4              cc  Ljdk/vm/ci/code/CallingConvention;
            1    6     5             asm  Lorg/graalvm/compiler/asm/amd64/AMD64Assembler;
            2    6     6             ret  Ljdk/vm/ci/code/Register;
            3    6     7             arg  Ljdk/vm/ci/code/Register;
    MethodParameters:
                Name  Flags
      compResult      
      target          
      registerConfig  
      cc              
}
SourceFile: "BitOpsTest.java"
EnclosingMethod: org.graalvm.compiler.asm.amd64.test.BitOpsTest.tzcntlTest:()V
NestHost: org.graalvm.compiler.asm.amd64.test.BitOpsTest
InnerClasses:
  public AMD64RMOp = org.graalvm.compiler.asm.amd64.AMD64Assembler$AMD64RMOp of org.graalvm.compiler.asm.amd64.AMD64Assembler
  public OperandSize = org.graalvm.compiler.asm.amd64.AMD64BaseAssembler$OperandSize of org.graalvm.compiler.asm.amd64.AMD64BaseAssembler
  org.graalvm.compiler.asm.amd64.test.BitOpsTest$5
  public abstract CodeGenTest = org.graalvm.compiler.asm.test.AssemblerTest$CodeGenTest of org.graalvm.compiler.asm.test.AssemblerTest