src/jdk.internal.vm.compiler/share/classes/org.graalvm.compiler.hotspot/src/org/graalvm/compiler/hotspot/CompilationTask.java

@@ -54,10 +54,11 @@
 import jdk.vm.ci.hotspot.HotSpotCompilationRequestResult;
 import jdk.vm.ci.hotspot.HotSpotInstalledCode;
 import jdk.vm.ci.hotspot.HotSpotJVMCIRuntime;
 import jdk.vm.ci.hotspot.HotSpotNmethod;
 import jdk.vm.ci.hotspot.HotSpotResolvedJavaMethod;
+import jdk.vm.ci.meta.ResolvedJavaMethod;
 import jdk.vm.ci.runtime.JVMCICompiler;
 
 public class CompilationTask {
 
     private final HotSpotJVMCIRuntime jvmciRuntime;

@@ -167,11 +168,17 @@
                 // Installation is included in compilation time and memory usage reported by printer
                 printer.finish(result);
             }
             stats.finish(method, installedCode);
             if (result != null) {
-                return HotSpotCompilationRequestResult.success(result.getBytecodeSize() - method.getCodeSize());
+                // For compilation of substitutions the method in the compilation request might be
+                // different than the actual method parsed. The root of the compilation will always
+                // be the first method in the methods list, so use that instead.
+                ResolvedJavaMethod rootMethod = result.getMethods()[0];
+                int inlinedBytecodes = result.getBytecodeSize() - rootMethod.getCodeSize();
+                assert inlinedBytecodes >= 0 : rootMethod + " " + method;
+                return HotSpotCompilationRequestResult.success(inlinedBytecodes);
             }
             return null;
         }
 
     }