Add quick diff

Commit migrated from https://github.com/mono/mono/commit/6360ccbfe31ebacdfb9e65ab05f8758513bb19be

diff --git a/src/mono/netcore/tools/jitdiff/jitdiff.cs b/src/mono/netcore/tools/jitdiff/jitdiff.cs
old mode 100755 (executable)
new mode 100644 (file)
index 85cf633..c40564b
--- a/src/mono/netcore/tools/jitdiff/jitdiff.cs
+++ b/src/mono/netcore/tools/jitdiff/jitdiff.cs
@@ -17,6 +17,7 @@ namespace JitDiffTools
 
                        string [] filesBefore = Directory.GetFiles (args [0], "*.dasm");
                        string [] filesAfter = Directory.GetFiles (args [1], "*.dasm");
+                       var pairs = new List<Tuple<string, string>> ();
 
                        foreach (string fileBefore in filesBefore)
                        {
@@ -24,8 +25,28 @@ namespace JitDiffTools
                                string fileAfter = filesAfter.FirstOrDefault (f =>
                                        Path.GetFileName (f).Equals (fileName, StringComparison.InvariantCultureIgnoreCase));
 
-                               if (fileAfter != null) 
-                                       PrintDiffs (fileBefore, fileAfter);
+                               if (fileAfter != null)
+                                       pairs.Add (new Tuple<string, string> (fileBefore, fileAfter));
+                       }
+
+                       long totalFileDiff = 0;
+                       Console.WriteLine ();
+                       foreach (var pair in pairs)
+                       {
+                               long sizeBefore = new FileInfo (pair.Item1).Length;
+                               long sizeAfter = new FileInfo (pair.Item2).Length;
+                               long diff = sizeAfter - sizeBefore;
+                               totalFileDiff += diff;
+                               if (diff != 0)
+                                       Console.WriteLine ($"Total diff for {Path.GetFileName (pair.Item1)}: {diff} bytes");
+                       }
+                       if (totalFileDiff != 0)
+                               Console.WriteLine ($"Total diff for all files: {totalFileDiff} bytes");
+
+                       Console.WriteLine ("\n=====================\n= Per-method diffs (may take a while):\n=====================\n");
+                       foreach (var pair in pairs)
+                       {
+                               PrintDiffs (pair.Item1, pair.Item2);
                        }
                        Console.WriteLine ("Done.");
                }
@@ -61,7 +82,7 @@ namespace JitDiffTools
                        Console.WriteLine (Path.GetFileNameWithoutExtension (fileBefore));
                        Console.WriteLine ($"Methods \"regressed\": {methodRegressed}");
                        Console.WriteLine ($"Methods \"improved\": {methodImproved}");
-                       Console.WriteLine ($"Total regression: {totalRegression}, Total improvement: {totalImprovement}");
+                       Console.WriteLine ($"Total regression: {totalRegression} lines, Total improvement: {totalImprovement} lines.");
                        Console.WriteLine ("\n");
                }
 
@@ -164,7 +185,7 @@ namespace JitDiffTools
                static int CalculateBytes (FunctionInfo info)
                {
                        // TODO: calculate bytes
-                       return info.Body.Count;
+                       return info?.Body?.Count ?? 0;
                }
 
                public bool HasChanges => Diff != 0;