[dart/fuzzer] Add flag to control FP operations

aartbik · commit-bot@chromium.org · commit c2af59f1ea53 · 2019-07-22T20:42:30.000Z
Rationale: Floating-point operations have some potential for false divergences (mostly when going through libc methods that are compiled differently between 32- and 64-bit. To avoid these, a --no-fp flag has been added to dartfuzz.dart which can be used to dartfuzz_test.dart to avoid floating-point operations when comparing 32-/64-bit execution modes. #37335 Change-Id: Ie3c28f2a6e2d257b8e9adbba79d088b3879264ac Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/109891 Reviewed-by: Felicitas Hetzelt <felih@google.com> Commit-Queue: Aart Bik <ajcbik@google.com>
diff --git a/runtime/tools/dartfuzz/README.md b/runtime/tools/dartfuzz/README.md
@@ -12,12 +12,13 @@ How to run DartFuzz
 ===================
 To generate a single random Dart program, run
 
-    dart dartfuzz.dart [--help] [--seed SEED] FILENAME
+    dart dartfuzz.dart [--help] [--seed SEED] [--[no-]fp] FILENAME
 
 where
 
-    --help : prints help and exits
-    --seed : defines random seed (system-set by default)
+    --help    : prints help and exits
+    --seed    : defines random seed (system-set by default)
+    --[no-]fp : enables/disables floating-point operations
 
 The tool provides a runnable main isolate. A typical single
 test run looks as:
@@ -52,7 +53,7 @@ where
         jit-[debug-]x64     = Dart JIT (x64)
         jit-[debug-]arm32   = Dart JIT (simarm)
         jit-[debug-]arm64   = Dart JIT (simarm64)
-        jit-[debug-]dbc     = Dart JIT (simdbc)
+        jit-[debug-]dbc32   = Dart JIT (simdbc)
         jit-[debug-]dbc64   = Dart JIT (simdbc64)
         aot-[debug-]x64     = Dart AOT (x64)
         aot-[debug-]arm32   = Dart AOT (simarm)
diff --git a/runtime/tools/dartfuzz/dartfuzz.dart b/runtime/tools/dartfuzz/dartfuzz.dart
@@ -13,7 +13,7 @@ import 'dartfuzz_api_table.dart';
 // Version of DartFuzz. Increase this each time changes are made
 // to preserve the property that a given version of DartFuzz yields
 // the same fuzzed program for a deterministic random seed.
-const String version = '1.13';
+const String version = '1.14';
 
 // Restriction on statements and expressions.
 const int stmtLength = 2;
@@ -29,7 +29,7 @@ const methodName = 'foo';
 
 /// Class that generates a random, but runnable Dart program for fuzz testing.
 class DartFuzz {
-  DartFuzz(this.seed, this.file);
+  DartFuzz(this.seed, this.fp, this.file);
 
   void run() {
     // Initialize program variables.
@@ -66,7 +66,7 @@ class DartFuzz {
   void emitHeader() {
     emitLn('// The Dart Project Fuzz Tester ($version).');
     emitLn('// Program generated as:');
-    emitLn('//   dart dartfuzz.dart --seed $seed');
+    emitLn('//   dart dartfuzz.dart --seed $seed --${fp ? "" : "no-"}fp');
     emitLn('');
     emitLn("import 'dart:async';");
     emitLn("import 'dart:cli';");
@@ -1008,7 +1008,7 @@ class DartFuzz {
         emitExpr(depth, DartType.INT);
         break;
       case 'D':
-        emitExpr(depth, DartType.DOUBLE);
+        emitExpr(depth, fp ? DartType.DOUBLE : DartType.INT);
         break;
       case 'S':
         emitExpr(depth, DartType.STRING);
@@ -1039,7 +1039,7 @@ class DartFuzz {
       case 1:
         return DartType.INT;
       case 2:
-        return DartType.DOUBLE;
+        return fp ? DartType.DOUBLE : DartType.INT;
       case 3:
         return DartType.STRING;
       case 4:
@@ -1119,6 +1119,9 @@ class DartFuzz {
   // Random seed used to generate program.
   final int seed;
 
+  // Enables floating-point operations.
+  final bool fp;
+
   // File used for output.
   final RandomAccessFile file;
 
@@ -1163,12 +1166,15 @@ int getSeed(String userSeed) {
 main(List<String> arguments) {
   final parser = new ArgParser()
     ..addOption('seed',
-        help: 'random seed (0 forces time-based seed)', defaultsTo: '0');
+        help: 'random seed (0 forces time-based seed)', defaultsTo: '0')
+    ..addFlag('fp',
+        help: 'enables floating-point operations', defaultsTo: true);
   try {
     final results = parser.parse(arguments);
     final seed = getSeed(results['seed']);
+    final fp = results['fp'];
     final file = new File(results.rest.single).openSync(mode: FileMode.write);
-    new DartFuzz(seed, file).run();
+    new DartFuzz(seed, fp, file).run();
     file.closeSync();
   } catch (e) {
     print('Usage: dart dartfuzz.dart [OPTIONS] FILENAME\n${parser.usage}\n$e');
diff --git a/runtime/tools/dartfuzz/dartfuzz_test.dart b/runtime/tools/dartfuzz/dartfuzz_test.dart
@@ -122,13 +122,13 @@ abstract class TestRunner {
     if (mode.endsWith('debug-x64')) return 'DebugX64';
     if (mode.endsWith('debug-arm32')) return 'DebugSIMARM';
     if (mode.endsWith('debug-arm64')) return 'DebugSIMARM64';
-    if (mode.endsWith('debug-dbc')) return 'DebugSIMDBC';
+    if (mode.endsWith('debug-dbc32')) return 'DebugSIMDBC';
     if (mode.endsWith('debug-dbc64')) return 'DebugSIMDBC64';
     if (mode.endsWith('ia32')) return 'ReleaseIA32';
     if (mode.endsWith('x64')) return 'ReleaseX64';
     if (mode.endsWith('arm32')) return 'ReleaseSIMARM';
     if (mode.endsWith('arm64')) return 'ReleaseSIMARM64';
-    if (mode.endsWith('dbc')) return 'ReleaseSIMDBC';
+    if (mode.endsWith('dbc32')) return 'ReleaseSIMDBC';
     if (mode.endsWith('dbc64')) return 'ReleaseSIMDBC64';
     throw ('unknown tag in mode: $mode');
   }
@@ -282,7 +282,8 @@ class DartFuzzTest {
     fileName = '${tmpDir.path}/fuzz.dart';
     runner1 = TestRunner.getTestRunner(mode1, top, tmpDir.path, env, rand);
     runner2 = TestRunner.getTestRunner(mode2, top, tmpDir.path, env, rand);
-    isolate = 'Isolate (${tmpDir.path}) '
+    fp = samePrecision(mode1, mode2);
+    isolate = 'Isolate (${tmpDir.path}) ${fp ? "" : "NO-"}FP : '
         '${runner1.description} - ${runner2.description}';
 
     start_time = new DateTime.now().millisecondsSinceEpoch;
@@ -297,6 +298,10 @@ class DartFuzzTest {
     numDivergences = 0;
   }
 
+  bool samePrecision(String mode1, String mode2) {
+    return mode1.contains('64') == mode2.contains('64');
+  }
+
   bool timeIsUp() {
     if (time > 0) {
       current_time = new DateTime.now().millisecondsSinceEpoch;
@@ -324,7 +329,7 @@ class DartFuzzTest {
 
   void generateTest() {
     final file = new File(fileName).openSync(mode: FileMode.write);
-    new DartFuzz(seed, file).run();
+    new DartFuzz(seed, fp, file).run();
     file.closeSync();
   }
 
@@ -415,6 +420,7 @@ class DartFuzzTest {
   String fileName;
   TestRunner runner1;
   TestRunner runner2;
+  bool fp;
   String isolate;
   int seed;
 
@@ -558,9 +564,9 @@ class DartFuzzTestSession {
   // Modes not used on cluster runs because they have outstanding issues.
   static const List<String> nonClusterModes = [
     // Deprecated.
-    'jit-debug-dbc',
+    'jit-debug-dbc32',
     'jit-debug-dbc64',
-    'jit-dbc',
+    'jit-dbc32',
     'jit-dbc64',
     // Times out often:
     'aot-debug-arm32',
