[vm] Enable multiple entry-points for unoptimized calls.

This also makes the entrypoints tests less sensitive to the order in which
functions are optimized and removes flaky checks.

Fixes #37144.
Fixes #39447.

Change-Id: I5ba23c74769ddb8415e2b635caefc798c2b70500
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/109704
Commit-Queue: Samir Jindel <[email protected]>
Reviewed-by: Martin Kustermann <[email protected]>

Author: sjindel-google

runtime/tests/vm/dart/entrypoints/aot/static_this_test.dart

@@ -2,7 +2,7 @@
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 //
-// VMOptions=--enable-testing-pragmas --no-background-compilation --optimization-counter-threshold=5 -Denable_inlining=true
+// VMOptions=--enable-testing-pragmas -Denable_inlining=true
 
 import '../static_this.dart';
 

runtime/tests/vm/dart/entrypoints/aot/super_test.dart

@@ -2,7 +2,7 @@
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 //
-// VMOptions=--enable-testing-pragmas --no-background-compilation --optimization-counter-threshold=5 -Denable_inlining=true
+// VMOptions=--enable-testing-pragmas -Denable_inlining=true
 
 import "../super.dart";
 

runtime/tests/vm/dart/entrypoints/common.dart

@@ -23,41 +23,53 @@ const pragma AlwaysInline = const bool.fromEnvironment("enable_inlining")
 // iterations.
 const bool benchmarkMode = const bool.fromEnvironment("benchmark_mode");
 
-int expectedEntryPoint = -1;
-int expectedTearoffEntryPoint = -1;
+class TargetCalls {
+  int checked = 0;
+  int unchecked = 0;
 
-// We check that this is true at the end of the test to ensure that the
-// introspection machinery is operational.
-bool validateRan = false;
+  // Leave a little room for some cases which always use the checked entry, like
+  // lazy compile stub or interpreter warm-up.
+  static const int wiggle = 10;
+
+  void expectChecked(int iterations) {
+    print("$checked, $unchecked");
+    Expect.isTrue(checked >= iterations - wiggle && unchecked == 0);
+  }
+
+  void expectUnchecked(int iterations) {
+    print("$checked, $unchecked");
+    Expect.isTrue(checked <= wiggle && unchecked >= iterations - wiggle);
+  }
+}
+
+TargetCalls entryPoint = TargetCalls();
+TargetCalls tearoffEntryPoint = TargetCalls();
+
+_validateHelper(int ep, TargetCalls calls) {
+  calls ??= entryPoint;
 
-_validateHelper(int expected, int ep) {
-  validateRan = true;
   if (ep < 0 || ep > 2) {
     Expect.fail("ERROR: invalid entry-point ($ep) passed by VM.");
   }
-  if (expected < -1 || expected > 2) {
-    Expect.fail("ERROR: invalid expected entry-point set ($expected)");
+  if (ep == 0) {
+    calls.checked++;
+  } else {
+    calls.unchecked++;
   }
-  if (expected == -1) return;
-  Expect.equals(expected, ep);
 }
 
-void _validateFn(String _, int ep) => _validateHelper(expectedEntryPoint, ep);
+void _validateFn(String _, int ep) => _validateHelper(ep, null);
 
 // Invocation of tearoffs go through a tearoff wrapper. We want to independently
 // test which entrypoint was used for the tearoff wrapper vs. which was used for
 // actual target.
-_validateTearoffFn(String name, int entryPoint) {
+_validateTearoffFn(String name, int ep) {
   _validateHelper(
-      name.endsWith("#tearoff")
-          ? expectedTearoffEntryPoint
-          : expectedEntryPoint,
-      entryPoint);
+      ep, name.endsWith("#tearoff") ? tearoffEntryPoint : entryPoint);
 }
 
 @pragma("vm:entry-point", "get")
 const validate = benchmarkMode ? null : _validateFn;
+
 @pragma("vm:entry-point", "get")
 const validateTearoff = benchmarkMode ? null : _validateTearoffFn;
-
-void bumpUsageCounter() {}

runtime/tests/vm/dart/entrypoints/jit/polymorphic_optional_this_test.dart

@@ -2,8 +2,9 @@
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 //
-// VMOptions=--enable-testing-pragmas --no-background-compilation --optimization-counter-threshold=10 -Denable_inlining=true
-// VMOptions=--enable-testing-pragmas --no-background-compilation --optimization-counter-threshold=10
+// VMOptions=--enable-testing-pragmas --no-background-compilation --optimization-counter-threshold=10 -Denable_inlining=true --compilation-counter-threshold=1
+// VMOptions=--enable-testing-pragmas --no-background-compilation --optimization-counter-threshold=10 --compilation-counter-threshold=1
+// VMOptions=--enable-testing-pragmas --no-background-compilation --optimization-counter-threshold=-1 --compilation-counter-threshold=1
 
 // Test that 'PolymorphicInstanceCall's against "this" go through the unchecked
 // entrypoint. The use of optional arguments here encourages prologue sharing
@@ -15,14 +16,6 @@ import "package:expect/expect.dart";
 abstract class C<T> {
   @NeverInline
   void samir1(T x) {
-    // Make sure this method gets optimized before main.
-    // Otherwise it might get inlined into warm-up loop, and subsequent
-    // loop will call an unoptimized version (which is not guaranteed to
-    // dispatch to unchecked entry point).
-    bumpUsageCounter();
-    bumpUsageCounter();
-    bumpUsageCounter();
-
     samir2(x, y: "hi");
   }
 
@@ -62,17 +55,10 @@ C getC() {
 }
 
 main(List<String> args) {
-  // Warmup.
-  expectedEntryPoint = -1;
-  for (int i = 0; i < 100; ++i) {
-    getC().samir1(i);
-  }
-
-  expectedEntryPoint = 2;
   const int iterations = benchmarkMode ? 100000000 : 100;
   for (int i = 0; i < iterations; ++i) {
     getC().samir1(i);
   }
 
-  Expect.isTrue(validateRan);
+  entryPoint.expectUnchecked(iterations);
 }

runtime/tests/vm/dart/entrypoints/jit/polymorphic_this_test.dart

@@ -2,8 +2,9 @@
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 //
-// VMOptions=--enable-testing-pragmas --no-background-compilation --optimization-counter-threshold=10 -Denable_inlining=true
-// VMOptions=--enable-testing-pragmas --no-background-compilation --optimization-counter-threshold=10
+// VMOptions=--enable-testing-pragmas --no-background-compilation --optimization-counter-threshold=10 -Denable_inlining=true --compilation-counter-threshold=1
+// VMOptions=--enable-testing-pragmas --no-background-compilation --optimization-counter-threshold=10 --compilation-counter-threshold=1
+// VMOptions=--enable-testing-pragmas --no-background-compilation --optimization-counter-threshold=-1 --compilation-counter-threshold=1
 
 // Test that 'PolymorphicInstanceCall's against "this" go through the unchecked
 // entrypoint.
@@ -14,14 +15,6 @@ import "package:expect/expect.dart";
 abstract class C<T> {
   @NeverInline
   void target1(T x) {
-    // Make sure this method gets optimized before main.
-    // Otherwise it might get inlined into warm-up loop, and subsequent
-    // loop will call an unoptimized version (which is not guaranteed to
-    // dispatch to unchecked entry point).
-    bumpUsageCounter();
-    bumpUsageCounter();
-    bumpUsageCounter();
-
     target2(x);
   }
 
@@ -57,24 +50,10 @@ C getC() {
 }
 
 main(List<String> args) {
-  // Warmup.
-  expectedEntryPoint = -1;
-  for (int i = 0; i < 100; ++i) {
-    getC().target1(0);
-  }
-
-  expectedEntryPoint = 1;
   const int iterations = benchmarkMode ? 200000000 : 100;
   for (int i = 0; i < iterations; ++i) {
     getC().target1(i);
   }
 
-  // Once for D and once for E.
-  expectedEntryPoint = 0;
-  dynamic x = getC();
-  x.target2(0);
-  x = getC();
-  x.target2(0);
-
-  Expect.isTrue(validateRan);
+  entryPoint.expectUnchecked(iterations);
 }

runtime/tests/vm/dart/entrypoints/jit/static_this_test.dart

@@ -2,8 +2,9 @@
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 //
-// VMOptions=--enable-testing-pragmas --no-background-compilation --optimization-counter-threshold=5
-// VMOptions=--enable-testing-pragmas --no-background-compilation --optimization-counter-threshold=5 -Denable_inlining=true
+// VMOptions=--enable-testing-pragmas --no-background-compilation --optimization-counter-threshold=5 --compilation-counter-threshold=5
+// VMOptions=--enable-testing-pragmas --no-background-compilation --optimization-counter-threshold=5 -Denable_inlining=true --compilation-counter-threshold=5
+// VMOptions=--enable-testing-pragmas --no-background-compilation --optimization-counter-threshold=-1 --compilation-counter-threshold=5
 
 import '../static_this.dart';
 

runtime/tests/vm/dart/entrypoints/jit/super_test.dart

@@ -2,8 +2,9 @@
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 //
-// VMOptions=--enable-testing-pragmas --no-background-compilation --optimization-counter-threshold=5 -Denable_inlining=true
-// VMOptions=--enable-testing-pragmas --no-background-compilation --optimization-counter-threshold=5
+// VMOptions=--enable-testing-pragmas --no-background-compilation --optimization-counter-threshold=5 -Denable_inlining=true --compilation-counter-threshold=5
+// VMOptions=--enable-testing-pragmas --no-background-compilation --optimization-counter-threshold=5 --compilation-counter-threshold=5
+// VMOptions=--enable-testing-pragmas --no-background-compilation --optimization-counter-threshold=-1 --compilation-counter-threshold=5
 
 import "../super.dart";
 

runtime/tests/vm/dart/entrypoints/static_this.dart

@@ -9,6 +9,7 @@ import "package:expect/expect.dart";
 
 class C<T> {
   @pragma("vm:testing.unsafe.trace-entrypoints-fn", validate)
+  @pragma("vm:entry-point")
   @NeverInline
   @AlwaysInline
   void target2(T x) {
@@ -17,14 +18,6 @@ class C<T> {
 
   @NeverInline
   void target1(T x) {
-    // Make sure this method gets optimized before main.
-    // Otherwise it might get inlined into warm-up loop, and subsequent
-    // loop will call an unoptimized version (which is not guaranteed to
-    // dispatch to unchecked entry point).
-    bumpUsageCounter();
-    bumpUsageCounter();
-    bumpUsageCounter();
-
     target2(x);
   }
 }
@@ -33,21 +26,10 @@ test(List<String> args) {
   // Make sure the precise runtime-type of C is not known below.
   C c = args.length == 0 ? C<int>() : C<String>();
 
-  // Warmup.
-  expectedEntryPoint = -1;
-  for (int i = 0; i < 100; ++i) {
-    c.target1(i);
-  }
-
-  expectedEntryPoint = 1;
   const int iterations = benchmarkMode ? 400000000 : 100;
   for (int i = 0; i < iterations; ++i) {
     c.target1(i);
   }
 
-  expectedEntryPoint = 0;
-  dynamic x = c;
-  x.target2(0);
-
-  Expect.isTrue(validateRan);
+  entryPoint.expectUnchecked(iterations);
 }

runtime/tests/vm/dart/entrypoints/super.dart

@@ -19,29 +19,13 @@ class C<T> {
 class D<T> extends C<T> {
   @NeverInline
   void target1(T x) {
-    // Make sure this method gets optimized before main.
-    // Otherwise it might get inlined into warm-up loop, and subsequent
-    // loop will call an unoptimized version (which is not guaranteed to
-    // dispatch to unchecked entry point).
-    bumpUsageCounter();
-    bumpUsageCounter();
-    bumpUsageCounter();
-
     super.target1(x);
   }
 }
 
 class E<T> extends C<T> {
   @NeverInline
   void target1(T x) {
-    // Make sure this method gets optimized before main.
-    // Otherwise it might get inlined into warm-up loop, and subsequent
-    // loop will call an unoptimized version (which is not guaranteed to
-    // dispatch to unchecked entry point).
-    bumpUsageCounter();
-    bumpUsageCounter();
-    bumpUsageCounter();
-
     super.target1(x);
   }
 }
@@ -60,26 +44,16 @@ C getC() {
   }
 }
 
-// This works around issues with OSR not totally respecting the optimization
-// counter threshold.
-void testOneC(C x, int i) => x.target1(i);
-
 test(List<String> args) {
   // Make sure the check on target1.x is not completely eliminated.
   if (args.length > 0) {
     (C<int>() as C<num>).target1(1.0);
   }
 
-  expectedEntryPoint = -1;
-  for (int i = 0; i < 100; ++i) {
-    testOneC(getC(), i);
-  }
-
-  expectedEntryPoint = 1;
   const int iterations = benchmarkMode ? 200000000 : 100;
   for (int i = 0; i < iterations; ++i) {
-    testOneC(getC(), i);
+    getC().target1(i);
   }
 
-  Expect.isTrue(validateRan);
+  entryPoint.expectUnchecked(iterations);
 }

runtime/tests/vm/dart/entrypoints/tearoff_prologue_test.dart

@@ -5,6 +5,7 @@
 // No type checks are removed here, but we can skip the argument count check.
 // VMOptions=--enable-testing-pragmas --no-background-compilation --optimization-counter-threshold=10
 // VMOptions=--enable-testing-pragmas --no-background-compilation --optimization-counter-threshold=10 -Denable_inlining=true
+// VMOptions=--enable-testing-pragmas --no-background-compilation --optimization-counter-threshold=-1
 
 import "package:expect/expect.dart";
 import "common.dart";
@@ -20,23 +21,19 @@ class C<T> {
   }
 }
 
+void run(void Function(int) test, int i) {
+  test(i);
+}
+
 main(List<String> args) {
   var c = new C<int>();
   var f = c.samir1;
 
-  // Warmup.
-  expectedEntryPoint = -1;
-  expectedTearoffEntryPoint = -1;
-  for (int i = 0; i < 100; ++i) {
-    f(i);
-  }
-
-  expectedEntryPoint = 0;
-  expectedTearoffEntryPoint = 1;
-  int iterations = benchmarkMode ? 100000000 : 100;
+  const int iterations = benchmarkMode ? 100000000 : 100;
   for (int i = 0; i < iterations; ++i) {
-    f(i);
+    run(f, i);
   }
 
-  Expect.isTrue(validateRan);
+  entryPoint.expectChecked(iterations);
+  tearoffEntryPoint.expectUnchecked(iterations);
 }

runtime/tests/vm/dart/entrypoints/tearoff_test.dart

@@ -4,6 +4,7 @@
 //
 // VMOptions=--enable-testing-pragmas --no-background-compilation --optimization-counter-threshold=10
 // VMOptions=--enable-testing-pragmas --no-background-compilation --optimization-counter-threshold=10 -Denable_inlining=true
+// VMOptions=--enable-testing-pragmas --no-background-compilation --optimization-counter-threshold=-1
 
 // Test that typed calls against tearoffs go into the unchecked entrypoint.
 
@@ -20,22 +21,18 @@ class C<T> {
   }
 }
 
+void run(void Function(int, String) fn, int i) {
+  fn(i, "foo");
+}
+
 main(List<String> args) {
   var f = (new C<int>()).target1;
 
-  // Warmup.
-  expectedEntryPoint = -1;
-  expectedTearoffEntryPoint = -1;
-  for (int i = 0; i < 100; ++i) {
-    f(i, "foo");
-  }
-
-  expectedEntryPoint = 0;
-  expectedTearoffEntryPoint = 1;
   const int iterations = benchmarkMode ? 100000000 : 100;
   for (int i = 0; i < iterations; ++i) {
-    f(i, "foo");
+    run(f, i);
   }
 
-  Expect.isTrue(validateRan);
+  entryPoint.expectChecked(iterations);
+  tearoffEntryPoint.expectUnchecked(iterations);
 }