Fix scheduler to correctly schedule nested diamonds.

test/cctest/compiler/test-scheduler.cc

Index: test/cctest/compiler/test-scheduler.cc
diff --git a/test/cctest/compiler/test-scheduler.cc b/test/cctest/compiler/test-scheduler.cc
index cf3312351d2e3dec04cb07660c50de96e8bd7aa8..e4f05d7b649c0443cec4ebc557e6e847c220fdf8 100644
--- a/test/cctest/compiler/test-scheduler.cc
+++ b/test/cctest/compiler/test-scheduler.cc
@@ -5,6 +5,7 @@
 #include "src/v8.h"
 #include "test/cctest/cctest.h"
 
+#include "src/compiler/access-builder.h"
 #include "src/compiler/common-operator.h"
 #include "src/compiler/generic-node-inl.h"
 #include "src/compiler/generic-node.h"
@@ -16,6 +17,7 @@
 #include "src/compiler/operator.h"
 #include "src/compiler/schedule.h"
 #include "src/compiler/scheduler.h"
+#include "src/compiler/simplified-operator.h"
 #include "src/compiler/verifier.h"
 
 using namespace v8::internal;
@@ -1710,4 +1712,46 @@ TEST(FloatingDiamond3) {
   ComputeAndVerifySchedule(33, &graph);
 }
 
+
+TEST(NestedFloatingDiamonds) {
+  HandleAndZoneScope scope;
+  Graph graph(scope.main_zone());
+  CommonOperatorBuilder common(scope.main_zone());
+  SimplifiedOperatorBuilder simplified(scope.main_zone());
+  MachineOperatorBuilder machine;
+
+  Node* start = graph.NewNode(common.Start(2));
+  graph.SetStart(start);
+
+  Node* p0 = graph.NewNode(common.Parameter(0), start);
+
+  Node* fv = graph.NewNode(common.Int32Constant(7));
+  Node* br = graph.NewNode(common.Branch(), p0, graph.start());
+  Node* t = graph.NewNode(common.IfTrue(), br);
+  Node* f = graph.NewNode(common.IfFalse(), br);
+  Node* ce = graph.NewNode(common.ControlEffect(), f);
+
+  Node* map =
+      graph.NewNode(simplified.LoadField(AccessBuilder::ForMap()), p0, ce);
+  Node* br1 = graph.NewNode(common.Branch(), map, graph.start());
+  Node* t1 = graph.NewNode(common.IfTrue(), br1);
+  Node* f1 = graph.NewNode(common.IfFalse(), br1);
+  Node* m1 = graph.NewNode(common.Merge(2), t1, f1);
+  Node* ttrue = graph.NewNode(common.Int32Constant(1));
+  Node* ffalse = graph.NewNode(common.Int32Constant(0));
+  Node* phi1 = graph.NewNode(common.Phi(kMachAnyTagged, 2), ttrue, ffalse, m1);
+
+
+  Node* m = graph.NewNode(common.Merge(2), t, f);
+  Node* phi = graph.NewNode(common.Phi(kMachAnyTagged, 2), fv, phi1, m);
+  Node* ephi1 = graph.NewNode(common.EffectPhi(2), start, map, m);
+
+  Node* ret = graph.NewNode(common.Return(), phi, ephi1, start);
+  Node* end = graph.NewNode(common.End(), ret, start);
+
+  graph.SetEnd(end);
+
+  ComputeAndVerifySchedule(24, &graph);
+}
+
 #endif