[turbofan] Verify nodes without kNoThrow have only IfSuccess or IfException uses.

src/compiler/verifier.cc

Index: src/compiler/verifier.cc
diff --git a/src/compiler/verifier.cc b/src/compiler/verifier.cc
index eabd99dcf479dbb93bc5c2834aac32509a08bf7a..5af425c2c99c19a98121431c6da1692258737364 100644
--- a/src/compiler/verifier.cc
+++ b/src/compiler/verifier.cc
@@ -149,6 +149,30 @@ void Verifier::Visitor::Check(Node* node) {
       CheckOutput(control, node, control->op()->ControlOutputCount(),
                   "control");
     }
+
+    // Verify that 2 control outputs is either a Branch or is followed by
+    // IfSuccess/IfException.
+    if (node->op()->ControlOutputCount() != 1 &&
+        node->opcode() != IrOpcode::kBranch &&
+        node->opcode() != IrOpcode::kSwitch) {

[bgeron, 2016/08/11 10:56:18]

Changed.

+      int count_success = 0, count_exception = 0;
+      for (Edge edge : node->use_edges()) {
+        if (!NodeProperties::IsControlEdge(edge)) {
+          continue;
+        }
+        Node* control_use = edge.from();
+        CHECK_EXTRA(control_use->opcode() == IrOpcode::kIfSuccess ||
+                        control_use->opcode() == IrOpcode::kIfException,
+                    "#%d:%s should be followed by IfSuccess/IfException, but "
+                    "is followed by #%d:%s",
+                    node->id(), node->op()->mnemonic(), control_use->id(),
+                    control_use->op()->mnemonic());
+        if (control_use->opcode() == IrOpcode::kIfSuccess) ++count_success;
+        if (control_use->opcode() == IrOpcode::kIfException) ++count_exception;
+        CHECK_LE(count_success, 1);
+        CHECK_LE(count_exception, 1);
+      }
+    }
   }
 
   switch (node->opcode()) {