From eb2d84f6596e37817c38c84767dae95df398e067 Mon Sep 17 00:00:00 2001
From: Sanjoy Das <sanjoy@google.com>
Date: Thu, 16 May 2019 15:17:49 -0700
Subject: [PATCH] Print out the deadness predicate on a mismatch

PiperOrigin-RevId: 248610290
---
 tensorflow/compiler/jit/deadness_analysis.cc  |  4 ++++
 tensorflow/compiler/jit/deadness_analysis.h   |  2 ++
 .../compiler/jit/mark_for_compilation_pass.cc | 20 +++++++++++++++----
 3 files changed, 22 insertions(+), 4 deletions(-)

diff --git a/tensorflow/compiler/jit/deadness_analysis.cc b/tensorflow/compiler/jit/deadness_analysis.cc
index 0a92c06ad10..d2501b9ef1e 100644
--- a/tensorflow/compiler/jit/deadness_analysis.cc
+++ b/tensorflow/compiler/jit/deadness_analysis.cc
@@ -1188,4 +1188,8 @@ Status ComputePredicates(const Graph& graph,
 }
 }  // namespace deadness_analysis_internal
 
+string DeadnessAnalysis::DebugString(DeadnessPredicate predicate) const {
+  return static_cast<Predicate*>(predicate.pred_)->ToString();
+}
+
 }  // namespace tensorflow
diff --git a/tensorflow/compiler/jit/deadness_analysis.h b/tensorflow/compiler/jit/deadness_analysis.h
index 08d8ad011bc..c8527de503d 100644
--- a/tensorflow/compiler/jit/deadness_analysis.h
+++ b/tensorflow/compiler/jit/deadness_analysis.h
@@ -82,6 +82,8 @@ class DeadnessAnalysis {
   virtual void Print() const = 0;
   virtual ~DeadnessAnalysis();
 
+  string DebugString(DeadnessPredicate predicate) const;
+
   // Run the deadness analysis over `graph` and returns an error or a populated
   // instance of DeadnessAnalysis in `result`.
   static Status Run(const Graph& graph,
diff --git a/tensorflow/compiler/jit/mark_for_compilation_pass.cc b/tensorflow/compiler/jit/mark_for_compilation_pass.cc
index 86b98505ab0..3d3497c5c36 100644
--- a/tensorflow/compiler/jit/mark_for_compilation_pass.cc
+++ b/tensorflow/compiler/jit/mark_for_compilation_pass.cc
@@ -401,6 +401,13 @@ class MarkForCompilationPassImpl {
     return true;
   }
 
+  string EdgeContractionFailureMsg(Cluster* from, Cluster* to,
+                                   absl::string_view reason) {
+    return absl::StrCat("Could not contract ", from->DebugString(*graph_),
+                        " -> ", to->DebugString(*graph_), " because ", reason,
+                        ".");
+  }
+
   DebugOptions debug_options_;
   Graph* graph_;
   FunctionLibraryDefinition* flib_def_;
@@ -1067,8 +1074,7 @@ bool MarkForCompilationPassImpl::CompilationDisallowedByXlaCompileAttr(
 
 bool MarkForCompilationPassImpl::LogNotContractableAndReturnFalse(
     Cluster* from, Cluster* to, absl::string_view reason) {
-  VLOG(3) << "Could not contract " << from->DebugString(*graph_) << " -> "
-          << to->DebugString(*graph_) << " because " << reason << ".";
+  VLOG(3) << EdgeContractionFailureMsg(from, to, reason);
   return false;
 }
 
@@ -1077,8 +1083,14 @@ StatusOr<bool> MarkForCompilationPassImpl::TryToContractEdge(Cluster* from,
   DCHECK(from->deadness_predicate().has_value() ==
          to->deadness_predicate().has_value());
   if (from->deadness_predicate() != to->deadness_predicate()) {
-    return LogNotContractableAndReturnFalse(
-        from, to, "the two nodes have mismatching deadness");
+    VLOG(3) << EdgeContractionFailureMsg(
+        from, to,
+        absl::StrCat(
+            "the two nodes have mismatching deadness: ",
+            deadness_analysis_->DebugString(*from->deadness_predicate()),
+            " and ",
+            deadness_analysis_->DebugString(*to->deadness_predicate())));
+    return false;
   }
 
   TF_ASSIGN_OR_RETURN(bool devices_compatible,