From 9c978dd6e12e5ffaf5441f459db47e9892b09a82 Mon Sep 17 00:00:00 2001
From: Fangrui Song <i@maskray.me>
Date: Fri, 18 Dec 2020 12:08:16 -0800
Subject: [PATCH] [TableGen] Fix D90844 introduced non-determinism due to
 iteration over a std::map over allocated object pointers

993eaf2d69d8beb97e4695cbd919b927ed1cfe86 (D90844) is still wrong.
The allocated const Record* pointers do not have an order guarantee
so switching from DenseMap to std::map does not help.

ProcModelMapTy = std::map<const Record*, unsigned>

Sort the values instead.
---
 llvm/utils/TableGen/CodeGenSchedule.cpp | 3 +++
 llvm/utils/TableGen/CodeGenSchedule.h   | 2 +-
 2 files changed, 4 insertions(+), 1 deletion(-)

diff --git a/llvm/utils/TableGen/CodeGenSchedule.cpp b/llvm/utils/TableGen/CodeGenSchedule.cpp
index f1bfe42..8b54ff0 100644
--- a/llvm/utils/TableGen/CodeGenSchedule.cpp
+++ b/llvm/utils/TableGen/CodeGenSchedule.cpp
@@ -1718,6 +1718,9 @@ std::vector<unsigned> CodeGenSchedModels::getAllProcIndices() const {
   for (const auto &PM : ProcModelMap)
     if (PM.second != 0)
       ProcIdVec.push_back(PM.second);
+  // The order of the keys (Record pointers) of ProcModelMap are not stable.
+  // Sort to stabalize the values.
+  llvm::sort(ProcIdVec);
   return ProcIdVec;
 }
 
diff --git a/llvm/utils/TableGen/CodeGenSchedule.h b/llvm/utils/TableGen/CodeGenSchedule.h
index 3fa6426..9020447 100644
--- a/llvm/utils/TableGen/CodeGenSchedule.h
+++ b/llvm/utils/TableGen/CodeGenSchedule.h
@@ -410,7 +410,7 @@ public:
   ArrayRef<OpcodeGroup> getGroups() const { return Groups; }
 };
 
-using ProcModelMapTy = std::map<const Record*, unsigned>;
+using ProcModelMapTy = DenseMap<const Record *, unsigned>;
 
 /// Top level container for machine model data.
 class CodeGenSchedModels {
-- 
2.7.4