From: Ana Pazos <apazos@codeaurora.org>
Date: Tue, 29 Aug 2017 17:13:24 +0000 (+0000)
Subject: [PGO] Fixed non-determinism with DenseSet storing function importing info.
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=42defb6c889214e9225a93b430c3118718fc82c7;p=llvm

[PGO] Fixed non-determinism with DenseSet storing function importing info.

Summary:
r296498 introduced a DenseSet to store function importing info.

Using this container causes a test failure in
test/Transform/SampleProfile/import.ll when in Reverse Iteration mode.

This patch orders IDs before iterating through this container.

Reviewers: danielcdh, mgrang

Reviewed By: danielcdh

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D37246

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@312012 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/IR/MDBuilder.cpp b/lib/IR/MDBuilder.cpp
index b9c4f482adf..84bad318591 100644
--- a/lib/IR/MDBuilder.cpp
+++ b/lib/IR/MDBuilder.cpp
@@ -62,9 +62,14 @@ MDNode *MDBuilder::createFunctionEntryCount(
   SmallVector<Metadata *, 8> Ops;
   Ops.push_back(createString("function_entry_count"));
   Ops.push_back(createConstant(ConstantInt::get(Int64Ty, Count)));
-  if (Imports)
-    for (auto ID : *Imports)
+  if (Imports) {
+    SmallVector<GlobalValue::GUID, 2> OrderID(Imports->begin(), Imports->end());
+    std::stable_sort(OrderID.begin(), OrderID.end(),
+      [] (GlobalValue::GUID A, GlobalValue::GUID B) {
+        return A < B;});
+    for (auto ID : OrderID)
       Ops.push_back(createConstant(ConstantInt::get(Int64Ty, ID)));
+  }
   return MDNode::get(Context, Ops);
 }