[llvm] 9a44760 - [UnifyLoopExits] Fix non-deterministic iteration order

[Jay Foad via llvm-commits]

Author: Jay Foad
Date: 2020-09-14T09:09:58+01:00
New Revision: 9a4476072e152881e00179bef2c6da9fea9b274e

URL: https://github.com/llvm/llvm-project/commit/9a4476072e152881e00179bef2c6da9fea9b274e
DIFF: https://github.com/llvm/llvm-project/commit/9a4476072e152881e00179bef2c6da9fea9b274e.diff

LOG: [UnifyLoopExits] Fix non-deterministic iteration order

This was causing random minor codegen differences in shaders compiled
with the AMDGPU backend.

Differential Revision: https://reviews.llvm.org/D87548

Added: 
    

Modified: 
    llvm/lib/Transforms/Utils/UnifyLoopExits.cpp

Removed: 
    


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diff  --git a/llvm/lib/Transforms/Utils/UnifyLoopExits.cpp b/llvm/lib/Transforms/Utils/UnifyLoopExits.cpp
index b10deee3907c..6eacb9a20e4c 100644
--- a/llvm/lib/Transforms/Utils/UnifyLoopExits.cpp
+++ b/llvm/lib/Transforms/Utils/UnifyLoopExits.cpp
@@ -16,6 +16,7 @@
 //
 //===----------------------------------------------------------------------===//
 
+#include "llvm/ADT/MapVector.h"
 #include "llvm/Analysis/LoopInfo.h"
 #include "llvm/IR/Dominators.h"
 #include "llvm/InitializePasses.h"
@@ -80,7 +81,7 @@ static void restoreSSA(const DominatorTree &DT, const Loop *L,
                        const SetVector<BasicBlock *> &Incoming,
                        BasicBlock *LoopExitBlock) {
   using InstVector = SmallVector<Instruction *, 8>;
-  using IIMap = DenseMap<Instruction *, InstVector>;
+  using IIMap = MapVector<Instruction *, InstVector>;
   IIMap ExternalUsers;
   for (auto BB : L->blocks()) {
     for (auto &I : *BB) {