[CGP] Ensure splitgep gives deterministic output

The output of splitLargeGEPOffsets does not appear to be deterministic because
of the way that we iterate over a DenseMap. I've changed it to a MapVector for
consistent output.

The test here isn't particularly great, only showing a consmetic difference in
output. The original reproducer is much larger but show a diffierence in
instruction ordering, leading to different codegen.

Differential Revision: https://reviews.llvm.org/D51851

llvm-svn: 342043

1 files changed, 1 insertions, 1 deletions

diff --git a/llvm/lib/CodeGen/CodeGenPrepare.cpp b/llvm/lib/CodeGen/CodeGenPrepare.cpp
index 2083869b032..cf1966f4677 100644
--- a/llvm/lib/CodeGen/CodeGenPrepare.cpp
+++ b/llvm/lib/CodeGen/CodeGenPrepare.cpp
@@ -278,7 +278,7 @@ class TypePromotionTransaction;
     /// Keep track of GEPs accessing the same data structures such as structs or
     /// arrays that are candidates to be split later because of their large
     /// size.
-    DenseMap<
+    MapVector<
         AssertingVH<Value>,
         SmallVector<std::pair<AssertingVH<GetElementPtrInst>, int64_t>, 32>>
         LargeOffsetGEPMap;