Fold arrays down to a single element. This causes huge wins on some benchmarks
for example: 197.parser (64M->14M), 164.gzip (14M->2.7M). The actual graphs
represented should not change at all.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@4643 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Analysis/DataStructure/DataStructure.cpp b/lib/Analysis/DataStructure/DataStructure.cpp
index a765311..3bb10d4 100644
--- a/lib/Analysis/DataStructure/DataStructure.cpp
+++ b/lib/Analysis/DataStructure/DataStructure.cpp
@@ -131,6 +131,16 @@
// Return true immediately if the node is completely folded.
if (isNodeCompletelyFolded()) return true;
+ // If this is an array type, eliminate the outside arrays because they won't
+ // be used anyway. This greatly reduces the size of large static arrays used
+ // as global variables, for example.
+ //
+ while (const ArrayType *AT = dyn_cast<ArrayType>(NewTy)) {
+ // FIXME: we might want to keep small arrays, but must be careful about
+ // things like: [2 x [10000 x int*]]
+ NewTy = AT->getElementType();
+ }
+
// Figure out how big the new type we're merging in is...
unsigned NewTySize = NewTy->isSized() ? TD.getTypeSize(NewTy) : 0;