Revert "In visitSTORE, always use FindBetterChain, rather than only when UseAA is enabled."

This reverts commit r284151 which appears to be triggering a LTO
failures on Hexagon

llvm-svn: 284157

1 files changed, 10 insertions, 0 deletions

diff --git a/llvm/lib/Target/AMDGPU/AMDGPUISelLowering.cpp b/llvm/lib/Target/AMDGPU/AMDGPUISelLowering.cpp
index d3f5c5d41e1..6f75c9cd924 100644
--- a/llvm/lib/Target/AMDGPU/AMDGPUISelLowering.cpp
+++ b/llvm/lib/Target/AMDGPU/AMDGPUISelLowering.cpp
@@ -445,6 +445,16 @@ AMDGPUTargetLowering::AMDGPUTargetLowering(const TargetMachine &TM,
 
   PredictableSelectIsExpensive = false;
 
+  // We want to find all load dependencies for long chains of stores to enable
+  // merging into very wide vectors. The problem is with vectors with > 4
+  // elements. MergeConsecutiveStores will attempt to merge these because x8/x16
+  // vectors are a legal type, even though we have to split the loads
+  // usually. When we can more precisely specify load legality per address
+  // space, we should be able to make FindBetterChain/MergeConsecutiveStores
+  // smarter so that they can figure out what to do in 2 iterations without all
+  // N > 4 stores on the same chain.
+  GatherAllAliasesMaxDepth = 16;
+
   // FIXME: Need to really handle these.
   MaxStoresPerMemcpy  = 4096;
   MaxStoresPerMemmove = 4096;