[DAGCombiner] Fix the type used in canFoldInAddressingMode to account for the

right scaling.

In the function canFoldInAddressingMode, VT is computed as the type of the
destination/source of a LOAD/STORE operations, instead of the memory type of the
operation.
On targets with a scaling factor on the offset of the LOAD/STORE operations, the
function may return false for actually valid cases. This may then prevent the
selection of profitable pre or post indexed load/store operations, and instead
select pre or post indexed load/store for unprofitable cases.

Patch by Francois de Ferriere <francois.de-ferriere@st.com>!

Differential Revision: http://reviews.llvm.org/D9146

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@235780 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
index 97043e1c0cd781954a9083884e2292df8650e727..df721e2d3b5e3fa27bac77e682faae04c7b6f306 100644 (file)
--- a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
+++ b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
@@ -8804,11 +8804,11 @@ static bool canFoldInAddressingMode(SDNode *N, SDNode *Use,
   if (LoadSDNode *LD  = dyn_cast<LoadSDNode>(Use)) {
     if (LD->isIndexed() || LD->getBasePtr().getNode() != N)
       return false;
-    VT = Use->getValueType(0);
+    VT = LD->getMemoryVT();
   } else if (StoreSDNode *ST  = dyn_cast<StoreSDNode>(Use)) {
     if (ST->isIndexed() || ST->getBasePtr().getNode() != N)
       return false;
-    VT = ST->getValue().getValueType();
+    VT = ST->getMemoryVT();
   } else
     return false;