Improve TryTransformStoreObjAsStoreInd optimization. (#55727)

* Fix `TryTransformStoreObjAsStoreInd` optimization. * Disable the assert. It was failing on DevDiv_280120 arm32 linux, did not repro with an altjit.
dotnet · Jul 15, 2021 · 6d3bb36 · 6d3bb36
1 parent 25686d5
commit 6d3bb36
Show file tree

Hide file tree

Showing 2 changed files with 6 additions and 5 deletions.
diff --git a/src/coreclr/jit/gentree.h b/src/coreclr/jit/gentree.h
@@ -1251,7 +1251,7 @@ struct GenTree
         return OperIsInitVal(OperGet());
     }
 
-    bool IsConstInitVal()
+    bool IsConstInitVal() const
     {
         return (gtOper == GT_CNS_INT) || (OperIsInitVal() && (gtGetOp1()->gtOper == GT_CNS_INT));
     }

diff --git a/src/coreclr/jit/lower.cpp b/src/coreclr/jit/lower.cpp
@@ -6730,7 +6730,7 @@ void Lowering::LowerBlockStoreCommon(GenTreeBlk* blkNode)
 bool Lowering::TryTransformStoreObjAsStoreInd(GenTreeBlk* blkNode)
 {
     assert(blkNode->OperIs(GT_STORE_BLK, GT_STORE_DYN_BLK, GT_STORE_OBJ));
-    if (comp->opts.OptimizationEnabled())
+    if (!comp->opts.OptimizationEnabled())
     {
         return false;
     }
@@ -6751,7 +6751,9 @@ bool Lowering::TryTransformStoreObjAsStoreInd(GenTreeBlk* blkNode)
     {
         return false;
     }
-    if (varTypeIsSIMD(regType))
+
+    GenTree* src = blkNode->Data();
+    if (varTypeIsSIMD(regType) && src->IsConstInitVal())
     {
         // TODO-CQ: support STORE_IND SIMD16(SIMD16, CNT_INT 0).
         return false;
@@ -6764,13 +6766,12 @@ bool Lowering::TryTransformStoreObjAsStoreInd(GenTreeBlk* blkNode)
         return false;
     }
 
-    GenTree* src = blkNode->Data();
     if (src->OperIsInitVal() && !src->IsConstInitVal())
     {
         return false;
     }
 
-    if (varTypeIsSmall(regType) && !src->IsConstInitVal())
+    if (varTypeIsSmall(regType) && !src->IsConstInitVal() && !src->IsLocal())
     {
         // source operand INDIR will use a widening instruction
         // and generate worse code, like `movzx` instead of `mov`