JIT: detect address of field as an invariant inlining arg (#845)

Update the check for arg invariance to include addresses of fields in local
structs. This allows the inliner to directly substitute more arguments into
the body of the inlinee.

Resolves dotnet/coreclr#27630.

diff --git a/src/coreclr/src/jit/importer.cpp b/src/coreclr/src/jit/importer.cpp
index 9bab752..a409192 100644 (file)
--- a/src/coreclr/src/jit/importer.cpp
+++ b/src/coreclr/src/jit/importer.cpp
@@ -18582,7 +18582,9 @@ void Compiler::impInlineRecordArgInfo(InlineInfo*   pInlineInfo,
     inlCurArgInfo->argNode = curArgVal;
 
     GenTree* lclVarTree;
-    if (impIsAddressInLocal(curArgVal, &lclVarTree) && varTypeIsStruct(lclVarTree))
+
+    const bool isAddressInLocal = impIsAddressInLocal(curArgVal, &lclVarTree);
+    if (isAddressInLocal && varTypeIsStruct(lclVarTree))
     {
         inlCurArgInfo->argIsByRefToStructLocal = true;
 #ifdef FEATURE_SIMD
@@ -18607,8 +18609,7 @@ void Compiler::impInlineRecordArgInfo(InlineInfo*   pInlineInfo,
         INDEBUG(curArgVal->AsLclVar()->gtLclILoffs = argNum;)
     }
 
-    if ((curArgVal->OperKind() & GTK_CONST) ||
-        ((curArgVal->gtOper == GT_ADDR) && (curArgVal->AsOp()->gtOp1->gtOper == GT_LCL_VAR)))
+    if ((curArgVal->OperKind() & GTK_CONST) || isAddressInLocal)
     {
         inlCurArgInfo->argIsInvariant = true;
         if (inlCurArgInfo->argIsThis && (curArgVal->gtOper == GT_CNS_INT) && (curArgVal->AsIntCon()->gtIconVal == 0))