Propagate static readonly loads by value during inlining

src/coreclr/jit/fgbasic.cpp

@@ -851,9 +851,10 @@ class FgStack
             return false;
         }
         const unsigned argNum = value - SLOT_ARGUMENT;
-        if (argNum < info->argCnt)
+        if ((argNum < info->argCnt) && info->inlArgInfo[argNum].argIsConstant)
         {
-            return info->inlArgInfo[argNum].argIsInvariant;
+            assert(info->inlArgInfo[argNum].argIsInvariant);
+            return true;
         }
         return false;
     }
@@ -2671,8 +2672,9 @@ void Compiler::fgObserveInlineConstants(OPCODE opcode, const FgStack& stack, boo
                     // Check for the double whammy of an incoming constant argument
                     // feeding a constant test.
                     unsigned varNum = FgStack::SlotTypeToArgNum(slot0);
-                    if (impInlineInfo->inlArgInfo[varNum].argIsInvariant)
+                    if (impInlineInfo->inlArgInfo[varNum].argIsConstant)
                     {
+                        assert(impInlineInfo->inlArgInfo[varNum].argIsInvariant);
                         compInlineResult->Note(InlineObservation::CALLSITE_CONSTANT_ARG_FEEDS_TEST);
                     }
                 }
@@ -2713,8 +2715,9 @@ void Compiler::fgObserveInlineConstants(OPCODE opcode, const FgStack& stack, boo
             compInlineResult->Note(InlineObservation::CALLEE_ARG_FEEDS_TEST);
 
             unsigned varNum = FgStack::SlotTypeToArgNum(slot0);
-            if (impInlineInfo->inlArgInfo[varNum].argIsInvariant)
+            if (impInlineInfo->inlArgInfo[varNum].argIsConstant)
             {
+                assert(impInlineInfo->inlArgInfo[varNum].argIsInvariant);
                 compInlineResult->Note(InlineObservation::CALLSITE_CONSTANT_ARG_FEEDS_TEST);
             }
         }
@@ -2724,8 +2727,9 @@ void Compiler::fgObserveInlineConstants(OPCODE opcode, const FgStack& stack, boo
             compInlineResult->Note(InlineObservation::CALLEE_ARG_FEEDS_TEST);
 
             unsigned varNum = FgStack::SlotTypeToArgNum(slot1);
-            if (impInlineInfo->inlArgInfo[varNum].argIsInvariant)
+            if (impInlineInfo->inlArgInfo[varNum].argIsConstant)
             {
+                assert(impInlineInfo->inlArgInfo[varNum].argIsInvariant);
                 compInlineResult->Note(InlineObservation::CALLSITE_CONSTANT_ARG_FEEDS_TEST);
             }
         }

src/coreclr/jit/importer.cpp

@@ -4258,7 +4258,7 @@ GenTree* Compiler::impImportStaticFieldAddress(CORINFO_RESOLVED_TOKEN* pResolved
             }
             if (isStaticReadOnlyInitedRef)
             {
-                indirFlags |= (GTF_IND_INVARIANT | GTF_IND_NONNULL);
+                indirFlags |= (GTF_IND_NONFAULTING | GTF_IND_INVARIANT | GTF_IND_NONNULL);
             }
             break;
         }
@@ -12638,7 +12638,9 @@ void Compiler::impFixPredLists()
 //
 bool Compiler::impIsInvariant(const GenTree* tree)
 {
-    return tree->OperIsConst() || impIsAddressInLocal(tree) || tree->OperIs(GT_FTN_ADDR);
+    return tree->OperIsConst() || impIsAddressInLocal(tree) || tree->OperIs(GT_FTN_ADDR) ||
+           (tree->OperIs(GT_IND) && tree->AsIndir()->IsInvariantLoad() &&
+            ((tree->AsIndir()->gtFlags & GTF_SIDE_EFFECT) == 0));
 }
 
 //------------------------------------------------------------------------
@@ -13073,6 +13075,7 @@ void Compiler::impInlineRecordArgInfo(InlineInfo*   pInlineInfo,
     if (impIsInvariant(curArgVal))
     {
         inlCurArgInfo->argIsInvariant = true;
+        inlCurArgInfo->argIsConstant  = !curArgVal->OperIs(GT_IND);
         if (inlCurArgInfo->argIsThis && (curArgVal->gtOper == GT_CNS_INT) && (curArgVal->AsIntCon()->gtIconVal == 0))
         {
             // Abort inlining at this call site
@@ -13083,6 +13086,7 @@ void Compiler::impInlineRecordArgInfo(InlineInfo*   pInlineInfo,
     else if (gtIsTypeof(curArgVal))
     {
         inlCurArgInfo->argIsInvariant = true;
+        inlCurArgInfo->argIsConstant  = true;
         inlCurArgInfo->argHasSideEff  = false;
     }
 
@@ -13216,6 +13220,7 @@ void Compiler::impInlineInitVars(InlineInfo* pInlineInfo)
                 if (arg.GetNode()->IsCnsIntOrI())
                 {
                     ctxInfo->argIsInvariant = true;
+                    ctxInfo->argIsConstant  = true;
                 }
                 else
                 {

src/coreclr/jit/inline.h

@@ -643,22 +643,23 @@ struct LateDevirtualizationInfo
 
 struct InlArgInfo
 {
-    CallArg* arg;                         // the caller argument
-    GenTree* argBashTmpNode;              // tmp node created, if it may be replaced with actual arg
-    unsigned argTmpNum;                   // the argument tmp number
-    unsigned argIsUsed               : 1; // is this arg used at all?
-    unsigned argIsInvariant          : 1; // the argument is a constant or a local variable address
-    unsigned argIsLclVar             : 1; // the argument is a local variable
-    unsigned argIsThis               : 1; // the argument is the 'this' pointer
-    unsigned argHasSideEff           : 1; // the argument has side effects
-    unsigned argHasGlobRef           : 1; // the argument has a global ref
+    CallArg* arg;                // the caller argument
+    GenTree* argBashTmpNode;     // tmp node created, if it may be replaced with actual arg
+    unsigned argTmpNum;          // the argument tmp number
+    unsigned argIsUsed      : 1; // is this arg used at all?
+    unsigned argIsInvariant : 1; // the argument is a constant, a local variable address or a static readonly field
+    unsigned argIsLclVar    : 1; // the argument is a local variable
+    unsigned argIsThis      : 1; // the argument is the 'this' pointer
+    unsigned argHasSideEff  : 1; // the argument has side effects
+    unsigned argHasGlobRef  : 1; // the argument has a global ref
     unsigned argHasCallerLocalRef    : 1; // the argument value depends on an aliased caller local
     unsigned argHasTmp               : 1; // the argument will be evaluated to a temp
     unsigned argHasLdargaOp          : 1; // Is there LDARGA(s) operation on this argument?
     unsigned argHasStargOp           : 1; // Is there STARG(s) operation on this argument?
     unsigned argIsByRefToStructLocal : 1; // Is this arg an address of a struct local or a normed struct local or a
                                           // field in them?
-    unsigned argIsExact : 1;              // Is this arg of an exact class?
+    unsigned argIsExact    : 1;           // Is this arg of an exact class?
+    unsigned argIsConstant : 1;           // the argument is a constant or a local variable address
 };
 
 // InlLclVarInfo describes inline candidate argument and local variable properties.