Remove GTF_ADDR_ONSTACK and IsVarAddr.

IsVarAddr was checking GTF_ADDR_ONSTACK  to determine if
the GT_ADDR node is an address of a local. This change removes both
GTF_ADDR_ONSTACK and  IsVarAddr and uses IsLocalAdrExpr instead.
IsLocalAddrExpr uses opcodes to determine if GT_ADDR node is
a local address.

GTF_ADDR_ONSTACK flag is ancient, added before 2002 so I couldn't find
the checkin that introduced it.

I changed the assert to a check and an assignment since simplifications
inside fgMorphArgs between
https://github.com/dotnet/coreclr/blob/1a1e4c4d5a8030cb8d82a2e5b06c2ab357b92534/src/jit/morph.cpp#L3709
(which causes https://github.com/dotnet/coreclr/blob/1a1e4c4d5a8030cb8d82a2e5b06c2ab357b92534/src/jit/morph.cpp#L3057)
and
https://github.com/dotnet/coreclr/blob/1a1e4c4d5a8030cb8d82a2e5b06c2ab357b92534/src/jit/morph.cpp#L3790
may result in more GT_ADDR nodes recognized by IsLocalAdrExpr.

x86 and x64 pmi frameworks had no code diffs and some gcinfo reductions
(15 methods with gcinfo diffs in x86).

Fixes #22190.

1 files changed, 7 insertions, 5 deletions

diff --git a/src/jit/morph.cpp b/src/jit/morph.cpp
index efe8ec9fe8..f83fdaeb17 100644
--- a/src/jit/morph.cpp
+++ b/src/jit/morph.cpp
@@ -1619,7 +1619,7 @@ void fgArgInfo::ArgsComplete()
                         case 7:
                             // If we have a stack based LclVar we can perform a wider read of 4 or 8 bytes
                             //
-                            if (argObj->gtObj.gtOp1->IsVarAddr() == false) // Is the source not a LclVar?
+                            if (argObj->gtObj.gtOp1->IsLocalAddrExpr() == nullptr) // Is the source not a LclVar?
                             {
                                 // If we don't have a LclVar we need to read exactly 3,5,6 or 7 bytes
                                 // For now we use a a GT_CPBLK to copy the exact size into a GT_LCL_VAR temp.
@@ -3052,7 +3052,7 @@ void Compiler::fgInitArgInfo(GenTreeCall* call)
         // Change the node to TYP_I_IMPL so we don't report GC info
         // NOTE: We deferred this from the importer because of the inliner.
 
-        if (argx->IsVarAddr())
+        if (argx->IsLocalAddrExpr() != nullptr)
         {
             argx->gtType = TYP_I_IMPL;
         }
@@ -3786,8 +3786,10 @@ GenTreeCall* Compiler::fgMorphArgs(GenTreeCall* call)
         assert(size != 0);
         argSlots += argEntry->getSlotCount();
 
-        // lclVar address should have been retyped to TYP_I_IMPL.
-        assert(!argx->IsVarAddr() || (argx->gtType == TYP_I_IMPL));
+        if (argx->IsLocalAddrExpr() != nullptr)
+        {
+            argx->gtType = TYP_I_IMPL;
+        }
 
         // Get information about this argument.
         var_types hfaType            = argEntry->hfaType;
@@ -4077,7 +4079,7 @@ GenTreeCall* Compiler::fgMorphArgs(GenTreeCall* call)
                             // There are a few special cases where we can omit using a CopyBlk
                             // where we normally would need to use one.
 
-                            if (argObj->gtObj.gtOp1->IsVarAddr()) // Is the source a LclVar?
+                            if (argObj->gtObj.gtOp1->IsLocalAddrExpr() != nullptr) // Is the source a LclVar?
                             {
                                 copyBlkClass = NO_CLASS_HANDLE;
                             }