JIT: fix profiler leave hook kill set for void returns on arm (#117201)

For arm void return methods, the profiler leave hook codegen kills R0.
Model this so we don't inadvertently report R0 as gc-live.

Fixes #117149.

Author: AndyAyersMS

src/coreclr/jit/lsra.h

@@ -1066,7 +1066,7 @@ class LinearScan : public LinearScanInterface
     regMaskTP getKillSetForCall(GenTreeCall* call);
     regMaskTP getKillSetForModDiv(GenTreeOp* tree);
     regMaskTP getKillSetForBlockStore(GenTreeBlk* blkNode);
-    regMaskTP getKillSetForReturn();
+    regMaskTP getKillSetForReturn(GenTree* returnNode);
     regMaskTP getKillSetForProfilerHook();
 #ifdef FEATURE_HW_INTRINSICS
     regMaskTP getKillSetForHWIntrinsic(GenTreeHWIntrinsic* node);

src/coreclr/jit/lsraarm.cpp

@@ -468,7 +468,7 @@ int LinearScan::BuildNode(GenTree* tree)
 
         case GT_RETURN:
             srcCount = BuildReturn(tree);
-            killMask = getKillSetForReturn();
+            killMask = getKillSetForReturn(tree);
             BuildKills(tree, killMask);
             break;
 

src/coreclr/jit/lsraarm64.cpp

@@ -780,7 +780,7 @@ int LinearScan::BuildNode(GenTree* tree)
 
         case GT_RETURN:
             srcCount = BuildReturn(tree);
-            killMask = getKillSetForReturn();
+            killMask = getKillSetForReturn(tree);
             BuildKills(tree, killMask);
             break;
 
@@ -789,7 +789,7 @@ int LinearScan::BuildNode(GenTree* tree)
             BuildUse(tree->gtGetOp1(), RBM_SWIFT_ERROR.GetIntRegSet());
             // Plus one for error register
             srcCount = BuildReturn(tree) + 1;
-            killMask = getKillSetForReturn();
+            killMask = getKillSetForReturn(tree);
             BuildKills(tree, killMask);
             break;
 #endif // SWIFT_SUPPORT

src/coreclr/jit/lsrabuild.cpp

@@ -1,4 +1,5 @@
 // Licensed to the .NET Foundation under one or more agreements.
+// Licensed to the .NET Foundation under one or more agreements.
 // The .NET Foundation licenses this file to you under the MIT license.
 
 /*XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
@@ -1003,14 +1004,28 @@ regMaskTP LinearScan::getKillSetForHWIntrinsic(GenTreeHWIntrinsic* node)
 // getKillSetForReturn: Determine the liveness kill set for a return node.
 //
 // Arguments:
-//    NONE (this kill set is independent of the details of the specific return.)
+//    returnNode - the return node
 //
 // Return Value:    a register mask of the registers killed
 //
-regMaskTP LinearScan::getKillSetForReturn()
+regMaskTP LinearScan::getKillSetForReturn(GenTree* returnNode)
 {
-    return compiler->compIsProfilerHookNeeded() ? compiler->compHelperCallKillSet(CORINFO_HELP_PROF_FCN_LEAVE)
-                                                : RBM_NONE;
+    regMaskTP killSet = RBM_NONE;
+
+    if (compiler->compIsProfilerHookNeeded())
+    {
+        killSet = compiler->compHelperCallKillSet(CORINFO_HELP_PROF_FCN_LEAVE);
+
+#if defined(TARGET_ARM)
+        // For arm methods with no return value R0 is also trashed.
+        if (returnNode->TypeIs(TYP_VOID))
+        {
+            killSet |= RBM_R0;
+        }
+#endif
+    }
+
+    return killSet;
 }
 
 //------------------------------------------------------------------------
@@ -1091,7 +1106,7 @@ regMaskTP LinearScan::getKillSetForNode(GenTree* tree)
         // more details.
         case GT_RETURN:
         case GT_SWIFT_ERROR_RET:
-            killMask = getKillSetForReturn();
+            killMask = getKillSetForReturn(tree);
             break;
 
         case GT_PROF_HOOK:

src/coreclr/jit/lsraloongarch64.cpp

@@ -169,7 +169,7 @@ int LinearScan::BuildNode(GenTree* tree)
 
         case GT_RETURN:
             srcCount = BuildReturn(tree);
-            killMask = getKillSetForReturn();
+            killMask = getKillSetForReturn(tree);
             BuildKills(tree, killMask);
             break;
 

src/coreclr/jit/lsrariscv64.cpp

@@ -173,7 +173,7 @@ int LinearScan::BuildNode(GenTree* tree)
 
         case GT_RETURN:
             srcCount = BuildReturn(tree);
-            killMask = getKillSetForReturn();
+            killMask = getKillSetForReturn(tree);
             BuildKills(tree, killMask);
             break;
 

src/coreclr/jit/lsraxarch.cpp

@@ -194,7 +194,7 @@ int LinearScan::BuildNode(GenTree* tree)
 
         case GT_RETURN:
             srcCount = BuildReturn(tree);
-            killMask = getKillSetForReturn();
+            killMask = getKillSetForReturn(tree);
             BuildKills(tree, killMask);
             break;
 
@@ -203,7 +203,7 @@ int LinearScan::BuildNode(GenTree* tree)
             BuildUse(tree->gtGetOp1(), RBM_SWIFT_ERROR.GetIntRegSet());
             // Plus one for error register
             srcCount = BuildReturn(tree) + 1;
-            killMask = getKillSetForReturn();
+            killMask = getKillSetForReturn(tree);
             BuildKills(tree, killMask);
             break;
 #endif // SWIFT_SUPPORT