Merge pull request #18696 from CarolEidt/Fix18362

Fix & test for #18362

3 files changed, 17 insertions, 7 deletions

diff --git a/src/jit/lsra.cpp b/src/jit/lsra.cpp
index 27d29dfb47..537aa06835 100644
--- a/src/jit/lsra.cpp
+++ b/src/jit/lsra.cpp
@@ -8728,6 +8728,10 @@ void LinearScan::dumpNodeInfo(GenTree* node, regMaskTP dstCandidates, int srcCou
 
 void LinearScan::dumpDefList()
 {
+    if (!VERBOSE)
+    {
+        return;
+    }
     JITDUMP("DefList: { ");
     bool first = true;
     for (RefInfoListNode *listNode = defList.Begin(), *end = defList.End(); listNode != end;
diff --git a/src/jit/lsraarmarch.cpp b/src/jit/lsraarmarch.cpp
index 1804d4caff..dad8a75197 100644
--- a/src/jit/lsraarmarch.cpp
+++ b/src/jit/lsraarmarch.cpp
@@ -512,16 +512,18 @@ int LinearScan::BuildPutArgSplit(GenTreePutArgSplit* argNode)
                 assert(!node->IsMultiRegNode());
                 currentRegCount = 1;
             }
-            regMaskTP sourceMask = RBM_NONE;
-            if (sourceRegCount < argNode->gtNumRegs)
+            // Consume all the registers, setting the appropriate register mask for the ones that
+            // go into registers.
+            for (unsigned regIndex = 0; regIndex < currentRegCount; regIndex++)
             {
-                for (unsigned regIndex = 0; regIndex < currentRegCount; regIndex++)
+                regMaskTP sourceMask = RBM_NONE;
+                if (sourceRegCount < argNode->gtNumRegs)
                 {
-                    sourceMask |= genRegMask((regNumber)((unsigned)argReg + sourceRegCount + regIndex));
+                    sourceMask = genRegMask((regNumber)((unsigned)argReg + sourceRegCount));
                 }
+                sourceRegCount++;
+                BuildUse(node, sourceMask, regIndex);
             }
-            sourceRegCount += currentRegCount;
-            BuildUse(node, sourceMask);
         }
         srcCount += sourceRegCount;
         assert(putArgChild->isContained());
diff --git a/src/jit/lsrabuild.cpp b/src/jit/lsrabuild.cpp
index 14a8ab7c6d..0d0efa9efa 100644
--- a/src/jit/lsrabuild.cpp
+++ b/src/jit/lsrabuild.cpp
@@ -2091,7 +2091,11 @@ void LinearScan::buildIntervals()
 
         // Note: the visited set is cleared in LinearScan::doLinearScan()
         markBlockVisited(block);
-        assert(defList.IsEmpty());
+        if (!defList.IsEmpty())
+        {
+            INDEBUG(dumpDefList());
+            assert(!"Expected empty defList at end of block");
+        }
 
         if (enregisterLocalVars)
         {