From 1acd2f954aefd17b77d662b97e1d0f25a440e8f4 Mon Sep 17 00:00:00 2001
From: Tanner Gooding <tagoo@outlook.com>
Date: Thu, 12 Dec 2024 15:03:16 -0800
Subject: [PATCH] Ensure simdTmpVar is inserted into the IR

---
 src/coreclr/jit/decomposelongs.cpp | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/src/coreclr/jit/decomposelongs.cpp b/src/coreclr/jit/decomposelongs.cpp
index 6ebef7d4ff60b3..3ebe2656b75e50 100644
--- a/src/coreclr/jit/decomposelongs.cpp
+++ b/src/coreclr/jit/decomposelongs.cpp
@@ -1881,12 +1881,17 @@ GenTree* DecomposeLongs::DecomposeHWIntrinsicMoveMask(LIR::Use& use, GenTreeHWIn
 
     if (varTypeIsByte(simdBaseType))
     {
+        // Create:
+        //      simdTmpVar = op1
+
         GenTree* simdTmpVar    = RepresentOpAsLocalVar(op1, node, &node->Op(1));
         unsigned simdTmpVarNum = simdTmpVar->AsLclVarCommon()->GetLclNum();
         JITDUMP("[DecomposeHWIntrinsicMoveMask]: Saving op1 tree to a temp var:\n");
         DISPTREERANGE(Range(), simdTmpVar);
         Range().Remove(simdTmpVar);
 
+        Range().InsertBefore(node, simdTmpVar);
+
         // Create:
         //      simdTmpLo = GT_HWINTRINSIC{GetLower}(simdTmpVar)
         //      loResult  = GT_HWINTRINSIC{MoveMask}(simdTmpLo)