diff --git a/src/coreclr/jit/gentree.cpp b/src/coreclr/jit/gentree.cpp
index 50a812624831da..c0d4c5a9c61a60 100644
--- a/src/coreclr/jit/gentree.cpp
+++ b/src/coreclr/jit/gentree.cpp
@@ -29356,6 +29356,9 @@ GenTree* Compiler::gtNewSimdShuffleNode(
     uint64_t value  = 0;
     simd_t   vecCns = {};
 
+    // i8x16.swizzle indexes bytes, so expand each element-granular selector into elementSize
+    // consecutive byte indices. An out-of-range selector becomes 0xFF bytes so swizzle's native
+    // "index >= 16 -> 0" behavior zero-fills that element.
     for (size_t index = 0; index < elementCount; index++)
     {
         value = op2->GetIntegralVectorConstElement(index, simdBaseType);
@@ -29369,8 +29372,6 @@ GenTree* Compiler::gtNewSimdShuffleNode(
         }
         else
         {
-            // Swizzle selects zero for any byte index that is out of range (>= 16), so mark every
-            // byte of an out-of-range element accordingly.
             for (uint32_t i = 0; i < elementSize; i++)
             {
                 vecCns.u8[(index * elementSize) + i] = 0xFF;
diff --git a/src/coreclr/jit/hwintrinsiccodegenwasm.cpp b/src/coreclr/jit/hwintrinsiccodegenwasm.cpp
index da4666b5e5d3e5..f093018d9dcb8f 100644
--- a/src/coreclr/jit/hwintrinsiccodegenwasm.cpp
+++ b/src/coreclr/jit/hwintrinsiccodegenwasm.cpp
@@ -43,7 +43,7 @@ void CodeGen::genHWIntrinsic(GenTreeHWIntrinsic* node)
                 if ((info.id == NI_PackedSimd_Swizzle) && node->Op(2)->isContained())
                 {
                     // A constant, fully in-range mask was lowered to an immediate i8x16.shuffle.
-                    // genConsumeMultiOpOperands left the source on the value stack once (the mask
+                    // prior codegen left the source on the value stack once (the mask
                     // operand is contained, so no v128.const was materialized). i8x16.shuffle
                     // selects from two vectors, so push the source a second time and encode the
                     // mask as the 16-byte shuffle immediate.