diff --git a/examples/ffi-objc-call-03-selector-sharing.sx b/examples/ffi-objc-call-03-selector-sharing.sx
index 652e4e2..a6fe809 100644
--- a/examples/ffi-objc-call-03-selector-sharing.sx
+++ b/examples/ffi-objc-call-03-selector-sharing.sx
@@ -9,12 +9,13 @@
 // at module init. Per call site becomes a single load.
 //
 // Runtime behavior is unchanged before vs. after 1.5; the
-// improvement is visible in `sx ir` only. After 1.5 we should
-// see exactly one `sel_registerName` call per unique selector
-// string in the emitted IR — verify with:
-//
-//   ./zig-out/bin/sx ir examples/ffi-objc-call-03-selector-sharing.sx \
-//       | grep -c "call ptr @sel_registerName"
+// improvement is visible in `sx ir` only. The IR snapshot at
+// `tests/expected/ffi-objc-call-03-selector-sharing.ir` locks
+// in today's shape (4 `call ptr @sel_registerName` instructions,
+// one per call site). After 1.5 lands selector interning, the
+// snapshot updates to ≤2 (one per unique selector string) plus
+// a static `@OBJC_SELECTOR_REFERENCES_<sel>` global and loads at
+// the call sites.
 
 #import "modules/std.sx";
 #import "modules/compiler.sx";
diff --git a/tests/expected/ffi-objc-call-03-selector-sharing.ir b/tests/expected/ffi-objc-call-03-selector-sharing.ir
new file mode 100644
index 0000000..e1100f2
--- /dev/null
+++ b/tests/expected/ffi-objc-call-03-selector-sharing.ir
@@ -0,0 +1,277 @@
+
+@context = internal global { { ptr, ptr, ptr }, ptr } zeroinitializer
+@OS = internal global i64 0
+@ARCH = internal global i64 0
+@POINTER_SIZE = internal global i64 8
+@str = private unnamed_addr constant [5 x i8] c"init\00", align 1
+@str.1 = private unnamed_addr constant [5 x i8] c"init\00", align 1
+@str.2 = private unnamed_addr constant [5 x i8] c"init\00", align 1
+@str.3 = private unnamed_addr constant [8 x i8] c"release\00", align 1
+@str.4 = private unnamed_addr constant [4 x i8] c"ok\0A\00", align 1
+@str.5 = private unnamed_addr constant [1 x i8] zeroinitializer, align 1
+
+; Function Attrs: nounwind
+declare void @out(ptr) #0
+
+declare ptr @malloc(i64)
+
+declare ptr @memcpy(ptr, ptr, i64)
+
+declare ptr @memset(ptr, i32, i64)
+
+declare void @free(ptr)
+
+; Function Attrs: nounwind
+declare void @GPA.create(ptr sret({ ptr, ptr, ptr }), ptr) #0
+
+; Function Attrs: nounwind
+define internal ptr @GPA.alloc(ptr %0, i64 %1) #0 {
+entry:
+  %alloca = alloca ptr, align 8
+  store ptr %0, ptr %alloca, align 8
+  %allocaN = alloca i64, align 8
+  store i64 %1, ptr %allocaN, align 8
+  %load = load ptr, ptr %alloca, align 8
+  %gep = getelementptr inbounds { i64 }, ptr %load, i32 0, i32 0
+  %loadN = load i64, ptr %gep, align 8
+  %add = add i64 %loadN, 1
+  store i64 %add, ptr %gep, align 8
+  %loadN = load i64, ptr %allocaN, align 8
+  %malloc = call ptr @malloc(i64 %loadN)
+  ret ptr %malloc
+}
+
+; Function Attrs: nounwind
+define internal void @GPA.dealloc(ptr %0, ptr %1) #0 {
+entry:
+  %alloca = alloca ptr, align 8
+  store ptr %0, ptr %alloca, align 8
+  %allocaN = alloca ptr, align 8
+  store ptr %1, ptr %allocaN, align 8
+  %load = load ptr, ptr %alloca, align 8
+  %gep = getelementptr inbounds { i64 }, ptr %load, i32 0, i32 0
+  %loadN = load i64, ptr %gep, align 8
+  %sub = sub i64 %loadN, 1
+  store i64 %sub, ptr %gep, align 8
+  %loadN = load ptr, ptr %allocaN, align 8
+  call void @free(ptr %loadN)
+  ret void
+}
+
+; Function Attrs: nounwind
+declare void @Arena.add_chunk(ptr, i64) #0
+
+; Function Attrs: nounwind
+declare void @Arena.create(ptr sret({ ptr, ptr, ptr }), ptr, ptr, i64) #0
+
+; Function Attrs: nounwind
+declare void @Arena.reset(ptr) #0
+
+; Function Attrs: nounwind
+declare void @Arena.deinit(ptr) #0
+
+; Function Attrs: nounwind
+declare ptr @Arena.alloc(ptr, i64) #0
+
+; Function Attrs: nounwind
+declare void @Arena.dealloc(ptr, ptr) #0
+
+; Function Attrs: nounwind
+declare void @BufAlloc.create(ptr sret({ ptr, ptr, ptr }), ptr, ptr, i64) #0
+
+; Function Attrs: nounwind
+declare void @BufAlloc.reset(ptr) #0
+
+; Function Attrs: nounwind
+declare ptr @BufAlloc.alloc(ptr, i64) #0
+
+; Function Attrs: nounwind
+declare void @BufAlloc.dealloc(ptr, ptr) #0
+
+; Function Attrs: nounwind
+define internal { ptr, i64 } @cstring(i64 %0) #0 {
+entry:
+  %alloca = alloca i64, align 8
+  store i64 %0, ptr %alloca, align 8
+  %load = load i64, ptr %alloca, align 8
+  %add = add i64 %load, 1
+  %heap = call ptr @malloc(i64 %add)
+  %allocaN = alloca ptr, align 8
+  store ptr %heap, ptr %allocaN, align 8
+  %loadN = load ptr, ptr %allocaN, align 8
+  %loadN = load i64, ptr %alloca, align 8
+  %addN = add i64 %loadN, 1
+  %1 = call ptr @memset(ptr %loadN, i32 0, i64 %addN)
+  %allocaN = alloca { ptr, i64 }, align 8
+  store { ptr, i64 } undef, ptr %allocaN, align 8
+  %loadN = load ptr, ptr %allocaN, align 8
+  %gep = getelementptr inbounds { ptr, i64 }, ptr %allocaN, i32 0, i32 0
+  store ptr %loadN, ptr %gep, align 8
+  %loadN = load i64, ptr %alloca, align 8
+  %gepN = getelementptr inbounds { ptr, i64 }, ptr %allocaN, i32 0, i32 1
+  store i64 %loadN, ptr %gepN, align 8
+  %loadN = load { ptr, i64 }, ptr %allocaN, align 8
+  ret { ptr, i64 } %loadN
+}
+
+; Function Attrs: nounwind
+declare ptr @int_to_string(i64) #0
+
+; Function Attrs: nounwind
+declare ptr @bool_to_string(i1) #0
+
+; Function Attrs: nounwind
+declare ptr @float_to_string(double) #0
+
+; Function Attrs: nounwind
+declare void @hex_group(ptr, i64, i64) #0
+
+; Function Attrs: nounwind
+declare ptr @int_to_hex_string(i64) #0
+
+; Function Attrs: nounwind
+define internal { ptr, i64 } @concat({ ptr, i64 } %0, { ptr, i64 } %1) #0 {
+entry:
+  %alloca = alloca { ptr, i64 }, align 8
+  store { ptr, i64 } %0, ptr %alloca, align 8
+  %allocaN = alloca { ptr, i64 }, align 8
+  store { ptr, i64 } %1, ptr %allocaN, align 8
+  %load = load { ptr, i64 }, ptr %alloca, align 8
+  %len = extractvalue { ptr, i64 } %load, 1
+  %allocaN = alloca i64, align 8
+  store i64 %len, ptr %allocaN, align 8
+  %loadN = load { ptr, i64 }, ptr %allocaN, align 8
+  %lenN = extractvalue { ptr, i64 } %loadN, 1
+  %allocaN = alloca i64, align 8
+  store i64 %lenN, ptr %allocaN, align 8
+  %loadN = load i64, ptr %allocaN, align 8
+  %loadN = load i64, ptr %allocaN, align 8
+  %add = add i64 %loadN, %loadN
+  %call = call { ptr, i64 } @cstring(i64 %add)
+  %allocaN = alloca { ptr, i64 }, align 8
+  store { ptr, i64 } %call, ptr %allocaN, align 8
+  %loadN = load { ptr, i64 }, ptr %allocaN, align 8
+  %dptr = extractvalue { ptr, i64 } %loadN, 0
+  %loadN = load { ptr, i64 }, ptr %alloca, align 8
+  %dptrN = extractvalue { ptr, i64 } %loadN, 0
+  %loadN = load i64, ptr %allocaN, align 8
+  %2 = call ptr @memcpy(ptr %dptr, ptr %dptrN, i64 %loadN)
+  %loadN = load i64, ptr %allocaN, align 8
+  %loadN = load { ptr, i64 }, ptr %allocaN, align 8
+  %igp.data = extractvalue { ptr, i64 } %loadN, 0
+  %igp.ptr = getelementptr i8, ptr %igp.data, i64 %loadN
+  %loadN = load { ptr, i64 }, ptr %allocaN, align 8
+  %dptrN = extractvalue { ptr, i64 } %loadN, 0
+  %loadN = load i64, ptr %allocaN, align 8
+  %3 = call ptr @memcpy(ptr %igp.ptr, ptr %dptrN, i64 %loadN)
+  %loadN = load { ptr, i64 }, ptr %allocaN, align 8
+  ret { ptr, i64 } %loadN
+}
+
+; Function Attrs: nounwind
+define internal { ptr, i64 } @substr({ ptr, i64 } %0, i64 %1, i64 %2) #0 {
+entry:
+  %alloca = alloca { ptr, i64 }, align 8
+  store { ptr, i64 } %0, ptr %alloca, align 8
+  %allocaN = alloca i64, align 8
+  store i64 %1, ptr %allocaN, align 8
+  %allocaN = alloca i64, align 8
+  store i64 %2, ptr %allocaN, align 8
+  %load = load i64, ptr %allocaN, align 8
+  %call = call { ptr, i64 } @cstring(i64 %load)
+  %allocaN = alloca { ptr, i64 }, align 8
+  store { ptr, i64 } %call, ptr %allocaN, align 8
+  %loadN = load { ptr, i64 }, ptr %allocaN, align 8
+  %dptr = extractvalue { ptr, i64 } %loadN, 0
+  %loadN = load i64, ptr %allocaN, align 8
+  %loadN = load { ptr, i64 }, ptr %alloca, align 8
+  %igp.data = extractvalue { ptr, i64 } %loadN, 0
+  %igp.ptr = getelementptr i8, ptr %igp.data, i64 %loadN
+  %loadN = load i64, ptr %allocaN, align 8
+  %3 = call ptr @memcpy(ptr %dptr, ptr %igp.ptr, i64 %loadN)
+  %loadN = load { ptr, i64 }, ptr %allocaN, align 8
+  ret { ptr, i64 } %loadN
+}
+
+; Function Attrs: nounwind
+declare ptr @any_to_string([2 x i64]) #0
+
+; Function Attrs: nounwind
+declare ptr @build_format(ptr) #0
+
+; Function Attrs: nounwind
+declare void @BuildOptions.add_link_flag(i64, ptr) #0
+
+; Function Attrs: nounwind
+declare void @BuildOptions.add_framework(i64, ptr) #0
+
+; Function Attrs: nounwind
+declare void @BuildOptions.set_output_path(i64, ptr) #0
+
+; Function Attrs: nounwind
+declare void @BuildOptions.set_wasm_shell(i64, ptr) #0
+
+; Function Attrs: nounwind
+declare i64 @build_options() #0
+
+; Function Attrs: nounwind
+define i32 @main() #0 {
+entry:
+  %alloca = alloca { i64 }, align 8
+  store { i64 } zeroinitializer, ptr %alloca, align 8
+  %si = insertvalue { ptr, ptr, ptr } undef, ptr %alloca, 0
+  %siN = insertvalue { ptr, ptr, ptr } %si, ptr @__thunk_GPA_Allocator_alloc, 1
+  %siN = insertvalue { ptr, ptr, ptr } %siN, ptr @__thunk_GPA_Allocator_dealloc, 2
+  %siN = insertvalue { { ptr, ptr, ptr }, ptr } undef, { ptr, ptr, ptr } %siN, 0
+  %siN = insertvalue { { ptr, ptr, ptr }, ptr } %siN, ptr null, 1
+  store { { ptr, ptr, ptr }, ptr } %siN, ptr @context, align 8
+  %call = call ptr @sel_registerName(ptr @str)
+  %callN = call ptr @objc_msgSend(ptr null, ptr %call)
+  %callN = call ptr @sel_registerName(ptr @str.1)
+  %callN = call ptr @objc_msgSend(ptr null, ptr %callN)
+  %callN = call ptr @sel_registerName(ptr @str.2)
+  %callN = call ptr @objc_msgSend(ptr null, ptr %callN)
+  %callN = call ptr @sel_registerName(ptr @str.3)
+  %callN = call ptr @objc_msgSend(ptr null, ptr %callN)
+  %allocaN = alloca { ptr, i64 }, align 8
+  %gep = getelementptr inbounds { ptr, i64 }, ptr %allocaN, i32 0, i32 0
+  store ptr null, ptr %gep, align 8
+  %gepN = getelementptr inbounds { ptr, i64 }, ptr %allocaN, i32 0, i32 1
+  store i64 0, ptr %gepN, align 8
+  %allocaN = alloca { ptr, i64 }, align 8
+  store { ptr, i64 } { ptr @str.4, i64 3 }, ptr %allocaN, align 8
+  %allocaN = alloca { ptr, i64 }, align 8
+  store { ptr, i64 } { ptr @str.5, i64 0 }, ptr %allocaN, align 8
+  %load = load { ptr, i64 }, ptr %allocaN, align 8
+  %loadN = load { ptr, i64 }, ptr %allocaN, align 8
+  %callN = call { ptr, i64 } @substr({ ptr, i64 } %loadN, i64 0, i64 3)
+  %callN = call { ptr, i64 } @concat({ ptr, i64 } %load, { ptr, i64 } %callN)
+  store { ptr, i64 } %callN, ptr %allocaN, align 8
+  %loadN = load { ptr, i64 }, ptr %allocaN, align 8
+  %str.ptr = extractvalue { ptr, i64 } %loadN, 0
+  %str.len = extractvalue { ptr, i64 } %loadN, 1
+  %0 = call i64 @write(i32 1, ptr %str.ptr, i64 %str.len)
+  ret i32 0
+}
+
+; Function Attrs: nounwind
+define internal ptr @__thunk_GPA_Allocator_alloc(ptr %0, i64 %1) #0 {
+entry:
+  %call = call ptr @GPA.alloc(ptr %0, i64 %1)
+  ret ptr %call
+}
+
+; Function Attrs: nounwind
+define internal void @__thunk_GPA_Allocator_dealloc(ptr %0, ptr %1) #0 {
+entry:
+  call void @GPA.dealloc(ptr %0, ptr %1)
+  ret void
+}
+
+; Function Attrs: nounwind
+declare ptr @sel_registerName(ptr) #0
+
+; Function Attrs: nounwind
+declare ptr @objc_msgSend(ptr, ptr) #0
+
+declare i64 @write(i32, ptr, i64)
diff --git a/tests/run_examples.sh b/tests/run_examples.sh
index 07ff2eb..2cb2742 100755
--- a/tests/run_examples.sh
+++ b/tests/run_examples.sh
@@ -25,6 +25,21 @@ normalize() {
     sed 's/0x[0-9a-f]\{4,\}/0xADDR/g'
 }
 
+# Normalize `sx ir` output for snapshot diffing. Strips host-specific
+# noise so a snapshot taken on one macOS machine matches another:
+#   - target triple / datalayout / module-id headers
+#   - function-attribute groups (target-cpu, frame-pointer string)
+#   - LLVM's auto-suffixed temporary names (%add1, %icmp29 → %add, %icmp)
+normalize_ir() {
+    sed -E \
+        -e '/^; ModuleID =/d' \
+        -e '/^source_filename =/d' \
+        -e '/^target datalayout =/d' \
+        -e '/^target triple =/d' \
+        -e '/^attributes #[0-9]+ = \{/d' \
+        -e 's/%([a-z]+)[0-9]+/%\1N/g'
+}
+
 for expected_file in "$EXPECTED_DIR"/*.txt; do
     name=$(basename "$expected_file" .txt)
     sx_file="$ROOT_DIR/examples/${name}.sx"
@@ -45,9 +60,27 @@ for expected_file in "$EXPECTED_DIR"/*.txt; do
         continue
     fi
 
+    # Optional IR-shape snapshot. When tests/expected/<name>.ir exists,
+    # also diff `sx ir <file>` against it. Used to lock down lowering
+    # changes that don't show up in runtime output (e.g., selector
+    # interning trims sel_registerName calls without changing what
+    # the program prints).
+    ir_file="$EXPECTED_DIR/${name}.ir"
+    actual_ir=""
+    has_ir_snapshot=false
+    if [[ -f "$ir_file" || ( $UPDATE -eq 1 && -f "$EXPECTED_DIR/${name}.ir" ) ]]; then
+        has_ir_snapshot=true
+    fi
+    if $has_ir_snapshot; then
+        actual_ir=$("$SX" ir "$sx_file" 2>&1 | normalize_ir)
+    fi
+
     if [[ $UPDATE -eq 1 ]]; then
         echo "$actual" > "$expected_file"
         echo "$actual_exit" > "$exit_file"
+        if $has_ir_snapshot; then
+            echo "$actual_ir" > "$ir_file"
+        fi
         echo "  updated $name (exit=$actual_exit)"
         continue
     fi
@@ -57,9 +90,14 @@ for expected_file in "$EXPECTED_DIR"/*.txt; do
     if [[ -f "$exit_file" ]]; then
         expected_exit=$(cat "$exit_file")
     fi
+    expected_ir=""
+    if $has_ir_snapshot; then
+        expected_ir=$(cat "$ir_file" | normalize_ir)
+    fi
 
     output_ok=true
     exit_ok=true
+    ir_ok=true
 
     if [[ "$actual" != "$expected" ]]; then
         output_ok=false
@@ -67,8 +105,11 @@ for expected_file in "$EXPECTED_DIR"/*.txt; do
     if [[ "$actual_exit" != "$expected_exit" ]]; then
         exit_ok=false
     fi
+    if $has_ir_snapshot && [[ "$actual_ir" != "$expected_ir" ]]; then
+        ir_ok=false
+    fi
 
-    if $output_ok && $exit_ok; then
+    if $output_ok && $exit_ok && $ir_ok; then
         PASS=$((PASS + 1))
         echo "ok"
     else
@@ -80,6 +121,10 @@ for expected_file in "$EXPECTED_DIR"/*.txt; do
         if ! $exit_ok; then
             echo "  exit code: expected=$expected_exit actual=$actual_exit"
         fi
+        if ! $ir_ok; then
+            echo "  IR diff:"
+            diff <(echo "$expected_ir") <(echo "$actual_ir") || true
+        fi
     fi
 done