Update comment for x18 register
PiperOrigin-RevId: 315455188
diff --git a/src/f32-igemm/4x8-aarch64-neonfma-cortex-a75.S.in b/src/f32-igemm/4x8-aarch64-neonfma-cortex-a75.S.in
index 98287f3..f7c96e2 100644
--- a/src/f32-igemm/4x8-aarch64-neonfma-cortex-a75.S.in
+++ b/src/f32-igemm/4x8-aarch64-neonfma-cortex-a75.S.in
@@ -19,7 +19,7 @@
# const float* zero, [sp + 16] -> x12
# const xnn_f32_minmax_params params [sp + 24] -> x8
-# d8-d15, x19-x30 need to be preserved if used. x18 is reserved on iOS.
+# d8-d15, x19-x30 need to be preserved if used. x18 is reserved by the OS.
# A pointers
# x20 a0