1 files changed, 19 insertions, 0 deletions
diff --git a/yjit/src/asm/arm64/arg/sf.rs b/yjit/src/asm/arm64/arg/sf.rs
new file mode 100644
index 0000000000..c2fd33302c
--- /dev/null
+++ b/yjit/src/asm/arm64/arg/sf.rs
@@ -0,0 +1,19 @@
+/// This is commonly the top-most bit in the encoding of the instruction, and
+/// represents whether register operands should be treated as 64-bit registers
+/// or 32-bit registers.
+pub enum Sf {
+    Sf32 = 0b0,
+    Sf64 = 0b1
+}
+
+/// A convenience function so that we can convert the number of bits of an
+/// register operand directly into an Sf enum variant.
+impl From<u8> for Sf {
+    fn from(num_bits: u8) -> Self {
+        match num_bits {
+            64 => Sf::Sf64,
+            32 => Sf::Sf32,
+            _ => panic!("Invalid number of bits: {}", num_bits)
+        }
+    }
+}