+
+-- Comparison of literal with narrowed/widened operand: perform
+-- the comparison at a different width, as long as the literal is
+-- within range.
+
+#if i386_TARGET_ARCH || x86_64_TARGET_ARCH
+-- powerPC NCG has a TODO for I8/I16 comparisons, so don't try
+
+cmmMachOpFold cmp [CmmMachOp conv [x], CmmLit (CmmInt i _)]
+ | Just (rep, narrow) <- maybe_conversion conv,
+ Just narrow_cmp <- maybe_comparison cmp rep,
+ let narrow_i = narrow rep i,
+ narrow_i == i
+ = cmmMachOpFold narrow_cmp [x, CmmLit (CmmInt narrow_i rep)]
+ where
+ maybe_conversion (MO_U_Conv from _) = Just (from, narrowU)
+ maybe_conversion (MO_S_Conv from _) = Just (from, narrowS)
+ maybe_conversion _ = Nothing
+
+ maybe_comparison (MO_U_Gt _) rep = Just (MO_U_Gt rep)
+ maybe_comparison (MO_U_Ge _) rep = Just (MO_U_Ge rep)
+ maybe_comparison (MO_U_Lt _) rep = Just (MO_U_Lt rep)
+ maybe_comparison (MO_U_Le _) rep = Just (MO_U_Le rep)
+ maybe_comparison (MO_S_Gt _) rep = Just (MO_S_Gt rep)
+ maybe_comparison (MO_S_Ge _) rep = Just (MO_S_Ge rep)
+ maybe_comparison (MO_S_Lt _) rep = Just (MO_S_Lt rep)
+ maybe_comparison (MO_S_Le _) rep = Just (MO_S_Le rep)
+ maybe_comparison (MO_Eq _) rep = Just (MO_Eq rep)
+ maybe_comparison _ _ = Nothing
+
+#endif
+