-- put arg1 on the left of the rearranged expression, we'll get into a
-- loop: (x1+x2)+x3 => x1+(x2+x3) => (x2+x3)+x1 => x2+(x3+x1) ...
--
+-- Also don't do it if arg1 is PicBaseReg, so that we don't separate the
+-- PicBaseReg from the corresponding label (or label difference).
+--
cmmMachOpFold mop1 [CmmMachOp mop2 [arg1,arg2], arg3]
- | mop1 == mop2 && isAssociativeMachOp mop1 && not (isLit arg1)
+ | mop1 == mop2 && isAssociativeMachOp mop1
+ && not (isLit arg1) && not (isPicReg arg1)
= cmmMachOpFold mop1 [arg1, cmmMachOpFold mop2 [arg2,arg3]]
-- Make a RegOff if we can
cmmMachOpFold (MO_Sub _) [CmmLit (CmmLabel lbl), CmmLit (CmmInt i rep)]
= CmmLit (CmmLabelOff lbl (fromIntegral (negate (narrowU rep i))))
+
+-- 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
+
-- We can often do something with constants of 0 and 1 ...
cmmMachOpFold mop args@[x, y@(CmmLit (CmmInt 0 _))]
maybeInvertConditionalExpr (CmmMachOp op args)
| Just op' <- maybeInvertComparison op = Just (CmmMachOp op' args)
maybeInvertConditionalExpr _ = Nothing
+
+isPicReg (CmmReg (CmmGlobal PicBaseReg)) = True
+isPicReg _ = False