X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=compiler%2Fcmm%2FCmmOpt.hs;h=9a5121541a824a677c9863b5083b4ff66181a72a;hb=d5c0de4518422315f0179121b222b0e3c7d82d86;hp=f279b84b6f1c98b98f1b14446ce9355ca7a13f63;hpb=49c98d143c382a1341e1046f5ca00819a25691ba;p=ghc-hetmet.git

diff --git a/compiler/cmm/CmmOpt.hs b/compiler/cmm/CmmOpt.hs
index f279b84..9a51215 100644
--- a/compiler/cmm/CmmOpt.hs
+++ b/compiler/cmm/CmmOpt.hs
@@ -19,6 +19,7 @@ import CmmUtils
 import CLabel
 import MachOp
 import SMRep
+import StaticFlags
 
 import UniqFM
 import Unique
@@ -311,8 +312,12 @@ cmmMachOpFold op [x@(CmmLit _), y]
 -- 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
@@ -334,6 +339,38 @@ cmmMachOpFold (MO_Add _) [CmmLit (CmmInt i rep), CmmLit (CmmLabel lbl)]
 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 _))]
@@ -526,3 +563,6 @@ maybeInvertConditionalExpr :: CmmExpr -> Maybe CmmExpr
 maybeInvertConditionalExpr (CmmMachOp op args) 
   | Just op' <- maybeInvertComparison op = Just (CmmMachOp op' args)
 maybeInvertConditionalExpr _ = Nothing
+
+isPicReg (CmmReg (CmmGlobal PicBaseReg)) = True
+isPicReg _ = False