X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=compiler%2FnativeGen%2FRegAllocLinear.hs;h=14d7eba5a4e77792e03016c5880b5abf36ae4075;hb=30c122df62ec75f9ed7f392f24c2925675bf1d06;hp=debda83aa16c18b09773cf731bafaf3f663464e1;hpb=982c1f494de8a691294a95aee108e765c3f592a0;p=ghc-hetmet.git

diff --git a/compiler/nativeGen/RegAllocLinear.hs b/compiler/nativeGen/RegAllocLinear.hs
index debda83..14d7eba 100644
--- a/compiler/nativeGen/RegAllocLinear.hs
+++ b/compiler/nativeGen/RegAllocLinear.hs
@@ -101,6 +101,7 @@ import UniqFM
 import UniqSupply
 import Outputable
 import State
+import FastString
 
 import Data.Maybe
 import Data.List
@@ -155,8 +156,9 @@ getFreeRegs :: RegClass -> FreeRegs -> [RegNo]	-- lazilly
 getFreeRegs cls (FreeRegs g f)
     | RcDouble <- cls = go f (0x80000000) 63
     | RcInteger <- cls = go g (0x80000000) 31
+    | otherwise = pprPanic "RegAllocLinear.getFreeRegs: Bad cls" (ppr cls)
     where
-        go x 0 i = []
+        go _ 0 _ = []
         go x m i | x .&. m /= 0 = i : (go x (m `shiftR` 1) $! i-1)
                  | otherwise    = go x (m `shiftR` 1) $! i-1
 
@@ -221,7 +223,8 @@ emptyStackMap = StackMap [0..maxSpillSlots] emptyUFM
 
 getStackSlotFor :: StackMap -> Unique -> (StackMap,Int)
 getStackSlotFor (StackMap [] _) _
-	= panic "RegAllocLinear.getStackSlotFor: out of stack slots"
+	= panic "RegAllocLinear.getStackSlotFor: out of stack slots, try -fregs-graph"
+        -- This happens with darcs' SHA1.hs, see #1993
 
 getStackSlotFor fs@(StackMap (freeSlot:stack') reserved) reg =
     case lookupUFM reserved reg of
@@ -1106,12 +1109,9 @@ pprStats code statss
 -- -----------------------------------------------------------------------------
 -- Utils
 
-#ifdef DEBUG
-my_fromJust s p Nothing  = pprPanic ("fromJust: " ++ s) p
+my_fromJust :: String -> SDoc -> Maybe a -> a
 my_fromJust _ _ (Just x) = x
-#else
-my_fromJust _ _ = fromJust
-#endif
+my_fromJust s p Nothing = pprPanic ("fromJust: " ++ s) p
 
 lookItUp :: Uniquable b => String -> UniqFM a -> b -> a
 lookItUp str fm x = my_fromJust str (ppr (getUnique x)) (lookupUFM fm x)