[commit: vector] simd: Push test of vector size into un-Boxing. (11b5182)

[Geoffrey Mainland]

Repository : http://darcs.haskell.org/ghc.git/

On branch  : simd

http://hackage.haskell.org/trac/ghc/changeset/11b51820681cce94c5bc733c67a851d1878c97b7

>---------------------------------------------------------------

commit 11b51820681cce94c5bc733c67a851d1878c97b7
Author: Geoffrey Mainland <mainland at apeiron.net>
Date:   Wed Jul 10 19:13:45 2013 +0100

    Push test of vector size into un-Boxing.
    
    Constructor specialization wasn't occurring prior to this change.

>---------------------------------------------------------------

 Data/Vector/Fusion/Bundle/Monadic.hs |   33 +++++++++------------------------
 1 file changed, 9 insertions(+), 24 deletions(-)

diff --git a/Data/Vector/Fusion/Bundle/Monadic.hs b/Data/Vector/Fusion/Bundle/Monadic.hs
index 922cbc2..23e47d9 100644
--- a/Data/Vector/Fusion/Bundle/Monadic.hs
+++ b/Data/Vector/Fusion/Bundle/Monadic.hs
@@ -1396,23 +1396,12 @@ mzipWithHackM p q v1 v2 =
 
     {-# INLINE leap #-}
     leap i | i+4*m > n           = return Done
-           | n < pREFETCH_THRESH = let Box !x1  = basicUnsafeIndexAsMultiM v1 i
-                                       Box !x2  = basicUnsafeIndexAsMultiM v1 (i+m)
-                                       Box !x3  = basicUnsafeIndexAsMultiM v1 (i+2*m)
-                                       Box !x4  = basicUnsafeIndexAsMultiM v1 (i+3*m)
-                                       Box !y1  = basicUnsafeIndexAsMultiM v2 i
-                                       Box !y2  = basicUnsafeIndexAsMultiM v2 (i+m)
-                                       Box !y3  = basicUnsafeIndexAsMultiM v2 (i+2*m)
-                                       Box !y4  = basicUnsafeIndexAsMultiM v2 (i+3*m)
-                                   in
-                                     do { z1 <- q x1 y1
-                                        ; z2 <- q x2 y2
-                                        ; z3 <- q x3 y3
-                                        ; z4 <- q x4 y4
-                                        ; return $ Yield (Leap z1 z2 z3 z4) (i+4*m)
-                                        }
-           | otherwise           = let Box !v1' = basicUnsafePrefetchDataM v1  i mAGIC_PREFETCH_CONSTANT
-                                       Box !v2' = basicUnsafePrefetchDataM v2  i mAGIC_PREFETCH_CONSTANT
+           | otherwise           = let Box !v1' = if n < pREFETCH_THRESH
+                                                  then Box v1
+                                                  else basicUnsafePrefetchDataM v1 i mAGIC_PREFETCH_CONSTANT
+                                       Box !v2' = if n < pREFETCH_THRESH
+                                                  then Box v2
+                                                  else basicUnsafePrefetchDataM v2 i mAGIC_PREFETCH_CONSTANT
                                        Box !x1  = basicUnsafeIndexAsMultiM v1' i
                                        Box !x2  = basicUnsafeIndexAsMultiM v1' (i+m)
                                        Box !x3  = basicUnsafeIndexAsMultiM v1' (i+2*m)
@@ -1580,13 +1569,9 @@ fromPackedVector v = v `seq` n `seq` Bundle (Stream step 0)
 
     {-# INLINE leap #-}
     leap i | i+4*m > n           = return Done
-           | n < pREFETCH_THRESH = let Box !x1  = basicUnsafeIndexAsMultiM v i
-                                       Box !x2  = basicUnsafeIndexAsMultiM v (i+m)
-                                       Box !x3  = basicUnsafeIndexAsMultiM v (i+2*m)
-                                       Box !x4  = basicUnsafeIndexAsMultiM v (i+3*m)
-                                   in
-                                     return $ Yield (Leap x1 x2 x3 x4) (i+4*m)
-           | otherwise           = let Box !v'  = basicUnsafePrefetchDataM v  i mAGIC_PREFETCH_CONSTANT
+           | otherwise           = let Box !v'  = if n < pREFETCH_THRESH
+                                                  then Box v
+                                                  else basicUnsafePrefetchDataM v i mAGIC_PREFETCH_CONSTANT
                                        Box !x1  = basicUnsafeIndexAsMultiM v' i
                                        Box !x2  = basicUnsafeIndexAsMultiM v' (i+m)
                                        Box !x3  = basicUnsafeIndexAsMultiM v' (i+2*m)