Vectorisation.m: Allow Powers to accumulate during vector optimisatio…

…n and convert them to pow afterwards
ianhinder · Mar 19, 2014 · eb79ae1 · eb79ae1
1 parent 7a366eb
commit eb79ae1
Showing 1 changed file with 8 additions and 2 deletions.
diff --git a/Tools/CodeGen/Vectorisation.m b/Tools/CodeGen/Vectorisation.m
@@ -156,7 +156,7 @@
       kdiv[ToReal[0.0],x_]           -> ToReal[0],
       (* kdiv[x_,ToReal[0]]           -> ToReal[nan], *)
       (* kdiv[x_,ToReal[0.0]]         -> ToReal[nan], *)
-      kdiv[x_,ToReal[y_]]            -> kmul[x,ToReal[pow[y,-1]]],
+      kdiv[x_,ToReal[y_]]            -> kmul[x,ToReal[1/y]],
       kdiv[x_,kdiv[y_,z_]]           -> kdiv[kmul[x,z],y],
       kdiv[kdiv[x_,y_],z_]           -> kdiv[x,kmul[y,z]],
       kmul[x_,kdiv[y_,z_]]           -> kdiv[kmul[x,y],z],
@@ -169,7 +169,7 @@
       kmul[ToReal[a_],ToReal[b_]]    -> ToReal[a b],
       (* kdiv[ToReal[a_],ToReal[b_]]    -> ToReal[a/b], *)
       kmul[x:Except[_ToReal],ToReal[a_]] -> kmul[ToReal[a],x],
-      kdiv[x:Except[_ToReal],ToReal[y_]] -> kmul[ToReal[pow[y,-1]],x],
+      kdiv[x:Except[_ToReal],ToReal[y_]] -> kmul[ToReal[1/y],x],
       kmul[kmul[ToReal[a_],x_],y_]   -> kmul[ToReal[a],kmul[x,y]],
       kmul[kmul[ToReal[a_],x_],
            kmul[ToReal[b_],y_]]      -> kmul[ToReal[a*b],kmul[x,y]],
@@ -193,6 +193,12 @@
       kneg[kfabs[xx_]]           -> kfnabs[xx],
       kneg[kfnabs[xx_]]          -> kfabs[xx]};
 
+
+    (* The above optimisations introduce divisions and multiplications
+       of unvectorised quantities which Mathematica sometimes converts
+       into Power.  Hence, we need to convert these back to pow. *)
+    expr = expr //. {x:ToReal[_] :> (x /. {Power[y_, power_] :> pow[y,power]})};
+
     (* FMA (fused multiply-add) *)
     (* kmadd (x,y,z) =   xy+z
        kmsub (x,y,z) =   xy-z