switch accelerator

Author: JonasRegehr

src/platforms/herbie20.rkt

@@ -201,5 +201,5 @@
   #:spec x #:fpcore (! :precision binary64 (cast x)) #:impl identity #:cost 64)
 
 (define-operation (81-cosz0PI190 [z0 <binary64>]) <binary64>
-  #:spec (cos (* (* z0 (PI)) -1/180)) #:impl (from-rival)
+  #:spec (* 1/2 (cos (* (* z0 (PI)) -1/90))) #:impl (from-rival)
   #:fpcore (! :precision binary64 (81-cosz0PI190 z0)) #:cost 1000)