Use mpfr_sqr

Author: obround

mpfr.rkt

@@ -138,13 +138,12 @@
 (define mpfr-atan2!
   (get-mpfr-fun 'mpfr_atan2 (_fun _mpfr-pointer _mpfr-pointer _mpfr-pointer _rnd_t -> _int)))
 
+(define mpfr-pow2! (get-mpfr-fun 'mpfr_sqr (_fun _mpfr-pointer _mpfr-pointer _rnd_t -> _int)))
+
 (define mpfr-set! (get-mpfr-fun 'mpfr_set (_fun _mpfr-pointer _mpfr-pointer _rnd_t -> _void)))
 
 (define mpfr-set-prec! set-mpfr-prec!)
 
-(define (mpfr-pow2! out a rnd)
-  (mpfr-mul! out a a rnd))
-
 (define (bfremainder x mod)
   (define out (bf 0))
   (mpfr-remainder! out x mod (bf-rounding-mode))