Fix endpoint max and min bugs

Author: obround

mpfr.rkt

@@ -124,6 +124,12 @@
 
 (define mpfr-trunc! (get-mpfr-fun 'mpfr_trunc (_fun _mpfr-pointer _mpfr-pointer -> _int)))
 
+(define mpfr-min!
+  (get-mpfr-fun 'mpfr_min (_fun _mpfr-pointer _mpfr-pointer _mpfr-pointer _rnd_t -> _int)))
+
+(define mpfr-max!
+  (get-mpfr-fun 'mpfr_max (_fun _mpfr-pointer _mpfr-pointer _mpfr-pointer _rnd_t -> _int)))
+
 (define mpfr-cosh! (get-mpfr-fun 'mpfr_cosh (_fun _mpfr-pointer _mpfr-pointer _rnd_t -> _int)))
 
 (define mpfr-init2! (get-mpfr-fun 'mpfr_init2 (_fun _mpfr-pointer _prec_t -> _void)))
@@ -333,6 +339,8 @@
          mpfr-ceil!
          mpfr-floor!
          mpfr-trunc!
+         mpfr-min!
+         mpfr-max!
          mpfr-log!
          mpfr-set-prec!
          mpfr-set!

ops/core.rkt

@@ -194,21 +194,19 @@
 (define (endpoint-min2 e1 e2 rnd)
   (match-define (endpoint x x!) e1)
   (match-define (endpoint y y!) e2)
-  (define src (endpoint-val (if (bflte? x y) e1 e2)))
   (define out
     (parameterize ([bf-precision (bf-precision)])
       (bf 0)))
-  (mpfr-set! out src rnd)
+  (mpfr-min! out x y rnd)
   (endpoint out (or (and (bf=? out x) x!) (and (bf=? out y) y!))))
 
 (define (endpoint-max2 e1 e2 rnd)
   (match-define (endpoint x x!) e1)
   (match-define (endpoint y y!) e2)
-  (define src (endpoint-val (if (bfgte? x y) e1 e2)))
   (define out
     (parameterize ([bf-precision (bf-precision)])
       (bf 0)))
-  (mpfr-set! out src rnd)
+  (mpfr-max! out x y rnd)
   (endpoint out (or (and (bf=? out x) x!) (and (bf=? out y) y!))))
 
 (define (ival-union x y)