--- /dev/null
+! { dg-do run }
+!
+! PR fortran/34209
+!
+! Test run-time implementation of NEAREST
+!
+program test
+ implicit none
+ real(4), volatile :: r4
+ real(8), volatile :: r8
+
+! Single precision with single-precision sign
+
+ r4 = 0.0_4
+ ! 0+ > 0
+ if (nearest(r4, 1.0) &
+ <= r4) &
+ call abort()
+ ! 0++ > 0+
+ if (nearest(nearest(r4, 1.0), 1.0) &
+ <= nearest(r4, 1.0)) &
+ call abort()
+ ! 0+++ > 0++
+ if (nearest(nearest(nearest(r4, 1.0), 1.0), 1.0) &
+ <= nearest(nearest(r4, 1.0), 1.0)) &
+ call abort()
+ ! 0+- = 0
+ if (nearest(nearest(r4, 1.0), -1.0) &
+ /= r4) &
+ call abort()
+ ! 0++- = 0+
+ if (nearest(nearest(nearest(r4, 1.0), 1.0), -1.0) &
+ /= nearest(r4, 1.0)) &
+ call abort()
+ ! 0++-- = 0
+ if (nearest(nearest(nearest(nearest(r4, 1.0), 1.0), -1.0), -1.0) &
+ /= r4) &
+ call abort()
+
+ ! 0- < 0
+ if (nearest(r4, -1.0) &
+ >= r4) &
+ call abort()
+ ! 0-- < 0+
+ if (nearest(nearest(r4, -1.0), -1.0) &
+ >= nearest(r4, -1.0)) &
+ call abort()
+ ! 0--- < 0--
+ if (nearest(nearest(nearest(r4, -1.0), -1.0), -1.0) &
+ >= nearest(nearest(r4, -1.0), -1.0)) &
+ call abort()
+ ! 0-+ = 0
+ if (nearest(nearest(r4, -1.0), 1.0) &
+ /= r4) &
+ call abort()
+ ! 0--+ = 0-
+ if (nearest(nearest(nearest(r4, -1.0), -1.0), 1.0) &
+ /= nearest(r4, -1.0)) &
+ call abort()
+ ! 0--++ = 0
+ if (nearest(nearest(nearest(nearest(r4, -1.0), -1.0), 1.0), 1.0) &
+ /= r4) &
+ call abort()
+
+ r4 = 42.0_4
+ ! 42++ > 42+
+ if (nearest(nearest(r4, 1.0), 1.0) &
+ <= nearest(r4, 1.0)) &
+ call abort()
+ ! 42-- < 42-
+ if (nearest(nearest(r4, -1.0), -1.0) &
+ >= nearest(r4, -1.0)) &
+ call abort()
+ ! 42-+ = 42
+ if (nearest(nearest(r4, -1.0), 1.0) &
+ /= r4) &
+ call abort()
+ ! 42+- = 42
+ if (nearest(nearest(r4, 1.0), -1.0) &
+ /= r4) &
+ call abort()
+
+ r4 = 0.0
+ ! INF+ = INF
+ if (nearest(1.0/r4, 1.0) /= 1.0/r4) call abort()
+ ! -INF- = -INF
+ if (nearest(-1.0/r4, -1.0) /= -1.0/r4) call abort()
+ ! NAN- = NAN
+ if (.not.isnan(nearest(0.0/r4, 1.0))) call abort()
+ ! NAN+ = NAN
+ if (.not.isnan(nearest(0.0/r4, -1.0))) call abort()
+
+! Double precision with single-precision sign
+
+ r8 = 0.0_8
+ ! 0+ > 0
+ if (nearest(r8, 1.0) &
+ <= r8) &
+ call abort()
+ ! 0++ > 0+
+ if (nearest(nearest(r8, 1.0), 1.0) &
+ <= nearest(r8, 1.0)) &
+ call abort()
+ ! 0+++ > 0++
+ if (nearest(nearest(nearest(r8, 1.0), 1.0), 1.0) &
+ <= nearest(nearest(r8, 1.0), 1.0)) &
+ call abort()
+ ! 0+- = 0
+ if (nearest(nearest(r8, 1.0), -1.0) &
+ /= r8) &
+ call abort()
+ ! 0++- = 0+
+ if (nearest(nearest(nearest(r8, 1.0), 1.0), -1.0) &
+ /= nearest(r8, 1.0)) &
+ call abort()
+ ! 0++-- = 0
+ if (nearest(nearest(nearest(nearest(r8, 1.0), 1.0), -1.0), -1.0) &
+ /= r8) &
+ call abort()
+
+ ! 0- < 0
+ if (nearest(r8, -1.0) &
+ >= r8) &
+ call abort()
+ ! 0-- < 0+
+ if (nearest(nearest(r8, -1.0), -1.0) &
+ >= nearest(r8, -1.0)) &
+ call abort()
+ ! 0--- < 0--
+ if (nearest(nearest(nearest(r8, -1.0), -1.0), -1.0) &
+ >= nearest(nearest(r8, -1.0), -1.0)) &
+ call abort()
+ ! 0-+ = 0
+ if (nearest(nearest(r8, -1.0), 1.0) &
+ /= r8) &
+ call abort()
+ ! 0--+ = 0-
+ if (nearest(nearest(nearest(r8, -1.0), -1.0), 1.0) &
+ /= nearest(r8, -1.0)) &
+ call abort()
+ ! 0--++ = 0
+ if (nearest(nearest(nearest(nearest(r8, -1.0), -1.0), 1.0), 1.0) &
+ /= r8) &
+ call abort()
+
+ r8 = 42.0_8
+ ! 42++ > 42+
+ if (nearest(nearest(r8, 1.0), 1.0) &
+ <= nearest(r8, 1.0)) &
+ call abort()
+ ! 42-- < 42-
+ if (nearest(nearest(r8, -1.0), -1.0) &
+ >= nearest(r8, -1.0)) &
+ call abort()
+ ! 42-+ = 42
+ if (nearest(nearest(r8, -1.0), 1.0) &
+ /= r8) &
+ call abort()
+ ! 42+- = 42
+ if (nearest(nearest(r8, 1.0), -1.0) &
+ /= r8) &
+ call abort()
+
+ r4 = 0.0
+ ! INF+ = INF
+ if (nearest(1.0/r4, 1.0) /= 1.0/r4) call abort()
+ ! -INF- = -INF
+ if (nearest(-1.0/r4, -1.0) /= -1.0/r4) call abort()
+ ! NAN- = NAN
+ if (.not.isnan(nearest(0.0/r4, 1.0))) call abort()
+ ! NAN+ = NAN
+ if (.not.isnan(nearest(0.0/r4, -1.0))) call abort()
+
+
+! Single precision with double-precision sign
+
+ r4 = 0.0_4
+ ! 0+ > 0
+ if (nearest(r4, 1.0d0) &
+ <= r4) &
+ call abort()
+ ! 0++ > 0+
+ if (nearest(nearest(r4, 1.0d0), 1.0d0) &
+ <= nearest(r4, 1.0d0)) &
+ call abort()
+ ! 0+++ > 0++
+ if (nearest(nearest(nearest(r4, 1.0d0), 1.0d0), 1.0d0) &
+ <= nearest(nearest(r4, 1.0d0), 1.0d0)) &
+ call abort()
+ ! 0+- = 0
+ if (nearest(nearest(r4, 1.0d0), -1.0d0) &
+ /= r4) &
+ call abort()
+ ! 0++- = 0+
+ if (nearest(nearest(nearest(r4, 1.0d0), 1.0d0), -1.0d0) &
+ /= nearest(r4, 1.0d0)) &
+ call abort()
+ ! 0++-- = 0
+ if (nearest(nearest(nearest(nearest(r4, 1.0d0), 1.0d0), -1.0d0), -1.0d0) &
+ /= r4) &
+ call abort()
+
+ ! 0- < 0
+ if (nearest(r4, -1.0d0) &
+ >= r4) &
+ call abort()
+ ! 0-- < 0+
+ if (nearest(nearest(r4, -1.0d0), -1.0d0) &
+ >= nearest(r4, -1.0d0)) &
+ call abort()
+ ! 0--- < 0--
+ if (nearest(nearest(nearest(r4, -1.0d0), -1.0d0), -1.0d0) &
+ >= nearest(nearest(r4, -1.0d0), -1.0d0)) &
+ call abort()
+ ! 0-+ = 0
+ if (nearest(nearest(r4, -1.0d0), 1.0d0) &
+ /= r4) &
+ call abort()
+ ! 0--+ = 0-
+ if (nearest(nearest(nearest(r4, -1.0d0), -1.0d0), 1.0d0) &
+ /= nearest(r4, -1.0d0)) &
+ call abort()
+ ! 0--++ = 0
+ if (nearest(nearest(nearest(nearest(r4, -1.0d0), -1.0d0), 1.0d0), 1.0d0) &
+ /= r4) &
+ call abort()
+
+ r4 = 42.0_4
+ ! 42++ > 42+
+ if (nearest(nearest(r4, 1.0d0), 1.0d0) &
+ <= nearest(r4, 1.0d0)) &
+ call abort()
+ ! 42-- < 42-
+ if (nearest(nearest(r4, -1.0d0), -1.0d0) &
+ >= nearest(r4, -1.0d0)) &
+ call abort()
+ ! 42-+ = 42
+ if (nearest(nearest(r4, -1.0d0), 1.0d0) &
+ /= r4) &
+ call abort()
+ ! 42+- = 42
+ if (nearest(nearest(r4, 1.0d0), -1.0d0) &
+ /= r4) &
+ call abort()
+
+ r4 = 0.0
+ ! INF+ = INF
+ if (nearest(1.0d0/r4, 1.0d0) /= 1.0d0/r4) call abort()
+ ! -INF- = -INF
+ if (nearest(-1.0d0/r4, -1.0d0) /= -1.0d0/r4) call abort()
+ ! NAN- = NAN
+ if (.not.isnan(nearest(0.0/r4, 1.0d0))) call abort()
+ ! NAN+ = NAN
+ if (.not.isnan(nearest(0.0/r4, -1.0d0))) call abort()
+
+! Double precision with double-precision sign
+
+ r8 = 0.0_8
+ ! 0+ > 0
+ if (nearest(r8, 1.0d0) &
+ <= r8) &
+ call abort()
+ ! 0++ > 0+
+ if (nearest(nearest(r8, 1.0d0), 1.0d0) &
+ <= nearest(r8, 1.0d0)) &
+ call abort()
+ ! 0+++ > 0++
+ if (nearest(nearest(nearest(r8, 1.0d0), 1.0d0), 1.0d0) &
+ <= nearest(nearest(r8, 1.0d0), 1.0d0)) &
+ call abort()
+ ! 0+- = 0
+ if (nearest(nearest(r8, 1.0d0), -1.0d0) &
+ /= r8) &
+ call abort()
+ ! 0++- = 0+
+ if (nearest(nearest(nearest(r8, 1.0d0), 1.0d0), -1.0d0) &
+ /= nearest(r8, 1.0d0)) &
+ call abort()
+ ! 0++-- = 0
+ if (nearest(nearest(nearest(nearest(r8, 1.0d0), 1.0d0), -1.0d0), -1.0d0) &
+ /= r8) &
+ call abort()
+
+ ! 0- < 0
+ if (nearest(r8, -1.0d0) &
+ >= r8) &
+ call abort()
+ ! 0-- < 0+
+ if (nearest(nearest(r8, -1.0d0), -1.0d0) &
+ >= nearest(r8, -1.0d0)) &
+ call abort()
+ ! 0--- < 0--
+ if (nearest(nearest(nearest(r8, -1.0d0), -1.0d0), -1.0d0) &
+ >= nearest(nearest(r8, -1.0d0), -1.0d0)) &
+ call abort()
+ ! 0-+ = 0
+ if (nearest(nearest(r8, -1.0d0), 1.0d0) &
+ /= r8) &
+ call abort()
+ ! 0--+ = 0-
+ if (nearest(nearest(nearest(r8, -1.0d0), -1.0d0), 1.0d0) &
+ /= nearest(r8, -1.0d0)) &
+ call abort()
+ ! 0--++ = 0
+ if (nearest(nearest(nearest(nearest(r8, -1.0d0), -1.0d0), 1.0d0), 1.0d0) &
+ /= r8) &
+ call abort()
+
+ r8 = 42.0_8
+ ! 42++ > 42+
+ if (nearest(nearest(r8, 1.0d0), 1.0d0) &
+ <= nearest(r8, 1.0d0)) &
+ call abort()
+ ! 42-- < 42-
+ if (nearest(nearest(r8, -1.0d0), -1.0d0) &
+ >= nearest(r8, -1.0d0)) &
+ call abort()
+ ! 42-+ = 42
+ if (nearest(nearest(r8, -1.0d0), 1.0d0) &
+ /= r8) &
+ call abort()
+ ! 42+- = 42
+ if (nearest(nearest(r8, 1.0d0), -1.0d0) &
+ /= r8) &
+ call abort()
+
+ r4 = 0.0
+ ! INF+ = INF
+ if (nearest(1.0d0/r4, 1.0d0) /= 1.0d0/r4) call abort()
+ ! -INF- = -INF
+ if (nearest(-1.0d0/r4, -1.0d0) /= -1.0d0/r4) call abort()
+ ! NAN- = NAN
+ if (.not.isnan(nearest(0.0/r4, 1.0d0))) call abort()
+ ! NAN+ = NAN
+ if (.not.isnan(nearest(0.0/r4, -1.0d0))) call abort()
+
+end program test