Import GotoBLAS2 1.13 BSD version codes.

reference/srotgf.f

@@ -0,0 +1,27 @@
+      subroutine srotgf(sa,sb,c,s)
+c
+c     construct givens plane rotation.
+c     jack dongarra, linpack, 3/11/78.
+c
+      real sa,sb,c,s,roe,scale,r,z
+c
+      roe = sb
+      if( abs(sa) .gt. abs(sb) ) roe = sa
+      scale = abs(sa) + abs(sb)
+      if( scale .ne. 0.0 ) go to 10
+         c = 1.0
+         s = 0.0
+         r = 0.0
+         z = 0.0
+         go to 20
+   10 r = scale*sqrt((sa/scale)**2 + (sb/scale)**2)
+      r = sign(1.0,roe)*r
+      c = sa/r
+      s = sb/r
+      z = 1.0
+      if( abs(sa) .gt. abs(sb) ) z = s
+      if( abs(sb) .ge. abs(sa) .and. c .ne. 0.0 ) z = 1.0/c
+   20 sa = r
+      sb = z
+      return
+      end