Merge pull request #1158 from michael-chuvelev/zdrscl_csrscl_infinite_loop

Prevent csrscl/zdrscl from going to infinite loop on Infinity input

Author: langou

SRC/csrscl.f

@@ -112,13 +112,19 @@ SUBROUTINE CSRSCL( N, SA, SX, INCX )
 *     ..
 *     .. Intrinsic Functions ..
       INTRINSIC          ABS
+      INTRINSIC          HUGE
 *     ..
 *     .. Executable Statements ..
 *
 *     Quick return if possible
 *
       IF( N.LE.0 )
      $   RETURN
+*
+      IF( SA.GT.HUGE(SA) .OR. SA.LT.-HUGE(SA) ) THEN
+         CALL CSSCAL( N, SA, SX, INCX )
+         RETURN
+      END IF
 *
 *     Get machine parameters
 *

SRC/zdrscl.f

@@ -112,13 +112,19 @@ SUBROUTINE ZDRSCL( N, SA, SX, INCX )
 *     ..
 *     .. Intrinsic Functions ..
       INTRINSIC          ABS
+      INTRINSIC          HUGE
 *     ..
 *     .. Executable Statements ..
 *
 *     Quick return if possible
 *
       IF( N.LE.0 )
      $   RETURN
+*
+      IF( SA.GT.HUGE(SA) .OR. SA.LT.-HUGE(SA) ) THEN
+         CALL ZDSCAL( N, SA, SX, INCX )
+         RETURN
+      END IF
 *
 *     Get machine parameters
 *