Merge pull request #463 from thijssteel/fix/XGGGLM-initialization

initialize x and y to zero in case N = 0 in xggglm

Author: langou

SRC/cggglm.f

@@ -271,8 +271,15 @@ SUBROUTINE CGGGLM( N, M, P, A, LDA, B, LDB, D, X, Y, WORK, LWORK,
 *
 *     Quick return if possible
 *
-      IF( N.EQ.0 )
-     $   RETURN
+      IF( N.EQ.0 ) THEN
+         DO I = 1, M
+            X(I) = CZERO
+         END DO
+         DO I = 1, P
+            Y(I) = CZERO
+         END DO
+         RETURN
+      END IF
 *
 *     Compute the GQR factorization of matrices A and B:
 *

SRC/dggglm.f

@@ -270,8 +270,15 @@ SUBROUTINE DGGGLM( N, M, P, A, LDA, B, LDB, D, X, Y, WORK, LWORK,
 *
 *     Quick return if possible
 *
-      IF( N.EQ.0 )
-     $   RETURN
+      IF( N.EQ.0 ) THEN
+         DO I = 1, M
+            X(I) = ZERO
+         END DO
+         DO I = 1, P
+            Y(I) = ZERO
+         END DO
+         RETURN
+      END IF
 *
 *     Compute the GQR factorization of matrices A and B:
 *

SRC/sggglm.f

@@ -270,8 +270,15 @@ SUBROUTINE SGGGLM( N, M, P, A, LDA, B, LDB, D, X, Y, WORK, LWORK,
 *
 *     Quick return if possible
 *
-      IF( N.EQ.0 )
-     $   RETURN
+      IF( N.EQ.0 ) THEN
+         DO I = 1, M
+            X(I) = ZERO
+         END DO
+         DO I = 1, P
+            Y(I) = ZERO
+         END DO
+         RETURN
+      END IF
 *
 *     Compute the GQR factorization of matrices A and B:
 *

SRC/zggglm.f

@@ -271,8 +271,15 @@ SUBROUTINE ZGGGLM( N, M, P, A, LDA, B, LDB, D, X, Y, WORK, LWORK,
 *
 *     Quick return if possible
 *
-      IF( N.EQ.0 )
-     $   RETURN
+      IF( N.EQ.0 ) THEN
+         DO I = 1, M
+            X(I) = CZERO
+         END DO
+         DO I = 1, P
+            Y(I) = CZERO
+         END DO
+         RETURN
+      END IF
 *
 *     Compute the GQR factorization of matrices A and B:
 *