update the parameters

chrwarm · Feb 14, 2021 · e29a36b · e29a36b
1 parent b19715e
commit e29a36b
Showing 1 changed file with 85 additions and 63 deletions.
diff --git a/SRC/iparmq.f b/SRC/iparmq.f
@@ -246,7 +246,7 @@ INTEGER FUNCTION IPARMQ( ISPEC, NAME, OPTS, N, ILO, IHI, LWORK )
      $                   ISHFTS = 15, IACC22 = 16, ICOST = 17 )
       INTEGER            NMIN, K22MIN, KACMIN, NIBBLE, KNWSWP, RCOST
       PARAMETER          ( NMIN = 75, K22MIN = 14, KACMIN = 14,
-     $                   NIBBLE = 14, KNWSWP = 500, RCOST = 10 )
+     $                   NIBBLE = 8, KNWSWP = 500, RCOST = 10 )
       REAL               TWO
       PARAMETER          ( TWO = 2.0 )
 *     ..
@@ -262,68 +262,6 @@ INTEGER FUNCTION IPARMQ( ISPEC, NAME, OPTS, N, ILO, IHI, LWORK )
       IF( ( ISPEC.EQ.ISHFTS ) .OR. ( ISPEC.EQ.INWIN ) .OR.
      $    ( ISPEC.EQ.IACC22 ) ) THEN
 *
-*        ==== Set the number simultaneous shifts ====
-*
-         NH = IHI - ILO + 1
-         NS = 2
-         IF( NH.GE.30 )
-     $      NS = 4
-         IF( NH.GE.60 )
-     $      NS = 10
-         IF( NH.GE.150 )
-     $      NS = MAX( 10, NH / NINT( LOG( REAL( NH ) ) / LOG( TWO ) ) )
-         IF( NH.GE.590 )
-     $      NS = 64
-         IF( NH.GE.3000 )
-     $      NS = 128
-         IF( NH.GE.6000 )
-     $      NS = 256
-         NS = MAX( 2, NS-MOD( NS, 2 ) )
-      END IF
-*
-      IF( ISPEC.EQ.INMIN ) THEN
-*
-*
-*        ===== Matrices of order smaller than NMIN get sent
-*        .     to xLAHQR, the classic double shift algorithm.
-*        .     This must be at least 11. ====
-*
-         IPARMQ = NMIN
-*
-      ELSE IF( ISPEC.EQ.INIBL ) THEN
-*
-*        ==== INIBL: skip a multi-shift qr iteration and
-*        .    whenever aggressive early deflation finds
-*        .    at least (NIBBLE*(window size)/100) deflations. ====
-*
-         IPARMQ = NIBBLE
-*
-      ELSE IF( ISPEC.EQ.ISHFTS ) THEN
-*
-*        ==== NSHFTS: The number of simultaneous shifts =====
-*
-         IPARMQ = NS
-*
-      ELSE IF( ISPEC.EQ.INWIN ) THEN
-*
-*        ==== NW: deflation window size.  ====
-*
-         IF( NH.LE.KNWSWP ) THEN
-            IPARMQ = NS
-         ELSE
-            IPARMQ = 3*NS / 2
-         END IF
-*
-      ELSE IF( ISPEC.EQ.IACC22 ) THEN
-*
-*        ==== IACC22: Whether to accumulate reflections
-*        .     before updating the far-from-diagonal elements
-*        .     and whether to use 2-by-2 block structure while
-*        .     doing it.  A small amount of work could be saved
-*        .     by making this choice dependent also upon the
-*        .     NH=IHI-ILO+1.
-*
-*
 *        Convert NAME to upper case if the first character is lower case.
 *
          IPARMQ = 0
@@ -373,6 +311,90 @@ INTEGER FUNCTION IPARMQ( ISPEC, NAME, OPTS, N, ILO, IHI, LWORK )
                END DO
             END IF
          END IF
+*
+*        ==== Set the number simultaneous shifts ====
+*
+         NH = IHI - ILO + 1
+         IF ( SUBNAM( 2:6 ).EQ.'LAQZ0' ) THEN
+            NS = 2
+            IF( NH.GE.30 )
+     $         NS = 4
+            IF( NH.GE.150 )
+     $         NS = 32
+            IF( NH.GE.590 )
+     $         NS = 40
+            IF( NH.GE.3000 )
+     $         NS = 64
+         ELSE
+            NS = 2
+            IF( NH.GE.30 )
+     $         NS = 4
+            IF( NH.GE.60 )
+     $         NS = 10
+            IF( NH.GE.150 )
+     $         NS = MAX( 10, NH /
+     $         NINT( LOG( REAL( NH ) ) / LOG( TWO ) ) )
+            IF( NH.GE.590 )
+     $         NS = 64
+            IF( NH.GE.3000 )
+     $         NS = 128
+            IF( NH.GE.6000 )
+     $         NS = 256
+         END IF
+         NS = MAX( 2, NS-MOD( NS, 2 ) )
+      END IF
+*
+      IF( ISPEC.EQ.INMIN ) THEN
+*
+*
+*        ===== Matrices of order smaller than NMIN get sent
+*        .     to xLAHQR, the classic double shift algorithm.
+*        .     This must be at least 11. ====
+*
+         IPARMQ = NMIN
+*
+      ELSE IF( ISPEC.EQ.INIBL ) THEN
+*
+*        ==== INIBL: skip a multi-shift qr iteration and
+*        .    whenever aggressive early deflation finds
+*        .    at least (NIBBLE*(window size)/100) deflations. ====
+*
+         IPARMQ = NIBBLE
+*
+      ELSE IF( ISPEC.EQ.ISHFTS ) THEN
+*
+*        ==== NSHFTS: The number of simultaneous shifts =====
+*
+         IPARMQ = NS
+*
+      ELSE IF( ISPEC.EQ.INWIN ) THEN
+*
+*        ==== NW: deflation window size.  ====
+*
+         IF ( SUBNAM( 2:6 ).EQ.'LAQZ0' ) THEN
+            IPARMQ = 4
+            IF( NH.GE.30 )
+     $         IPARMQ = 8
+            IF( NH.GE.150 )
+     $         IPARMQ = 48
+            IF( NH.GE.590 )
+     $         IPARMQ = 96
+         ELSE
+            IF( NH.LE.KNWSWP ) THEN
+               IPARMQ = NS
+            ELSE
+               IPARMQ = 3*NS / 2
+            END IF
+         END IF
+*
+      ELSE IF( ISPEC.EQ.IACC22 ) THEN
+*
+*        ==== IACC22: Whether to accumulate reflections
+*        .     before updating the far-from-diagonal elements
+*        .     and whether to use 2-by-2 block structure while
+*        .     doing it.  A small amount of work could be saved
+*        .     by making this choice dependent also upon the
+*        .     NH=IHI-ILO+1.
 *
          IF( SUBNAM( 2:6 ).EQ.'GGHRD' .OR.
      $       SUBNAM( 2:6 ).EQ.'GGHD3' ) THEN