From 271bf8f3dc7de24dc98601e6c38239a57f456b64 Mon Sep 17 00:00:00 2001
From: Kyungmin Lee <kyungmin.lee.42@gmail.com>
Date: Sun, 3 May 2026 22:47:50 -0700
Subject: [PATCH] fix post-loop SIDE/TRANS guard in p?ormrz / p?unmrz

In PCUNMRZ/PDORMRZ/PSORMRZ/PZUNMRZ, the post-loop guard that controls
the leading-partial-block PORMR3/PUNMR3 fix-up was a byte-for-byte copy
of the pre-loop guard. The same condition gated both blocks, so the
post-loop fired together with the pre-loop in the (LEFT,!NOTRAN) /
(RIGHT,NOTRAN) directions (over-applying K-1 reflectors to an already
transformed C) and never fired in the complementary (LEFT,NOTRAN) /
(RIGHT,!NOTRAN) directions (silently skipping the leading partial block
of reflectors). All four SIDE/TRANS combinations produced numerically
incorrect results.

Replace the post-loop guard with the complement of the pre-loop guard,
matching the analogous structure in p?ormrq.f.
---
 SRC/pcunmrz.f | 4 ++--
 SRC/pdormrz.f | 4 ++--
 SRC/psormrz.f | 4 ++--
 SRC/pzunmrz.f | 4 ++--
 4 files changed, 8 insertions(+), 8 deletions(-)

diff --git a/SRC/pcunmrz.f b/SRC/pcunmrz.f
index e5ccc3d2..a162162e 100644
--- a/SRC/pcunmrz.f
+++ b/SRC/pcunmrz.f
@@ -455,8 +455,8 @@ SUBROUTINE PCUNMRZ( SIDE, TRANS, M, N, K, L, A, IA, JA, DESCA,
      $                 WORK( IPW ) )
    10 CONTINUE
 *
-      IF( ( LEFT .AND. .NOT.NOTRAN ) .OR.
-     $    ( .NOT.LEFT .AND. NOTRAN ) ) THEN
+      IF( ( LEFT .AND. NOTRAN ) .OR.
+     $    ( .NOT.LEFT .AND. .NOT.NOTRAN ) ) THEN
          IB = I2 - IA
          IF( LEFT ) THEN
             MI = M
diff --git a/SRC/pdormrz.f b/SRC/pdormrz.f
index f2d48dc2..946aa341 100644
--- a/SRC/pdormrz.f
+++ b/SRC/pdormrz.f
@@ -455,8 +455,8 @@ SUBROUTINE PDORMRZ( SIDE, TRANS, M, N, K, L, A, IA, JA, DESCA,
      $                 WORK( IPW ) )
    10 CONTINUE
 *
-      IF( ( LEFT .AND. .NOT.NOTRAN ) .OR.
-     $    ( .NOT.LEFT .AND. NOTRAN ) ) THEN
+      IF( ( LEFT .AND. NOTRAN ) .OR.
+     $    ( .NOT.LEFT .AND. .NOT.NOTRAN ) ) THEN
          IB = I2 - IA
          IF( LEFT ) THEN
             MI = M
diff --git a/SRC/psormrz.f b/SRC/psormrz.f
index 0947b594..82a21ea9 100644
--- a/SRC/psormrz.f
+++ b/SRC/psormrz.f
@@ -455,8 +455,8 @@ SUBROUTINE PSORMRZ( SIDE, TRANS, M, N, K, L, A, IA, JA, DESCA,
      $                 WORK( IPW ) )
    10 CONTINUE
 *
-      IF( ( LEFT .AND. .NOT.NOTRAN ) .OR.
-     $    ( .NOT.LEFT .AND. NOTRAN ) ) THEN
+      IF( ( LEFT .AND. NOTRAN ) .OR.
+     $    ( .NOT.LEFT .AND. .NOT.NOTRAN ) ) THEN
          IB = I2 - IA
          IF( LEFT ) THEN
             MI = M
diff --git a/SRC/pzunmrz.f b/SRC/pzunmrz.f
index d5d95d5e..27916970 100644
--- a/SRC/pzunmrz.f
+++ b/SRC/pzunmrz.f
@@ -456,8 +456,8 @@ SUBROUTINE PZUNMRZ( SIDE, TRANS, M, N, K, L, A, IA, JA, DESCA,
      $                 WORK( IPW ) )
    10 CONTINUE
 *
-      IF( ( LEFT .AND. .NOT.NOTRAN ) .OR.
-     $    ( .NOT.LEFT .AND. NOTRAN ) ) THEN
+      IF( ( LEFT .AND. NOTRAN ) .OR.
+     $    ( .NOT.LEFT .AND. .NOT.NOTRAN ) ) THEN
          IB = I2 - IA
          IF( LEFT ) THEN
             MI = M