From 21d3c574f4c94ea499843d42b0c1622822706d6a Mon Sep 17 00:00:00 2001
From: aboisnea <antonin.boisneault@inria.fr>
Date: Thu, 18 Dec 2025 14:37:04 +0100
Subject: [PATCH] Fix: wrong boolean tests in triangular_matrix_matrix_solve

---
 CHANGELOG.md                                  | 1 +
 include/htool/matrix/linalg/factorization.hpp | 4 ++--
 2 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 1d0ef60b..bf63daa3 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -32,6 +32,7 @@ All notable changes to this project will be documented in this file.
 
 ### Fixed
 
+- Fix wrong boolean tests in triangular_matrix_matrix_solve, PR #75 from @ABoisneault
 - Avoid empty-sized gemv, PR #64 from @prj-
 
 ## [1.0.0] - 2027-09-24
diff --git a/include/htool/matrix/linalg/factorization.hpp b/include/htool/matrix/linalg/factorization.hpp
index 3370b52e..09b34833 100644
--- a/include/htool/matrix/linalg/factorization.hpp
+++ b/include/htool/matrix/linalg/factorization.hpp
@@ -32,7 +32,7 @@ void triangular_matrix_matrix_solve(char side, char UPLO, char transa, char diag
     if (ipiv.size() > 0) {
         int index = 0;
         while (index < ipiv.size() and not is_pivoted) {
-            is_pivoted = (ipiv[index] == index + 1);
+            is_pivoted = !(ipiv[index] == index + 1);
             index += 1;
         }
     }
@@ -53,7 +53,7 @@ void triangular_matrix_matrix_solve(char side, char UPLO, char transa, char diag
     }
 
     Blas<T>::trsm(&side, &UPLO, &transa, &diag, &m, &n, &alpha, A.data(), &lda, B.data(), &ldb);
-    // std::cout <<"TEST "<<ipiv<<" "<<is_pivoted<<"\n";
+
     if (is_pivoted and UPLO == 'L') {
         if (side == 'L' and transa != 'N') {
             int K1   = 1;