From 9d81c5eba766ec143bbccf33542897d5397b8b98 Mon Sep 17 00:00:00 2001
From: Martin Diehl <mail@martin-diehl.net>
Date: Tue, 13 Sep 2022 23:29:15 +0200
Subject: [PATCH] flush to zero could be problematic

https://www.heise.de/news/Python-Compiler-Optionen-koennen-bei-Gleitkommaberechnungen-zu-Fehlern-fuehren-7257654.html
---
 cmake/Compiler-Intel.cmake     | 4 ++--
 cmake/Compiler-IntelLLVM.cmake | 4 ++--
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/cmake/Compiler-Intel.cmake b/cmake/Compiler-Intel.cmake
index 4125aa8ef..b8aa2609e 100644
--- a/cmake/Compiler-Intel.cmake
+++ b/cmake/Compiler-Intel.cmake
@@ -29,8 +29,8 @@ set (LINKER_FLAGS   "${LINKER_FLAGS} -shared-intel")
 set (COMPILE_FLAGS "${COMPILE_FLAGS} -fpp")
 # preprocessor
 
-set (COMPILE_FLAGS "${COMPILE_FLAGS} -ftz")
-# flush underflow to zero, automatically set if -O[1,2,3]
+set (COMPILE_FLAGS "${COMPILE_FLAGS} -no-ftz")
+# disable flush underflow to zero, will be set if -O[1,2,3]
 
 set (COMPILE_FLAGS "${COMPILE_FLAGS} -diag-disable")
 # disables warnings ...
diff --git a/cmake/Compiler-IntelLLVM.cmake b/cmake/Compiler-IntelLLVM.cmake
index bd0f07ee8..57a14a322 100644
--- a/cmake/Compiler-IntelLLVM.cmake
+++ b/cmake/Compiler-IntelLLVM.cmake
@@ -29,8 +29,8 @@ set (LINKER_FLAGS   "${LINKER_FLAGS} -shared-intel")
 set (COMPILE_FLAGS "${COMPILE_FLAGS} -fpp")
 # preprocessor
 
-set (COMPILE_FLAGS "${COMPILE_FLAGS} -ftz")
-# flush underflow to zero, automatically set if -O[1,2,3]
+set (COMPILE_FLAGS "${COMPILE_FLAGS} -no-ftz")
+# disable flush underflow to zero, will be set if -O[1,2,3]
 
 set (COMPILE_FLAGS "${COMPILE_FLAGS} -diag-disable")
 # disables warnings ...