commit 151f6d0: [Minor] Fix fast math usage

[Vsevolod Stakhov]

Author: Vsevolod Stakhov
Date: 2019-12-20 14:07:54 +0000
URL: https://github.com/rspamd/rspamd/commit/151f6d05f04cc97cc9031c2bdd281303f9f0173a

[Minor] Fix fast math usage

---
 cmake/Toolset.cmake | 16 +++++++++++-----
 1 file changed, 11 insertions(+), 5 deletions(-)

diff --git a/cmake/Toolset.cmake b/cmake/Toolset.cmake
index f96fc39f9..dc4b17bf5 100644
--- a/cmake/Toolset.cmake
+++ b/cmake/Toolset.cmake
@@ -1,15 +1,21 @@
 option (ENABLE_FAST_MATH     "Build rspamd with fast math compiler flag [default: ON]" ON)
 
-SET (COMPILER_FAST_MATH "")
-if (ENABLE_FAST_MATH MATCHES "ON")
-    SET (COMPILER_FAST_MATH "-ffast-math")
-endif ()
-
 if(CMAKE_C_COMPILER_ID STREQUAL "GNU")
     SET (COMPILER_GCC 1)
 elseif(CMAKE_C_COMPILER_ID MATCHES "Clang|AppleClang")
     SET (COMPILER_CLANG 1)
 endif()
+
+SET (COMPILER_FAST_MATH "")
+if (ENABLE_FAST_MATH MATCHES "ON")
+    # We need to keep nans and infinities, so cannot keep all fast math there
+    IF (COMPILER_CLANG)
+        SET (COMPILER_FAST_MATH "-fassociative-math -freciprocal-math -fno-signed-zeros -ffp-contract=fast")
+    ELSE()
+        SET (COMPILER_FAST_MATH "-funsafe-math-optimizations -fno-math-errno")
+    ENDIF ()
+endif ()
+
 if (CMAKE_GENERATOR STREQUAL "Ninja")
     # Turn on colored output. https://github.com/ninja-build/ninja/wiki/FAQ
     set (CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fdiagnostics-color=always")