remove suppression of -ffast-math when building with ICC

The Intel C Compiler does not support the `-ffast-math` command line option, so
this logic was suppressing it. But it is coming before anything in the Graphviz
build system itself that would add `-ffast-math`. So it is actually suppressing
a `-ffast-math` addition coming from the user’s environment. If you are a user
compiling Graphviz with ICC, I have a very simple alternative for you: do not
pass `-ffast-math` explicitly.

Gitlab: #1412, #2296

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 8747caf57f072f64d1c85b6b69e949dc86919dfc..2a8265b46f4e0fcb7a732f19ac0ef8696283687d 100644 (file)
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -14,6 +14,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
   struct.
 - When using the CMake build system, the minimum requirement has been increased
   from CMake 3.9 to CMake 3.10.2.
+- When compiling Graphviz with the Intel C Compiler, the Autotools build system
+  no longer suppresses `-ffast-math`. Users relying on this are encouraged to
+  investigate what in their build environment is appending a flag their C
+  compiler does not support.
 
 ### Removed
 

diff --git a/configure.ac b/configure.ac
index 90212ad9f5b62c2039d3f36e3e11b52c058dc1c1..49dd28cefd3a7daf628b736e378bbc422a77b22a 100644 (file)
--- a/configure.ac
+++ b/configure.ac
@@ -382,8 +382,6 @@ else
            CFLAGS="${CFLAGS} -wd269"
            # icc doesn't like -pipe
            CFLAGS=`echo ${CFLAGS} | sed 's/ -pipe//'`
-           # icc doesn't like -ffast-math
-           CFLAGS=`echo ${CFLAGS} | sed 's/ -ffast-math//'`
            ;;
        * )
            case "${build}" in