Fix #423: change -ffast-math to -mtune=native

Update the default gcc optimization configuration to -mtune=native instead of -ffast-math. The latter causes various floating-point exceptions on newer cpus and compilers. Note that if everything is compiled and run on identical cpu, then the more aggressive -march=native option should be considered during configuration.
nrc-cnrc · Apr 19, 2018 · 2641e83 · 2641e83
1 parent 98126e4
commit 2641e83
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Showing 3 changed files with 12 additions and 12 deletions.
diff --git a/HEN_HOUSE/gui/egs_configure/egs_tools.cpp b/HEN_HOUSE/gui/egs_configure/egs_tools.cpp
@@ -788,7 +788,7 @@ void MCompiler::init(){
     dso = 0;
     the_name = "gfortran"; vopt = "--version";
     opt = is_x86_64() ? "-fPIC" : QString(); // Only for 64-bit GNU compilers
-    optimiz = "-O3 -ffast-math";
+    optimiz = "-O3 -mtune=native";
     deb = "-g";
     eext = QString();
     oflag = "-o ";
@@ -809,15 +809,15 @@ void MCompiler::setLanguage(Language l){
     switch(l){
       case F:
         the_name = "gfortran";
-        optimiz = "-O3 -ffast-math";
+        optimiz = "-O3 -mtune=native";
         break;
       case C:
         the_name = "gcc";
         optimiz = "-O2";
         break;
       case CPP:
         the_name = "g++";
-        optimiz = "-O3 -ffast-math";
+        optimiz = "-O3 -mtune=native";
         dso = new EGS_DSO(name());// Creates dso, sets flibs to -lgfortran literally
         dso->flibs = getFlibs2LinkCPP("gfortran",path());
         break;
@@ -922,7 +922,7 @@ void MCompiler::setUpCCompiler(){
     optimiz  = "-O3 -no-prec-div -fp-model fast=2";
   }
   else if ( the_name.contains("gcc") ){
-    optimiz  = "-O3 -ffast-math";
+    optimiz  = "-O3 -mtune=native";
   }
   else{
     optimiz  = "-O2";
@@ -940,14 +940,14 @@ void MCompiler::setUpCPPCompiler(const QString& link_to_name){
     vopt = QString();
   }
   else if ( the_name.contains("g++") ){
-    optimiz  = "-O3 -ffast-math -DWIN32";
+    optimiz  = "-O3 -mtune=native -DWIN32";
   }
   else if (the_name.toLower()== "icpc"){
     optimiz  = "-O3 -no-prec-div -fp-model fast=2 -DWIN32";
   }
 #else
   if ( the_name.contains("g++") ){
-    optimiz  = "-O3 -ffast-math";
+    optimiz  = "-O3 -mtune=native";
   }
   else if (the_name.toLower()== "icpc"){
     optimiz  = "-O3 -no-prec-div -fp-model fast=2";
@@ -1034,7 +1034,7 @@ void MCompiler::setUpFortranCompiler(){
          the_name.contains("g77")      ){
         vopt = "--version";
         opt = is_x86_64() ? "-fPIC" : QString(); // Only for 64-bit GNU compilers
-        optimiz = "-O3 -ffast-math";
+        optimiz = "-O3 -mtune=native";
     }
     else if (the_name == "ifl"){
         vopt = "-V";
@@ -1080,7 +1080,7 @@ void MCompiler::setUpFortranCompiler(){
     if ( the_name.contains("gfortran") || the_name == "g95" || the_name.contains("g77") ){ // GNU Fortran
         vopt = "-v --version";
         opt = is_x86_64() ? "-fPIC" : QString(); // Only for 64-bit GNU compilers
-        optimiz = "-O3 -ffast-math";
+        optimiz = "-O3 -mtune=native";
         deb = "-g";
     }
     _version = getVersion(); _version = _version.split("\n").takeFirst();
@@ -1101,7 +1101,7 @@ void MCompiler::setUpFortranCompiler(){
     _version = getVersion(); _version = _version.split("\n").takeFirst();
 #elif defined(Q_OS_LINUX) || defined(Q_OS_UNIX)
     if ( the_name.contains("gfortran") || the_name == "g95" || the_name.contains("g77")){ // GNU Fortran
-        vopt = "--version"; optimiz = "-O3 -ffast-math"; deb = "-g";
+        vopt = "--version"; optimiz = "-O3 -mtune=native"; deb = "-g";
         opt = is_x86_64() ? "-fPIC" : QString(); // Only for 64-bit GNU compilers
     }
     else if (the_name == "ifort"){

diff --git a/HEN_HOUSE/scripts/configure b/HEN_HOUSE/scripts/configure
@@ -346,7 +346,7 @@ for test_arg in -v; do
                 f_version="GNU F77 version $junk"
                 #f_fflags="-fno-automatic -finit-local-zero"
                 # don't need this with new EGSnrc
-                f_oflags="-O2"
+                f_oflags="-O2 -mtune=native"
                 f_dflags="-g"
                 if test ! x$is_x86_64 = x; then
                     f_fflags="-fPIC"
@@ -357,7 +357,7 @@ for test_arg in -v; do
             if test "x$junk" != x; then
                 junk=$(echo $junk | sed 's/.*GNU F95 version//g' | awk '{print $1}')
                 f_version="GNU F95 version $junk"
-                f_oflags="-O2"
+                f_oflags="-O2 -mtune=native"
                 f_dflags="-g"
                 if test ! x$is_x86_64 = x; then
                     f_fflags="-fPIC"

diff --git a/HEN_HOUSE/scripts/configure_c++ b/HEN_HOUSE/scripts/configure_c++
@@ -165,7 +165,7 @@ if test $create_config=yes; then
 
 case $CXX in
 
-    *g++*) opt="-O3 -ffast-math";;# mingw32-g++ and g++4 also taken into account
+    *g++*) opt="-O3 -mtune=native";;# mingw32-g++ and g++4 also taken into account
     icpc)  opt="-O3 -no-prec-div -fp-model fast=2";;
     icc)   opt="-O3 -no-prec-div -fp-model fast=2";;
     cl)    opt="-Ox -Ob2 -MD -GX -GR -nologo";;