[vlc-commits] configure: check only for adequate math optimizations (fix #16907)

[Rémi Denis-Courmont]

vlc/vlc-2.2 | branch: master | Rémi Denis-Courmont <remi at remlab.net> | Wed Aug 24 12:49:05 2016 +0200| [d5427879e56147bc9c7316d3cbb757ec013624c1] | committer: Hugo Beauzée-Luyssen

configure: check only for adequate math optimizations (fix #16907)

Manually cherry-picked from 273ec260a1f1912d39c2180db642f24127b8f6b7

Signed-off-by: Hugo Beauzée-Luyssen <hugo at beauzee.fr>

> http://git.videolan.org/gitweb.cgi/vlc/vlc-2.2.git/?a=commit;h=d5427879e56147bc9c7316d3cbb757ec013624c1
---

 configure.ac | 23 +++++++----------------
 1 file changed, 7 insertions(+), 16 deletions(-)

diff --git a/configure.ac b/configure.ac
index e663f99..cb1de25 100644
--- a/configure.ac
+++ b/configure.ac
@@ -981,24 +981,15 @@ AS_IF([test "${enable_optimizations}" != "no"], [
     ])
   ])
 
-  dnl Check for -ffast-math
-  VLC_SAVE_FLAGS
-  CFLAGS="${CFLAGS} -ffast-math"
-  CXXFLAGS="${CXXFLAGS} -ffast-math"
-  OBJCFLAGS="${OBJCFLAGS} -ffast-math"
-  AC_CACHE_CHECK([if $CC accepts -ffast-math], [ac_cv_c_fast_math], [
-    AC_COMPILE_IFELSE([AC_LANG_PROGRAM()], [
-      ac_cv_c_fast_math=yes
-    ], [
-      ac_cv_c_fast_math=no
-    ])
-  ])
-  AS_IF([test "${ac_cv_c_fast_math}" = "no"], [VLC_RESTORE_FLAGS])
-  AH_BOTTOM([
-#ifndef __FAST_MATH__
+  dnl Check for fast maths
+  RDC_PROG_CC_FFLAGS([no-math-errno unsafe-math-optimizations no-rounding-math no-signaling-nans cx-limited-range])
+  AC_LANG_PUSH(C++)
+  RDC_PROG_CXX_FFLAGS([no-math-errno unsafe-math-optimizations no-rounding-math no-signaling-nans cx-limited-range])
+  AC_LANG_POP
+
+AH_BOTTOM([
 # pragma STDC FENV_ACCESS OFF
 # pragma STDC FP_CONTRACT ON
-#endif
 ])
 
   dnl Check for -funroll-loops