From eaf1c41bde2b58446697360af454266c4dc594a4 Mon Sep 17 00:00:00 2001
From: "Matthias P. Braendli" <matthias.braendli@mpb.li>
Date: Sun, 25 Dec 2016 21:58:24 +0100
Subject: Add -ffast-math configure option

---
 INSTALL      |  2 ++
 Makefile.am  | 12 +++---------
 configure.ac | 30 ++++++++++++++++++++++--------
 3 files changed, 27 insertions(+), 17 deletions(-)

diff --git a/INSTALL b/INSTALL
index 8e529a6..e0c7bd4 100644
--- a/INSTALL
+++ b/INSTALL
@@ -25,6 +25,8 @@ The configure script can be launch with a variety of options:
  --disable-zeromq       Disable ZeroMQ input (to be used with ODR-DabMux),
                         output and remotecontrol.
  --disable-output-uhd   Disable the binding to the UHD driver for USRPs
+ --enable-fast-math     Compile using the -ffast-math option that gives a substantial
+                        speedup at the cost of correctness.
 
 Debugging options: You should not enable debug if you need good performance.
 By default, debug is disabled.
diff --git a/Makefile.am b/Makefile.am
index c52405e..a778975 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -1,7 +1,7 @@
 # Copyright (C) 2007, 2008, 2009, 2010 Her Majesty the Queen in Right
 # of Canada (Communications Research Center Canada)
 #
-#  Copyright (C) 2014, 2015
+#  Copyright (C) 2016
 #  Matthias P. Braendli, matthias.braendli@mpb.li
 
 #   http://opendigitalradio.org
@@ -31,20 +31,14 @@ else
 GITVERSION_FLAGS =
 endif
 
-if DEBUG
-DEBUG_FLAGS = -DDEBUG
-else
-DEBUG_FLAGS =
-endif
-
 bin_PROGRAMS = odr-dabmod
 
 FFT_LDADD=
 
 odr_dabmod_CXXFLAGS = -Wall -Isrc -std=c++11 \
-					  $(GITVERSION_FLAGS) $(DEBUG_FLAGS)
+					  $(GITVERSION_FLAGS)
 odr_dabmod_CFLAGS   = -Wall -Isrc \
-					  $(GITVERSION_FLAGS) $(DEBUG_FLAGS)
+					  $(GITVERSION_FLAGS)
 odr_dabmod_LDADD    = $(FFT_LDADD)
 odr_dabmod_SOURCES  = src/DabMod.cpp \
 					  src/PcDebug.h \
diff --git a/configure.ac b/configure.ac
index f0688c8..ed35cdd 100644
--- a/configure.ac
+++ b/configure.ac
@@ -28,8 +28,6 @@ AC_CONFIG_SRCDIR([src/DabMod.cpp])
 AM_CONFIG_HEADER([config.h])
 AM_SILENT_RULES([yes])
 
-ACLOCAL_AMFLAGS = -I m4
-
 case $target_cpu in
     x86_64)
 AC_DEFINE([__64BIT__], [], [__16BIT__, __32BIT__])
@@ -56,6 +54,9 @@ AC_ARG_ENABLE([debug],
 AC_ARG_ENABLE([prof],
         [AS_HELP_STRING([--enable-prof], [Enable profiling])],
         [], [enable_prof=no])
+AC_ARG_ENABLE([fast-math],
+        [AS_HELP_STRING([--enable-fast-math], [Set -ffast-math])],
+        [], [enable_fast_math=no])
 AC_ARG_WITH([debug-malloc],
         [AS_HELP_STRING([--with-debug-malloc[=no|yes|duma|efence|...]],
             [Add malloc debugger support])],
@@ -79,16 +80,26 @@ PKG_CHECK_MODULES([FFTW], [fftw3f], enable_fftw=yes, enable_fftw=no)
 echo "Checking zeromq"
 
 AS_IF([test "x$enable_zeromq" = "xyes"],
-        [AC_DEFINE(HAVE_ZEROMQ, [1], [Define if ZeroMQ is enabled]) ,
-         AC_CHECK_LIB(zmq, zmq_init, ZMQ_LIBS="-lzmq" ,[AC_MSG_ERROR([ZeroMQ libzmq is required])])])
+         [AC_CHECK_LIB([zmq], [zmq_init], [ZMQ_LIBS="-lzmq"],
+                       [AC_MSG_ERROR([ZeroMQ libzmq is required])])])
+
+AS_IF([test "x$enable_zeromq" = "xyes"],
+        [AC_DEFINE(HAVE_ZEROMQ, [1], [Define if ZeroMQ is enabled])])
+
 AS_IF([test "x$enable_debug" = "xno"],
         [EXTRA="$EXTRA -DNDEBUG"],
         [EXTRA="$EXTRA"])
+
 AS_IF([test "x$enable_prof" != "xno"],
         [EXTRA="$EXTRA -pg"])
 
+AS_IF([test "x$enable_fast_math" != "xno"],
+        [EXTRA="$EXTRA -ffast-math"])
+
+AS_IF([test "x$enable_trace" != "xno"],
+        [EXTRA="$EXTRA -DDEBUG"])
+
 # Define conditionals for Makefile.am
-AM_CONDITIONAL([DEBUG], [test "x$enable_trace" = "xyes"])
 AM_CONDITIONAL([IS_GIT_REPO], [test -d '.git'])
 
 # Defines for config.h
@@ -100,8 +111,11 @@ AC_SUBST([LIBS], ["$FFTW_LIBS $PTHREAD_LIBS $ZMQ_LIBS"])
 
 # Checks for UHD.
 AS_IF([test "x$enable_output_uhd" = "xyes"],
-        [AC_DEFINE(HAVE_OUTPUT_UHD, [1], [Define if UHD output is enabled]) ,
-         AC_CHECK_LIB([uhd], [main], [], [AC_MSG_ERROR([library uhd is missing])])])
+      [AC_CHECK_LIB([uhd], [main], [],
+                   [AC_MSG_ERROR([library uhd is missing])] )])
+
+AS_IF([test "x$enable_output_uhd" = "xyes"],
+      [AC_DEFINE(HAVE_OUTPUT_UHD, [1], [Define if UHD output is enabled])])
 
 AX_BOOST_BASE([1.55.0], [], AC_MSG_ERROR([BOOST 1.55 or later is required]))
 AC_CHECK_LIB([boost_system], [main], [], [AC_MSG_ERROR([library boost_system is missing])])
@@ -192,7 +206,7 @@ echo
 echo
 enabled=""
 disabled=""
-for feat in with_debug_malloc has_sse
+for feat in with_debug_malloc has_sse enable_fast_math
 do
     eval var=\$$feat
     AS_IF([test "x$var" != "xno"],
-- 
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