From 1df08cc492020c9e663f122fc3f293a2d20b1565 Mon Sep 17 00:00:00 2001
From: Christophe CURIS <christophe.curis@free.fr>
Date: Sun, 24 May 2015 15:49:05 +0200
Subject: [PATCH] configure: Add compiler detection on non optimal floating
 point constant

Signed-off-by: Christophe CURIS <christophe.curis@free.fr>
---
 configure.ac | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/configure.ac b/configure.ac
index 40f76fb3..c5d31671 100644
--- a/configure.ac
+++ b/configure.ac
@@ -153,6 +153,11 @@ AS_IF([test "x$debug" = "xyes"],
      dnl too complicated to maintain
      AX_CFLAGS_GCC_OPTION([-Wdisabled-optimization])
      dnl
+     dnl Because of C's type promotion, the compiler has to generate
+     dnl less optimal code when a double constant is used in a
+     dnl float expression
+     AX_CFLAGS_GCC_OPTION([-Wdouble-promotion])
+     dnl
      dnl Floating-point comparison is not a good idea
      AX_CFLAGS_GCC_OPTION([-Wfloat-equal])
      dnl