From 67ab447959b62454f4e0273177baa19711babb96 Mon Sep 17 00:00:00 2001
From: Alan Coopersmith <alan.coopersmith@oracle.com>
Date: Tue, 20 Dec 2011 21:47:56 -0800
Subject: Use lrint() from math library if available
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Moves -lm from being hardcoded in Makefile.am to being added via
AC_SEARCH_LIBS in configure.ac setting it in $(MATH_LIBS)

Using lrint() [returns long int] instead of rint() [returns double]
clears a bunch of gcc warnings of the form:
"cast from function call of type ‘double’ to non-matching type ‘short int’"

Signed-off-by: Alan Coopersmith <alan.coopersmith@oracle.com>
---
 Graphics.c   | 10 +++++++++-
 Makefile.am  |  2 +-
 configure.ac | 12 ++++++++++++
 3 files changed, 22 insertions(+), 2 deletions(-)

diff --git a/Graphics.c b/Graphics.c
index b3ec1bc..43c48b9 100644
--- a/Graphics.c
+++ b/Graphics.c
@@ -30,6 +30,10 @@ from The Open Group.
  * Author:  Davor Matic, MIT X Consortium
  */
 
+#ifdef HAVE_CONFIG_H
+# include "config.h"
+#endif
+
 #include <X11/IntrinsicP.h>
 #include <X11/StringDefs.h>
 #include <X11/Xfuncs.h>
@@ -46,7 +50,11 @@ from The Open Group.
 #define min(x, y)                     (((int)(x) < (int)(y)) ? (x) : (y))
 #define max(x, y)                     (((int)(x) > (int)(y)) ? (x) : (y))
 #ifndef rint
-#define rint(x)                       floor(x + 0.5)
+# if HAVE_LRINT
+#  define rint(x)                     lrint(x)
+# else
+#  define rint(x)                     floor(x + 0.5)
+# endif
 #endif
 
 /*****************************************************************************\
diff --git a/Makefile.am b/Makefile.am
index 7a5ca35..88cc611 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -23,7 +23,7 @@ SUBDIRS=man
 bin_PROGRAMS = bitmap bmtoa atobm
 
 bitmap_CFLAGS = $(CWARNFLAGS) $(BITMAP_CFLAGS)
-bitmap_LDADD = $(BITMAP_LIBS) -lm
+bitmap_LDADD = $(BITMAP_LIBS) $(MATH_LIBS)
 bitmap_SOURCES = \
          BitEdit.c \
          CutPaste.c \
diff --git a/configure.ac b/configure.ac
index ecb71ce..c3fcba9 100644
--- a/configure.ac
+++ b/configure.ac
@@ -42,6 +42,18 @@ AM_PROG_CC_C_O
 
 AC_CHECK_FUNCS([mkstemp])
 
+# Math libraries & functions
+# - some compilers use builtin inlines for floor when optimizing
+# - lrint() is a C99 addition not found on some older systems
+# - must do the libm check first so that the lrint check will have it in $LIBS
+save_LIBS="$LIBS"
+AC_SEARCH_LIBS([floor], [m])
+AC_SEARCH_LIBS([lrint], [m])
+AC_CHECK_FUNCS([lrint])
+MATH_LIBS="$LIBS"
+LIBS="$save_LIBS"
+AC_SUBST([MATH_LIBS])
+
 # Obtain compiler/linker options from dependencies
 PKG_CHECK_MODULES(BMTOA, x11 xmu)
 PKG_CHECK_MODULES(ATOBM, xproto)
-- 
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