From 23d3931a6a8a37bb7e86bd6cb4709eb46031bfe1 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Martin=20Storsj=C3=B6?= <martin@martin.st>
Date: Thu, 21 Apr 2011 13:02:38 +0200
Subject: [PATCH] Provide a fallback version of the libm function trunc
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This fixes compilation on DOS.

Signed-off-by: Martin Storsjö <martin@martin.st>
---
 configure        | 2 ++
 libavutil/libm.h | 7 +++++++
 2 files changed, 9 insertions(+)

diff --git a/configure b/configure
index 32c3544fb3..dd44ba4739 100755
--- a/configure
+++ b/configure
@@ -1119,6 +1119,7 @@ HAVE_LIST="
     sys_videoio_h
     ten_operands
     threads
+    trunc
     truncf
     vfp_args
     VirtualAlloc
@@ -2852,6 +2853,7 @@ check_mathfunc lrint
 check_mathfunc lrintf
 check_mathfunc round
 check_mathfunc roundf
+check_mathfunc trunc
 check_mathfunc truncf
 
 # these are off by default, so fail if requested and not available
diff --git a/libavutil/libm.h b/libavutil/libm.h
index 704bcf9554..783f3cdfab 100644
--- a/libavutil/libm.h
+++ b/libavutil/libm.h
@@ -86,6 +86,13 @@ static av_always_inline av_const float roundf(float x)
 }
 #endif /* HAVE_ROUNDF */
 
+#if !HAVE_TRUNC
+static av_always_inline av_const double trunc(double x)
+{
+    return (x > 0) ? floor(x) : ceil(x);
+}
+#endif /* HAVE_TRUNC */
+
 #if !HAVE_TRUNCF
 static av_always_inline av_const float truncf(float x)
 {