From 9bb4c87bb11fb2e2c5daa9b2fc135c6577b3f7be Mon Sep 17 00:00:00 2001
From: David Schultz <das@FreeBSD.org>
Date: Fri, 3 Dec 2010 00:05:49 +0000
Subject: [PATCH] Disable gcc's built-in rint() function when compiling
 s_nearbyint.c. It results in incorrect optimizations that break nearbyint().

PR:		143358
Reviewed by:	bde
---
 lib/msun/Makefile | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/lib/msun/Makefile b/lib/msun/Makefile
index 87bd95441ad..929af97335c 100644
--- a/lib/msun/Makefile
+++ b/lib/msun/Makefile
@@ -113,6 +113,12 @@ COMMON_SRCS:=  ${COMMON_SRCS:N${i:R}.c}
 .endfor
 .endif
 
+# Some files need certain gcc built-in functions to be disabled, since gcc's
+# model of the functions bogusly assumes -fno-trapping-math.
+XRINT_CFLAGS=	-fno-builtin-rint -fno-builtin-rintf -fno-builtin-rintl
+CFLAGS+=	${XRINT_CFLAGS}
+XRINT_CFLAGS:=	${.IMPSRC:M*/s_nearbyint.c:C/^.+$/${XRINT_CFLAGS}/:C/^$//}
+
 SRCS=	${COMMON_SRCS} ${ARCH_SRCS}
 
 INCS=	fenv.h math.h