From db89cf8efbca70802c25321a2e835012a2c51e6d Mon Sep 17 00:00:00 2001
From: Steve Kargl <kargl@FreeBSD.org>
Date: Wed, 6 Nov 2013 23:44:52 +0000
Subject: [PATCH] * Use "math.h" instead of <math.h>. * Use bit twiddling. 
 This requires inclusion of math_private.h   and inclusion of float.h in
 s_roundl.c.  Raise invalid exception. * Use literal integer constants where
 possible.  Let the compiler   do the appropriate conversion. * In s_roundf.c,
 use an F suffix on float constants instead of   promoting float to double and
 then converting the result back   to float. In s_roundl.c, use an L suffix. *
 In s_roundl.c, use the ENTERI and RETURNI macros.  This requires   the
 inclusion of fpmath.h and on __i386__ class hardware ieeefp.h.

Reviewed by:	bde
---
 lib/msun/src/s_round.c  | 15 +++++++++------
 lib/msun/src/s_roundf.c | 19 +++++++++++--------
 lib/msun/src/s_roundl.c | 31 +++++++++++++++++++++----------
 3 files changed, 41 insertions(+), 24 deletions(-)

diff --git a/lib/msun/src/s_round.c b/lib/msun/src/s_round.c
index 65de31b6373a..8fd407db769e 100644
--- a/lib/msun/src/s_round.c
+++ b/lib/msun/src/s_round.c
@@ -27,25 +27,28 @@
 #include <sys/cdefs.h>
 __FBSDID("$FreeBSD$");
 
-#include <math.h>
+#include "math.h"
+#include "math_private.h"
 
 double
 round(double x)
 {
 	double t;
+	uint32_t hx;
 
-	if (!isfinite(x))
-		return (x);
+	GET_HIGH_WORD(hx, x);
+	if ((hx & 0x7fffffff) == 0x7ff00000)
+		return (x + x);
 
-	if (x >= 0.0) {
+	if (!(hx & 0x80000000)) {
 		t = floor(x);
 		if (t - x <= -0.5)
-			t += 1.0;
+			t += 1;
 		return (t);
 	} else {
 		t = floor(-x);
 		if (t + x <= -0.5)
-			t += 1.0;
+			t += 1;
 		return (-t);
 	}
 }
diff --git a/lib/msun/src/s_roundf.c b/lib/msun/src/s_roundf.c
index 952e8e79549d..e7e2eb928cf0 100644
--- a/lib/msun/src/s_roundf.c
+++ b/lib/msun/src/s_roundf.c
@@ -27,25 +27,28 @@
 #include <sys/cdefs.h>
 __FBSDID("$FreeBSD$");
 
-#include <math.h>
+#include "math.h"
+#include "math_private.h"
 
 float
 roundf(float x)
 {
 	float t;
+	uint32_t hx;
 
-	if (!isfinite(x))
-		return (x);
+	GET_FLOAT_WORD(hx, x);
+	if ((hx & 0x7fffffff) == 0x7f800000)
+		return (x + x);
 
-	if (x >= 0.0) {
+	if (!(hx & 0x80000000)) {
 		t = floorf(x);
-		if (t - x <= -0.5)
-			t += 1.0;
+		if (t - x <= -0.5F)
+			t += 1;
 		return (t);
 	} else {
 		t = floorf(-x);
-		if (t + x <= -0.5)
-			t += 1.0;
+		if (t + x <= -0.5F)
+			t += 1;
 		return (-t);
 	}
 }
diff --git a/lib/msun/src/s_roundl.c b/lib/msun/src/s_roundl.c
index a70b617cf923..2d15e134f646 100644
--- a/lib/msun/src/s_roundl.c
+++ b/lib/msun/src/s_roundl.c
@@ -27,25 +27,36 @@
 #include <sys/cdefs.h>
 __FBSDID("$FreeBSD$");
 
-#include <math.h>
+#include <float.h>
+#ifdef __i386__
+#include <ieeefp.h>
+#endif
+
+#include "fpmath.h"
+#include "math.h"
+#include "math_private.h"
 
 long double
 roundl(long double x)
 {
 	long double t;
+	uint16_t hx;
 
-	if (!isfinite(x))
-		return (x);
+	GET_LDBL_EXPSIGN(hx, x);
+	if ((hx & 0x7fff) == 0x7fff)
+		return (x + x);
 
-	if (x >= 0.0) {
+	ENTERI();
+
+	if (!(hx & 0x8000)) {
 		t = floorl(x);
-		if (t - x <= -0.5)
-			t += 1.0;
-		return (t);
+		if (t - x <= -0.5L)
+			t += 1;
+		RETURNI(t);
 	} else {
 		t = floorl(-x);
-		if (t + x <= -0.5)
-			t += 1.0;
-		return (-t);
+		if (t + x <= -0.5L)
+			t += 1;
+		RETURNI(-t);
 	}
 }