From 1559a978100762efd84666befd134d5975ae8d4b Mon Sep 17 00:00:00 2001
From: Damien George
Date: Fri, 31 Oct 2014 11:28:50 +0000
Subject: py: Add builtin round function.

Addresses issue #934.
---
 lib/libm/roundf.c | 33 +++++++++++++++++++++++++++++++++
 1 file changed, 33 insertions(+)
 create mode 100644 lib/libm/roundf.c

(limited to 'lib/libm')

diff --git a/lib/libm/roundf.c b/lib/libm/roundf.c
new file mode 100644
index 000000000..3da1f0595
--- /dev/null
+++ b/lib/libm/roundf.c
@@ -0,0 +1,33 @@
+/*****************************************************************************/
+/*****************************************************************************/
+// roundf from musl-0.9.15
+/*****************************************************************************/
+/*****************************************************************************/
+
+#include "libm.h"
+
+float roundf(float x)
+{
+	union {float f; uint32_t i;} u = {x};
+	int e = u.i >> 23 & 0xff;
+	float_t y;
+
+	if (e >= 0x7f+23)
+		return x;
+	if (u.i >> 31)
+		x = -x;
+	if (e < 0x7f-1) {
+		FORCE_EVAL(x + 0x1p23f);
+		return 0*u.f;
+	}
+	y = (float)(x + 0x1p23f) - 0x1p23f - x;
+	if (y > 0.5f)
+		y = y + x - 1;
+	else if (y <= -0.5f)
+		y = y + x + 1;
+	else
+		y = y + x;
+	if (u.i >> 31)
+		y = -y;
+	return y;
+}
-- 
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