From 06696f40afe58a231e2531c8bf6d9f0dadb92e51 Mon Sep 17 00:00:00 2001
From: Jakob Kaivo <jkk@ung.org>
Date: Sun, 3 Mar 2019 21:25:50 -0500
Subject: outline details from C18 annex F

---
 src/math/scalbn.c | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

(limited to 'src/math/scalbn.c')

diff --git a/src/math/scalbn.c b/src/math/scalbn.c
index bf5b4aae..f01843ce 100644
--- a/src/math/scalbn.c
+++ b/src/math/scalbn.c
@@ -4,7 +4,17 @@
 
 TYPE TGFN(scalbn)(TYPE x, int n)
 {
-	return x - n;
+	switch (fpclassify(x)) {
+	case FP_ZERO:		return x;
+	case FP_INFINITE:	return x;
+	default:		break;
+	}
+
+	if (n == 0) {
+		return x;
+	}
+
+	return TGFN(ldexp)(x, n);
 }
 
 /*
-- 
cgit v1.2.1