From fac90264413e3b510c14ee8245a5abfd9ab65dff Mon Sep 17 00:00:00 2001
From: zimmerma <zimmerma@280ebfd0-de03-0410-8827-d642c229c3f4>
Date: Mon, 1 Feb 2021 10:58:22 +0000
Subject: [src/asinu.c] improved a comment

git-svn-id: https://scm.gforge.inria.fr/anonscm/svn/mpfr/trunk@14305 280ebfd0-de03-0410-8827-d642c229c3f4
---
 src/asinu.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

(limited to 'src')

diff --git a/src/asinu.c b/src/asinu.c
index 3c7d7d527..befdd0db0 100644
--- a/src/asinu.c
+++ b/src/asinu.c
@@ -51,7 +51,8 @@ mpfr_asinu (mpfr_ptr y, mpfr_srcptr x, unsigned long u, mpfr_rnd_t rnd_mode)
       else /* necessarily x=0 */
         {
           MPFR_ASSERTD(MPFR_IS_ZERO(x));
-          /* asin(0)=0 with same sign (even when u=0?) */
+          /* asin(0)=0 with same sign, even when u=0 to ensure
+             asinu(-x,u) = -asinu(x,u) */
           MPFR_SET_ZERO (y);
           MPFR_SET_SAME_SIGN (y, x);
           MPFR_RET (0); /* exact result */
-- 
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