From: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Date: Mon, 5 May 2025 12:36:51 +0000 (-0300)
Subject: math: Fix UB in ldbl-128 llrintl
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=c1540fcdde6972b913b58831afd4e2358639573a;p=thirdparty%2Fglibc.git

math: Fix UB in ldbl-128 llrintl

testing _Float128 (without inline functions)
UBSAN: Undefined behaviour in ../sysdeps/ieee754/float128/../ldbl-128/s_llrintl.c:83:31 left shift of 281474976710656 by 15 cannot be represented in type 'long long int'
---

diff --git a/sysdeps/ieee754/ldbl-128/s_llrintl.c b/sysdeps/ieee754/ldbl-128/s_llrintl.c
index 07f5aca347..959f06be59 100644
--- a/sysdeps/ieee754/ldbl-128/s_llrintl.c
+++ b/sysdeps/ieee754/ldbl-128/s_llrintl.c
@@ -80,7 +80,7 @@ __llrintl (_Float128 x)
       else if (j0 <= 48)
 	result = i0 >> (48 - j0);
       else
-	result = ((long long int) i0 << (j0 - 48)) | (i1 >> (112 - j0));
+	result = (i0 << (j0 - 48)) | (i1 >> (112 - j0));
     }
   else
     {