From: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Date: Mon, 5 May 2025 12:39:07 +0000 (-0300)
Subject: math: Fix UB in ldbl-128 lrintl
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=712ff06cd6ef45aba23900cf552fc00a5ba78788;p=thirdparty%2Fglibc.git

math: Fix UB in ldbl-128 lrintl

$ math/test-float128-llrint

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'
Aborted

UBSAN: Undefined behaviour in ../sysdeps/ieee754/float128/../ldbl-128/s_lrintl.c:111:30 left shift of 281474976710656 by 15 cannot be represented in type 'long int'
Aborted
---

diff --git a/sysdeps/ieee754/ldbl-128/s_lrintl.c b/sysdeps/ieee754/ldbl-128/s_lrintl.c
index e5c0d5adb8..210c47fb3b 100644
--- a/sysdeps/ieee754/ldbl-128/s_lrintl.c
+++ b/sysdeps/ieee754/ldbl-128/s_lrintl.c
@@ -81,7 +81,7 @@ __lrintl (_Float128 x)
 	  result = (j0 < 0 ? 0 : i0 >> (48 - j0));
 	}
       else if (j0 >= 112)
-	result = ((long int) i0 << (j0 - 48)) | (i1 << (j0 - 112));
+	result = (i0 << (j0 - 48)) | (i1 << (j0 - 112));
       else
 	{
 #if defined FE_INVALID || defined FE_INEXACT
@@ -108,7 +108,7 @@ __lrintl (_Float128 x)
 	  if (j0 == 48)
 	    result = (long int) i0;
 	  else
-	    result = ((long int) i0 << (j0 - 48)) | (i1 >> (112 - j0));
+	    result = (i0 << (j0 - 48)) | (i1 >> (112 - j0));
 	}
     }
   else