From: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Date: Thu, 1 May 2025 21:14:37 +0000 (-0300)
Subject: x86: Fix UB in isinfl
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=258ea844481e987583dc27435960abd44d3cc889;p=thirdparty%2Fglibc.git

x86: Fix UB in isinfl

Building with --enable-ubasn triggers:

$ math/test-ldouble-isinf
UBSAN: Undefined behaviour in ../sysdeps/x86/fpu/s_isinfl.c:25:8 negation of 2147483648 cannot be represented in type 'int'

Also move the isinfl implementation to sysdeps/x86 and remove the
sysdeps/x86_64 version.
---

diff --git a/sysdeps/i386/fpu/s_isinfl.c b/sysdeps/x86/fpu/s_isinfl.c
similarity index 88%
rename from sysdeps/i386/fpu/s_isinfl.c
rename to sysdeps/x86/fpu/s_isinfl.c
index ff6048e3f57..66543e2e2ce 100644
--- a/sysdeps/i386/fpu/s_isinfl.c
+++ b/sysdeps/x86/fpu/s_isinfl.c
@@ -17,14 +17,15 @@ static char rcsid[] = "$NetBSD: $";
 
 int __isinfl(long double x)
 {
-	int32_t se,hx,lx;
+	int se;
+	unsigned int hx, lx;
 	GET_LDOUBLE_WORDS(se,hx,lx,x);
 	/* This additional ^ 0x80000000 is necessary because in Intel's
 	   internal representation of the implicit one is explicit.  */
 	lx |= (hx ^ 0x80000000) | ((se & 0x7fff) ^ 0x7fff);
 	lx |= -lx;
 	se &= 0x8000;
-	return ~(lx >> 31) & (1 - (se >> 14));
+	return ~((int)lx >> 31) & (1 - (se >> 14));
 }
 hidden_def (__isinfl)
 weak_alias (__isinfl, isinfl)
diff --git a/sysdeps/x86_64/fpu/s_isinfl.c b/sysdeps/x86_64/fpu/s_isinfl.c
deleted file mode 100644
index ca818b5e906..00000000000
--- a/sysdeps/x86_64/fpu/s_isinfl.c
+++ /dev/null
@@ -1 +0,0 @@
-#include <sysdeps/i386/fpu/s_isinfl.c>