From: Uros Bizjak <ubizjak@gmail.com>
Date: Mon, 18 Aug 2025 09:19:47 +0000 (+0200)
Subject: i386: Use TESTB instead of TESTL in ____longjmp_chk()
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=f80dddbe291b23b6851b22f734e2c421a4f9a4bc;p=thirdparty%2Fglibc.git

i386: Use TESTB instead of TESTL in ____longjmp_chk()

There is no need to use TESTL when checking the least-significant bit
with a TEST instruction. Use TESTB, which is three bytes shorter:

   f6 44 24 04 01          testb  $0x1,0x4(%esp)

vs:

   f7 44 24 04 01 00 00    testl  $0x1,0x4(%esp)
   00

for the same effect.

No functional changes intended.

Signed-off-by: Uros Bizjak <ubizjak@gmail.com>
Cc: H.J.Lu <hjl.tools@gmail.com>
Cc: Carlos O'Donell <carlos@redhat.com>
Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
---

diff --git a/sysdeps/unix/sysv/linux/i386/____longjmp_chk.S b/sysdeps/unix/sysv/linux/i386/____longjmp_chk.S
index e468d346d6..3e09f15662 100644
--- a/sysdeps/unix/sysv/linux/i386/____longjmp_chk.S
+++ b/sysdeps/unix/sysv/linux/i386/____longjmp_chk.S
@@ -67,7 +67,7 @@ ENTRY (____longjmp_chk)
 	/* Without working sigaltstack we cannot perform the test.  */
 	test	%eax, %eax
 	jne	.Lok2
-	testl	$1, 4(%esp)
+	testb	$1, 4(%esp)
 	jz	.Lfail
 
 	movl	(%esp), %eax