linux-kernel - [PATCH] x86: math-emu: fix up 'cmp' insn for clang ias

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Message-Id: <20200527135352.1198078-1-arnd@arndb.de>
Date:   Wed, 27 May 2020 15:53:46 +0200
From:   Arnd Bergmann <arnd@...db.de>
To:     Bill Metzenthen <billm@...bpc.org.au>,
        Thomas Gleixner <tglx@...utronix.de>,
        Ingo Molnar <mingo@...hat.com>, Borislav Petkov <bp@...en8.de>,
        x86@...nel.org
Cc:     Arnd Bergmann <arnd@...db.de>, "H. Peter Anvin" <hpa@...or.com>,
        Jiri Slaby <jslaby@...e.cz>, linux-kernel@...r.kernel.org,
        clang-built-linux@...glegroups.com
Subject: [PATCH] x86: math-emu: fix up 'cmp' insn for clang ias

The clang integrated assembler requires the 'cmp' instruction to
have a length prefix here:

arch/x86/math-emu/wm_sqrt.S:212:2: error: ambiguous instructions require an explicit suffix (could be 'cmpb', 'cmpw', or 'cmpl')
 cmp $0xffffffff,-24(%ebp)
 ^

Make this a 32-bit comparison, which it was clearly meant to be.

Signed-off-by: Arnd Bergmann <arnd@...db.de>
---
 arch/x86/math-emu/wm_sqrt.S | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/math-emu/wm_sqrt.S b/arch/x86/math-emu/wm_sqrt.S
index 3b2b58164ec1..40526dd85137 100644
--- a/arch/x86/math-emu/wm_sqrt.S
+++ b/arch/x86/math-emu/wm_sqrt.S
@@ -209,7 +209,7 @@ sqrt_stage_2_finish:
 
 #ifdef PARANOID
 /* It should be possible to get here only if the arg is ffff....ffff */
-	cmp	$0xffffffff,FPU_fsqrt_arg_1
+	cmpl	$0xffffffff,FPU_fsqrt_arg_1
 	jnz	sqrt_stage_2_error
 #endif /* PARANOID */
 
-- 
2.26.2