linux-kernel - [PATCH 1/3] x86: verify_cpu: use 32-bit arithmetic

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Date:   Fri, 18 May 2018 00:30:01 +0300
From:   Alexey Dobriyan <adobriyan@...il.com>
To:     tglx@...utronix.de, mingo@...hat.com, hpa@...or.com
Cc:     x86@...nel, linux-kernel@...r.kernel.org
Subject: [PATCH 1/3] x86: verify_cpu: use 32-bit arithmetic

32-bit instructions are 1 byte shorter than 16-bit instructions.

Signed-off-by: Alexey Dobriyan <adobriyan@...il.com>
---

 arch/x86/kernel/verify_cpu.S |    8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

--- a/arch/x86/kernel/verify_cpu.S
+++ b/arch/x86/kernel/verify_cpu.S
@@ -56,14 +56,14 @@ ENTRY(verify_cpu)
 	cmpl	$0x1,%eax
 	jb	.Lverify_cpu_no_longmode	# no cpuid 1
 
-	xor	%di,%di
+	xor	%edi, %edi
 	cmpl	$0x68747541,%ebx	# AuthenticAMD
 	jnz	.Lverify_cpu_noamd
 	cmpl	$0x69746e65,%edx
 	jnz	.Lverify_cpu_noamd
 	cmpl	$0x444d4163,%ecx
 	jnz	.Lverify_cpu_noamd
-	mov	$1,%di			# cpu is from AMD
+	mov	$1, %edi		# cpu is from AMD
 	jmp	.Lverify_cpu_check
 
 .Lverify_cpu_noamd:
@@ -122,13 +122,13 @@ ENTRY(verify_cpu)
 	andl	$SSE_MASK,%edx
 	cmpl	$SSE_MASK,%edx
 	je	.Lverify_cpu_sse_ok
-	test	%di,%di
+	test	%edi, %edi
 	jz	.Lverify_cpu_no_longmode	# only try to force SSE on AMD
 	movl	$MSR_K7_HWCR,%ecx
 	rdmsr
 	btr	$15,%eax		# enable SSE
 	wrmsr
-	xor	%di,%di			# don't loop
+	xor	%edi, %edi		# don't loop
 	jmp	.Lverify_cpu_sse_test	# try again
 
 .Lverify_cpu_no_longmode: