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Re: [PATCH] x86-64: memcmp-avx2-movbe.S needs saturating subtraction [BZ #21662]

On 06/23/2017 06:51 AM, Florian Weimer wrote:

+	shll	$8, %eax
+	shll	$8, %ecx
  	bswap	%eax
  	bswap	%ecx
+	movzbl	-1(%rdi, %rdx), %edi
+	movzbl	-1(%rsi, %rdx), %esi
+	orl	%edi, %eax
+	orl	%esi, %ecx


Do you really need to re-load and merge the final byte?
It would appear you could leave the low byte zero.


r~
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