[llvm-commits] [patch][pr12251] Use the range metadata in computeMaskedBits and add an optimization to InstructionSimplify.

[Chris Lattner]

On Mar 24, 2012, at 10:04 PM, Joerg Sonnenberger wrote:

> On Fri, Mar 23, 2012 at 10:56:50PM -0400, Rafael Espíndola wrote:
>> And the assembly changes from
>> 
>> 	movb	(%rdi), %al
>> 	andb	$1, %al
>> 	ret
>> 
>> To
>> 
>> 	cmpb	$0, (%rdi)
>> 	setne	%al
>> 	ret
>> 
>> Not sure if the assembly change is an improvement, so maybe this patch
>> should go in with a change to return i8, but I am sending it for
>> review first.
> 
> The second form is 2 Bytes larger at least.

Right.  I'm just saying that improving information in IR is exposing a latent code quality issue.  It would be great for that issue to be fixed, but it shouldn't block this progress.

-Chris