llvm dev - Jun 2017 - How to use FileCheck to check that two registers are different

Can FileCheck be used to check that two registers are not the same?

Context: the AMDGPU v_qsad_pk_u16_8 instructions looks like this:
v_qsad_pk_u16_8 dst, src0, src1, src2

The destination register must be different than the source registers. I
know how how to check that, say, src2 is the same as the dst register but
not how to check that src2 is not the same as the dst register.

Here's my initial try, but as you can see it'll pass, rather than fail,
if
dst and src2 are the same.
 v_qsad_pk_u16_u8 [[DEST:v\[[0-9]+:[0-9]+\]]], s[{{[0-9]+:[0-9]+}}],
v{{[0-9]+}}, [[DEST]]

Thanks for any suggestions,

Mark
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On 05/31/2017 09:17 PM, Mark Searles via llvm-dev wrote:
> Can FileCheck be used to check that two registers are not the same?
> 
> Context: the AMDGPU v_qsad_pk_u16_8 instructions looks like this:
> v_qsad_pk_u16_8 dst, src0, src1, src2
> 
> The destination register must be different than the source registers. I
know how how to check that, say, src2 is the same as the dst register but not
how to check that src2 is not the same as the dst register.
> 
> Here's my initial try, but as you can see it'll pass, rather than
fail, if dst and src2 are the same.
>  v_qsad_pk_u16_u8 [[DEST:v\[[0-9]+:[0-9]+\]]], s[{{[0-9]+:[0-9]+}}],
v{{[0-9]+}}, [[DEST]]
> 
> Thanks for any suggestions,
> 
You can use the CHECK-NOT: label to tell it to fail if it matches the pattern.

-Tom
> Mark
> 
> 
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