[PATCH] Add support to FileCheck for out-of-order matching

[Jakob Stoklund Olesen]

On Apr 10, 2013, at 2:31 PM, Hal Finkel <hfinkel at anl.gov> wrote:

> At the risk of being off-topic: It would be really nice to be able to write regression tests that don't depend on the order chosen by the instruction scheduler. I think that, for that, it would be useful to be able to define groups of check lines for which the order does not matter. Maybe something like this:
> 
> ; CHECK-GROUP-BEGIN
> ; CHECK: add [[REG1:r[0-9]+]], r1, r2
> ; CHECK: add [[REG2:r[0-9]+]], r3, r4
> ; CHECK: mul [[REG1]], [[REG2]]
> ; CHECK-GROUP-END
> 
> The first two add instructions are independent, and I don't care in which order they appear. The dependence of the mul on the adds is still captured by the named regex patterns. FileCheck could check all patterns in the group at each line, removing those that have matched from consideration.
> 
> What do you think?

I think that would be great! It is particularly important now that we are adding new scheduling models and a whole new MI scheduler is about to be enabled. Test cases should express the invariant they care about, not some nebulous 'stability' property.

I was coincidentally just about to propose something very similar, using the regex variables to encode DAG edges. I wouldn't add the GROUP-BEGIN and GROUP-END markers, though. I would simply use surrounding CHECK markers, the same as CHECK-NOT:

; CHECK: testfunctionname
; CHECK-DAG: add [[REG1:r[0-9]+]], r1, r2
; CHECK-DAG: add [[REG2:r[0-9]+]], r3, r4
; CHECK-DAG: mul [[REG1]], [[REG2]]
; CHECK: ret

This would make CHECK-DAG and CHECK-NOT work the same, except you can't define variables in a CHECK-NOT, of course.

/jakob