[PATCH] D86395: [InstCombine] transform pattern "(~A & B) ^ A -> (A | B)" added

[Roman Lebedev via Phabricator via llvm-commits]

lebedev.ri added a comment.

In D86395#2274565 <https://reviews.llvm.org/D86395#2274565>, @Jac1494 wrote:

> In D86395#2274541 <https://reviews.llvm.org/D86395#2274541>, @lebedev.ri wrote:
>
>> In D86395#2274522 <https://reviews.llvm.org/D86395#2274522>, @Jac1494 wrote:
>>
>>> In D86395#2269436 <https://reviews.llvm.org/D86395#2269436>, @spatel wrote:
>>>
>>>> In D86395#2268634 <https://reviews.llvm.org/D86395#2268634>, @Jac1494 wrote:
>>>>
>>>>> test53 and test55 has been removed.
>>>>
>>>> We are going in circles. I'll give this 1 more try, and if it still doesn't make sense, then maybe another reviewer can better communicate what we expect for the tests:
>>>>
>>>> 1. There are 4 commutative patterns variations in the code.
>>>> 2. Each one of those patterns should have a test (we should have at least 4 tests).
>>>> 3. Each test corresponds to exactly one of the commutative patterns.
>>>> 4. Each test should be in canonical form without this patch (the baseline CHECK lines should correspond exactly to the IR as written).
>>>> 5. The 8 step check I provided earlier may be used to confirm that the tests provide the expected coverage for the code.
>>>
>>> @spatel, apologies for the confusion created due to multiple revisions.
>>>
>>> Let's consider the initial pattern and associated commutative version of this.
>>>
>>>   initial pattern:-
>>>   (~A & B) ^ A -> (A | B) 
>>>   
>>>   And 8 possible commutative version of this.
>>>   1) (~A & B) ^ A -> (A | B) 
>>>   2) (~B & A) ^ B -> (A | B)
>>>   3) (B & ~A) ^ A -> (A | B)  --> identical to 1)
>>>   4) A ^ (~A & B) -> (A | B)  --> identical to 1)
>>>   5) A ^ (B & ~A) -> (A | B)  --> identical to 1)
>>>   6) (A & ~B) ^ B -> (A | B)  --> identical to 2)
>>>   7) B ^ (~B & A) -> (A | B)  --> identical to 2)
>>>   8) B ^ (A & ~B) -> (A | B)  --> identical to 2)
>>>
>>> As you may notice that all these patterns (IR) are reducing to 2 unique patterns (pattern 1 and pattern 2).
>>> So pattern 1 and 2 are sufficient for the coverage of all commutative variations of the primary pattern.
>>
>> How so?
>> If you only have a test for pattern 1 and pattern 2, how do you know that the commutative variants are handled?
>>
>>> Does this matches with you understandings ??
>
> @lebedev.ri , I have manually tested and verified.

And do you plan on "manually testing and re-verifying" that on each commit to LLVM as a whole made by everyone for the forseeable future?


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