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

[Jaydeep Chauhan via Phabricator via llvm-commits]

Jac1494 added a comment.

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.  
Does this matches with you understandings ??


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https://reviews.llvm.org/D86395