[PATCH] D61307: [InstCombine] Add new combine to sub folding

[Roman Lebedev via Phabricator via llvm-commits]

lebedev.ri added a comment.

Right, no commit rights i guess?
This looks good to me. I think this needs one more test.



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Comment at: llvm/lib/Transforms/InstCombine/InstCombineAddSub.cpp:1531-1532
 
-  // If this is a 'B = x-(-A)', change to B = x+A.
   Value *Op0 = I.getOperand(0), *Op1 = I.getOperand(1);
+  // (X | Y) - Y --> (X | Y) ^ Y
+  // (Y | X) - Y --> (Y | X) ^ Y
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This needs a newline


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Comment at: llvm/test/Transforms/InstCombine/sub.ll:1287
+  %C = or i32 %A, %B
+  %D = sub i32 %C, %B
+  ret i32 %D
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This needs a negative test, with swapped order in `sub`.


CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D61307/new/

https://reviews.llvm.org/D61307