[PATCH] D48789: [X86] Replace (32/64 - n) shift amounts with (neg n) since the shift amount is masked in hardware

[Craig Topper via Phabricator via llvm-commits]

craig.topper added a comment.

@niravd would it be better to just do the full manual isel instead of trying to do it this way? Selecting the negate is easy. It just the variations of the shift that kind of ugly due to legacy vs BMI2 and BMI2 allowing load folding.


https://reviews.llvm.org/D48789