[PATCH] D98335: [AVR] Refactor 8-bit & 16-bit shifts

[Ben Shi via Phabricator via llvm-commits]

benshi001 added a comment.

As @aykevl suggested in https://aykevl.nl/2021/02/avr-bitshift,

there could be further optimizations for 8-bit and 16-bit shifts, besides current llvm's optimization.

If we continue current llvm's way, more AVR specific SDNode would be introduced, and introducing new SDNodes for each shift amount seems stupid.

And this patch removes those stupid SDNodes and introducing 6 new ones, which have an extra immediate shift amount operand.

This way make it easy to add optimization for other immediate shift amount.


Repository:
  rG LLVM Github Monorepo

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  https://reviews.llvm.org/D98335/new/

https://reviews.llvm.org/D98335