mirror of
https://github.com/c64scene-ar/llvm-6502.git
synced 2025-01-27 14:34:58 +00:00
bd357588a1
lanes. By special casing these we can often either reduce the total number of shuffles significantly or reduce the number of (high latency on Haswell) AVX2 shuffles that potentially cross 128-bit lanes. Even when these don't actually cross lanes, they have much higher latency to support that. Doing two of them and a blend is worse than doing a single insert across the 128-bit lanes to blend and then doing a single interleaved shuffle. While this seems like a narrow case, it kept cropping up on me and the difference is *huge* as you can see in many of the test cases. I first hit this trying to perfectly fix the interleaving shuffle patterns used by Halide for AVX2. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@222533 91177308-0d34-0410-b5e6-96231b3b80d8