On Mon, Jul 01, 2019 at 04:13:40PM +0100, Kyrill Tkachov wrote: > Hi all, > > Some scheduling descriptions, like the Cortex-A57 one, are reused for > multiple -mcpu options. > Sometimes those other -mcpu cores support more architecture features > than the Armv8-A Cortex-A57. > For example, the Cortex-A75 and Cortex-A76 support Armv8.2-A as well as > the Dot Product instructions. > These Dot Product instructions have the neon_dot and neon_dot_q > scheduling type, but that type is not > handled in cortex-a57.md, since the Cortex-A57 itself doesn't need to > care about these instructions. > > But if we just ignore the neon_dot(_q) type at scheduling we get really > terrible codegen when compiling > for -mcpu=cortex-a76, for example, because the scheduler just pools all > the UDOT instructions at the end > of the basic block, since it doesn't assume anything about their behaviour. > > This patch ameliorates the situation somewhat by telling the Cortex-A57 > scheduling model to treat any > insn that doesn't get assigned a cortex_a57_neon_type but is actually a > is_neon_type instruction as > a simple neon_arith_basic instruction. This allows us to treat > post-Armv8-A SIMD instructions more sanely > without having to model each of them explicitly in cortex-a57.md. > > Bootstrapped and tested on arm-none-linux-gnueabihf and > aarch64-none-linux-gnu. > > Ok for trunk from an aarch64 perspective?
OK. Thansk, James > > Thanks, > Kyrill >
