I suggest we implement vector calling convention even though it is not ratified yet. We can allow calling convention to be enabled only when --param=riscv-autovec-preference=fixed-vlmax. We have such issue: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110119 if we don't have calling convention for fixed-vlmax.
juzhe.zh...@rivai.ai From: Jeff Law Date: 2023-06-13 03:16 To: Robin Dapp; gcc-patches; palmer; Kito Cheng; juzhe.zh...@rivai.ai Subject: Re: [PATCH] RISC-V: Implement vec_set and vec_extract. On 6/12/23 08:55, Robin Dapp wrote: > Hi, > > this implements the vec_set and vec_extract patterns for integer and > floating-point data types. For vec_set we broadcast the insert value to > a vector register and then perform a vslideup with effective length 1 to > the requested index. > > vec_extract is done by sliding down the requested element to index 0 > and v(f)mv.[xf].s to a scalar register. > > The patch does not include vector-vector extraction which > will be done at a later time. > > The vec_set tests required a vector calling convention/ABI because > a vector is being returned. I'm currently experimenting with adding > preliminary vector ABI support locally and still finishing some tests > after discussing with Juzhe. Consequently, I would not push this > before ABI support is upstream. I'm not sure how fast the vector ABI stuff is going to move. So I'd be a bit leery of tying this work to the ABI effort, particularly if it's just to test. Could you use asms to force vec_set/vec_extract to cross register files? Jeff
