On 6/28/23 16:56, 钟居哲 wrote:
------------------------------------------------------------------------
juzhe.zh...@rivai.ai
*From:* Jeff Law <mailto:jeffreya...@gmail.com>
*Date:* 2023-06-29 06:43
*To:* 钟居哲 <mailto:juzhe.zh...@rivai.ai>; gcc-patches
<mailto:gcc-patches@gcc.gnu.org>
*CC:* kito.cheng <mailto:kito.ch...@gmail.com>; kito.cheng
<mailto:kito.ch...@sifive.com>; palmer <mailto:pal...@dabbelt.com>;
palmer <mailto:pal...@rivosinc.com>; rdapp.gcc
<mailto:rdapp....@gmail.com>
*Subject:* Re: [PATCH] RISC-V: Support vfwnmacc/vfwmsac/vfwnmsac
combine lowering
On 6/28/23 16:10, 钟居哲 wrot
> Sure.
>
> https://godbolt.org/z/8857KzTno <https://godbolt.org/z/8857KzTno>
>
> Failed to match this instruction:
> (set (reg:VNx2DF 134 [ vect__31.47 ])
> (fma:VNx2DF (neg:VNx2DF (float_extend:VNx2DF (reg:VNx2SF 136 [
> vect__28.44 ])))
> (reg:VNx2DF 150 [ vect__8.12 ])
> (reg:VNx2DF 171 [ vect__29.45 ])))
Please attach the full dump. I would expect to see additional attempts
with more operands replaced.
THanks for the dump. I think this fundamentally the same issue as the
widening problem.
Drop those intermediate patterns. They're not needed/helpful. You may
need a dependency height reduction pattern to get the code you want, but
I see no evidence those extra patterns will solve anything.
jeff
