2024-06-01 12:34 Jeff Law <jeffreya...@gmail.com> wrote: > > > >On 5/30/24 5:38 AM, Xiao Zeng wrote: >> 1 In the previous patch, the libcall for BF16 was implemented: >> <https://gcc.gnu.org/git/?p=gcc.git;a=commit;h=8c7cee80eb50792e57d514be1418c453ddd1073e> >> >> 2 Riscv provides Zfbfmin extension, which completes the "Scalar BF16 >> Converts": >> <https://github.com/riscv/riscv-bfloat16/blob/main/doc/riscv-bfloat16-zfbfmin.adoc> >> >> 3 Implemented replacing libcall with Zfbfmin extension instruction. >> >> 4 Reused previous testcases in: >> <https://gcc.gnu.org/git/?p=gcc.git;a=commit;h=8c7cee80eb50792e57d514be1418c453ddd1073e> >> >> gcc/ChangeLog: >> >> * config/riscv/riscv.cc (riscv_output_move): Handle BFmode move >> for zfbfmin. >> * config/riscv/riscv.md (truncsfbf2): New pattern for BFmode. >> (trunchfbf2): Dotto. >> (truncdfbf2): Dotto. >> (trunctfbf2): Dotto. >> (extendbfsf2): Dotto. >> (*movhf_hardfloat): Add BFmode. >> (*mov<mode>_hardfloat): Dotto. >> >> gcc/testsuite/ChangeLog: >> >> * gcc.target/riscv/zfbfmin-bf16_arithmetic.c: New test. >> * gcc.target/riscv/zfbfmin-bf16_comparison.c: New test. >> * gcc.target/riscv/zfbfmin-bf16_float_libcall_convert.c: New test. >> * gcc.target/riscv/zfbfmin-bf16_integer_libcall_convert.c: New test. >> --- > >> > > > >> + >> +;; The conversion of HF/DF/TF to BF needs to be done with SF if there is a >> +;; chance to generate at least one instruction, otherwise just using >> +;; libfunc __trunc[h|d|t]fbf2. >> +(define_expand "trunchfbf2" >> + [(set (match_operand:BF 0 "register_operand" "=f") >> + (float_truncate:BF >> + (match_operand:HF 1 "register_operand" " f")))] >> + "TARGET_ZFBFMIN" >> + { >> + convert_move (operands[0], >> + convert_modes (SFmode, HFmode, operands[1], 0), 0); >> + DONE; >> + } >> + [(set_attr "type" "fcvt") >> + (set_attr "mode" "BF")]) >I would suggest using a mode iterator to avoid explicit pattern duplication.
> >Essentially a mode iterator allows you to specify that the pattern >should be repeated over a series of modes. Yes, this will make the code look more concise and avoid redundancy. > >It looks like you've deine a conversion from HF, DF, TF. Yes. >So you define an iterator that includes just those modes. Yes. >You would use the mode iterator rather than BF, DF or TF in your pattern. Fixed. > >That just fixes the mode in the pattern. >You also need to have the name automagically adjust as well. Use <mode> in >the name. so the name >would be somethig like trunc<mode>bf2. Of course, this is necessary. > >When you want to reference the mode in code you can do something like >E_<MODE>mode Yes. > >And that will map down to HFmode, BFmode, TFmode appropriately. > >I suspect you can do something similar for the extension patterns. > >In fact, it looks like you did this for the move<mode>hardfloat pattern. > >Jeff Thank you for Jeff's suggestion. v2 has already been uploaded. <https://patchwork.sourceware.org/project/gcc/patch/20240601074547.80271-1-zengx...@eswincomputing.com/> Thanks Xiao Zeng
