llvm dev - Jun 2021 - [proposal] change default ABI for special riscv arch

That one line change doesn't look like it handles multiletter extension
names correctly. For example, Zbf contains "f".

~Craig


On Mon, Jun 7, 2021 at 8:13 PM Ben Shi via llvm-dev <llvm-dev at
lists.llvm.org>
wrote:
> Hello,
>
> In the clang's riscv driver,
>
>
https://github.com/llvm/llvm-project/blob/main/clang/lib/Driver/ToolChains/Arch/RISCV.cpp
>
> the default abi is fomulated according to arch if no explicit -mabi is
> specified.
>
> Is it possible to set the default abi to ilp32f for -march=rv32imacf. For
> my exployer's chip, HW F is used while SW D is used. Each time I have
to
> write "-march=rv32imacf -mabi=ilp32f“， can it be simplified to only
> "-march=imacf" ? Just adding a line is enough.
>
> if (MArch.substr(4).contains_lower("f") &&
!MArch.substr(4).contains_lower
> ("d"))
> return "ilp32f";
>
> Can I submit a patch to fix it?
>
> Ben
>
> _______________________________________________
> LLVM Developers mailing list
> llvm-dev at lists.llvm.org
> https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev
>
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I will figure out all corner cases, thanks for your support. :)





At 2021-06-08 12:06:15, "Craig Topper" <craig.topper at
gmail.com> wrote:

That one line change doesn't look like it handles multiletter extension
names correctly. For example, Zbf contains "f".


~Craig




On Mon, Jun 7, 2021 at 8:13 PM Ben Shi via llvm-dev <llvm-dev at
lists.llvm.org> wrote:

Hello,


In the clang's riscv driver,
https://github.com/llvm/llvm-project/blob/main/clang/lib/Driver/ToolChains/Arch/RISCV.cpp


the default abi is fomulated according to arch if no explicit -mabi is
specified.


Is it possible to set the default abi to ilp32f for -march=rv32imacf. For my
exployer's chip, HW F is used while SW D is used. Each time I have to write
"-march=rv32imacf -mabi=ilp32f“， can it be simplified to only
"-march=imacf" ? Just adding a line is enough.


if (MArch.substr(4).contains_lower("f") &&
!MArch.substr(4).contains_lower("d"))
return "ilp32f";


Can I submit a patch to fix it?


Ben


_______________________________________________
LLVM Developers mailing list
llvm-dev at lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev
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I also think the logic of fomulating default arch according to -mabi can be
improved.


  // 3. Choose a default based on `-mabi=`
  //
  // ilp32e -> rv32e
  // ilp32 | ilp32f | ilp32d -> rv32imafdc
  // lp64 | lp64f | lp64d -> rv64imafdc
  
it can be
  // ilp32e -> rv32e
  // ilp32 -> rv32imac
  // ilp32f -> rv32imacf
  // ilp32d -> rv32 imacfd
  // lp64 -> rv64imac
  // lp64f -> rv64imacf
  // lp64d -> rv64imacfd

















At 2021-06-08 12:06:15, "Craig Topper" <craig.topper at
gmail.com> wrote:

That one line change doesn't look like it handles multiletter extension
names correctly. For example, Zbf contains "f".


~Craig




On Mon, Jun 7, 2021 at 8:13 PM Ben Shi via llvm-dev <llvm-dev at
lists.llvm.org> wrote:

Hello,


In the clang's riscv driver,
https://github.com/llvm/llvm-project/blob/main/clang/lib/Driver/ToolChains/Arch/RISCV.cpp


the default abi is fomulated according to arch if no explicit -mabi is
specified.


Is it possible to set the default abi to ilp32f for -march=rv32imacf. For my
exployer's chip, HW F is used while SW D is used. Each time I have to write
"-march=rv32imacf -mabi=ilp32f“， can it be simplified to only
"-march=imacf" ? Just adding a line is enough.


if (MArch.substr(4).contains_lower("f") &&
!MArch.substr(4).contains_lower("d"))
return "ilp32f";


Can I submit a patch to fix it?


Ben


_______________________________________________
LLVM Developers mailing list
llvm-dev at lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev
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