[RISCV] Add vadd with mask and without mask builtin.

[HsiangKai]

Summary

Demonstrate how to add RISC-V V builtins and lower them to IR intrinsics for V extension.

Authored-by: Roger Ferrer Ibanez <[e-mail]>
Co-Authored-by: Hsiangkai Wang <[e-mail]>

[HsiangKai]

Update test cases to include rv32 target.

[craig.topper]

clang/lib/CodeGen/CGBuiltin.cpp

17940

I think this whole sequence is equivalent to

std::rotate(Ops.begin(), Ops.begin() + 1, Ops.end() - 1);

[HsiangKai]

Address @craig.topper's comments.

[khchen]

clang/lib/Basic/Targets/RISCV.cpp

283

HasRISCVVTypes is an undefined variable?

[HsiangKai]

clang/lib/Basic/Targets/RISCV.cpp

283

I should move the snippet to D92715.

[HsiangKai]

Address @khchen's comments.

[HsiangKai]

D95016 focuses on the Clang RVV builtin generator and it depends on this commit. I know it is clumsy to list the combinations for vadd plainly, but it is a simple way to demonstrate how to add RVV builtins in Clang. Could we accept this patch and D92715 first if there is no concern about these two patches?

[HsiangKai]

Rebase.

[Jim]

clang/test/CodeGen/RISCV/vadd.c

23

Is it necessary with prefix "__builtin_"?
Refer to https://github.com/riscv/rvv-intrinsic-doc/blob/master/rvv_intrinsic_funcs_vl/06_vector_integer_arithmetic_functions.md.

[jrtc27]

clang/test/CodeGen/RISCV/vadd.c

23

rvvintrin.h or whatever it's called will define wrappers. Providing things under a name that's not prefixed by __ can cause collisions with existing code that's not trying to use these intrinsics, since the names are technically available for it to use, though in practice that seems extremely unlikely for these names. However, using proper __-prefixed names is convention, as is using __builtin_ for anything that's a compiler builtin. This is purely an implementation detail that the user should not need to care about unless they want to not include the header they're meant to include, at which point we provide no guarantees.

[Jim]

clang/include/clang/Basic/DiagnosticSemaKinds.td

11139

Add blank line.
Is it "err_riscvv_builtin_not_enabled"?

clang/lib/Basic/Targets/RISCV.cpp

89

Builtins for other extension don't have "__builtin_rvv_" prefix.

[khchen]

clang/lib/Basic/Targets/RISCV.cpp

89

maybe we could rename BuiltinsRISCV.def as BuiltinsRVV.def, and other extension defines their own .def file?

@Jim do you have any suggestion?

[craig.topper]

clang/lib/Basic/Targets/RISCV.cpp

89

Don't most targets pass the full name with the prefix to the BUILTIN macro?

[Jim]

clang/lib/Basic/Targets/RISCV.cpp

89

Most of targets pass the full name with the prefix to the BUILTIN macro.
It can define the full name with the prefix in BuiltinsRISCV.def

[HsiangKai]

Address @Jim's comments.

[HsiangKai]

clang/include/clang/Basic/DiagnosticSemaKinds.td

11139

I use the name that is defined in BSC version. It makes sense to me that it means "the risc-v V builtins are not useable."

@rogfer01, do you have any opinion on it?

[Jim]

clang/lib/Basic/Targets/RISCV.cpp

89

Should it put together with getTargetBuiltins function?

[HsiangKai]

Move BuiltinInfo closed to getTargetBuiltins.

[craig.topper]

clang/include/clang/Basic/BuiltinsRISCV.def

2

Need copyright header

clang/include/clang/Basic/DiagnosticSemaKinds.td

11139

I'm not sure that's the right spelling of useable. It can also be spelled usable. But it doesn't appear in the message so maybe the name should be closer to wording of the message? Maybe err_riscv_builtin_requires_v. That makes it like err_mips_builtin_requires_dsp

[HsiangKai]

Address @craig.topper's comments.

[craig.topper]

LGTM