Re: [PATCH] manual: Avoid name collision in libm ULP table [BZ #28956]

[Adhemerval Zanella <adhemerval.zanella@linaro.org>]

On 05/04/2022 06:46, Tom Coldrick via Libc-alpha wrote:
> The 32-bit and 64-bit variants of RISC-V share the same name - "RISC-V"
> - when generating the libm error table for the info pages. This
> collision, and the way how the table is generated, mean that the values
> in the final table for "RISC-V" may be either for the 32- or 64-bit
> variant, with no indication as to which.
> 
> As an additional side-effect, this makes the build non-reproducible, as
> the error table generated is dependent upon the host filesystem
> implementation.
> 
> To solve this issue, the libm-test-ulps-name files for both variants
> have been modified to include their word size, so as to remove the
> collision and provide more accurate information in the table.
> 
> An alternative proposed was to merge the two variants' ULP values into a
> single file, but this would mean that information about error values is
> lost, as the two variants are not identical. Some differences are
> considerable, notably the values for the exp() function are large.

Path looks ok, but is there any expectation that RV64 and RV32 hardware
floating-point implementation or compiler generate code to have different
precision? Otherwise it would be simple to just use one ulp tests file.

> ---
>  sysdeps/riscv/rv32/rvd/libm-test-ulps-name | 2 +-
>  sysdeps/riscv/rv64/rvd/libm-test-ulps-name | 2 +-
>  2 files changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/sysdeps/riscv/rv32/rvd/libm-test-ulps-name b/sysdeps/riscv/rv32/rvd/libm-test-ulps-name
> index 827fcdca19..6d2816082e 100644
> --- a/sysdeps/riscv/rv32/rvd/libm-test-ulps-name
> +++ b/sysdeps/riscv/rv32/rvd/libm-test-ulps-name
> @@ -1 +1 @@
> -RISC-V
> +RISC-V 32-bit
> diff --git a/sysdeps/riscv/rv64/rvd/libm-test-ulps-name b/sysdeps/riscv/rv64/rvd/libm-test-ulps-name
> index 827fcdca19..9cb50380df 100644
> --- a/sysdeps/riscv/rv64/rvd/libm-test-ulps-name
> +++ b/sysdeps/riscv/rv64/rvd/libm-test-ulps-name
> @@ -1 +1 @@
> -RISC-V
> +RISC-V 64-bit