Re: [RFC PATCH v2 3/5] tests/tcg/ppc64le: drop __int128 usage in bcdsub

[Richard Henderson]

On 3/3/22 07:20, matheus.ferst@eldorado.org.br wrote:
> I'm avoiding newer insns like mtvsrdd/mfvsrld to move values between VSR
> and GPR so we can run this test in a POWER8 machine.

This...

> +#define BCDSUB(AH, AL, BH, BL, PS)                          \
> +    asm ("mtvsrd 32, %3\n\t"                                \
> +         "mtvsrd 33, %4\n\t"                                \
> +         "xxmrghd 32, 32, 33\n\t"                           \
> +         "mtvsrd 33, %5\n\t"                                \
> +         "mtvsrd 34, %6\n\t"                                \
> +         "xxmrghd 33, 33, 34\n\t"                           \
> +         "bcdsub. 0, 0, 1, %7\n\t"                          \
> +         "mfocrf %0, 0b10\n\t"                              \
> +         "mfvsrd %1, 32\n\t"                                \
> +         "xxswapd 32, 32\n\t"                               \
> +         "mfvsrd %2, 32\n\t"                                \
> +         : "=r" (cr), "=r" (th), "=r" (tl)                  \
> +         : "r" (AH), "r" (AL), "r" (BH), "r" (BL), "i" (PS) \
> +         : "v0", "v1", "v2");

... belongs here as a comment.

> +        if (TH || TL) {                         \

Would be clearer with TH != UNDEF || TL != UNDEF.

Otherwise,
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>


r~