From: Daniel Henrique Barboza <danielhb413@gmail.com>
To: Richard Henderson <richard.henderson@linaro.org>, qemu-devel@nongnu.org
Cc: alex.bennee@linaro.org, qemu-ppc@nongnu.org, balaton@eik.bme.hu
Subject: Re: [PATCH] target/ppc: Merge COMPUTE_CLASS and COMPUTE_FPRF
Date: Sun, 28 May 2023 07:05:37 -0300 [thread overview]
Message-ID: <846f8f80-e100-b004-f793-489df3f8e2d9@gmail.com> (raw)
In-Reply-To: <20230523202507.688859-1-richard.henderson@linaro.org>
On 5/23/23 17:25, Richard Henderson wrote:
> Instead of computing an artifical "class" bitmask then
> converting that to the fprf value, compute the final
> value from the start.
>
> Reorder the tests to check the most likely cases first.
Queued in ppc-next ("artifical" typo fixed).
Thanks,
Daniel
>
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
> ---
> target/ppc/fpu_helper.c | 78 ++++++++++++-----------------------------
> 1 file changed, 22 insertions(+), 56 deletions(-)
>
> diff --git a/target/ppc/fpu_helper.c b/target/ppc/fpu_helper.c
> index a66e16c212..03150a0f10 100644
> --- a/target/ppc/fpu_helper.c
> +++ b/target/ppc/fpu_helper.c
> @@ -141,62 +141,28 @@ static inline int ppc_float64_get_unbiased_exp(float64 f)
> return ((f >> 52) & 0x7FF) - 1023;
> }
>
> -/* Classify a floating-point number. */
> -enum {
> - is_normal = 1,
> - is_zero = 2,
> - is_denormal = 4,
> - is_inf = 8,
> - is_qnan = 16,
> - is_snan = 32,
> - is_neg = 64,
> -};
> -
> -#define COMPUTE_CLASS(tp) \
> -static int tp##_classify(tp arg) \
> -{ \
> - int ret = tp##_is_neg(arg) * is_neg; \
> - if (unlikely(tp##_is_any_nan(arg))) { \
> - float_status dummy = { }; /* snan_bit_is_one = 0 */ \
> - ret |= (tp##_is_signaling_nan(arg, &dummy) \
> - ? is_snan : is_qnan); \
> - } else if (unlikely(tp##_is_infinity(arg))) { \
> - ret |= is_inf; \
> - } else if (tp##_is_zero(arg)) { \
> - ret |= is_zero; \
> - } else if (tp##_is_zero_or_denormal(arg)) { \
> - ret |= is_denormal; \
> - } else { \
> - ret |= is_normal; \
> - } \
> - return ret; \
> -}
> -
> -COMPUTE_CLASS(float16)
> -COMPUTE_CLASS(float32)
> -COMPUTE_CLASS(float64)
> -COMPUTE_CLASS(float128)
> -
> -static void set_fprf_from_class(CPUPPCState *env, int class)
> -{
> - static const uint8_t fprf[6][2] = {
> - { 0x04, 0x08 }, /* normalized */
> - { 0x02, 0x12 }, /* zero */
> - { 0x14, 0x18 }, /* denormalized */
> - { 0x05, 0x09 }, /* infinity */
> - { 0x11, 0x11 }, /* qnan */
> - { 0x00, 0x00 }, /* snan -- flags are undefined */
> - };
> - bool isneg = class & is_neg;
> -
> - env->fpscr &= ~FP_FPRF;
> - env->fpscr |= fprf[ctz32(class)][isneg] << FPSCR_FPRF;
> -}
> -
> -#define COMPUTE_FPRF(tp) \
> -void helper_compute_fprf_##tp(CPUPPCState *env, tp arg) \
> -{ \
> - set_fprf_from_class(env, tp##_classify(arg)); \
> +#define COMPUTE_FPRF(tp) \
> +void helper_compute_fprf_##tp(CPUPPCState *env, tp arg) \
> +{ \
> + bool neg = tp##_is_neg(arg); \
> + target_ulong fprf; \
> + if (likely(tp##_is_normal(arg))) { \
> + fprf = neg ? 0x08 << FPSCR_FPRF : 0x04 << FPSCR_FPRF; \
> + } else if (tp##_is_zero(arg)) { \
> + fprf = neg ? 0x12 << FPSCR_FPRF : 0x02 << FPSCR_FPRF; \
> + } else if (tp##_is_zero_or_denormal(arg)) { \
> + fprf = neg ? 0x18 << FPSCR_FPRF : 0x14 << FPSCR_FPRF; \
> + } else if (tp##_is_infinity(arg)) { \
> + fprf = neg ? 0x09 << FPSCR_FPRF : 0x05 << FPSCR_FPRF; \
> + } else { \
> + float_status dummy = { }; /* snan_bit_is_one = 0 */ \
> + if (tp##_is_signaling_nan(arg, &dummy)) { \
> + fprf = 0x00 << FPSCR_FPRF; \
> + } else { \
> + fprf = 0x11 << FPSCR_FPRF; \
> + } \
> + } \
> + env->fpscr = (env->fpscr & ~FP_FPRF) | fprf; \
> }
>
> COMPUTE_FPRF(float16)
prev parent reply other threads:[~2023-05-28 10:06 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-05-23 20:25 [PATCH] target/ppc: Merge COMPUTE_CLASS and COMPUTE_FPRF Richard Henderson
2023-05-23 22:50 ` BALATON Zoltan
2023-05-23 23:02 ` BALATON Zoltan
2023-05-23 23:06 ` Richard Henderson
2023-05-24 8:52 ` BALATON Zoltan
2023-05-24 13:18 ` Alex Bennée
2023-05-28 10:05 ` Daniel Henrique Barboza [this message]
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