From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:58837) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1eyp2o-0001VT-UN for qemu-devel@nongnu.org; Wed, 21 Mar 2018 21:29:32 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1eyp2k-0001Dc-Fh for qemu-devel@nongnu.org; Wed, 21 Mar 2018 21:29:30 -0400 Received: from mail-wm0-x243.google.com ([2a00:1450:400c:c09::243]:38993) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1eyp2k-0001D9-6T for qemu-devel@nongnu.org; Wed, 21 Mar 2018 21:29:26 -0400 Received: by mail-wm0-x243.google.com with SMTP id f125so13086506wme.4 for ; Wed, 21 Mar 2018 18:29:25 -0700 (PDT) References: <1521663109-32262-1-git-send-email-cota@braap.org> <1521663109-32262-13-git-send-email-cota@braap.org> From: Alex =?utf-8?Q?Benn=C3=A9e?= In-reply-to: <1521663109-32262-13-git-send-email-cota@braap.org> Date: Thu, 22 Mar 2018 01:29:23 +0000 Message-ID: <871sgckido.fsf@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Subject: Re: [Qemu-devel] [PATCH v1 12/14] hostfloat: support float32/64 square root List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: "Emilio G. Cota" Cc: qemu-devel@nongnu.org, Aurelien Jarno , Peter Maydell , Laurent Vivier , Richard Henderson , Paolo Bonzini , Mark Cave-Ayland Emilio G. Cota writes: > Performance results for fp-bench run under aarch64-linux-user > on an Intel(R) Core(TM) i7-4790K CPU @ 4.00GHz host: > > - before: > sqrt-single: 13.23 MFlops > sqrt-double: 13.24 MFlops > > - after: > sqrt-single: 15.02 MFlops > sqrt-double: 15.07 MFlops > > Note that sqrt in soft-ft is relatively fast, which means > that fp-bench is not very sensitive to changes to sqrt's > emulation speed. Weird, I thought we had slowed it down quite a bit in the re-factor as we eschewed the estimate step for an easier to read but slower iterative process. That's why I chose sqrt for my hostfp hack experiment. > > Signed-off-by: Emilio G. Cota > --- > include/fpu/hostfloat.h | 2 ++ > include/fpu/softfloat.h | 4 ++-- > fpu/hostfloat.c | 20 ++++++++++++++++++++ > fpu/softfloat.c | 6 ++++-- > 4 files changed, 28 insertions(+), 4 deletions(-) > > diff --git a/include/fpu/hostfloat.h b/include/fpu/hostfloat.h > index c006576..b1e0689 100644 > --- a/include/fpu/hostfloat.h > +++ b/include/fpu/hostfloat.h > @@ -16,11 +16,13 @@ float32 float32_sub(float32 a, float32 b, float_statu= s *status); > float32 float32_mul(float32 a, float32 b, float_status *status); > float32 float32_div(float32 a, float32 b, float_status *status); > float32 float32_muladd(float32 a, float32 b, float32 c, int f, float_sta= tus *s); > +float32 float32_sqrt(float32 a, float_status *status); > > float64 float64_add(float64 a, float64 b, float_status *status); > float64 float64_sub(float64 a, float64 b, float_status *status); > float64 float64_mul(float64 a, float64 b, float_status *status); > float64 float64_div(float64 a, float64 b, float_status *status); > float64 float64_muladd(float64 a, float64 b, float64 c, int f, float_sta= tus *s); > +float64 float64_sqrt(float64 a, float_status *status); > > #endif /* HOSTFLOAT_H */ > diff --git a/include/fpu/softfloat.h b/include/fpu/softfloat.h > index 866bd3b..8d5a50a 100644 > --- a/include/fpu/softfloat.h > +++ b/include/fpu/softfloat.h > @@ -348,7 +348,7 @@ float32 soft_float32_mul(float32, float32, float_stat= us *status); > float32 soft_float32_div(float32, float32, float_status *status); > float32 float32_rem(float32, float32, float_status *status); > float32 soft_float32_muladd(float32, float32, float32, int, float_status= *s); > -float32 float32_sqrt(float32, float_status *status); > +float32 soft_float32_sqrt(float32, float_status *status); > float32 float32_exp2(float32, float_status *status); > float32 float32_log2(float32, float_status *status); > int float32_eq(float32, float32, float_status *status); > @@ -488,7 +488,7 @@ float64 soft_float64_mul(float64, float64, float_stat= us *status); > float64 soft_float64_div(float64, float64, float_status *status); > float64 float64_rem(float64, float64, float_status *status); > float64 soft_float64_muladd(float64, float64, float64, int, float_status= *s); > -float64 float64_sqrt(float64, float_status *status); > +float64 soft_float64_sqrt(float64, float_status *status); > float64 float64_log2(float64, float_status *status); > int float64_eq(float64, float64, float_status *status); > int float64_le(float64, float64, float_status *status); > diff --git a/fpu/hostfloat.c b/fpu/hostfloat.c > index a56b70a..974bd57 100644 > --- a/fpu/hostfloat.c > +++ b/fpu/hostfloat.c > @@ -270,3 +270,23 @@ GEN_FPU_DIV(float64_div, float64, double, fabs, DBL_= MIN) > GEN_FPU_FMA(float32_muladd, float32, float, fmaf, fabsf, FLT_MIN) > GEN_FPU_FMA(float64_muladd, float64, double, fma, fabs, DBL_MIN) > #undef GEN_FPU_FMA > + > +#define GEN_FPU_SQRT(name, soft_t, host_t, host_sqrt_func) \ > + soft_t name(soft_t a, float_status *s) \ > + { \ > + soft_t ## _input_flush1(&a, s); \ > + if (likely((soft_t ## _is_normal(a) || soft_t ## _is_zero(a)) &&= \ > + !soft_t ## _is_neg(a) && \ > + s->float_exception_flags & float_flag_inexact && \ > + s->float_rounding_mode =3D=3D float_round_nearest_eve= n)) { \ > + host_t ha =3D soft_t ## _to_ ## host_t(a); = \ > + host_t hr =3D host_sqrt_func(ha); = \ > + \ > + return host_t ## _to_ ## soft_t(hr); \ > + } \ > + return soft_ ## soft_t ## _sqrt(a, s); \ > + } > + > +GEN_FPU_SQRT(float32_sqrt, float32, float, sqrtf) > +GEN_FPU_SQRT(float64_sqrt, float64, double, sqrt) > +#undef GEN_FPU_SQRT > diff --git a/fpu/softfloat.c b/fpu/softfloat.c > index da81ec9..096b658 100644 > --- a/fpu/softfloat.c > +++ b/fpu/softfloat.c > @@ -1980,14 +1980,16 @@ float16 __attribute__((flatten)) float16_sqrt(flo= at16 a, float_status *status) > return float16_round_pack_canonical(pr, status); > } > > -float32 __attribute__((flatten)) float32_sqrt(float32 a, float_status *s= tatus) > +float32 __attribute__((flatten)) > +soft_float32_sqrt(float32 a, float_status *status) > { > FloatParts pa =3D float32_unpack_canonical(a, status); > FloatParts pr =3D sqrt_float(pa, status, &float32_params); > return float32_round_pack_canonical(pr, status); > } > > -float64 __attribute__((flatten)) float64_sqrt(float64 a, float_status *s= tatus) > +float64 __attribute__((flatten)) > +soft_float64_sqrt(float64 a, float_status *status) > { > FloatParts pa =3D float64_unpack_canonical(a, status); > FloatParts pr =3D sqrt_float(pa, status, &float64_params); -- Alex Benn=C3=A9e