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From: "Gabriel F. T. Gomes" <gabriel@inconstante.eti.br>
To: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Cc: <libc-alpha@sourceware.org>
Subject: Re: [PATCH 03/28] powerpc: Remove power4 mpa optimization
Date: Wed, 24 Apr 2019 18:51:44 -0300	[thread overview]
Message-ID: <20190424215144.pyv35t5ceovhfqxc@tereshkova> (raw)
In-Reply-To: <20190329133529.22523-4-adhemerval.zanella@linaro.org>


On Fri, Mar 29 2019, Adhemerval Zanella wrote:
> This patch removes the POWER4 optimized mpa optimization used for power4+
> build.  For newer chips, GCC generates *worse* code than generic
> implementation as benchmaks result below.

I don't think I have access to POWER4 hardware, but when running
power4-targeted builds on newer processors, I saw no performance
degradation even in that scenario.

> One possibilty would to add
> IFUNC variants for the mpa routines (as x86_64), but it will add complexity
> only for older chips (and one would need to check if power5, power5+, and
> power6 do benefict from this optimization), and only for specific
> implementation (since most used ones such as sin, cos, exp, pow already
> avoid calling the slow multiprecision path).

I don't think it's worth the effort.

> Checked on powerpc-linux-gnu (built without --with-cpu, with
> --with-cpu=power4 and with --with-cpu=power5+ and --disable-multi-arch),
> powerpc64-linux-gnu (built without --with-cp and with --with-cpu=power5+
> and --disable-multi-arch).

Thanks for the thorough checking.

> 	* sysdeps/powerpc/power4/fpu/Makefile: Remove file.
> 	* sysdeps/powerpc/power4/fpu/mpa-arch.h: Likewise.
> 	* sysdeps/powerpc/power4/fpu/mpa.c: Likewise.

Looks good to me.

Reviewed-by: Gabriel F. T. Gomes <gabriel@inconstante.eti.br>

  reply	other threads:[~2019-04-24 21:51 UTC|newest]

Thread overview: 85+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-03-29 13:35 [PATCH 00/28] powerpc floating-point optimization refactor Adhemerval Zanella
2019-03-29 13:35 ` [PATCH 01/28] powerpc: Use generic fabs{f} implementations Adhemerval Zanella
2019-04-01 20:04   ` Joseph Myers
2019-04-03  1:04     ` Adhemerval Zanella
2019-04-15 20:23       ` Gabriel F. T. Gomes
2019-04-15 21:32         ` Tulio Magno Quites Machado Filho
2019-04-17 17:08           ` Adhemerval Zanella
2019-03-29 13:35 ` [PATCH 02/28] powerpc: fma using builtins Adhemerval Zanella
2019-04-01 20:05   ` Joseph Myers
2019-04-03  1:06     ` Adhemerval Zanella
2019-04-15 21:44       ` Gabriel F. T. Gomes
2019-04-17 21:10       ` Joseph Myers
2019-04-17 21:28         ` Adhemerval Zanella
2019-03-29 13:35 ` [PATCH 03/28] powerpc: Remove power4 mpa optimization Adhemerval Zanella
2019-04-24 21:51   ` Gabriel F. T. Gomes [this message]
2019-04-25 12:19     ` Adhemerval Zanella
2019-03-29 13:35 ` [PATCH 04/28] powerpc: ceil/ceilf refactor Adhemerval Zanella
2019-04-25  1:56   ` Gabriel F. T. Gomes
2019-04-25 21:58     ` Adhemerval Zanella
2019-05-02 18:41       ` Gabriel F. T. Gomes
2019-05-04 21:46         ` Gabriel F. T. Gomes
2019-05-06 12:22           ` Adhemerval Zanella
2019-05-09 19:56             ` Gabriel F. T. Gomes
2019-03-29 13:35 ` [PATCH 05/28] powerpc: floor/floorf refactor Adhemerval Zanella
2019-05-03 21:44   ` Gabriel F. T. Gomes
2019-03-29 13:35 ` [PATCH 06/28] powerpc: round/roundf refactor Adhemerval Zanella
2019-05-04  1:10   ` Gabriel F. T. Gomes
2019-03-29 13:35 ` [PATCH 07/28] powerpc: trunc/truncf refactor Adhemerval Zanella
2019-05-09 20:06   ` Gabriel F. T. Gomes
2019-05-09 20:54     ` Adhemerval Zanella
2019-05-09 21:36       ` Gabriel F. T. Gomes
2019-03-29 13:35 ` [PATCH 08/28] powerpc: generic nearbyint/nearbyintf Adhemerval Zanella
2019-05-27 20:42   ` Gabriel F. T. Gomes
2019-03-29 13:35 ` [PATCH 09/28] powerpc: consolidate rint Adhemerval Zanella
2019-05-30 14:36   ` Gabriel F. T. Gomes
2019-03-29 13:35 ` [PATCH 10/28] powerpc: copysign cleanup Adhemerval Zanella
2019-05-31 14:14   ` Gabriel F. T. Gomes
2019-03-29 13:35 ` [PATCH 11/28] benchtests: Add isnan/isinf/isfinite benchmark Adhemerval Zanella
2019-06-05 22:45   ` Gabriel F. T. Gomes
2019-03-29 13:35 ` [PATCH 12/28] math: Use wordsize-64 version for isnan Adhemerval Zanella
2019-06-05 22:45   ` Gabriel F. T. Gomes
2019-03-29 13:35 ` [PATCH 13/28] powerpc: Remove optimized isnan Adhemerval Zanella
2019-06-05 22:46   ` Gabriel F. T. Gomes
2019-03-29 13:35 ` [PATCH 14/28] math: Use wordsize-64 version for isinf Adhemerval Zanella
2019-06-11 13:13   ` Gabriel F. T. Gomes
2019-06-13  8:57   ` Szabolcs Nagy
2019-06-13  9:11     ` Szabolcs Nagy
2019-03-29 13:35 ` [PATCH 15/28] powerpc: Remove optimized isinf Adhemerval Zanella
2019-06-11 13:45   ` Gabriel F. T. Gomes
2019-03-29 13:35 ` [PATCH 16/28] math: Use wordsize-64 version for finite Adhemerval Zanella
2019-06-11 16:20   ` Gabriel F. T. Gomes
2019-03-29 13:35 ` [PATCH 17/28] powerpc: Remove optimized finite Adhemerval Zanella
2019-06-11 18:08   ` Gabriel F. T. Gomes
2019-03-29 13:35 ` [PATCH 18/28] powerpc: refactor powerpc64 lrint/lrintf/llrint/llrintf Adhemerval Zanella
2019-06-13 19:30   ` Gabriel F. T. Gomes
2019-03-29 13:35 ` [PATCH 19/28] powerpc: Refactor powerpc32 lrint/lrintf/llrint/llrintf Adhemerval Zanella
2019-06-14 18:34   ` Gabriel F. T. Gomes
2019-03-29 13:35 ` [PATCH 20/28] powerpc: Refactor powerpc64 lround/lroundf/llround/llroundf Adhemerval Zanella
2019-06-13 19:30   ` Gabriel F. T. Gomes
2019-03-29 13:35 ` [PATCH 21/28] powerpc: Refactor powerpc32 lround/lroundf/llround/llroundf Adhemerval Zanella
2019-06-24 21:07   ` Gabriel F. T. Gomes
2019-06-25 18:34     ` Adhemerval Zanella
2019-06-25 18:44       ` Gabriel F. T. Gomes
2019-03-29 13:35 ` [PATCH 22/28] powerpc: Use generic e_expf Adhemerval Zanella
2019-06-26 12:59   ` Gabriel F. T. Gomes
2019-03-29 13:35 ` [PATCH 23/28] benchtests: hypot benchmark Adhemerval Zanella
2019-06-26 19:58   ` Gabriel F. T. Gomes
2019-03-29 13:35 ` [PATCH 24/28] powerpc: hypot refactor and optimization Adhemerval Zanella
2019-04-01 20:14   ` Joseph Myers
2019-04-03  1:08     ` Adhemerval Zanella
2019-06-26 19:59   ` Gabriel F. T. Gomes
2019-07-08 15:37     ` Adhemerval Zanella
2019-07-08 18:30       ` Adhemerval Zanella
2019-03-29 13:35 ` [PATCH 25/28] powerpc: Refactor modf{f} Adhemerval Zanella
2019-07-05  1:23   ` Gabriel F. T. Gomes
2019-07-08 18:30     ` Adhemerval Zanella
2019-03-29 13:35 ` [PATCH 26/28] benchtests: Add logb{f} benchmark Adhemerval Zanella
2019-07-05  1:23   ` Gabriel F. T. Gomes
2019-07-08 18:31     ` Adhemerval Zanella
2019-03-29 13:35 ` [PATCH 27/28] math: Use wordsize-64 version for s_logb Adhemerval Zanella
2019-07-05  1:23   ` Gabriel F. T. Gomes
2019-07-08 18:31     ` Adhemerval Zanella
2019-03-29 13:35 ` [PATCH 28/28] powerpc: refactor logb{f,l} Adhemerval Zanella
2019-07-05  1:24   ` Gabriel F. T. Gomes
2019-07-08 18:31     ` Adhemerval Zanella

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