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From: "tkoenig at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug middle-end/97738] Optimizing division by value & - value for HAKMEM 175
Date: Fri, 06 Nov 2020 14:21:40 +0000	[thread overview]
Message-ID: <bug-97738-4-bR3qO30ki2@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-97738-4@http.gcc.gnu.org/bugzilla/>

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97738

--- Comment #2 from Thomas Koenig <tkoenig at gcc dot gnu.org> ---
Created attachment 49516
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=49516&action=edit
Small benchmark

Here's a small benchmark for counting all 32-bit numbers with 16 bits set
according to the HAKMEM source.

Timing is (first float is elapsed time in seconds for version with division,
second float is for the shift):

2.319526 601080391
1.147284 601080391

with -O3 -march=native on an AMD Ryzen 7 1700X,

4.539288 601080391
2.700514 601080391

on POWER9.

  parent reply	other threads:[~2020-11-06 14:21 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-11-06  8:23 [Bug rtl-optimization/97738] New: " tkoenig at gcc dot gnu.org
2020-11-06  8:45 ` [Bug middle-end/97738] " rguenth at gcc dot gnu.org
2020-11-06 14:21 ` tkoenig at gcc dot gnu.org [this message]
2020-11-06 17:52 ` tkoenig at gcc dot gnu.org
2020-11-06 18:27 ` jakub at gcc dot gnu.org
2020-11-07 10:21 ` tkoenig at gcc dot gnu.org
2021-09-26  8:23 ` pinskia at gcc dot gnu.org
2021-09-26  8:24 ` pinskia at gcc dot gnu.org

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