From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 1724 invoked by alias); 13 Nov 2019 22:04:42 -0000 Mailing-List: contact dwz-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Post: List-Help: List-Subscribe: Sender: dwz-owner@sourceware.org Received: (qmail 1706 invoked by uid 89); 13 Nov 2019 22:04:41 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Checked: by ClamAV 0.100.3 on sourceware.org X-Virus-Found: No X-Spam-SWARE-Status: No, score=-12.6 required=5.0 tests=AWL,BAYES_00,SPF_PASS autolearn=ham version=3.3.1 spammy=Definition X-Spam-Status: No, score=-12.6 required=5.0 tests=AWL,BAYES_00,SPF_PASS autolearn=ham version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on sourceware.org X-Spam-Level: X-HELO: mx1.suse.de X-Virus-Scanned: by amavisd-new at test-mx.suse.de Subject: Re: [RFC] Implement C++ One Definition Rule for struct, class and union From: Tom de Vries To: dwz@sourceware.org, Jakub Jelinek , Mark Wielaard Cc: Michael Matz References: <8fdf524a-8cdb-8f9e-3b02-104a07f3f072@suse.de> Autocrypt: addr=tdevries@suse.de; keydata= xsBNBF0ltCcBCADDhsUnMMdEXiHFfqJdXeRvgqSEUxLCy/pHek88ALuFnPTICTwkf4g7uSR7 HvOFUoUyu8oP5mNb4VZHy3Xy8KRZGaQuaOHNhZAT1xaVo6kxjswUi3vYgGJhFMiLuIHdApoc u5f7UbV+egYVxmkvVLSqsVD4pUgHeSoAcIlm3blZ1sDKviJCwaHxDQkVmSsGXImaAU+ViJ5l CwkvyiiIifWD2SoOuFexZyZ7RUddLosgsO0npVUYbl6dEMq2a5ijGF6/rBs1m3nAoIgpXk6P TCKlSWVW6OCneTaKM5C387972qREtiArTakRQIpvDJuiR2soGfdeJ6igGA1FZjU+IsM5ABEB AAHNH1RvbSBkZSBWcmllcyA8dGRldnJpZXNAc3VzZS5kZT7CwKsEEwEIAD4WIQSsnSe5hKbL MK1mGmjuhV2rbOJEoAUCXSW0JwIbAwUJA8JnAAULCQgHAgYVCgkICwIEFgIDAQIeAQIXgAAh CRDuhV2rbOJEoBYhBKydJ7mEpsswrWYaaO6FXats4kSgc48H/Ra2lq5p3dHsrlQLqM7N68Fo eRDf3PMevXyMlrCYDGLVncQwMw3O/AkousktXKQ42DPJh65zoXB22yUt8m0g12xkLax98KFJ 5NyUloa6HflLl+wQL/uZjIdNUQaHQLw3HKwRMVi4l0/Jh/TygYG1Dtm8I4o708JS4y8GQxoQ UL0z1OM9hyM3gI2WVTTyprsBHy2EjMOu/2Xpod95pF8f90zBLajy6qXEnxlcsqreMaqmkzKn 3KTZpWRxNAS/IH3FbGQ+3RpWkNGSJpwfEMVCeyK5a1n7yt1podd1ajY5mA1jcaUmGppqx827 8TqyteNe1B/pbiUt2L/WhnTgW1NC1QDOwE0EXSW0JwEIAM99H34Bu4MKM7HDJVt864MXbx7B 1M93wVlpJ7Uq+XDFD0A0hIal028j+h6jA6bhzWto4RUfDl/9mn1StngNVFovvwtfzbamp6+W pKHZm9X5YvlIwCx131kTxCNDcF+/adRW4n8CU3pZWYmNVqhMUiPLxElA6QhXTtVBh1RkjCZQ Kmbd1szvcOfaD8s+tJABJzNZsmO2hVuFwkDrRN8Jgrh92a+yHQPd9+RybW2l7sJv26nkUH5Z 5s84P6894ebgimcprJdAkjJTgprl1nhgvptU5M9Uv85Pferoh2groQEAtRPlCGrZ2/2qVNe9 XJfSYbiyedvApWcJs5DOByTaKkcAEQEAAcLAkwQYAQgAJhYhBKydJ7mEpsswrWYaaO6FXats 4kSgBQJdJbQnAhsMBQkDwmcAACEJEO6FXats4kSgFiEErJ0nuYSmyzCtZhpo7oVdq2ziRKD3 twf7BAQBZ8TqR812zKAD7biOnWIJ0McV72PFBxmLIHp24UVe0ZogtYMxSWKLg3csh0yLVwc7 H3vldzJ9AoK3Qxp0Q6K/rDOeUy3HMqewQGcqrsRRh0NXDIQk5CgSrZslPe47qIbe3O7ik/MC q31FNIAQJPmKXX25B115MMzkSKlv4udfx7KdyxHrTSkwWZArLQiEZj5KG4cCKhIoMygPTA3U yGaIvI/BGOtHZ7bEBVUCFDFfOWJ26IOCoPnSVUvKPEOH9dv+sNy7jyBsP5QxeTqwxC/1ZtNS DUCSFQjqA6bEGwM22dP8OUY6SC94x1G81A9/xbtm9LQxKm0EiDH8KBMLfQ== Message-ID: <199ef515-41a1-0323-9e92-359e04b850a7@suse.de> Date: Tue, 01 Jan 2019 00:00:00 -0000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.2.1 MIME-Version: 1.0 In-Reply-To: <8fdf524a-8cdb-8f9e-3b02-104a07f3f072@suse.de> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit X-SW-Source: 2019-q4/txt/msg00050.txt.bz2 On 12-11-2019 14:56, Tom de Vries wrote: > V. Effect > > We use a cc1 executable to generate executables compressed with no odr, > --odr and --odr-unify: > ... > $ dwz -l50000000 cc1 -o 1 > $ dwz -l50000000 cc1 -o 2 --odr > $ dwz -l50000000 cc1 -o 3 --odr-unify > ... > > Then we can inspect the differences: > ... > $ diff.sh cc1 1 > .debug_info red: 44.80% 111527248 61570632 > .debug_abbrev red: 40.16% 1722726 1030935 > .debug_str red: 0% 6609355 6609355 > total red: 42.26% 119859329 69210922 > $ diff.sh cc1 2 > .debug_info red: 55.16% 111527248 50019425 > .debug_abbrev red: 68.13% 1722726 549035 > .debug_str red: 0% 6609355 6609355 > total red: 52.30% 119859329 57177815 > $ diff.sh cc1 3 > .debug_info red: 58.18% 111527248 46649959 > .debug_abbrev red: 79.57% 1722726 352080 > .debug_str red: 0% 6609355 6609355 > total red: 55.28% 119859329 53611394 > ... > > So, the .debug_info and .debug_abbrev sections are reduced in size by: > - by 42% when not using odr, > - by 52% when using --odr, and > - by 55% when using --odr-unify. > > VI. Cost > > Using the same cc1 example as in V, we can see the cost of the optimization: At V, I correctly used -l50000000 (l lower-case), but here I accidentally used -L50000000 (L upper-case). Which means low-mem mode kicked in and disabled the optimization midway, so the time and mem results presented here earlier were off. Let's try again: ... $ time.sh dwz -l50000000 cc1 -o 1 maxmem: 1341888 real: 7.09 user: 6.90 system: 0.18 $ time.sh dwz -l50000000 cc1 -o 2 --odr maxmem: 1336612 real: 18.72 user: 18.54 system: 0.17 $ time.sh dwz -l50000000 cc1 -o 3 --odr-unify maxmem: 1336216 real: 13.76 user: 13.57 system: 0.18 ... > It's good to note though that without the patch series applied, we use less > memory, due to the struct dw_die not having the copy/origin fields: And here again: ... $ time.sh dwz -lnone cc1 -o 1 maxmem: 1179928 real: 6.98 user: 6.83 system: 0.14 ... Thanks, - Tom