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From: "redi at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org> To: gcc-bugs@gcc.gnu.org Subject: [Bug target/97653] Incorrect long double calculation with -mabi=ibmlongdouble Date: Tue, 08 Dec 2020 14:09:04 +0000 [thread overview] Message-ID: <bug-97653-4-f62SOdwB0G@http.gcc.gnu.org/bugzilla/> (raw) In-Reply-To: <bug-97653-4@http.gcc.gnu.org/bugzilla/> https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97653 --- Comment #6 from Jonathan Wakely <redi at gcc dot gnu.org> --- This was committed, but with the wrong PR number so didn't get added here: The master branch has been updated by Michael Meissner <meissner@gcc.gnu.org>: https://gcc.gnu.org/g:9f1a6501994a2d18ec4fe2a6664637f48021b210 commit r11-5728-g9f1a6501994a2d18ec4fe2a6664637f48021b210 Author: Michael Meissner <meissner@linux.ibm.com> Date: Thu Dec 3 14:50:26 2020 -0500 PowerPC: PR libgcc/97543 and libgcc/97643, fix long double issues If you use a compiler with long double defaulting to 64-bit instead of 128-bit with IBM extended double, you get linker warnings about mis-matches in the gnu attributes for long double (PR libgcc/97543). Even if the compiler is configured to have long double be 64 bit as the default with the configuration option '--without-long-double-128' you get the warnings. You also get the same issues if you use a compiler with long double defaulting to IEEE 128-bit instead of IBM extended double (PR libgcc/97643). The issue is the way libgcc.a/libgcc.so is built. Right now when building libgcc under Linux, the long double size is set to 128-bits when building libgcc. However, the gnu attributes are set, leading to the warnings. One feature of the current GNU attribute implementation is if you have a shared library (such as libgcc_s.so), the GNU attributes for the shared library is an inclusive OR of all of the objects within the library. This means if any object file that uses the -mlong-double-128 option and uses long double, the GNU attributes for the library will indicate that it uses 128-bit IBM long doubles. If you have a static library, you will get the warning only if you actually reference an object file with the attribute set. This patch does two things: 1) All of the object files that support IBM 128-bit long doubles explicitly set the ABI to IBM extended double. 2) I turned off GNU attributes for building the shared library or for building the IBM 128-bit long double support. libgcc/ 2020-12-03 Michael Meissner <meissner@linux.ibm.com> PR libgcc/97543 PR libgcc/97643 * config/rs6000/t-linux (IBM128_STATIC_OBJS): New make variable. (IBM128_SHARED_OBJS): New make variable. (IBM128_OBJS): New make variable. Set all objects to use the explicit IBM format, and disable gnu attributes. (IBM128_CFLAGS): New make variable. (gcc_s_compile): Add -mno-gnu-attribute to all shared library modules.
next prev parent reply other threads:[~2020-12-08 14:09 UTC|newest] Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top 2020-10-31 8:57 [Bug target/97653] New: " redi at gcc dot gnu.org 2020-10-31 8:58 ` [Bug target/97653] " redi at gcc dot gnu.org 2020-10-31 9:00 ` redi at gcc dot gnu.org 2020-10-31 9:12 ` redi at gcc dot gnu.org 2020-11-03 19:51 ` meissner at gcc dot gnu.org 2020-11-03 19:58 ` meissner at gcc dot gnu.org 2020-11-04 12:02 ` redi at gcc dot gnu.org 2020-12-08 14:09 ` redi at gcc dot gnu.org [this message] 2021-01-21 1:41 ` meissner at gcc dot gnu.org 2021-01-21 1:44 ` meissner at gcc dot gnu.org 2021-03-23 18:07 ` redi at gcc dot gnu.org 2021-03-23 18:08 ` redi at gcc dot gnu.org 2021-03-30 11:28 ` jakub at gcc dot gnu.org 2021-03-30 11:44 ` redi at gcc dot gnu.org 2021-03-30 11:49 ` redi at gcc dot gnu.org 2021-03-30 12:02 ` jakub at gcc dot gnu.org 2021-03-31 10:58 ` [Bug target/97653] [11 Regression] " jakub at gcc dot gnu.org 2021-03-31 11:59 ` jakub at gcc dot gnu.org 2021-03-31 12:24 ` jakub at gcc dot gnu.org 2021-04-03 8:06 ` cvs-commit at gcc dot gnu.org 2021-04-03 8:16 ` jakub at gcc dot gnu.org 2021-04-20 9:45 ` cvs-commit at gcc dot gnu.org
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