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* [Bug build/28680] New: i686 builds broken with -ftree-vectorize @ 2021-12-10 16:48 siddhesh at sourceware dot org 2021-12-10 16:49 ` [Bug build/28680] " siddhesh at sourceware dot org ` (3 more replies) 0 siblings, 4 replies; 5+ messages in thread From: siddhesh at sourceware dot org @ 2021-12-10 16:48 UTC (permalink / raw) To: glibc-bugs https://sourceware.org/bugzilla/show_bug.cgi?id=28680 Bug ID: 28680 Summary: i686 builds broken with -ftree-vectorize Product: glibc Version: 2.35 Status: NEW Severity: normal Priority: P2 Component: build Assignee: unassigned at sourceware dot org Reporter: siddhesh at sourceware dot org CC: carlos at redhat dot com Target Milestone: --- See also: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103646 How to reproduce: configure with vectorizer enabled: $ ../configure --prefix=/usr CC="gcc -m32" CXX="g++ -m32" CFLAGS="-O2 -g -Wp,-D_GLIBCXX_ASSERTIONS -m32 -march=i686 -mtune=generic -msse2 -mfpmath=sse -mstackrealign -fasynchronous-unwind-tables -fstack-clash-protection -ftree-vectorize" --build=i686-redhat-linux Actual results: ../sysdeps/unix/sysv/linux/select.c: In function ‘__select64’: ../sysdeps/unix/sysv/linux/select.c:117:1: error: bp cannot be used in ‘asm’ here 117 | } | ^ make[2]: *** [/home/siddhesh/src/upstream/glibc/build-32/sysd-rules:229: /home/siddhesh/src/upstream/glibc/build-32/misc/select.os] Error 1 Expected results: Successful build. Additional Information: The vectorizer may end up having to realign stack and hence use up ebp, making it unavailable as a logal register variable. Adapting the configure test to account for vectorization may prove to be flaky, so it probably makes sense to simply disable the 6 argument syscall inlining if the vectorizer is enabled since the vectorizer gains may potentially outstrip the benefit of the inlining. This will become a wider issue with gcc12, where the vectorizer is enabled at -O2. -- You are receiving this mail because: You are on the CC list for the bug. ^ permalink raw reply [flat|nested] 5+ messages in thread
* [Bug build/28680] i686 builds broken with -ftree-vectorize 2021-12-10 16:48 [Bug build/28680] New: i686 builds broken with -ftree-vectorize siddhesh at sourceware dot org @ 2021-12-10 16:49 ` siddhesh at sourceware dot org 2021-12-10 17:01 ` fweimer at redhat dot com ` (2 subsequent siblings) 3 siblings, 0 replies; 5+ messages in thread From: siddhesh at sourceware dot org @ 2021-12-10 16:49 UTC (permalink / raw) To: glibc-bugs https://sourceware.org/bugzilla/show_bug.cgi?id=28680 Siddhesh Poyarekar <siddhesh at sourceware dot org> changed: What |Removed |Added ---------------------------------------------------------------------------- Target| |i686 -- You are receiving this mail because: You are on the CC list for the bug. ^ permalink raw reply [flat|nested] 5+ messages in thread
* [Bug build/28680] i686 builds broken with -ftree-vectorize 2021-12-10 16:48 [Bug build/28680] New: i686 builds broken with -ftree-vectorize siddhesh at sourceware dot org 2021-12-10 16:49 ` [Bug build/28680] " siddhesh at sourceware dot org @ 2021-12-10 17:01 ` fweimer at redhat dot com 2021-12-10 17:48 ` siddhesh at sourceware dot org 2022-01-10 16:25 ` [Bug libc/28680] " fweimer at redhat dot com 3 siblings, 0 replies; 5+ messages in thread From: fweimer at redhat dot com @ 2021-12-10 17:01 UTC (permalink / raw) To: glibc-bugs https://sourceware.org/bugzilla/show_bug.cgi?id=28680 Florian Weimer <fweimer at redhat dot com> changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |fweimer at redhat dot com --- Comment #1 from Florian Weimer <fweimer at redhat dot com> --- We will likely have to disable the vectorizer for i686 in Fedora, then. I do not think this is a glibc issue. -- You are receiving this mail because: You are on the CC list for the bug. ^ permalink raw reply [flat|nested] 5+ messages in thread
* [Bug build/28680] i686 builds broken with -ftree-vectorize 2021-12-10 16:48 [Bug build/28680] New: i686 builds broken with -ftree-vectorize siddhesh at sourceware dot org 2021-12-10 16:49 ` [Bug build/28680] " siddhesh at sourceware dot org 2021-12-10 17:01 ` fweimer at redhat dot com @ 2021-12-10 17:48 ` siddhesh at sourceware dot org 2022-01-10 16:25 ` [Bug libc/28680] " fweimer at redhat dot com 3 siblings, 0 replies; 5+ messages in thread From: siddhesh at sourceware dot org @ 2021-12-10 17:48 UTC (permalink / raw) To: glibc-bugs https://sourceware.org/bugzilla/show_bug.cgi?id=28680 --- Comment #2 from Siddhesh Poyarekar <siddhesh at sourceware dot org> --- I don't know, it seems quite like a glibc issue to me. The configure check to see if ebp is usable with the current flags is simplistic compared to actual usage and any enhancement of that check would be flaky since it relies on knowledge of when the compiler needs ebp for the frame pointer. The ebp based inlining is a hack and may not make sense in the long term but I don't know if i686 will exist in that time frame :) I can confirm that disabling the vectorizer with gcc12 works FWIW, but I think dropping the asm("ebp") hack is a better idea. -- You are receiving this mail because: You are on the CC list for the bug. ^ permalink raw reply [flat|nested] 5+ messages in thread
* [Bug libc/28680] i686 builds broken with -ftree-vectorize 2021-12-10 16:48 [Bug build/28680] New: i686 builds broken with -ftree-vectorize siddhesh at sourceware dot org ` (2 preceding siblings ...) 2021-12-10 17:48 ` siddhesh at sourceware dot org @ 2022-01-10 16:25 ` fweimer at redhat dot com 3 siblings, 0 replies; 5+ messages in thread From: fweimer at redhat dot com @ 2022-01-10 16:25 UTC (permalink / raw) To: glibc-bugs https://sourceware.org/bugzilla/show_bug.cgi?id=28680 Florian Weimer <fweimer at redhat dot com> changed: What |Removed |Added ---------------------------------------------------------------------------- Component|build |libc Flags| |security- Status|NEW |RESOLVED Resolution|--- |DUPLICATE CC| |drepper.fsp at gmail dot com --- Comment #3 from Florian Weimer <fweimer at redhat dot com> --- Let's track this under the earlier bug. *** This bug has been marked as a duplicate of bug 27997 *** -- You are receiving this mail because: You are on the CC list for the bug. ^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2022-01-10 16:25 UTC | newest] Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2021-12-10 16:48 [Bug build/28680] New: i686 builds broken with -ftree-vectorize siddhesh at sourceware dot org 2021-12-10 16:49 ` [Bug build/28680] " siddhesh at sourceware dot org 2021-12-10 17:01 ` fweimer at redhat dot com 2021-12-10 17:48 ` siddhesh at sourceware dot org 2022-01-10 16:25 ` [Bug libc/28680] " fweimer at redhat dot com
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