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Re: [PATCH] tilegx: work around vector insn bug in gcc
On 12/5/2017 11:22 AM, Joseph Myers wrote:
On Tue, 5 Dec 2017, Adhemerval Zanella wrote:
On 04/12/2017 13:56, Chris Metcalf wrote:
Avoid an issue in gcc where some of the vector (aka SIMD) ops will
sometimes end up getting wrongly optimized out. We use these
instructions in many of the string implementations. If/when we
have an upstreamed fix for this problem in gcc we can conditionalize
the use of the extended assembly workaround in glibc.
Do you the conditions to trigger this issue (compiler option, gcc
It would seem appropriate for the comment saying "buggy in current
compiler versions" to link to a corresponding bug report in GCC Bugzilla.
Good point. A bug was filed for this a year ago (78117) and I added a
comment with my small use case, and pushed a tweak to the comment
in sysdeps/tile/tilegx/string-endian.h referencing the bug.
Chris Metcalf, Mellanox Technologies