[Issue 16087] Alignment (.alignof) and stack space incorrect for SIMD types.

May 28, 2016

ZombineDev

May 29, 2016

Marco Leise

May 30, 2016

Marco Leise

Nov 20, 2016

Walter Bright

Jul 02, 2017

Vladimir Panteleev

https://issues.dlang.org/show_bug.cgi?id=16087 ZombineDev <petar.p.kirov@gmail.com> changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |petar.p.kirov@gmail.com --

https://issues.dlang.org/show_bug.cgi?id=16087 --- Comment #1 from Marco Leise <Marco.Leise@gmx.de> --- Just a clarification, that doesn't change the subject of this report: It occurred to me today that the stack is aligned to 16 bytes and therefore we cannot guarantee correct alignment for AVX vectors placed on the stack. --

https://issues.dlang.org/show_bug.cgi?id=16087 --- Comment #2 from Marco Leise <Marco.Leise@gmx.de> --- Ok, different sources report that major compilers (llvm, gcc, icc) respect alignments >= 16 on the stack. I'll open a separate issue for that. --

https://issues.dlang.org/show_bug.cgi?id=16087 Walter Bright <bugzilla@digitalmars.com> changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |bugzilla@digitalmars.com --- Comment #3 from Walter Bright <bugzilla@digitalmars.com> --- Partial fix: https://github.com/dlang/dmd/pull/6265 dmd simply doesn't support 32 byte vectors at the moment, so the rest will have to wait. --

July 02, 2017

[Issue 16087] Alignment (.alignof) and stack space incorrect for SIMD types.

Posted by Vladimir Panteleev

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Vladimir Panteleev

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https://issues.dlang.org/show_bug.cgi?id=16087

Vladimir Panteleev <dlang-bugzilla@thecybershadow.net> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |RESOLVED
                 CC|                            |dlang-bugzilla@thecybershad
                   |                            |ow.net
           See Also|                            |https://issues.dlang.org/sh
                   |                            |ow_bug.cgi?id=17237
         Resolution|---                         |WORKSFORME

--- Comment #4 from Vladimir Panteleev <dlang-bugzilla@thecybershadow.net> ---
(In reply to Marco Leise from comment #0)
>     writefln("float8.alignof yields %s but should yield 32.",
> float8.alignof);
>     writefln("void16.alignof yields %s but should yield 16.",
> void16.alignof);

Fixed in https://github.com/dlang/dmd/pull/6265

>     writefln("When embedded, a float4 exposes some hidden alignment, as it
> changes to %s.", Matrix4x4.alignof);

Fixed in https://github.com/dlang/dmd/pull/6582 (issue 17237)

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