Date: Sat, 25 Jul 2020 13:59:26 -0700 From: Mark Millard <marklmi@yahoo.com> To: =?utf-8?Q?Stefan_E=C3=9Fer?= <se@freebsd.org> Cc: svn-src-head@freebsd.org, FreeBSD Toolchain <freebsd-toolchain@freebsd.org>, freebsd-ppc <freebsd-ppc@freebsd.org> Subject: Re: Introduce WITH(OUT)_LTO? (was: Re: svn commit: r362987 - in head: contrib/bc usr.bin/gh-bc) (LLVMgold.so and gnu's ld.gold) Message-ID: <8B43A4F4-E44D-40C0-8984-FD0FD43198FE@yahoo.com> In-Reply-To: <d96b12df-cbff-387d-7bf4-bc5b279b10f4@freebsd.org> References: <64523602-7EFC-4A97-90EA-C776BF2A0AF7.ref@yahoo.com> <64523602-7EFC-4A97-90EA-C776BF2A0AF7@yahoo.com> <d96b12df-cbff-387d-7bf4-bc5b279b10f4@freebsd.org>
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On 2020-Jul-8, at 01:28, Stefan E=C3=9Fer <se at freebsd.org> wrote:
> Am 08.07.20 um 09:01 schrieb Mark Millard:
>> The following is more informational than anything as far
>> as I'm concerned. But there may be implications that I'm
>> unaware of. (I sometimes experiment with toolchain use
>> to see what the current status is for such use.)
>>=20
>> I attempted to build a system for 32-bit powerpc using clang
>> and binutils, building head -r363000 ( from -r363000 ). (This
>> was a cross build, amd64 -> powerpc.) It got a new type of
>> failure, compared to my past experience:
>=20
> Hi Mark,
>=20
> thank you for the report. I have tested with "make universe" (with
> default settings) that this version builds on all architectures,
> but Ed Maste has already disabled -flto for powerpc64, due to run
> time issues (floating point exception, IIRC).
>=20
> I know that you are actively working on PowerPC and I'd appreciate,
> if you could provide me with information on which parameters cause
> breakage and which work for you. The combination of CLANG with LTO
> and GNU binutils cannot work - CLANG and GCC use incompatible file
> formats to represent the intermediate object files.
Hmm. It looks a little more complicated than that . . .
Looks like the devel/llvm80 devel/llvm90 and devel/llvm10
options for powerpc64 include one for:
GOLD=3Don: Build the LLVM Gold plugin for LTO
That produces a plugin (LLVMgold.so) for use with gnu's
ld.gold ( from devel/binutils ).
The system-clang/llvm materials do not seem to include
LLVMgold.so and so prevent use of that toolchain for
LTO via devel/binutils . (A FreeBSD choice rather than
a llvm* vs. binutils technically-blocking issue?)
devel/binutils builds and installs /usr/local/bin/ld.gold
for both 32-bit powerpc contexts and for powerpc64 contexts.
However, for the 32-bit powerpc context, the devel/llvm*
do not include an option to enable building LLVMgold.so .
I do not know if this is just a ports choice vs. if this
has a technically-blocking issue involved.
=3D=3D=3D
Mark Millard
marklmi at yahoo.com
( dsl-only.net went
away in early 2018-Mar)
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