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* [Bug target/107727] New: error: multiversioning needs 'ifunc' which is not supported on this target (x86_64-w64-mingw32 target)
@ 2022-11-16 21:19 unlvsur at live dot com
2022-11-16 21:20 ` [Bug target/107727] " unlvsur at live dot com
` (4 more replies)
0 siblings, 5 replies; 6+ messages in thread
From: unlvsur at live dot com @ 2022-11-16 21:19 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107727
Bug ID: 107727
Summary: error: multiversioning needs 'ifunc' which is not
supported on this target (x86_64-w64-mingw32 target)
Product: gcc
Version: 13.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: target
Assignee: unassigned at gcc dot gnu.org
Reporter: unlvsur at live dot com
Target Milestone: ---
#include<cstdio>
[[__gnu__::__target__("avx2")]]
inline void foo()
{
puts("avx2\n");
}
[[__gnu__::__target__("default")]]
inline void foo()
{
puts("default\n");
}
int main()
{
foo();
}
$ clang++ -o a a.cc --target=x86_64-windows-gnu -s -flto=thin -fuse-ld=lld
$ wine a.exe
avx2
$ x86_64-w64-mingw32-g++ -o a a.cc -s -flto
a.cc: In function 'int main()':
a.cc:10:13: error: multiversioning needs 'ifunc' which is not supported on this
target
10 | inline void foo()
| ^~~
a.cc:18:1: error: use of multiversioned function without a default
18 | }
| ^
^ permalink raw reply [flat|nested] 6+ messages in thread
* [Bug target/107727] error: multiversioning needs 'ifunc' which is not supported on this target (x86_64-w64-mingw32 target)
2022-11-16 21:19 [Bug target/107727] New: error: multiversioning needs 'ifunc' which is not supported on this target (x86_64-w64-mingw32 target) unlvsur at live dot com
@ 2022-11-16 21:20 ` unlvsur at live dot com
2022-11-16 21:29 ` unlvsur at live dot com
` (3 subsequent siblings)
4 siblings, 0 replies; 6+ messages in thread
From: unlvsur at live dot com @ 2022-11-16 21:20 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107727
--- Comment #1 from cqwrteur <unlvsur at live dot com> ---
Here is how clang deals with it on x86_64-windows-gnu (it is how clang calls
x86_64-w64-mingw32)
https://godbolt.org/z/z5cexGEMK
^ permalink raw reply [flat|nested] 6+ messages in thread
* [Bug target/107727] error: multiversioning needs 'ifunc' which is not supported on this target (x86_64-w64-mingw32 target)
2022-11-16 21:19 [Bug target/107727] New: error: multiversioning needs 'ifunc' which is not supported on this target (x86_64-w64-mingw32 target) unlvsur at live dot com
2022-11-16 21:20 ` [Bug target/107727] " unlvsur at live dot com
@ 2022-11-16 21:29 ` unlvsur at live dot com
2022-11-16 21:50 ` pinskia at gcc dot gnu.org
` (2 subsequent siblings)
4 siblings, 0 replies; 6+ messages in thread
From: unlvsur at live dot com @ 2022-11-16 21:29 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107727
--- Comment #2 from cqwrteur <unlvsur at live dot com> ---
BTW. how could i detect this feature being available? I think
#if __has_cpp_attribute(__gnu__::__target__)
#endif
should not be true on targets that do not support it.
^ permalink raw reply [flat|nested] 6+ messages in thread
* [Bug target/107727] error: multiversioning needs 'ifunc' which is not supported on this target (x86_64-w64-mingw32 target)
2022-11-16 21:19 [Bug target/107727] New: error: multiversioning needs 'ifunc' which is not supported on this target (x86_64-w64-mingw32 target) unlvsur at live dot com
2022-11-16 21:20 ` [Bug target/107727] " unlvsur at live dot com
2022-11-16 21:29 ` unlvsur at live dot com
@ 2022-11-16 21:50 ` pinskia at gcc dot gnu.org
2022-11-16 21:50 ` [Bug middle-end/107727] " pinskia at gcc dot gnu.org
2022-11-16 21:51 ` pinskia at gcc dot gnu.org
4 siblings, 0 replies; 6+ messages in thread
From: pinskia at gcc dot gnu.org @ 2022-11-16 21:50 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107727
--- Comment #3 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
What they do is basically have the resolver always called:
callq __cpu_indicator_init
movl __cpu_model+12(%rip), %eax
andl $1024, %eax # imm = 0x400
cmpl $1024, %eax # imm = 0x400
sete %al
andb $1, %al
testb $1, %al
jne .LBB1_1
jmp .LBB1_2
.LBB1_1:
addq $40, %rsp
jmp _Z3foov.avx2 # TAILCALL
.LBB1_2:
nop
addq $40, %rsp
jmp _Z3foov # TAILCALL
Not the fastest way of implementing this either.
A faster way to caching the result of the resolver.
Anyways we currently don't support multiversioning for non-ifuncs supported
targets. Someone will need to program up that support but it might be years
unless you pay someone to do it.
^ permalink raw reply [flat|nested] 6+ messages in thread
* [Bug middle-end/107727] error: multiversioning needs 'ifunc' which is not supported on this target (x86_64-w64-mingw32 target)
2022-11-16 21:19 [Bug target/107727] New: error: multiversioning needs 'ifunc' which is not supported on this target (x86_64-w64-mingw32 target) unlvsur at live dot com
` (2 preceding siblings ...)
2022-11-16 21:50 ` pinskia at gcc dot gnu.org
@ 2022-11-16 21:50 ` pinskia at gcc dot gnu.org
2022-11-16 21:51 ` pinskia at gcc dot gnu.org
4 siblings, 0 replies; 6+ messages in thread
From: pinskia at gcc dot gnu.org @ 2022-11-16 21:50 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107727
Andrew Pinski <pinskia at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|UNCONFIRMED |NEW
Build|x86_64-linux-gnu |
Ever confirmed|0 |1
Severity|normal |enhancement
Target|x86_64-w64-mingw32 |ones which don't support
| |ifunc
Last reconfirmed| |2022-11-16
Host|x86_64-linux-gnu |
Component|target |middle-end
--- Comment #4 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
What they do is basically have the resolver always called:
callq __cpu_indicator_init
movl __cpu_model+12(%rip), %eax
andl $1024, %eax # imm = 0x400
cmpl $1024, %eax # imm = 0x400
sete %al
andb $1, %al
testb $1, %al
jne .LBB1_1
jmp .LBB1_2
.LBB1_1:
addq $40, %rsp
jmp _Z3foov.avx2 # TAILCALL
.LBB1_2:
nop
addq $40, %rsp
jmp _Z3foov # TAILCALL
Not the fastest way of implementing this either.
A faster way to caching the result of the resolver.
Anyways we currently don't support multiversioning for non-ifuncs supported
targets. Someone will need to program up that support but it might be years
unless you pay someone to do it.
^ permalink raw reply [flat|nested] 6+ messages in thread
* [Bug middle-end/107727] error: multiversioning needs 'ifunc' which is not supported on this target (x86_64-w64-mingw32 target)
2022-11-16 21:19 [Bug target/107727] New: error: multiversioning needs 'ifunc' which is not supported on this target (x86_64-w64-mingw32 target) unlvsur at live dot com
` (3 preceding siblings ...)
2022-11-16 21:50 ` [Bug middle-end/107727] " pinskia at gcc dot gnu.org
@ 2022-11-16 21:51 ` pinskia at gcc dot gnu.org
4 siblings, 0 replies; 6+ messages in thread
From: pinskia at gcc dot gnu.org @ 2022-11-16 21:51 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107727
--- Comment #5 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
(In reply to cqwrteur from comment #2)
> BTW. how could i detect this feature being available? I think
>
> #if __has_cpp_attribute(__gnu__::__target__)
>
> #endif
>
> should not be true on targets that do not support it.
That is related to PR 93419 .
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2022-11-16 21:51 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
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2022-11-16 21:19 [Bug target/107727] New: error: multiversioning needs 'ifunc' which is not supported on this target (x86_64-w64-mingw32 target) unlvsur at live dot com
2022-11-16 21:20 ` [Bug target/107727] " unlvsur at live dot com
2022-11-16 21:29 ` unlvsur at live dot com
2022-11-16 21:50 ` pinskia at gcc dot gnu.org
2022-11-16 21:50 ` [Bug middle-end/107727] " pinskia at gcc dot gnu.org
2022-11-16 21:51 ` pinskia at gcc dot gnu.org
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