https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94482
Bug ID: 94482
Summary: Inserting into vector with optimization enabled on x86
generates incorrect result
Product: gcc
Version: 9.3.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: target
Assignee: unassigned at gcc dot gnu.org
Reporter: e...@coeus-group.com
Target Milestone: ---
Created attachment 48193
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=48193&action=edit
Test case
I'm tyring to implement _mm_insert_epi64 without relying on intrinsics. The
GCC-generated executable fails on x86 (but not x86_64) at -O2 and above.
AFAICT it works on every other architecture and optimiaztion level I've tried.
It happens on every version of GCC I've tested (7 - 9.3.0), in both C and C++
modes.
I've attached a test case (generated with C-Reduce, slightly modified to remove
some unnecessary macros) which reproduces the issue. Line 4 is interesting;
the j field isn't used anywhere but if you remove it the code works
(unfortunately not an option in my project).
Please let me know if you need any additional information.
