https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105650
--- Comment #3 from Sergei Trofimovich <slyfox at gcc dot gnu.org> ---
(In reply to Hongtao.liu from comment #1)
> What's the platform are you running on, does it with SSE2?
> GCC default arch is SSE2, and I didn't see any suspicious obove-sse2
> instruction.
It's a znver3 CPU:
$ LANG=C lscpu
Architecture: x86_64
CPU op-mode(s): 32-bit, 64-bit
Address sizes: 48 bits physical, 48 bits virtual
Byte Order: Little Endian
CPU(s): 32
On-line CPU(s) list: 0-15
Off-line CPU(s) list: 16-31
Vendor ID: AuthenticAMD
Model name: AMD Ryzen 9 5950X 16-Core Processor
CPU family: 25
Model: 33
Thread(s) per core: 1
Core(s) per socket: 16
Socket(s): 1
Stepping: 0
Frequency boost: enabled
CPU max MHz: 5083.3979
CPU min MHz: 0.0000
BogoMIPS: 6787.31
Flags: fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge
mca cmov pat pse36 clflush mmx fxsr sse sse2 ht syscall nx mmxext fxsr_opt
pdpe1gb rdtscp lm constant_tsc rep_good nopl nonstop_tsc cpu
id extd_apicid aperfmperf rapl pni pclmulqdq monitor
ssse3 fma cx16 sse4_1 sse4_2 movbe popcnt aes xsave avx f16c rdrand lahf_lm
cmp_legacy svm extapic cr8_legacy abm sse4a misalignsse 3dn
owprefetch osvw ibs skinit wdt tce topoext
perfctr_core perfctr_nb bpext perfctr_llc mwaitx cpb cat_l3 cdp_l3 hw_pstate
ssbd mba ibrs ibpb stibp vmmcall fsgsbase bmi1 avx2 smep bmi2 erms i
nvpcid cqm rdt_a rdseed adx smap clflushopt clwb
sha_ni xsaveopt xsavec xgetbv1 xsaves cqm_llc cqm_occup_llc cqm_mbm_total
cqm_mbm_local clzero irperf xsaveerptr rdpru wbnoinvd arat npt lb
rv svm_lock nrip_save tsc_scale vmcb_clean flushbyasid
decodeassists pausefilter pfthreshold avic v_vmsave_vmload vgif v_spec_ctrl
umip pku ospke vaes vpclmulqdq rdpid overflow_recov succo
r smca fsrm
Virtualization features:
Virtualization: AMD-V
Caches (sum of all):
L1d: 512 KiB (16 instances)
L1i: 512 KiB (16 instances)
L2: 8 MiB (16 instances)
L3: 64 MiB (2 instances)
NUMA:
NUMA node(s): 1
NUMA node0 CPU(s): 0-15
Vulnerabilities:
Itlb multihit: Not affected
L1tf: Not affected
Mds: Not affected
Meltdown: Not affected
Spec store bypass: Vulnerable
Spectre v1: Vulnerable: __user pointer sanitization and usercopy
barriers only; no swapgs barriers
Spectre v2: Vulnerable, IBPB: disabled, STIBP: disabled
Srbds: Not affected
Tsx async abort: Not affected
I think the problem for me is value mismatch in compare of `if (v != cnt)
__builtin_trap();`. Invalid instruction is generated by `__builtin_trap()`.
