https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80080
--- Comment #8 from Dominik Vogt <vogt at linux dot vnet.ibm.com> ---
The patch has a performance regression on s390x.
.L1
lr %r3,%r1
cs %r1,%r4,0(%r2)
jne .L1
becomes
.L1
cs %r1,%r3,0(%r2)
ipm %r4
sra %r4,28
cijne %r4,0,.L1
Although this can be fixed on s390/s390x in a follow-up patch, I cannot really
prove that something similar won't happen on other targets without testing
them.
