https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78132
--- Comment #3 from Uroš Bizjak <ubizjak at gmail dot com> ---
The failing instruction is pre-existing movdi_internal.
movzwl c(%rip), %eax # 5 zero_extendhidi2/1 [length = 8]
kmovw e(%rip), %k1 # 9 *movhi_internal/6 [length = 9]
movzbl a(%rip), %edx # 13 *movqi_internal/3 [length = 8]
kmovq %rax, %k0 # 51 *movdi_internal/23 [length = 4]
kmovw %k0, %ecx # 40 *movqi_internal/10 [length = 4]
Unsupported insn alternatives should be also conditionally enabled in QI, SI
and DI move patterns, in the same way as the fix for PR 77476.
