https://gcc.gnu.org/bugzilla/show_bug.cgi?id=83393
--- Comment #1 from Zdenek Sojka <zsojka at seznam dot cz> ---
(In reply to Zdenek Sojka from comment #0)
> ... even though insn 16 output (r108) should be used insn 20; ...
s/insn 16/insn 14/
Later, there is:
Trying 18 -> 20:
18: r116:SI=0
20: {r108:HI=r108:HI<<r116:SI#0;clobber flags:CC;}
REG_DEAD r116:SI
REG_UNUSED flags:CC
...
Successfully matched this instruction:
(set (reg/v:HI 108 [ fD.1899 ])
(reg/v:HI 108 [ fD.1899 ]))
allowing combination of insns 18 and 20
original costs 4 + 4 = 8
replacement cost 4
deferring deletion of insn with uid = 18.
modifying insn i3 20: r108:HI=r108:HI
deferring rescan insn with uid = 20.
