Backend fix timing

[xiaofeibao-xjtu]

No description provided.

[XiangShanRobot]

[Generated by IPC robot]
commit: f18e22e

commit	astar	copy_and_run	coremark	gcc	gromacs	lbm	linux	mcf	microbench	milc	namd	povray	wrf	xalancbmk
f18e22e	1.812	0.451	2.043	1.199	2.941	2.507	2.196	0.934	1.373	1.397	3.181	2.669	2.403	2.961

master branch:

commit	astar	copy_and_run	coremark	gcc	gromacs	lbm	linux	mcf	microbench	milc	namd	povray	wrf	xalancbmk
d64fbe5	1.812	0.451	2.043	1.199	2.941	2.507	2.196	0.934	1.373	1.397	3.181	2.669	2.403	2.961
939a787	1.812	0.451	2.047	1.199	2.941	2.507	2.196	0.934	1.373	1.397	3.181	2.669	2.403	2.961
9705db6	1.812	0.451	2.047	1.199	2.941	2.507	2.196	0.934	1.373	1.397	3.181	2.669	2.403	2.961
78d7c65	1.812	0.451	2.043	1.199	2.941	2.507	2.196	0.934	1.373	1.397	3.181	2.669	2.403	2.961
5c1e8bf	1.812	0.451	2.043	1.199	2.941	2.507	2.196	0.934	1.373	1.397	3.181	2.669	2.403	2.961
7c26eb0	1.809	0.451	2.043	1.190	2.940	2.496	2.197	0.932	1.373	1.411	3.181	2.669	2.403	2.948
1436b76	1.811	0.451	2.047	1.190	2.940	2.496	2.197	0.932	1.373	1.411	3.181	2.669	2.403	2.948
84c44d2	1.809	0.451	2.047	1.190	2.940	2.496	2.197	0.932	1.373	1.411	3.181	2.669	2.403	2.948
9134676	1.809	0.451	2.047	1.190	2.940	2.496	2.197	0.932	1.373	1.411	3.181	2.669	2.403	2.948
7ffbf5f	1.809	0.452	2.052	1.196	2.951	2.499	2.199	0.930	1.377	1.407	3.436	2.653	2.398	2.941