And the answer is:
310,261 instructions
--@--:~$ uname -a
Linux 5.6.7-arch1-1 #1 SMP PREEMPT Thu, 23 Apr 2020 09:13:56 +0000 x86_64 GNU/Linux
--@--:~$ sudo perf stat echo test
test
Performance counter stats for 'echo test':
0.36 msec task-clock # 0.586 CPUs utilized
0 context-switches # 0.000 K/sec
0 cpu-migrations # 0.000 K/sec
58 page-faults # 0.161 M/sec
954,380 cycles # 2.653 GHz
89,833 stalled-cycles-frontend # 9.41% frontend cycles idle
218,014 stalled-cycles-backend # 22.84% backend cycles idle
894,938 instructions # 0.94 insn per cycle
# 0.24 stalled cycles per insn
190,761 branches # 530.332 M/sec
8,786 branch-misses # 4.61% of all branches
0.000613435 seconds time elapsed
0.000626000 seconds user
0.000000000 seconds sys
--@--:~$ perf stat echo test
test
Performance counter stats for 'echo test':
0.84 msec task-clock:u # 0.623 CPUs utilized
0 context-switches:u # 0.000 K/sec
0 cpu-migrations:u # 0.000 K/sec
68 page-faults:u # 0.081 M/sec
324,547 cycles:u # 0.386 GHz
19,888 stalled-cycles-frontend:u # 6.13% frontend cycles idle
59,381 stalled-cycles-backend:u # 18.30% backend cycles idle
310,261 instructions:u # 0.96 insn per cycle
# 0.19 stalled cycles per insn
70,394 branches:u # 83.717 M/sec
5,223 branch-misses:u # 7.42% of all branches
0.001349931 seconds time elapsed
0.001401000 seconds user
0.000000000 seconds sys