For many times I noticed the following C2 JIT code in specJBB2005 when checking array length:

    311 0x0000007f7cd8b4f8: ldr w11, [x17,#12] ;*arraylength
    312 ; - java.lang.String::hashCode@13 (line 1467)
    313 ; implicit exception: dispatches to 0x0000007f7cd8b604
    314 0x0000007f7cd8b4fc: cmp w11, #0x0
    315 0x0000007f7cd8b500: b.le 0x0000007f7cd8b5e8 ;*ifle
    316 ; - java.lang.String::hashCode@14 (line 1467)
    317
    318 0x0000007f7cd8b504: cmp w11, #0x0
    319 0x0000007f7cd8b508: b.ls 0x0000007f7cd8b5f0
    320 0x0000007f7cd8b50c: sub w12, w11, #0x1
    321 0x0000007f7cd8b510: cmp w12, w11
    322 0x0000007f7cd8b514: b.cs 0x0000007f7cd8b5f0 ;*bipush
    323 ; - java.lang.String::hashCode@33 (line 1471)
    324
    325 0x0000007f7cd8b518: ldrh w0, [x17,#16] ;*caload
    326 ; - java.lang.String::hashCode@39 (line 1471)
    327
    328 0x0000007f7cd8b51c: sub w13, w11, #0x3
    329 0x0000007f7cd8b520: cmp w12, w13
    330 0x0000007f7cd8b524: orr w16, wzr, #0x80000000
    331 0x0000007f7cd8b528: lsl w10, w0, #5
    332 0x0000007f7cd8b52c: csel w16, w16, w13, lt
    333 0x0000007f7cd8b530: orr w1, wzr, #0x1
    334 0x0000007f7cd8b534: sub w14, w10, w0
    335 0x0000007f7cd8b538: cmp w16, #0x1
    336 0x0000007f7cd8b53c: b.le 0x0000007f7cd8b5a4
    337 0x0000007f7cd8b540: b 0x0000007f7cd8b554

  The following two instructions can be combined into one cbzw instruction:
    318 0x0000007f7cd8b504: cmp w11, #0x0
    319 0x0000007f7cd8b508: b.ls 0x0000007f7cd8b5f0