block frequency is zero

public class Test {
    static final int arrsz = 64;
    private static int[] tbuf = new int[arrsz];
    private static int[] tbuf2 = new int[arrsz];

    private static void test(int iter) {
      for (int i = 0; i < iter; i++) {
        System.arraycopy(tbuf, 0, tbuf2, 0, 32);
      }
    }

    public static void main(String[] args) {
      for (int i = 0; i < arrsz; i++) {
        tbuf[i] = i;
      }
      for (int i = 0; i < 5; i++) {
        test(10000);
      }
    }
}

gamma -Xbatch -XX:+PrintCompilation -XX:+PrintOptoAssembly -XX:-CICompileOSR Test

1cc B29: # B40 B30 <- B5 B6 Freq: 0.026448
1cc + MOV R_O0,R_L0 ! spill
1d0 + MOV #0,R_O1
1d4 MOV R_O2,R_L2 ! spill
1d8 + MOV #0,R_O3
1dc MOV #32,R_O4
1e0 CALL,static ; NOP ==> wrapper for: slow_arraycopy
        # Test::test @ bci:17 L[0]=R_I0 L[1]=R_L3 STK[0]=R_L0 STK[1]=#0 STK[2]=R_L2 STK[3]=#0 STK[4]=#32
        # L0=Oop L2=Oop L4=Oop
1e8
1e8 B30: # B8 <- B29 Freq: 0
        # Block is sole successor of call
1e8 + BA B8
1e8

=======================================================
An other case.

test/closed/compiler/6563987/Test.java
.hotspot_compiler
print Test testc

gamma -Xbatch -XX:LoopUnrollLimit=0 -XX:CICompilerCount=1 -XX:+PrintCompilation -XX:+PrintOptoAssembly -XX:-CICompileOSR Test

3c0 B47: # B50 B48 <- B10 B17 Loop: B47-B17 inner stride: not constant Freq: 0.181598
3c0 movl [rsp + #28], RBX # spill
3c4 movq RSI, [rsp + #8] # spill
3c9 xorl RDX, RDX # int
3cb movq RCX, RSI # spill
3ce movl R8, [rsp + #0] # spill
3d2 movl R9, [rsp + #4] # spill
3d7 call,static wrapper for: slow_arraycopy
        # Test::testc @ bci:19 L[0]=rsp + #8 L[1]=rsp + #0 L[2]=rsp + #4 L[3]=rsp + #28 L[4]=rsp + #16 L[5]=rsp + #24 L[6]=rsp + #160 L[7]=rsp + #32 L[8]=_ L[9]=RBP L[10]=_ STK[0]=rsp + #8 STK[1]=#0 STK[2]=rsp + #8 STK[3]=rsp + #0 STK[4]=rsp + #4
        # AllocatedObj(0xfffffd7f73f70088)
AllocatedObj(0xfffffd7f73f70088)

3dc
3dc B48: # B17 B49 <- B47 Freq: 0.181595
        # Block is sole successor of call
3dc
3dc incl RBP # int
3de cmpl RBP, [RSP + #28 (32-bit)]
3e2 jlt B17 # loop end P=0.999999 C=996701.000000
3e2
3e8 B49: # B14 <- B48 Freq: 0
3e8 jmp B14
3e8
3ed B50: # B64 <- B47 Freq: 1.81598e-06
3ed # exception oop is in rax; no code emitted
3ed jmp B64
3ed