Comment 0 for bug 1817452

The following C code:

int Rem8(int n)
    {
    return n % 8 ;
    }

is recognized as a special case (divisor is power of 2) and compiled by gcc version 5.4 with -O3 into:

Rem8: ldr r3, .L5
        ands r3, r3, r0
        cmp r3, #0
        blt .L4
        mov r0, r3
        bx lr
.L4: subs r3, r3, #1
        orn r3, r3, #7
        adds r3, r3, #1
        mov r0, r3
        bx lr
.L5: .word -2147483641 // Same as 0x80000007

However, there's a much simpler and faster solution:

Rem8: AND R1,R0,7 // R1 = n MOD 8
 TST R1,R0,ASR 31 // Is n < 0 && (n MOD 8) != 0 ?
 ITE NE
 SUBNE R0,R1,8 // Yes: Return (n MOD 8) - 8
 MOVEQ R0,R1 // No: Return (n MOD 8)
 BX LR