The value of a signed immediate operand of a machine instruction is beyond the allowed range for the instruction, where the normal allowed range of values for a 16-bit signed immediate operand is -32768 through to 32767, and for a 32-bit signed immediate operand is -2147483648 through to 2147483647. Immediate operands used in an arithmetic context are signed, with bit 0 of the immediate field being used to hold the sign bit. This reduces by one the number of bits available to hold the absolute value of the operand; for example:

AHI  r1,-30000 is valid, but

AHI r1,50000 is not because bits 1-15 of the immediate field can only hold a maximum absolute value of 32767.