Negate (NEG)

Operand 2: Numeric scalar.

Operand 3-6:

• Branch Form-Branch point, instruction pointer, relative instruction number, or absolute instruction number.

• Indicator Form-Numeric variable scalar or character variable scalar.

Short forms

Operand 2-5:

• Branch Form-Branch point, instruction pointer, relative instruction number, or absolute instruction number.

• Indicator Form-Numeric variable scalar or character variable scalar.

Description:   The numeric value in the source operand is changed as if it had been multiplied by a negative one (-1). The result is placed in the receiver operand.

The sign changing of the source operand value (positive to negative and negative to positive) is performed as follows:

• Binary

  • Extract the numeric value and form the twos complement of it.

• Packed/Zoned

  • Extract the numeric value and force its sign to positive if it is negative or to negative if it is positive.

• Floating-point

  • Extract the numeric value and force the significand sign to positive if it is negative or to negative if it is positive.

The result of the operation is copied into the receiver operand. If this operand is not the same type as that used in performing the operation, the resultant value is converted to its type. If necessary, the resultant value is adjusted to the length of the receiver operand, aligned at the assumed decimal point of the receiver operand, or both before being copied to it. Length adjustment and decimal point alignment are performed according to the rules of arithmetic operations outlined in the Arithmetic Operations. If significant digits are truncated on the left end of the resultant value, a size  (hex 0C0A) exception is signaled. An attempt to negate a maximum negative signed binary value to a signed binary scalar of the same size also results in a size  (hex 0C0A) exception. If a packed or zoned 0 is negated, the result is always positive 0.

When the source floating-point operand represents not-a-number, the sign field of the source is not forced to positive and this value is not altered in the receiver.

For a fixed-point operation, if significant digits are truncated from the left end of the resultant value, a size  (hex 0C0A) exception is signaled. An attempt to negate a maximum negative binary value into a binary scalar of the same size also results in a size  (hex 0C0A) exception.

For floating-point operations that involve a fixed-point receiver, if nonzero digits would be truncated from the left end of the resultant value, an invalid floating-point conversion  (hex 0C0C) exception is signaled.

For a floating-point receiver operand, if the exponent of the resultant value is either too large or too small to be represented in the receiver, the floating-point overflow  (hex 0C06) exception and the floating-point underflow  (hex 0C07) exception are signaled.

If a decimal to binary conversion causes a size  (hex 0C0A) exception to be signaled or if the size exception was suppressed, the binary value contains the correct truncated result only if the decimal value contains 15 or fewer significant nonfractional digits.

Resultant Conditions:  

• Positive-The algebraic value of the receiver operand is positive.

• Negative-The algebraic value of the receiver operand is negative.

• Zero-The algebraic value of the receiver operand is zero.

• Unordered-The value assigned a floating-point receiver operand is NaN.

Authorization Required

• None

Lock Enforcement

• None

Exceptions

06 Addressing

• 0601 Space Addressing Violation
• 0602 Boundary Alignment
• 0603 Range

08 Argument/Parameter

• 0801 Parameter Reference Violation

0C Computation

• 0C02 Decimal Data
• 0C06 Floating-Point Overflow
• 0C07 Floating-Point Underflow
• 0C09 Floating-Point Invalid Operand
• 0C0A Size
• 0C0C Invalid Floating-Point Conversion
• 0C0D Floating-Point Inexact Result

10 Damage Encountered

• 1004 System Object Damage State
• 1044 Partial System Object Damage

1C Machine-Dependent

• 1C03 Machine Storage Limit Exceeded

20 Machine Support

• 2002 Machine Check
• 2003 Function Check

22 Object Access

• 2201 Object Not Found
• 2202 Object Destroyed
• 2203 Object Suspended
• 2208 Object Compressed
• 220B Object Not Available

24 Pointer Specification

• 2401 Pointer Does Not Exist
• 2402 Pointer Type Invalid

2C Program Execution

• 2C04 Branch Target Invalid

2E Resource Control Limit

• 2E01 User Profile Storage Limit Exceeded

36 Space Management

• 3601 Space Extension/Truncation

44 Protection Violation

• 4401 Object Domain or Hardware Storage Protection Violation
• 4402 Literal Values Cannot Be Changed