Retrieve Computational Attributes (RETCA)

Built-in number for RETCA is 145.
RETCA (
       selector   : unsigned binary(4) literal value; its rightmost byte
                    specifies the computational attributes to retrieve
) :   unsigned binary(4) value which contains the computational attributes
      specified by selector

Description:   The right-most byte of selector specifies the computational attributes to retrieve. The format of this byte is as follows:

All other bytes of selector are reserved (must be 0).

The value returned by RETCA has the following structure:

• Byte 0: Exception mask
  

  Bit	Meaning
  0-1	Reserved (binary 0)
  2	Floating-point overflow
  3	Floating-point underflow
  4	Floating-point zero divide
  5	Floating-point inexact result
  6	Floating-point invalid operand
  7	Reserved (binary 0)

• Byte 1: Reserved (binary 0)

• Byte 2: Exception occurrence
  

  Bit	Meaning
  0-1	Reserved (binary 0)
  2	Floating-point overflow
  3	Floating-point underflow
  4	Floating-point zero divide
  5	Floating-point inexact result
  6	Floating-point invalid operand
  7	Reserved (binary 0)

• Byte 3: Computational mode
  

  Bit	Meaning
  0	Reserved (binary 0)
  1-2	Binary floating-point rounding mode 00 - Round toward positive infinity 01 - Round toward negative infinity 10 - Round toward zero 11 - Round to nearest
  3-4	Reserved (binary 0)
  5-7	Decimal floating-point rounding mode 000 - Round to nearest, ties to even 001 - Round toward zero 010 - Round toward positive infinity 011 - Round toward negative infinity 100 - Round to nearest, ties away from zero 101 - Round to nearest, ties toward zero 110 - Round away from zero 111 - Round to prepare for shorter precision

Note: Any floating-point operations currently on the value stack will be computed prior to retrieving the computational attributes. Therefore, the effect of such floating-point operations on the exception occurrence byte, for example, will be reflected in the value returned by the function.

Authorization Required

• None

Lock Enforcement

• None

Exceptions

• None