56 results about "Decimal floating point" patented technology

A compiler (or interpreter) detects source language instructions performing arithmetic operations using a fixed point format (preferably packed decimal). Where the operation can be performed without loss of precision or violation of other constraints of the source language, the compiler automatically converts the operands to a floating point format (preferably Decimal Floating Point (DFP)) having hardware support, and re-converts results to the original fixed point format. Preferably, the compiler may combine multiple operations and instructions in an expression tree, analyze the tree, and selectively convert where possible. The compiler preferably performs a heuristic cost judgment in determining whether to use a particular conversion.

A decimal floating point finite number in a decimal floating point format is composed from the number in a different format. A decimal floating point format includes fields to hold information relating to the sign, exponent and significand of the decimal floating point finite number. Other decimal floating point data, including infinities and NaNs (not a number), are also composed. Decimal floating point data are also decomposed from the decimal floating point format to a different format. For composition and decomposition, one or more instructions may be employed, including one or more convert instructions.

A decimal floating point finite number in a decimal floating point format is composed from the number in a different format. A decimal floating point format includes fields to hold information relating to the sign, exponent and significand of the decimal floating point finite number. Other decimal floating point data, including infinities and NaNs (not a number), are also composed. Decimal floating point data are also decomposed from the decimal floating point format to a different format.

A decimal floating point finite number in a decimal floating point format is composed from the number in a different format. A decimal floating point format includes fields to hold information relating to the sign, exponent and significand of the decimal floating point finite number. Other decimal floating point data, including infinities and NaNs (not a number), are also composed. Decimal floating point data are also decomposed from the decimal floating point format to a different format.

Each binary floating-point value in a set of binary floating-point values is converted to a decimal floating-point value. Data are determined including an exponent, a mantissa and a quantity of decimal digits of the mantissa for each decimal floating-point value. The exponents, the mantissas and the quantity of decimal digits are individually compressed to produce compressed floating-point values based on the individual compressions.

A decimal floating point finite number in a decimal floating point format is composed from the number in a different format. A decimal floating point format includes fields to hold information relating to the sign, exponent and significand of the decimal floating point finite number. Other decimal floating point data, including infinities and NaNs (not a number), are also composed. Decimal floating point data are also decomposed from the decimal floating point format to a different format.

Machine instructions, referred to herein as a long Convert from Zoned instruction (CDZT) and extended Convert from Zoned instruction (CXZT), are provided that read EBCDIC or ASCII data from memory, convert it to the appropriate decimal floating point format, and write it to a target floating point register or floating point register pair. Further, machine instructions, referred to herein as a long Convert to Zoned instruction (CZDT) and extended Convert to Zoned instruction (CZXT), are provided that convert a decimal floating point (DFP) operand in a source floating point register or floating point register pair to EBCDIC or ASCII data and store it to a target memory location.

A method for performing a decimal floating point operation. A first operand including a first coefficient and a first exponent is received. The method also includes receiving a second operand that includes a second coefficient and a second exponent. An operation associated with the first operand and the second operand is received. The operation is an addition or a subtraction. Three concurrent calculations are performed on the first operand and the second operand. The first concurrent calculation includes applying the operation to the first operand and the second operand based on a first assumption that the first exponent is equal to the second exponent. The applying the operation based on the first assumption results in a first result and includes utilizing a two cycle adder. The second concurrent calculation includes applying the operation to the first operand and the second operand based on a second assumption that an absolute difference between the first exponent and the second exponent is less than or equal to a number of leading zeros in the coefficient of the operand with the larger exponent. The applying the operation based on the second assumption results in a second result and includes utilizing the two cycle adder. The third concurrent calculation includes applying the operation to the first operand and the second operand based on a third assumption that the absolute difference between the first exponent and the second exponent is greater than the number of leading zeros in the coefficient of the operand with the larger exponent. The applying the operation based on the third assumption results in a third result and includes utilizing the two cycle adder. A final result is selected from the first result, the second result and the third result.

A method for performing a decimal floating-point division, including: receiving, by a decimal floating-point divider, a decimal floating-point dividend and a decimal floating-point divisor; obtaining, by the decimal floating-point divider, a preliminary quotient having a first precision level, where the preliminary quotient is calculated from the decimal floating-point dividend and the decimal-floating point divisor; receiving, by the decimal floating-point divider, a rounding mode; selecting a rounding action based on the preliminary quotient and the rounding mode; and obtaining a rounded quotient having a second precision level by rounding the preliminary quotient according to the rounding action, where the first precision level is at least one digit greater than the second precision level.

A system and method for detecting decimal floating point data processing exceptions. A processor accepts at least one decimal floating point operand and performs a decimal floating point operation on the at least one decimal floating point operand to produce a decimal floating point result. A determination is made as to whether the decimal floating point result fails to maintain a preferred quantum. The preferred quantum indicates a value represented by a least significant digit of a significand of the decimal floating point result. An output is provided, in response to the determining that the decimal floating point result fails to maintain the preferred quantum, indicating an occurrence of a quantum exception. A maskable exception can be generated that is immediately trapped or later detected to control conditional processing.

Each binary floating-point value in a set of binary floating-point values is converted to a decimal floating-point value. Data are determined including an exponent, a mantissa and a quantity of decimal digits of the mantissa for each decimal floating-point value. The exponents, the mantissas and the quantity of decimal digits are individually compressed to produce compressed floating-point values based on the individual compressions.

A method for conversion between a decimal floating-point number and an order-preserving format has been disclosed. The method encodes numbers in the decimal floating-point format into a format which preserves value ordering. This encoding allows for fast and direct string comparison of two values. Such an encoding provides normalized representations for decimal floating-point numbers and supports type-insensitive comparisons. Type-insensitive comparisons are often used in database management systems, where the data type is not specified for values to compare. In addition, the original decimal floating-point format can be recovered from the order-preserving format.