Methods and systems for computing floating-point intervals
View Patent ↗Computing an output interval includes producing a first product resulting from a conditional multiplication using a first operand, a second operand, and a third operand. Next a second product is produced resulting from the conditional multiplication using the first operand, the second operand, and the third operand. Then a third product is produced resulting from the conditional multiplication using the first operand, the second operand, and the third operand. Next a fourth product is produced resulting from the conditional multiplication using the first operand, the second operand, and the third operand. And finally, the output interval is produced including an output interval lower-point and an output interval upper-point, the output interval lower-point being the minimum of the first product and the third product, and the output interval upper-point being the maximum of the second product and the fourth product.
1. A system for computing an output interval comprising:
a component for producing a first product resulting from a conditional multiplication using a first operand, a second operand, and a third operand, the operands respectively including a first input interval lower-point, a second input interval lower-point, and a second input interval upper-point;
a component for producing a second product resulting from the conditional multiplication using the first operand, the second operand, and the third operand, the operands respectively including a first input interval upper-point, the second input interval lower-point, and the second input interval upper-point;
a component for producing a third product resulting from the conditional multiplication using the first operand, the second operand, and the third operand, the operands respectively including the first input interval lower-point, the second input interval upper-point, and the second input interval lower-point;
a component for producing a fourth product resulting from the conditional multiplication using the first operand, the second operand, and the third operand, the operands respectively including the first input interval upper-point, the second input interval upper-point, and the second input interval lower-point; and
a component for producing the output interval including an output interval lower-point and an output interval upper-point, the output interval lower-point being the minimum of the first product and the third product, and the output interval upper-point being the maximum of the second product and the fourth product.
2. The system for computing the output interval of claim 1 , wherein at least one of the first product, the second product, the third product, and the fourth product is one of rounded up and rounded down.
3. The system for computing the output interval of claim 1 , wherein the first product and the second product are rounded down and the third product and the fourth product are rounded up.
4. The system for computing the output interval of claim 1 , wherein at least one of the first input interval lower-point, the first input interval upper-point, the second input interval lower-point, and the second input interval upper-point comprises a floating point number.
5. The system for computing the output interval of claim 1 , wherein the result of the conditional multiplication is the product of the first operand and the second operand if the sign of the first operand is positive.
6. The system for computing the output interval of claim 5 , wherein the result of the conditional multiplication comprises a special case value when at least one of the first operand and the second operand comprise at least one of −∞, +∞, +0, and −0.
7. The system for computing the output interval of claim 1 , wherein the result of the conditional multiplication is the product of the first operand and the third operand if the sign of the first operand is negative.
8. The system for computing the output interval of claim 7 , wherein the result of the conditional multiplication comprises a special case value when at least one of the first operand and the third operand comprise at least one of −∞, +∞, +0, and −0.
9. The system for computing the output interval of claim 1 , wherein at least one of the component for producing the first product, the component for producing the second product, the component for producing the third product, and the component for producing the fourth product further comprises:
a component for receiving the first operand;
a component for receiving the second operand;
a component for receiving the third operand;
a component for selecting a fourth operand based upon a sign of the first operand, the fourth operand comprising one of the second operand and the third operand; and
a component for multiplying the first operand and the fourth operand.
10. The system for computing the output interval of claim 9 , wherein the component for multiplying the first operand and the fourth operand is further configured for rounding the result of the multiplication based upon a rounding mode.
11. A computer-readable medium on which is stored a set of instructions for computing an output interval, which when executed perform stages comprising:
producing a first product resulting from a conditional multiplication using a first operand, a second operand, and a third operand, the operands respectively including a first input interval lower-point, a second input interval lower-point, and a second input interval upper-point;
producing a second product resulting from the conditional multiplication using the first operand, the second operand, and the third operand, the operands respectively including a first input interval upper-point, the second input interval lower-point, and the second input interval upper-point;
producing a third product resulting from the conditional multiplication using the first operand, the second operand, and the third operand, the operands respectively including the first input interval lower-point, the second input interval upper-point, and the second input interval lower-point;
producing a fourth product resulting from the conditional multiplication using the first operand, the second operand, and the third operand, the operands respectively including the first input interval upper-point, the second input interval upper-point, and the second input interval lower-point; and
producing the output interval including an output interval lower-point and an output interval upper-point, the output interval lower-point being the minimum of the first product and the third product, and the output interval upper-point being the maximum of the second product and the fourth product.
12. The computer-readable medium for computing the output interval of claim 11 , wherein at least one of the first product, the second product, the third product, and the fourth product is one of rounded up and rounded down.
13. The computer-readable medium for computing the output interval of claim 11 , wherein the first product and the second product are rounded down and the third product and the fourth product are rounded up.
14. The computer-readable medium for computing the output interval of claim 11 , wherein at least one of the first input interval lower-point, the first input interval upper-point, the second input interval lower-point, and the second input interval upper-point comprises a floating point number.
15. The computer-readable medium for computing the output interval of claim 11 , wherein the result of the conditional multiplication is the product of the first operand and the second operand if the sign of the first operand is positive.
16. The computer-readable medium for computing the output interval of claim 15 , wherein the result of the conditional multiplication comprises a special case value when at least one of the first operand and the second operand comprise at least one of −∞, +∞, +0, and −0.
17. The computer-readable medium for computing the output interval of claim 11 , wherein the result of the conditional multiplication is the product of the first operand and the third operand if the sign of the first operand is negative.
18. The computer-readable medium for computing the output interval of claim 17 , wherein the result of the conditional multiplication comprises a special case value when at least one of the first operand and the third operand comprise at least one of −∞, +∞, +0, and −0.
19. The computer-readable medium for computing the output interval of claim 11 , wherein producing at least one of the first product, the second product, the third product, and the fourth product resulting from the conditional multiplication using the first operand, the second operand, and the third operand further comprises:
receiving the first operand;
receiving the second operand;
receiving the third operand;
selecting a fourth operand based upon a sign of the first operand, the fourth operand comprising one of the second operand and the third operand; and
multiplying the first operand and the fourth operand.
20. The computer-readable medium for computing the output interval of claim 19 , wherein multiplying the first operand and the fourth operand further comprises rounding the result of the multiplication based upon a rounding mode.