Executing Perform Floating Point Operation Instructions

A computer program product for performing an instruction for converting a floating-point operand, the instruction having implied operands consisting of a first general register and a second general register, comprising at least one non-transitory computer usable storage medium having computer readable program code logic tangibly embodied therein for execution by a computer for performing a method comprising:

• executing, by a processor, the instruction, the executing comprising:
• (a) based on a test bit of the first general register being a first value:
• (1) performing a floating-point conversion function specified by a plurality of function fields of the first general register to produce a result, wherein the floating-point conversion function specified is one of a plurality of specifiable floating-point conversion functions, wherein the processor is configured to execute installed floating-point conversion functions of the plurality of specifiable floating-point conversion functions;
• and
• (2) storing the result in the second general register and setting a condition code, the condition code indicating whether the performing the floating-point conversion function specified encountered an exceptional condition;
• and
• (b) based on the test bit of the first general register being a second value:
• (1) determining whether the floating-point conversion function specified by the plurality of function fields of the first general register is an installed specifiable floating-point conversion function;
• (2) setting a condition code without storing a result, the condition code indicating whether the floating-point conversion function specified is an installed specifiable floating-point conversion function;
• and
• (3) setting a return code in the second general register.

A system for performing an instruction for converting a floating-point operand, the instruction having implied operands consisting of a first general register and a second general register, the system comprising a memory and a processor connected to the memory, the system being configured to perform a method comprising:

• executing, by a processor, the instruction, the executing comprising:
• (a) based on a test bit of the first general register being a first value:
• (1) performing a floating-point conversion function specified by a plurality of function fields of the first general register to produce a result, wherein the floating-point conversion function specified is one of a plurality of specifiable floating-point conversion functions, wherein the processor is configured to execute installed floating-point conversion functions of the plurality of specifiable floating-point conversion functions;
• and
• (2) storing the result in the second general register and setting a condition code, the condition code indicating whether the performing the floating-point conversion function specified encountered an exceptional condition;
• (b) based on the test bit of the first general register being a second value:
• (1) determining whether the floating-point conversion function specified by the plurality of function fields of the first general register is an installed specifiable floating-point conversion function;
• (2) setting a condition code without storing a result, the condition code indicating whether the floating-point conversion function specified is an installed specifiable floating-point conversion function;
• and
• (3) setting a return code in the second general register.