Abstract: A method in a computer system, one embodiment includes accessing a packed data instruction and generating a corresponding set of control bits to cause a processor to alter a top of stack to zero of a programmer visible register file, accessing a floating point instruction and generating a corresponding set of control bits that cause the processor to operate on the programmer visible register file as a stack, but accessing a transition instruction between the packed data instruction and the scalar floating point instruction and generating a corresponding set of control bits to cause the processor to alter tag data to indicate that programmer visible register file is empty. The method advantageously provides a means for clearing the packed data state at the end of blocks of packed data instructions to leave the floating point state in a clear condition for subsequent operations (e.g. floating point calculations).

Abstract: A processor with instructions to operate on different data types stored in a single logical register file. According to one embodiment of the invention, a processor includes a number of physical registers, a memory unit, and a decode/execution unit. The memory unit is to make the number of physical registers appear to software as a single software-visible register file. The decode/execution unit is to execute on the contents of the single software-visible register file instructions of a first instruction type and of a second instruction type, wherein the single software-visible register file is to be operated as a flat register file during execution of instructions of the second instruction type and as a stack referenced register file during execution of instructions of the first instruction type.

Abstract: A processor with instructions to operate on different data types stored in a single logical register file. According to one embodiment of the invention, a processor includes a number of physical registers, a memory unit, and a decode/execution unit. The memory unit is to make the number of physical registers appear to software as a single software-visible register file. The decode/execution unit is to execute on the contents of the single software-visible register file instructions of a first instruction type and of a second instruction type, wherein the single software-visible register file is to be operated as a flat register file during execution of instructions of the second instruction type and as a stack referenced register file during execution of instructions of the first instruction type.

Abstract: A processor with instructions to operate on different data types stored in a single logical register file. According to one embodiment of the invention, a processor includes a number of physical registers, a memory unit, and a decode/execution unit. The memory unit is to make the number of physical registers appear to software as a single software-visible register file. The decode/execution unit is to execute on the contents of the single software-visible register file instructions of a first instruction type and of a second instruction type, wherein the single software-visible register file is to be operated as a flat register file during execution of instructions of the second instruction type and as a stack referenced register file during execution of instructions of the first instruction type.

Abstract: A method in a computer system, one embodiment includes accessing a packed data instruction and generating a corresponding set of control bits to cause a processor to alter a top of stack to zero of a programmer visible register file, accessing a floating point instruction and generating a corresponding set of control bits that cause the processor to operate on the programmer visible register file as a stack, but accessing a transition instruction between the packed data instruction and the scalar floating point instruction and generating a corresponding set of control bits to cause the processor to alter tag data to indicate that programmer visible register file is empty. The method advantageously provides a means for clearing the packed data state at the end of blocks of packed data instructions to leave the floating point state in a clear condition for subsequent operations (e.g. floating point calculations).

Abstract: A processor with instructions to operate on different data types stored in a single logical register file. According to one aspect of the invention, a first set of instructions of a first instruction type operates on the contents of what at least logically appears to software as a single logical register file. The first set of instructions appears to access the single logical register file as a flat register file. In addition, a first instruction of a second instruction type operates on the logical register file. However, the first instruction appears to access the logical register file as a stack referenced register file. Furthermore, sometime between starting the execution of the first set of instructions and completing the execution of the first instruction, all tags in a set of tags indicating whether corresponding registers in the single logical register file are empty or non-empty are caused to indicate non-empty states.

Abstract: Methods and apparatuses to clear state for operation of a stack. According to one embodiment of the invention, a processor comprises a set of one or more storage areas and a decode unit. The set of one or more storage areas are to store a plurality of tags and a top of stack indication, where each of the plurality of tags is to indicate if a register is in an empty or non-empty state. The decode unit is to decode scalar floating point instructions and packed data instructions, where at least certain of said scalar floating point instructions specify registers in a stack referenced manner and at least certain of said packed data instructions specify registers in a non-stack referenced manner. In addition, the packed data instructions include an instruction to mark the end of blocks of the packed data instructions in programs. The processor also comprises circuitry to cause the plurality of tags to indicate the empty state responsive to execution of the instruction.

Abstract: A method in a computer system which includes receiving a first instruction which indicates termination of execution of instructions which operate upon packed data stored in a first storage area. The first storage area is used for modifying data responsive to execution of floating point instructions. A plurality of tags is associated with the first storage area indicating that locations in the first storage area are either empty or non-empty responsive to the execution of the floating point instructions which modify data contained in the first storage area. Responsive to the receiving of the first instruction which indicates termination of execution of instructions which operate upon the packed data stored in the first storage area, the method sets only the plurality of tags to an empty state. In different embodiments, setting of the plurality of tags to a non-empty state occurs responsive to receiving a second instruction.

Abstract: A method in a computer system which includes receiving a first instruction which indicates indicates termination of execution of instructions which operate upon packed data stored in a first storage area. The first storage area is used for modifying data responsive to execution of floating point instructions. A plurality of tags is associated with the first storage area indicating that locations in the first storage area are either empty or non-empty responsive to the execution of the floating point instructions which modify data contained in the first storage area. Responsive to the receiving of the first instruction which indicates termination of execution of instructions which operate upon the packed data stored in the first storage area, the method sets only the plurality of tags to an empty state. In different embodiments, setting of the plurality of tags to a non-empty state occurs responsive to receiving a second instruction.

Abstract: A method for executing different sets of instructions that cause a processor to perform different data type operations in a manner that is invisible to various operating system techniques, that promotes good programming practices, and that is invisible to existing software conventions. According to one aspect of the invention, a data processing apparatus executes a first set of instructions of a first instruction type on what at least logically appears to software as a single logical register file. While the data processing apparatus is executing the first set of instructions, the single logical register file appears to be operated as a flat register file. In addition, the data processing apparatus executes a first instruction of a second instruction type using the logical register file. However, while the data processing apparatus is executing the first instruction, the logical register file appears to be operated as a stack referenced register file.

Abstract: A method in a computer system which includes receiving a first instruction which indicates indicates termination of execution of instructions which operate upon packed data stored in a first storage area. The first storage area is used for modifying data responsive to execution of floating point instructions. A plurality of tags is associated with the first storage area indicating that locations in the first storage area are either empty or non-empty responsive to the execution of the floating point instructions which modify data contained in the first storage area. Responsive to the receiving of the first instruction which indicates termination of execution of instructions which operate upon the packed data stored in the first storage area, the method sets only the plurality of tags to an empty state. In different embodiments, setting of the plurality of tags to a non-empty state occurs responsive to receiving a second instruction.

Abstract: An apparatus (e.g. a microarchitecture of a microprocessor) comprising a plurality of tags associated with a first storage area indicating that locations in the first storage area are either empty or non-empty responsive to execution of floating point instructions which modify data contained in the first storage area. A first circuit is coupled to the plurality of tags which sets only the plurality of tags to an empty state responsive to receipt of a first instruction. The first instruction indicates termination of execution of instructions which operate upon the packed data stored in the first storage area. The apparatus further comprises a second circuit coupled to the plurality of tags for setting the plurality of tags to a non-empty state responsive to receipt of a second instruction (or instructions). The second instruction specifies an operation upon packed data stored in the first storage area.

Abstract: A method and apparatus for executing floating point and packed data instructions using a single physical register file that is aliased. According to one aspect of the invention, a processor is provided that includes a decode unit, a mapping unit, and a storage unit. The decode unit is configured to decode instructions and their operands from at least one instruction set including at least a first and second set of instructions. The storage unit includes a physical register file. The mapping unit is configured to map operands used by the first set of instructions to the physical register file in a stack referenced manner. In addition, the mapping unit is configured to map operands used by the second set of instructions to the same physical register file in a non-stack reference manner.

Abstract: A method and apparatus for executing different sets of instructions that cause a processor to perform different data type operations on different physical registers files that logically appear to software as a single aliased register file. According to one aspect of the invention, a processor is provided that includes at least two physical register files--one for executing scalar data type operations and the other for executing packed data type operations. In addition, the processor includes a transition unit that is configured to cause the two physical register files to logically appear to software executing on the processor as a single logical register file.

Abstract: A method for executing different sets of instructions that cause a processor to perform different data type operations in a manner that is invisible to various operating system techniques, that promotes good programming practices, and that is invisible to existing software conventions. According to one aspect of the invention, a data processing apparatus executes a first set of instructions of a first instruction type on what at least logically appears to software as a single logical register file. While the data processing apparatus is executing the first set of instructions, the single logical register file appears to be operated as a flat register file. In addition, the data processing apparatus executes a first instruction of a second instruction type using the logical register file. However, while the data processing apparatus is executing the first instruction, the logical register file appears to be operated as a stack referenced register file.