摘要:
A method, information processing system, and computer program product manage instruction execution based on machine state. At least one instruction is received. The at least one instruction is decoded. A current machine state is determined in response to the decoding. The at least one instruction is organized into a set of unit of operations based on the current machine state that has been determined. The set of unit of operations is executed.
摘要:
A method, information processing system, and computer program product crack and/or shorten computer executable instructions. At least one instruction is received. The at least on instruction is analyzed. An instruction type associated with the at least one instruction is identified. At least one of a base field, an index field, one or more operands, and a mask field of the instruction are analyzed. At least one of the following is then performed: the at least one instruction is organized into a set of unit of operation; and the at least one instruction is shortened. The set of unit of operations is then executed.
摘要:
A method, information processing system, and computer program product manage variable operand length instructions. At least one variable operand length instruction is received. The at least one variable operand length instruction is analyzed. A length of at least one operand in the variable operand length instruction is identified based on the analyzing. The at least one variable operand length instruction is organized into a set of unit of operations. The set of unit of operations are executed. The executing increases one or more performance metrics of the at least one variable operand length instruction.
摘要:
A method, information processing system, and computer program product manage variable operand length instructions. At least one variable operand length instruction is received. The at least one variable operand length instruction is analyzed. A length of at least one operand in the variable operand length instruction is identified based on the analyzing. The at least one variable operand length instruction is organized into a set of unit of operations. The set of unit of operations are executed. The executing increases one or more performance metrics of the at least one variable operand length instruction.
摘要:
Store multiple instructions are managed based on previous execution history and their alignment. At least one store multiple instruction is detected. A flag is determined to be associated with the at least one store multiple instruction. The flag indicates that the at least one store multiple instruction has previously encountered an operand store compare hazard. The at least one store multiple instruction is organized into a set of unit of operations. The set of unit of operations is executed. The executing avoids the operand store compare hazard previously encountered by the at least one store multiple instruction.
摘要:
Store multiple instructions are managed based on previous execution history and their alignment. At least one store multiple instruction is detected. A flag is determined to be associated with the at least one store multiple instruction. The flag indicates that the at least one store multiple instruction has previously encountered an operand store compare hazard. The at least one store multiple instruction is organized into a set of unit of operations. The set of unit of operations is executed. The executing avoids the operand store compare hazard previously encountered by the at least one store multiple instruction.
摘要:
A method, information processing system, and computer program product manage computer executable instructions. At least one machine instruction for execution is received. The at least one machine instruction is analyzed. The machine instruction is identified as a predefined instruction for storing a variable length first operand in a memory location. Responsive to this identification and based on fields of the machine instruction, a relative location of a variable length second operand of the instruction with location of the first operand is determined. Responsive to the relative location having the predefined relationship, a first cracking operation is performed. The first cracking operation cracks the instruction into a first set of micro-ops (Uops) to be executed in parallel. The first set of Uops is for storing a first plurality of first blocks in the first operand. Each of said first block to be stored are identical. The first set Uops are executed.
摘要:
A method, information processing system, and computer program product manage computer executable instructions. At least one machine instruction for execution is received. The at least one machine instruction is analyzed. The machine instruction is identified as a predefined instruction for storing a variable length first operand in a memory location. Responsive to this identification and based on fields of the machine instruction, a relative location of a variable length second operand of the instruction with location of the first operand is determined. Responsive to the relative location having the predefined relationship, a first cracking operation is performed. The first cracking operation cracks the instruction into a first set of micro-ops (Uops) to be executed in parallel. The second set of Uops is for storing a first plurality of first blocks in the first operand. Each of said first block to be stored are identical. The first set Uops are executed.
摘要:
Disclosed is a method and apparatus providing the capability to prevent particular branches from being written into the BTB, thereby making them non-predictable. By making certain branches only detectable at decode time frame, branch prediction can completely run asynchronous of decode. By allowing branch prediction logic to cover as wide a range of branches as possible, the efficiency of fetching of branch targets way before the branch itself achieves a higher level of precision. This increased level of precision eliminates pipeline stalls between branches and targets where prior concerns of creating data integrity within the pipeline of a microprocessor existed.
摘要:
A method and system for processing instructions in a floating point unit for executing denormalized numbers in floating point pipeline via serializing uses an instruction unit and having a control unit and a pipelined data flow unit, a shifter and a rounding unit. The floating point unit has an external feedback path for providing intermediate result data from said rounding unit to an input of the pipelined data flow unit to reuse the pipeline for denormalization by passing intermediate results in the pipeline which have a denormalized condition computed after the exponent calculation of the shifting circuit directly from the rounding unit to the top of the dataflow in the pipeline via an external feedback path. The pipelined has two paths which are selected based on the presence of other instructions in the pipeline. If no other instructions are in the pipeline a first path is taken which uses the external feedback path from the rounding unit back into the top of the dataflow. When there are instructions in the pipeline a shifter unit performing normalization of the fraction indicates possible underflow of the exponent, and prepares to hold the exponent and the fraction in a floating point data flow register; and upon detection of exponent underflow during the rounder stage and detection of any other instructions in pipeline; then the control unit forces an interrupt for serialization, and cancels execution of this instruction and other instructions in pipeline.