Fujitsu Corporation

Takeo Asakawa

Aiichiro Inoue

Hiroshi Kawano

Kyoko Tashima

The present invention relates to an instruction control device, and more particularly to an instruction control device which has achieved a high speed operational processing, such as a reduction in the amount of components, so as to enable an out-of-order instruction execution to thereby execute an instruction processing at high speed in an information processor. An instruction control device having instruction storing means for temporarily storing a plurality of decoded instructions yet unissued to an execution unit; wherein the storing means is constituted such that an arranged order of entries of the storing means indicates a decoded order of decoded instructions stored in the entries; wherein that entry, from which the decoded instruction stored therein has been issued, is deleted; wherein information stored in the entries is shifted among the entries such that the entries storing the unissued instructions constitute entries in a continuous order; and wherein a shifting amount between entries is, at the most, equal to the number of instructions which can be simultaneously decoded.

Instruction control device and method therefor

An information processor having a control unit in which a plurality of instructions to simultaneously be executed are decoded by a decoder section, an executing unit to be dispatched of a plurality of executing units is selected by an index selecting section according to a result of the decoding, and dispatch to any of the plurality of executing units is inhibited by a dispatch inhibiting section according to a result of the decoding by the decoder section as well as to a result of the selection by the index selecting section.

Information processor

A general-purpose register address output from an instruction register is read and changed to a corresponding register update buffer address in an update table. Additionally, the update reservation instructing bit corresponding to the general-purpose register address is read out from a register update reservation table. If its value is '0', the general-purpose register address is provided to the general-purpose register, and the data stored at that address is input to an arithmetic unit. If the value of the bit is '1', the contents of the corresponding entry in the update table is registered to a reservation station. The reservation station determines the execution order of respective entries, and sequentially provides a register update buffer address to a register update buffer, and inputs the data stored at that address to the arithmetic unit.

Instruction controlling system and method thereof

A pipeline operation control method and system in which, in the execution of successive first and second instructions, to avoid a pipeline disturbance, the second instruction is shifted from a calculating state to a special state as a final state that does not conflict with the final state of the first instruction when the first instruction has two or more calculating states immediately before the final state, and when the special state can be inserted as the final state of the second instruction and the calculating state of the second instruction is carried out within a single machine cycle, whereby the final state of the first instruction and the special state of the second instruction are carried out at the same time.

Method and apparatus overcoming delay introduced by instruction

A circuit for executing conditional branch instructions in a pipeline process comprises registers for retaining condition codes settled set or determined at different stages, respectively, registers for retaining pipeline tags identifying instructions at the respective stages and indicating the stage where the condition codes are settled or set by the instructions, and a branch controller for deciding whether the settlement of condition codes for conditional branch instructions existing at the respective stage has occured responsive to the tags in a plurality of stages, and for selecting the settled condition codes from among the condition codes stored in the registers and indicating whether a branch should be performed.

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Kawasaki, Japan

Takeo Asakawa