摘要:
A processor according to the present invention includes a decoding unit 20, an operation unit 40 and others. When the decoding unit 20 decodes Instruction vcchk, the operation unit 40 and the like judges whether vector condition flags VC0˜VC3 (110) of a condition flag register (CFR) 32 are all zero or not, and (i) sets condition flags C4 and C5 of the condition flag register (CFR) 32 to 1 and 0, respectively, when all of the vector condition flags VC0˜VC3 are zero, and (ii) sets the condition flags C4 and C5 to 0 and 1, respectively, when not all the vector condition flags are zero. Then, the vector condition flags VC0˜VC3 are stored in the condition flags C0˜C3.
摘要:
A processor according to the present invention includes a decoding unit 20, an operation unit 40 and others. When the decoding unit 20 decodes Instruction vcchk, the operation unit 40 and the like judges whether vector condition flags VC0˜VC3 (110) of a condition flag register (CFR) 32 are all zero or not, and (i) sets condition flags C4 and C5 of the condition flag register (CFR) 32 to 1 and 0, respectively, when all of the vector condition flags VC0˜VC3 are zero, and (ii) sets the condition flags C4 and C5 to 0 and 1, respectively, when not all the vector condition flags are zero. Then, the vector condition flags VC0˜VC3 are stored in the condition flags C0˜C3.
摘要:
A processor according to the present invention includes a decoding unit, an operation unit and others. When the decoding unit decodes an instruction “vxaddh Rc, Ra, Rb”, an arithmetic and logic/comparison operation unit and others (i) adds the higher 16 bits of a register Ra to the lower 16 bits of the register Rb, stores the result in the higher 16 bits of a register Rc, and in parallel with this, (ii) adds the lower 16 bits of the register Ra to the higher 16 bits of the register Rb, and stores the result in the lower 16 bits of the register Rc.
摘要:
A cache memory according to the present invention includes: a W flag setting unit (40) that modifies order data indicating an access order per cache entry that holds a data unit of a cache so as to reflect an actual access order; and a replace unit (39) that selects a cache entry for replacement based on the modified order data and replaces the cache entry.
摘要:
The cache memory in the present invention is a cache entry having, in a correspondence with a cache entry which holds a data unit of caching, a valid flag indicating whether or not the cache entry is valid, and a dirty flag indicating whether or not the cache entry has been written into. The cache memory in the present invention includes an altering unit which, based on an instruction from a processor, sets, in the cache entry, an address serving as a tag and sets the valid flag, without loading data from a memory, or resets the dirty flag in a state in which the cache entry holds rewritten data that has not been written back.
摘要:
The cache memory in the present invention is a cache entry having, in a correspondence with a cache entry which holds a data unit of caching, a valid flag indicating whether or not the cache entry is valid, and a dirty flag indicating whether or not the cache entry has been written into. The cache memory in the present invention includes an altering unit which, based on an instruction from a processor, sets, in the cache entry, an address serving as a tag and sets the valid flag, without loading data from a memory, or resets the dirty flag in a state in which the cache entry holds rewritten data that has not been written back.
摘要:
The cache memory in the present invention includes a C flag setting unit 40 which adds, to each cache entry holding line data, a cleaning flag C indicating whether or not a write operation will be performed hereafter, and a cleaning unit 39 which writes back, to the memory, line data of a cache entry that has been added with a cleaning flag C indicating that a write operation will not be performed, and has been set with a dirty flag D indicating that the cache entry has been written into.
摘要:
A cache memory of the present invention includes: for each cache entry, way 0 to way 3 which hold use flags U indicating whether or not the use flags U have been accessed; and a control unit which: updates, when a cache entry is hit, a use flag U corresponding to the hit cache entry so that the use flag U indicates that the cache entry has been accessed; and reset, in the case where all other use flags in the same set indicates that the cache entries have been accessed herein, the all other use flags so that the use flags indicate that the cache entries have not been accessed; and select a cache entry to be replaced from among the cache entries corresponding to the use flags indicating that the cache entries have not been accessed.
摘要:
The present invention provides a processor which has a small-scale circuit and is capable of executing loop processing at a high speed while consuming a small amount of power. When the processor decodes an instruction “jloop C6,C1:C4,TAR,Ra”, the processor (i) sets a conditional flag C4 to 0 when the value of a register Ra is smaller than 0, (ii) moves the value of a conditional flag C2 to a conditional flag C1, moves the value of a conditional flag C3 to the conditional flag C2, and moves the value of the conditional flag C4 to the conditional flags C3 and C6, (iii) adds −1 to the register Ra and stores the result into the register Ra, and (iv) branches to an address specified by a branch register (TAR). When not filled with a branch target instruction, the jump buffer will be filled with a branch target instruction.
摘要:
The present invention provides a processor which has a small-scale circuit and is capable of executing loop processing at a high speed while consuming a small amount of power. When the processor decodes an instruction “jloop C6,C1:C4,TAR,Ra”, the processor (i) sets a conditional flag C4 to 0 when the value of a register Ra is smaller than 0, (ii) moves the value of a conditional flag C2 to a conditional flag C1, moves the value of a conditional flag C3 to the conditional flag C2, and moves the value of the conditional flag C4 to the conditional flags C3 and C6, (iii) adds −1 to the register Ra and stores the result into the register Ra, and (iv) branches to an address specified by a branch register (TAR). When not filled with a branch target instruction, the jump buffer will be filled with a branch target instruction.