发明授权
- 专利标题: Pairing floating point exchange instruction with another floating point instruction to reduce dispatch latency
- 专利标题(中): 将浮点交换指令与另一个浮点指令配对,以减少调度延迟
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申请号: US960189申请日: 1997-10-29
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公开(公告)号: US5913047A公开(公告)日: 1999-06-15
- 发明人: Rupaka Mahalingaiah , Paul K. Miller
- 申请人: Rupaka Mahalingaiah , Paul K. Miller
- 申请人地址: CA Sunnyvale
- 专利权人: Advanced Micro Devices, Inc.
- 当前专利权人: Advanced Micro Devices, Inc.
- 当前专利权人地址: CA Sunnyvale
- 主分类号: G06F9/30
- IPC分类号: G06F9/30 ; G06F9/315 ; G06F9/318 ; G06F9/38
摘要:
A microprocessor detects a floating point exchange instruction followed by a floating point instruction and dispatches the two instructions to the floating point unit as one combined instruction. The predecode unit marks the two instructions as a single instruction. A start bit is asserted for the first byte of the floating point exchange instruction and an end bit is asserted for the last byte of the floating point instruction. The combined instruction is dispatched into the instruction execution pipeline. A decode unit decodes the opcodes of the two instructions and passes the opcode of the floating point instruction to the floating point unit and passes exchange register information to the floating point unit. The exchange register information includes a sufficient number of bits to specify a floating point register and a valid bit. The floating point instruction unit receives the exchange register information, exchanges the top-of-stack with the register specified by the exchange register information and then performs the floating point operation. In the above manner, two floating point operations may be executed in a single clock cycle.
公开/授权文献
- US5311542A Spread spectrum communication system 公开/授权日:1994-05-10
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