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VerticalResearchGroup / miaow

An open source GPU based off of the AMD Southern Islands ISA.
BSD 3-Clause "New" or "Revised" License
1.07k stars 237 forks source link

Issue unit not properly tracking LSU operations #7

Closed zwabbit closed 8 years ago

zwabbit commented 8 years ago

The issue unit tracks memory operations by examining the operation complete signals the sgpr and vgpr sends to the lsu. In the past when the lsu was able to perform a single register operation for each load and store this worked. Now however the lsu needs to perform multiple such operations for each memory operation. As a consequence the issue unit is prematurely advancing the program instead of waiting for the lsu to actually complete an operation. How it tracks memory operations needs to be revamped.

zwabbit commented 8 years ago

Addendum to previous remark, the LSU itself doesn't track a memory operation over the lifetime of said memory operation. Need to rearchitecture it.