Implement initial Fetch Target Queue (FTQ)#869
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xThaid wants to merge 1 commit intokuznia-rdzeni:masterfrom
Draft
Implement initial Fetch Target Queue (FTQ)#869xThaid wants to merge 1 commit intokuznia-rdzeni:masterfrom
xThaid wants to merge 1 commit intokuznia-rdzeni:masterfrom
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xThaid
added
enhancement
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The Fetch Target Queue (FTQ) is a buffer that decouples branch prediction from instruction fetch. The branch predictor writes predicted fetch addresses (along with some prediction metadata) into the FTQ ahead of time, while the fetch unit consumes entries from the queue to retrieve the corresponding instruction blocks. FTQ stores prediction information so it can be later sent back to the BPU for predictor training after instruction commit. FTQ maintains the complete lifecycle of instructions from prediction to commit.
In this PR I'm adding an initial implementation of FTQ. It doesn't do anything meaningful at this point: it simply stores basic predictions from the branch prediction unit and then sends them to the fetch unit.
TODO in this PR: