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RISC-V

Nov 4, 2026

RISC-V Branches and Jumps: Resolve Stage, JAL/JALR, Return-Address Stack Hints

Part 18 of the RISC-V series. I added the branch resolve stage, JAL redirect in ID, BTFN static prediction, and a RAS that follows the hints in spec section 2.5 to a pipeline model and compared them. CPI dropped from 1.368 to 1.227, and an 8-entry RAS predicted 98.3% of fib's returns.

RISC-V

Nov 4, 2026

RV32I 3: Branches, Jumps, Loads/Stores and Alignment, FENCE, ECALL/EBREAK

Part 4 of the RISC-V series. I ran the six branches, jal/jalr, load sign extension, misaligned accesses, and fence/ecall/ebreak on QEMU. jalr turned 0x80000021 into 0x80000020, and all 56 results matched a reference model.