The Floating-Point Unit of the Jaguar x86 Core
Bibliographic record
Abstract
The AMD Jaguar x86 core uses a fully-synthesized, 128-bit native floating-point unit (FPU) built as a co-processor model. The Jaguar FPU supports several x86 ISA extensions, including x87, MMX, SSE1 through SSE4.2, AES, CLMUL, AVX, and F16C instruction sets. The front end of the unit decodes two complex operations per cycle and uses a dedicated renamer (RN), free list (FL), and retire queue (RQ) for in-order dispatch and retire. The FPU issues to the execution units with a dedicated out-of-order, dual-issue scheduler. Execution units source operands from a synthesized physical register file (PRF) and bypass network. The back end of the unit has two execution pipes: the first pipe contains a vector integer ALU, a vector integer MUL unit, and a floating-point adder (FPA), the second pipe contains a vector integer ALU, a store-convert unit, and a floating-point iterative multiplier (FPM). The implementation of the unit focused on low-power design and on vectorized single-precision (SP) performance optimizations. The verification of the unit required complex pseudo-random and formal verification techniques. The Jaguar FPU is built in a 28nm CMOS process.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.001 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.002 | 0.001 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.018 | 0.011 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".