docs(upstream): file Path C tracker B + C as PRs #2146/#2147

After re-author against current PR #2142 macro shape (the previous probe-
failed drafts targeted a non-existent tileop scheduler hierarchy), both
patches now apply cleanly on jorgecurious metal-gemm-upstream-rebase + #2142
prereq stack.

Filed:
- PR tile-ai/tilelang#2146 (Path C tracker B): fused FP8 scale broadcast
  into T.fp8_scaled_matmul K-loop. 16/8 LOC delta in tilelang/language/
  fp8_op.py. Closes the 3-6× audiohacking perf gap on FP8 scaled matmul
  per the cppmega.mlx Path C consumer at fp8_vecmat_path_c.py.
- PR tile-ai/tilelang#2147 (Path C tracker C): T.BlockScaledLayout.e8m0_k32
  + T.e8m0_to_float DSL primitive. 5 files touched (tilelang/language/
  blockscaled_layout.py new, fp8_op.py extended, __init__.py re-export,
  metal_quant.py Metal lowering, e8m0 layout test). Unblocks Sparse-MLA
  blockscaled Path C QK reducer.

Both stack on PR #2142 (T.fp8_scaled_matmul intrinsic) which stacks on
PR #2130 (jorgecurious base). Independent of each other — different gaps,
different files (B touches the macro body, C adds the layout primitive).

Receipt _filed_prs_2026_05_04.md updated with rows 13-14.

Total filed PRs: 14 (across ml-explore/mlx, apache/tvm, tile-ai/tilelang,
tile-ai/tvm). All OPEN.

Path C tracker A (pipelined_32x32) shipped in commit 3cb6457 + 6746ff9.
Path C tracker B (#2146) and C (#2147) now filed upstream. All three
Path C follow-up entries from docs/upstream/_path_c_blockers_tracker.md
have landing receipts.

Author: apstenku123

docs/upstream/_filed_prs_2026_05_04.md

@@ -103,6 +103,20 @@ GitHub user: apstenku123 (David Gornshtein, davidgornshtein@gmail.com)
       <td>[Metal] FP8 vector cast lanes 2/3/4 (extends storage-only FP8) (TVM-mirror half)</td>
       <td>filed against tilelang_main @ 0e15b274, depends on #38 + paired with #2145</td>
     </tr>
+    <tr>
+      <td>13</td>
+      <td>tile-ai/tilelang</td>
+      <td>[#2146](https://github.com/tile-ai/tilelang/pull/2146)</td>
+      <td>[Metal] fuse per-load FP8 scale broadcast into T.fp8_scaled_matmul K-loop (Path C tracker B)</td>
+      <td>filed against main, **stacks on PR #2142** which stacks on PR #2130; closes audiohacking 3-6× perf gap on FP8 scaled matmul</td>
+    </tr>
+    <tr>
+      <td>14</td>
+      <td>tile-ai/tilelang</td>
+      <td>[#2147](https://github.com/tile-ai/tilelang/pull/2147)</td>
+      <td>[Metal] add T.BlockScaledLayout.e8m0_k32 + T.e8m0_to_float (blockscaled FP8) (Path C tracker C)</td>
+      <td>filed against main, **stacks on PR #2142** which stacks on PR #2130; unblocks Sparse-MLA blockscaled Path C QK reducer</td>
+    </tr>
   </tbody>
 </table>