From 5b6a4fbef97a1feaf090def2f7f32f24509ad85e Mon Sep 17 00:00:00 2001 From: biondizzle Date: Sat, 23 May 2026 19:22:28 +0000 Subject: [PATCH] Update STAGE_D.md: manual SMEM addressing blocked on layout mapping --- STAGE_D.md | 27 +++++++++++++++++---------- 1 file changed, 17 insertions(+), 10 deletions(-) diff --git a/STAGE_D.md b/STAGE_D.md index 6cda9c40..7b3a9f05 100644 --- a/STAGE_D.md +++ b/STAGE_D.md @@ -778,15 +778,22 @@ The following are real potential wins but go beyond what the V4 paper explicitly **Decision:** Manual SMEM addressing it is. Abandon `make_tiled_copy_C` entirely. -**Approach:** -1. Get thread's position in QK C-fragment partition -2. Compute which P values this thread owns (range in QK C-fragment space) -3. For each P value, compute destination SMEM address in PV A-operand layout -4. Write P values to computed SMEM addresses +**Status:** STUCK — Manual addressing harder than expected due to CuTeDSL JIT constraints. -**Implementation Plan:** -- Use `cute.coord` to get thread's logical coordinates in QK C-fragment partition -- Compute mapping: (thread_coord, element_idx) → SMEM_offset -- Write via `sP[smem_offset] = p_value` +**Problems Encountered:** +1. `cute.coord` doesn't exist — can't get thread's logical coordinates +2. Array indexing requires compile-time constants or vectorized loops +3. Layouts are completely different: + - TMEM P layout: `((128,128),1,1):((65536,1),0,0)` + - SMEM P layout: `((128,16),1,(4,2),1):((64,1),0,(16,8192),0)` +4. No clear mapping from TMEM coordinates to SMEM coordinates -**Expected Complexity:** Few hours. Need to understand QK C-fragment layout and PV A-operand SMEM layout coordinate systems. \ No newline at end of file +**Root Issue:** Manual layout conversion in CuTeDSL requires understanding coordinate systems and offset computation, which is complex without proper documentation/examples. + +**Options:** +1. Continue trying to implement manual conversion (high risk, time-consuming) +2. Find existing example of layout conversion in codebase +3. Ask for more specific guidance on coordinate mapping +4. Try different approach: make PV read from TMEM with different layout + +**Blocked:** Need coordinate mapping formula or example. \ No newline at end of file