dylanyunlong/project_6
1
0
Fork 0
Code Issues Pull Requests Actions Projects Releases Wiki Activity

fix(tuning_reduce): auto [t,i] → auto [i,t] matching CCCL scaling_result

Browse Source 
scale_mem_bound now returns {items, threads} (items-first) to match
CCCL's scaling_result struct. All 7 call sites in this file updated.

Previously: auto [t, i] bound threads→t, items→i
Now:        auto [i, t] binds items→i, threads→t

The ReducePassPolicy{t, i, ...} constructors remain correct because
they take (threads, items, ...) — t is threads, i is items in both cases.
The old code worked by accident (two reversals canceling out).
This commit is contained in:
dylanyunlon
2026-08-01 00:31:41 +08:00
parent ec1c85cd9a
commit 3a2b67c166
1 changed files with 12 additions and 8 deletions
Download Patch File Download Diff File Expand all files Collapse all files

20
muh/include/muh/tuning/tuning_reduce.cuh
View File

@@ -20,6 +20,10 @@
// Similarly int64 uses threads=512, items=15 → tile = 61440 > 49152.
//
// Fix: derive threads/items from SMEM constraint, not copy from SM100.
//
// NOTE: scale_mem_bound returns {items, threads} (items-first), matching
// CCCL's scaling_result struct. Destructure as auto [i, t] = ...;
// NOT auto [t, i] which was the old (buggy) order.
#pragma once
@@ -127,19 +131,19 @@ struct policy_selector {
constexpr ReducePolicy get_deterministic(const hardware_capability& hw) const {
if (hw.at_least(hardware_capability::vendor_t::iluvatar, 100)) {
if (accum_t == type_t::float32) {
auto [t, i] = scale_mem_bound(bi100_det_float32::threads,
auto [i, t] = scale_mem_bound(bi100_det_float32::threads,
bi100_det_float32::items, accum_size);
ReducePassPolicy rp{t, i, 1, BLOCK_REDUCE_RAKING, LOAD_DEFAULT};
return {rp, rp};
}
if (accum_t == type_t::float64) {
auto [t, i] = scale_mem_bound(bi100_det_float64::threads,
auto [i, t] = scale_mem_bound(bi100_det_float64::threads,
bi100_det_float64::items, accum_size);
ReducePassPolicy rp{t, i, 1, BLOCK_REDUCE_RAKING, LOAD_DEFAULT};
return {rp, rp};
}
}
auto [t, i] = scale_mem_bound(256, 16, accum_size);
auto [i, t] = scale_mem_bound(256, 16, accum_size);
ReducePassPolicy rp{t, i, 1, BLOCK_REDUCE_RAKING, LOAD_DEFAULT};
return {rp, rp};
}
@@ -149,35 +153,35 @@ struct policy_selector {
hw.at_least(hardware_capability::vendor_t::iluvatar, 100)) {
if (accum_t == type_t::float32 && offset_size == 4 && accum_size == 4) {
auto [t, i] = scale_mem_bound(bi100_float32_plus_o4::threads,
auto [i, t] = scale_mem_bound(bi100_float32_plus_o4::threads,
bi100_float32_plus_o4::items, accum_size);
ReducePassPolicy rp{t, i, bi100_float32_plus_o4::items_per_vec_load,
BLOCK_REDUCE_WARP_REDUCTIONS, LOAD_LDG};
return {rp, rp};
}
if (accum_t == type_t::float64 && offset_size == 4 && accum_size == 8) {
auto [t, i] = scale_mem_bound(bi100_float64_plus_o4::threads,
auto [i, t] = scale_mem_bound(bi100_float64_plus_o4::threads,
bi100_float64_plus_o4::items, accum_size);
ReducePassPolicy rp{t, i, bi100_float64_plus_o4::items_per_vec_load,
BLOCK_REDUCE_WARP_REDUCTIONS, LOAD_LDG};
return {rp, rp};
}
if (offset_size == 4 && accum_size == 8) {
auto [t, i] = scale_mem_bound(bi100_int64_plus_o4::threads,
auto [i, t] = scale_mem_bound(bi100_int64_plus_o4::threads,
bi100_int64_plus_o4::items, accum_size);
ReducePassPolicy rp{t, i, bi100_int64_plus_o4::items_per_vec_load,
BLOCK_REDUCE_WARP_REDUCTIONS, LOAD_LDG};
return {rp, rp};
}
if (offset_size == 8 && accum_size == 8) {
auto [t, i] = scale_mem_bound(bi100_int64_plus_o8::threads,
auto [i, t] = scale_mem_bound(bi100_int64_plus_o8::threads,
bi100_int64_plus_o8::items, accum_size);
ReducePassPolicy rp{t, i, bi100_int64_plus_o8::items_per_vec_load,
BLOCK_REDUCE_WARP_REDUCTIONS, LOAD_LDG};
return {rp, rp};
}
}
auto [t, i] = scale_mem_bound(bi100_default::threads, bi100_default::items, accum_size);
auto [i, t] = scale_mem_bound(bi100_default::threads, bi100_default::items, accum_size);
ReducePassPolicy rp{t, i, bi100_default::items_per_vec_load,
BLOCK_REDUCE_WARP_REDUCTIONS, LOAD_LDG};
return {rp, rp};