CUDA: refactor topk-moe to enable more models (GLM 4.7, Nemotron etc.) (#19126)

This commit is contained in:
Aman Gupta
2026-01-29 10:31:28 +08:00
committed by GitHub
parent d4964a7c66
commit 3bcc990997
3 changed files with 426 additions and 225 deletions
+215 -72
View File
@@ -3080,63 +3080,166 @@ static bool ggml_cuda_should_fuse_rope_set_rows(const ggml_tensor * rope,
return true;
}
static bool ggml_cuda_can_fuse(const struct ggml_cgraph * cgraph, int node_idx, std::initializer_list<enum ggml_op> ops, std::initializer_list<enum ggml_unary_op> unary_ops) {
static bool ggml_cuda_topk_moe_fusion(const struct ggml_cgraph * cgraph, int node_idx, ggml_cuda_topk_moe_args & args) {
args.sigmoid = false;
args.softmax = false;
args.delayed_softmax = false;
args.prob_bias = false;
args.norm = false;
const int n_nodes = cgraph->n_nodes;
ggml_tensor ** nodes = cgraph->nodes;
if (nodes[node_idx]->op == GGML_OP_SOFT_MAX) {
args.softmax = true;
}
if (nodes[node_idx]->op == GGML_OP_UNARY) {
if (ggml_get_unary_op(nodes[node_idx]) != GGML_UNARY_OP_SIGMOID) {
return false;
}
args.sigmoid = true;
}
if (nodes[node_idx]->op == GGML_OP_ARGSORT) {
args.delayed_softmax = true;
}
node_idx++;
if (args.sigmoid || args.softmax) {
// SOFTMAX -> RESHAPE
if (node_idx >= n_nodes || nodes[node_idx]->op != GGML_OP_RESHAPE ||
nodes[node_idx]->src[0] != nodes[node_idx - 1]) {
return false;
}
ggml_tensor * probs_reshaped = nodes[node_idx];
node_idx++;
if (node_idx >= n_nodes) {
return false;
}
// src of bias add is the unreshaped probs (-2 instead of -1)
if (nodes[node_idx]->op == GGML_OP_ADD && nodes[node_idx]->src[0] == nodes[node_idx - 2]) {
args.prob_bias = true;
node_idx++;
}
// RESHAPE/ADD -> ARGSORT
if (node_idx >= n_nodes || nodes[node_idx]->op != GGML_OP_ARGSORT) {
return false;
}
if (args.prob_bias && nodes[node_idx]->src[0] != nodes[node_idx - 1]) {
return false;
} else if (!args.prob_bias && nodes[node_idx]->src[0] != nodes[node_idx - 2]) {
return false;
}
node_idx++;
// ARGSORT-> VIEW
if (node_idx >= n_nodes || nodes[node_idx]->op != GGML_OP_VIEW ||
nodes[node_idx]->src[0] != nodes[node_idx - 1]) {
return false;
}
node_idx++;
if (node_idx >= n_nodes || nodes[node_idx]->op != GGML_OP_GET_ROWS) {
return false;
}
// GET_ROWS
if (nodes[node_idx]->src[0] != probs_reshaped || nodes[node_idx]->src[1] != nodes[node_idx - 1]) {
return false;
}
node_idx++;
} else if (args.delayed_softmax) {
if (node_idx - 2 < 0) {
return false;
}
ggml_tensor * probs_reshaped = nodes[node_idx - 2];
// VIEW->ARGSORT
if (node_idx >= n_nodes || nodes[node_idx]->op != GGML_OP_VIEW ||
nodes[node_idx]->src[0] != nodes[node_idx - 1]) {
return false;
}
node_idx++;
// GET_ROWS
if (node_idx >= n_nodes || nodes[node_idx]->src[1] != nodes[node_idx - 1] ||
nodes[node_idx]->src[0] != probs_reshaped) {
return false;
}
node_idx++;
static const std::vector<ggml_op> remaining_ops = { GGML_OP_RESHAPE, GGML_OP_SOFT_MAX, GGML_OP_RESHAPE };
for (const ggml_op op : remaining_ops) {
if (node_idx >= n_nodes || nodes[node_idx]->op != op || nodes[node_idx]->src[0] != nodes[node_idx - 1]) {
return false;
}
node_idx++;
}
}
// At this point we can check for norm + scale. Everything is now at least valid till the norm
if (node_idx >= n_nodes) {
return true;
}
if (nodes[node_idx]->op == GGML_OP_RESHAPE) {
//check RESHAPE->SUM_ROWS->CLAMP->DIV->RESHAPE
static const std::vector<ggml_op> norm_ops = { GGML_OP_RESHAPE, GGML_OP_SUM_ROWS, GGML_OP_CLAMP };
args.norm = true;
for (const ggml_op op : norm_ops) {
if (nodes[node_idx]->op == op && nodes[node_idx]->src[0] == nodes[node_idx - 1]) {
node_idx++;
} else {
args.norm = false;
return true;
}
}
// DIV <- CLAMP, RESHAPE
if (nodes[node_idx]->op != GGML_OP_DIV || nodes[node_idx]->src[1] != nodes[node_idx - 1] ||
nodes[node_idx]->src[0] != nodes[node_idx - 3]) {
args.norm = false;
return true;
}
node_idx++;
if (nodes[node_idx]->op != GGML_OP_RESHAPE || nodes[node_idx]->src[0] != nodes[node_idx - 1]) {
args.norm = false;
return true;
}
node_idx++;
}
if (nodes[node_idx]->op == GGML_OP_SCALE && nodes[node_idx]->src[0] == nodes[node_idx - 1]) {
args.scale = true;
}
return true;
}
static bool ggml_cuda_can_fuse(const struct ggml_cgraph * cgraph,
int node_idx,
std::initializer_list<enum ggml_op> ops,
std::initializer_list<enum ggml_unary_op> unary_ops) {
#ifndef NDEBUG
const size_t num_unary = std::count(ops.begin(), ops.end(), GGML_OP_UNARY);
GGML_ASSERT(unary_ops.size() == num_unary);
#endif
//TODO: remove special case once ggml_can_fuse can handle empty nodes
std::initializer_list<enum ggml_op> topk_moe_ops =
ggml_cuda_topk_moe_ops(/*with_norm*/ false, /*delayed_softmax=*/false);
std::initializer_list<enum ggml_op> topk_moe_ops_with_norm =
ggml_cuda_topk_moe_ops(/*with_norm=*/true, /*delayed_softmax=*/false);
std::initializer_list<enum ggml_op> topk_moe_ops_delayed_softmax =
ggml_cuda_topk_moe_ops(/*with_norm=*/false, /*delayed_softmax=*/true);
const auto is_equal = [](const std::initializer_list<enum ggml_op> & list1,
const std::initializer_list<enum ggml_op> & list2) {
return std::equal(list1.begin(), list1.end(), list2.begin(), list2.end());
};
if (is_equal(topk_moe_ops_with_norm, ops) &&
ggml_can_fuse_subgraph(cgraph, node_idx, ops, { node_idx + 3, node_idx + 9 })) {
ggml_tensor * softmax = cgraph->nodes[node_idx];
ggml_tensor * weights = cgraph->nodes[node_idx + 9];
ggml_tensor * get_rows = cgraph->nodes[node_idx + 4];
ggml_tensor * argsort = cgraph->nodes[node_idx + 2];
int n_expert = cgraph->nodes[node_idx]->src[0]->ne[0];
if (ggml_cuda_should_use_topk_moe(softmax, weights, get_rows, argsort, nullptr, n_expert)) {
return true;
}
}
if (is_equal(topk_moe_ops, ops) && ggml_can_fuse_subgraph(cgraph, node_idx, ops, { node_idx + 3, node_idx + 4 })) {
ggml_tensor * softmax = cgraph->nodes[node_idx];
ggml_tensor * weights = cgraph->nodes[node_idx + 4];
ggml_tensor * get_rows = cgraph->nodes[node_idx + 4];
ggml_tensor * argsort = cgraph->nodes[node_idx + 2];
int n_expert = cgraph->nodes[node_idx]->src[0]->ne[0];
if (ggml_cuda_should_use_topk_moe(softmax, weights, get_rows, argsort, nullptr, n_expert)) {
return true;
}
}
if (is_equal(topk_moe_ops_delayed_softmax, ops) &&
ggml_can_fuse_subgraph(cgraph, node_idx, ops, { node_idx + 1, node_idx + 5 })) {
ggml_tensor * softmax = cgraph->nodes[node_idx + 4];
ggml_tensor * weights = cgraph->nodes[node_idx + 5];
ggml_tensor * get_rows = cgraph->nodes[node_idx + 2];
ggml_tensor * argsort = cgraph->nodes[node_idx + 0];
int n_expert = cgraph->nodes[node_idx]->src[0]->ne[0];
if (ggml_cuda_should_use_topk_moe(softmax, weights, get_rows, argsort, nullptr, n_expert)) {
return true;
}
}
std::initializer_list<enum ggml_op> mul_mat_bias_glu_ops = { GGML_OP_MUL_MAT, GGML_OP_ADD, GGML_OP_MUL_MAT, GGML_OP_ADD, GGML_OP_GLU };
std::initializer_list<enum ggml_op> mul_mat_id_bias_glu_ops = { GGML_OP_MUL_MAT_ID, GGML_OP_ADD_ID, GGML_OP_MUL_MAT_ID, GGML_OP_ADD_ID, GGML_OP_GLU };
@@ -3398,35 +3501,75 @@ static void ggml_cuda_graph_evaluate_and_capture(ggml_backend_cuda_context * cud
// start of fusion operations
static bool disable_fusion = (getenv("GGML_CUDA_DISABLE_FUSION") != nullptr);
if (!disable_fusion) {
ggml_cuda_topk_moe_args args;
if (ggml_cuda_can_fuse(cgraph, i, ggml_cuda_topk_moe_ops(/*with norm*/ true), {})) {
ggml_tensor * weights = cgraph->nodes[i + 9];
ggml_tensor * selected_experts = cgraph->nodes[i + 3];
ggml_tensor * clamp = cgraph->nodes[i + 7];
ggml_cuda_op_topk_moe(*cuda_ctx, node->src[0], weights, selected_experts, /*with norm*/ true,
/*delayed softmax*/ false, clamp);
i += 9;
continue;
}
if (cgraph->nodes[i]->op == GGML_OP_UNARY || cgraph->nodes[i]->op == GGML_OP_SOFT_MAX ||
cgraph->nodes[i]->op == GGML_OP_ARGSORT) {
const bool can_fuse = ggml_cuda_topk_moe_fusion(cgraph, i, args);
if (ggml_cuda_can_fuse(cgraph, i, ggml_cuda_topk_moe_ops(/*with norm*/ false), {})) {
ggml_tensor * weights = cgraph->nodes[i + 4];
ggml_tensor * selected_experts = cgraph->nodes[i + 3];
ggml_cuda_op_topk_moe(*cuda_ctx, node->src[0], weights, selected_experts, /*with norm*/ false,
/*delayed softmax*/ false);
i += 4;
continue;
}
std::vector<ggml_op> ops;
if (ggml_cuda_can_fuse(cgraph, i,
ggml_cuda_topk_moe_ops(/*with norm*/ false, /*delayed softmax*/ true), {})) {
ggml_tensor * weights = cgraph->nodes[i + 5];
ggml_tensor * ids = cgraph->nodes[i + 1];
if (can_fuse) {
const ggml_tensor * logits = node->src[0];
ggml_tensor * weights = nullptr;
ggml_tensor * ids = nullptr;
const ggml_tensor * bias = nullptr;
const ggml_tensor * clamp = nullptr;
const ggml_tensor * scale = nullptr;
ggml_cuda_op_topk_moe(*cuda_ctx, node->src[0], weights, ids, /*with norm*/ false,
/*delayed_softmax*/ true);
i += 5;
continue;
if (!args.delayed_softmax) {
ggml_op gating_op = args.sigmoid ? GGML_OP_UNARY : GGML_OP_SOFT_MAX;
int out_nodes[2]; // nodes which can't be elided
if (args.prob_bias) {
bias = cgraph->nodes[i + 2]->src[1];
ops.insert(ops.end(), { gating_op, GGML_OP_RESHAPE, GGML_OP_ADD, GGML_OP_ARGSORT,
GGML_OP_VIEW, GGML_OP_GET_ROWS });
out_nodes[0] = i + 4;
ids = cgraph->nodes[i + 4];
} else {
ops.insert(ops.end(), { gating_op, GGML_OP_RESHAPE, GGML_OP_ARGSORT, GGML_OP_VIEW,
GGML_OP_GET_ROWS });
out_nodes[0] = i + 3;
ids = cgraph->nodes[i + 3];
}
if (args.norm) {
ops.insert(ops.end(), { GGML_OP_RESHAPE, GGML_OP_SUM_ROWS, GGML_OP_CLAMP,
GGML_OP_DIV, GGML_OP_RESHAPE });
clamp = cgraph->nodes[i + ops.size() - 3];
}
if (args.scale) {
ops.insert(ops.end(), { GGML_OP_SCALE });
scale = cgraph->nodes[i + ops.size() - 1];
}
weights = cgraph->nodes[i + ops.size() - 1];
out_nodes[1] = i + ops.size() - 1;
if (ggml_can_fuse_subgraph(cgraph, i, ops.size(), ops.data(), out_nodes, 2) &&
ggml_cuda_should_use_topk_moe(node, logits, weights, ids)) {
ggml_cuda_op_topk_moe(*cuda_ctx, logits, weights, ids, clamp, scale, bias, args);
i += ops.size() - 1;
continue;
}
} else if (!args.norm && !args.prob_bias) {
//special case gpt-oss, no norm, no bias.
ops.insert(ops.end(), { GGML_OP_ARGSORT, GGML_OP_VIEW, GGML_OP_GET_ROWS,
GGML_OP_RESHAPE, GGML_OP_SOFT_MAX, GGML_OP_RESHAPE });
weights = cgraph->nodes[i + 5];
ids = cgraph->nodes[i + 1];
const ggml_tensor * softmax = cgraph->nodes[i + 4];
int out_nodes[2] = { i + 1, i + 5 };
if (ggml_can_fuse_subgraph(cgraph, i, ops.size(), ops.data(), out_nodes, 2) &&
ggml_cuda_should_use_topk_moe(softmax, logits, weights, ids)) {
ggml_cuda_op_topk_moe(*cuda_ctx, logits, weights, ids, clamp, scale, bias, args);
i += ops.size() - 1;
continue;
}
}
}
}
if (ggml_cuda_can_fuse(cgraph, i, { GGML_OP_ROPE, GGML_OP_VIEW, GGML_OP_SET_ROWS }, {})) {