Threaded dequantizing and f16 to f32 conversion

This commit is contained in:
KerfuffleV2 2023-06-05 13:18:55 -06:00
parent 5c7b0e79a7
commit fe9ed7d36f

View file

@ -2123,6 +2123,64 @@ llama_token llama_sample_token(struct llama_context * ctx, llama_token_data_arra
// quantization
//
static void llama_convert_tensor_internal(const llama_load_tensor & tensor, llama_buffer & output, const int nelements, const int nthread) {
if (output.size < nelements * sizeof(float)) {
output.resize(nelements * sizeof(float));
}
float * f32_output = (float *) output.addr;
quantize_fns_t qtype;
if (ggml_is_quantized(tensor.type)) {
qtype = ggml_internal_get_quantize_fn(tensor.type);
if (qtype.dequantize_row_q == NULL) {
throw format("type %s unsupported for integer quantization: no dequantization available", ggml_type_name(tensor.type));
}
} else if (tensor.type != GGML_TYPE_F16) {
throw format("cannot dequantize/convert tensor type %s", ggml_type_name(tensor.type));
}
if (nthread < 2) {
if (tensor.type == GGML_TYPE_F16) {
ggml_fp16_to_fp32_row((ggml_fp16_t *)tensor.data, f32_output, nelements);
} else if (ggml_is_quantized(tensor.type)) {
qtype.dequantize_row_q(tensor.data, f32_output, nelements);
} else {
LLAMA_ASSERT(false); // unreachable
}
return;
}
auto block_size = tensor.type == GGML_TYPE_F16 ? 1 : (size_t)ggml_blck_size(tensor.type);
auto block_size_bytes = ggml_type_size(tensor.type);
LLAMA_ASSERT(nelements % block_size == 0);
auto nblocks = nelements / block_size;
auto blocks_per_thread = nblocks / nthread;
auto spare_blocks = nblocks - (blocks_per_thread * nthread); // if blocks aren't divisible by thread count
std::vector<std::thread> workers;
for (auto tnum = 0, in_buff_offs = 0, out_buff_offs = 0; tnum < nthread; tnum++) {
auto thr_blocks = blocks_per_thread + (tnum == nthread - 1 && spare_blocks ? spare_blocks : 0); // num blocks for this thread
auto thr_elems = thr_blocks * block_size; // number of elements for this thread
auto thr_block_bytes = thr_blocks * block_size_bytes; // number of input bytes for this thread
auto compute = [qtype] (ggml_type typ, uint8_t * inbuf, float * outbuf, int nels) {
if (typ == GGML_TYPE_F16) {
ggml_fp16_to_fp32_row((ggml_fp16_t *)inbuf, outbuf, nels);
} else {
qtype.dequantize_row_q(inbuf, outbuf, nels);
}
};
workers.push_back(std::thread(compute, tensor.type, tensor.data + in_buff_offs, f32_output + out_buff_offs, thr_elems));
in_buff_offs += thr_block_bytes;
out_buff_offs += thr_elems;
}
for (auto & worker : workers) {
worker.join();
}
}
static void llama_model_quantize_internal(const std::string & fname_inp, const std::string & fname_out, const llama_model_quantize_params * params) {
ggml_type quantized_type;
llama_ftype ftype = params->ftype;
@ -2199,6 +2257,7 @@ static void llama_model_quantize_internal(const std::string & fname_inp, const s
if (!params->quantize_output_tensor && tensor.name == "output.weight") {
quantize = false;
}
quantize = quantize && quantized_type != tensor.type;
enum ggml_type new_type;
void * new_data;
@ -2239,23 +2298,11 @@ static void llama_model_quantize_internal(const std::string & fname_inp, const s
if (tensor.type == GGML_TYPE_F32) {
f32_data = (float *) tensor.data;
} else if (ggml_is_quantized(tensor.type) && !params->allow_requantize) {
throw format("requantizing from type %s is disabled", ggml_type_name(tensor.type));
} else {
f32_conv_buf.resize(nelements * sizeof(float));
llama_convert_tensor_internal(tensor, f32_conv_buf, nelements, nthread);
f32_data = (float *) f32_conv_buf.addr;
if (tensor.type == GGML_TYPE_F16) {
const auto * f16_data = (const ggml_fp16_t *) tensor.data;
for (size_t i = 0; i < nelements; i++) {
f32_data[i] = ggml_fp16_to_fp32(f16_data[i]);
}
} else if (!params->allow_requantize) {
throw format("requantizing from type %s is disabled", ggml_type_name(tensor.type));
} else {
quantize_fns_t qtype = ggml_internal_get_quantize_fn(tensor.type);
if (qtype.dequantize_row_q == NULL) {
throw format("type %s unsupported for integer quantization: no dequantization available", ggml_type_name(tensor.type));
}
qtype.dequantize_row_q((void *)tensor.data, f32_data, nelements);
}
}
printf("quantizing .. ");