Spaces:
Runtime error
Runtime error
File size: 4,180 Bytes
8a42f8f |
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 |
#include <ATen/ATen.h>
#include <ATen/AccumulateType.h>
#include <ATen/cuda/CUDAContext.h>
#include <ATen/cuda/Exceptions.h>
// Another possibility:
// #include <torch/all.h>
#include <assert.h>
// Stringstream is a big hammer, but I want to rely on operator<< for dtype.
#include <sstream>
#include "type_shim.h"
#include "multi_tensor_apply.cuh"
#define BLOCK_SIZE 512
#define ILP 4
template<typename T>
__device__ __forceinline__ bool is_aligned(T* p){
return ((uint64_t)p) % (ILP*sizeof(T)) == 0;
}
template<typename T>
__device__ __forceinline__ void load_store(T* dst, T* src, int dst_offset, int src_offset){
typedef typename std::aligned_storage<ILP*sizeof(T), ILP*alignof(T)>::type LT;
((LT*)dst)[dst_offset] = ((LT*)src)[src_offset];
}
template<typename in_t, typename out_t>
struct ScaleFunctor
{
__device__ __forceinline__ void operator()(
int chunk_size,
volatile int* noop_gmem,
TensorListMetadata<2>& tl,
float scale)
{
// I'd like this kernel to propagate infs/nans.
// if(*noop_gmem == 1)
// return;
int tensor_loc = tl.block_to_tensor[blockIdx.x];
int chunk_idx = tl.block_to_chunk[blockIdx.x];
int n = tl.sizes[tensor_loc];
in_t* in = (in_t*)tl.addresses[0][tensor_loc];
in += chunk_idx*chunk_size;
out_t* out = (out_t*)tl.addresses[1][tensor_loc];
out += chunk_idx*chunk_size;
n -= chunk_idx*chunk_size;
bool finite = true;
in_t r_in[ILP];
out_t r_out[ILP];
// to make things simple, we put aligned case in a different code path
if(n % ILP == 0 && chunk_size % ILP == 0 && is_aligned(in) && is_aligned(out))
{
for(int i_start = threadIdx.x; i_start*ILP < n && i_start*ILP < chunk_size; i_start += blockDim.x)
{
// load
load_store(r_in, in, 0 , i_start);
#pragma unroll
for(int ii = 0; ii < ILP; ii++)
{
r_out[ii] = static_cast<float>(r_in[ii]) * scale;
finite = finite && isfinite(r_in[ii]);
}
// store
load_store(out, r_out, i_start, 0);
}
}
else
{
// Non-divergent exit condition for __syncthreads, not necessary here
for(int i_start = 0; i_start < n && i_start < chunk_size; i_start += blockDim.x*ILP)
{
#pragma unroll
for(int ii = 0; ii < ILP; ii++)
{
r_in[ii] = 0;
int i = i_start + threadIdx.x + ii*blockDim.x;
if(i < n && i < chunk_size)
r_in[ii] = in[i];
}
// note for clarification to future michael:
// From a pure memory dependency perspective, there's likely no point unrolling
// the write loop, since writes just fire off once their LDGs arrive.
// Put another way, the STGs are dependent on the LDGs, but not on each other.
// There is still compute ILP benefit from unrolling the loop though.
#pragma unroll
for(int ii = 0; ii < ILP; ii++)
{
r_out[ii] = static_cast<float>(r_in[ii]) * scale;
finite = finite && isfinite(r_in[ii]);
}
#pragma unroll
for(int ii = 0; ii < ILP; ii++)
{
int i = i_start + threadIdx.x + ii*blockDim.x;
if(i < n && i < chunk_size)
out[i] = r_out[ii];
}
}
}
if(!finite)
*noop_gmem = 1; // Blindly fire off a write. These will race but that's ok.
}
};
void multi_tensor_scale_cuda(
int chunk_size,
at::Tensor noop_flag,
std::vector<std::vector<at::Tensor>> tensor_lists,
float scale)
{
using namespace at;
// The output (downscaled) type is always float.
// If build times suffer, think about where to put this dispatch,
// and what logic should be moved out of multi_tensor_apply.
DISPATCH_FLOAT_HALF_AND_BFLOAT(tensor_lists[0][0].scalar_type(), 0, "multi_tensor_scale_cuda",
DISPATCH_FLOAT_HALF_AND_BFLOAT(tensor_lists[1][0].scalar_type(), 1, "multi_tensor_scale_cuda",
multi_tensor_apply<2>(
BLOCK_SIZE,
chunk_size,
noop_flag,
tensor_lists,
ScaleFunctor<scalar_t_0, scalar_t_1>(),
scale); ))
AT_CUDA_CHECK(cudaGetLastError());
// AT_CUDA_CHECK(cudaDeviceSynchronize());
}
|