Files
AstrAI/csrc/kernels/fp8/gemm/policy.cuh
T
ViperEkura 1c17e80882 refactor: root kernel includes at csrc/kernels
- add the kernels directory to CMake target include paths and drop all ../-relative includes in kernel sources
- reference shared primitives as common/*.cuh and the fp8 type header as fp8/common.h
- update standalone test nvcc commands in file headers and cuda_kernels.md to -I csrc/kernels
2026-09-01 14:43:38 +08:00

54 lines
2.3 KiB
Plaintext

#pragma once
// Kernel policy layer: shared-memory budget, occupancy hint and the
// single Policy type the kernel and collectives take (CUTLASS-style
// consolidation of traits + layout tags + scheduling knobs).
#include <type_traits>
#include "fp8/common.h"
namespace astrai {
namespace fp8 {
// m16n8k32 (see astrai::mma_shape<fp8 type>::k in common/mma.cuh)
constexpr int kMmaK = 32;
// Layout-aware shared-memory budget and occupancy hint. Every operand ring
// holds kStages+1 buffers: the load for tile i+kStages targets slot
// (i-1)%(kStages+1) — already consumed — so neither load path needs a
// post-compute barrier (one __syncthreads per k-tile; see the design notes
// in docs/developer/cuda_kernels.md). The 48KB static watermark picks the
// resident-CTA hint for __launch_bounds__.
template <typename Traits, typename LayoutA, typename LayoutB>
struct Fp8GemmSmem {
// Crosswise (direct-load) operands: A ColMajor storage, B RowMajor
// storage (B's tag is relative to the canonical [K][N]).
static constexpr bool kDirectA = std::is_same_v<LayoutA, ColMajor>;
static constexpr bool kDirectB = std::is_same_v<LayoutB, RowMajor>;
static constexpr int kRingDepth = Traits::kStages + 1;
static constexpr int kBytes =
kRingDepth * (Traits::kBlockM + Traits::kBlockN) * Traits::kK;
static constexpr int kMinCtas = kBytes <= 48 * 1024 ? 2 : 1;
};
template <FP8Format Fmt_, int BlockM_, int BlockN_, typename LayoutA_,
typename LayoutB_, int WarpM_, int WarpN_, int kK_, int Stages_,
int GroupRaster_, bool StreamOut_ = false, bool FastLoop_ = false>
struct Fp8GemmPolicy {
using Traits =
Fp8GemmTraits<Fmt_, BlockM_, BlockN_, kK_, Stages_, WarpM_, WarpN_>;
using LayoutTagA = LayoutA_;
using LayoutTagB = LayoutB_;
static constexpr int kGroupRaster = GroupRaster_;
static constexpr bool kStreamOut = StreamOut_;
static constexpr bool kFastLoop = FastLoop_;
using Smem = Fp8GemmSmem<Traits, LayoutA_, LayoutB_>;
// Flattened for __launch_bounds__, which takes no dependent type names.
static constexpr int kCtaThreads = Traits::kCtaThreads;
static constexpr int kMinCtas = Smem::kMinCtas;
static constexpr int kSmemBytes = Smem::kBytes;
};
} // namespace fp8
} // namespace astrai