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Mojo struct

MmaOpSM100_SS

struct MmaOpSM100_SS[c_type: DType, a_type: DType, b_type: DType, block_tile_shape: IndexList[Int(3)], mma_shape: IndexList[Int(3)], /, *, accum_type: DType = DType.float32, cta_group: Int = Int(1), cluster_shape: IndexList[Int(3)] = Index[Int, Int, Int](Int(1), Int(1), Int(1)), a_swizzle: TensorMapSwizzle = TensorMapSwizzle.SWIZZLE_128B, b_swizzle: TensorMapSwizzle = TensorMapSwizzle.SWIZZLE_128B, transpose_b: Bool = False]

SM100 (Blackwell) warp-specialized MMA operation for standard (non-block-scaled) GEMM.

Encapsulates a UMMA instruction descriptor and multicast mask for issuing asynchronous tensor-core MMA operations from shared memory to tensor memory (TMEM) on NVIDIA SM100 GPUs. Supports optional CTA clustering for multicast.

Parameters

• ​c_type (DType): Output accumulator element type.
• ​a_type (DType): A operand element type.
• ​b_type (DType): B operand element type; must match a_type.
• ​block_tile_shape (IndexList[Int(3)]): (BM, BN, BK) shape of the shared-memory tile processed per CTA.
• ​mma_shape (IndexList[Int(3)]): (MMA_M, MMA_N, MMA_K) shape of a single UMMA instruction.
• ​accum_type (DType): Accumulator precision; defaults to float32.
• ​cta_group (Int): Number of CTAs collaborating on one tile (1 or 2).
• ​cluster_shape (IndexList[Int(3)]): CTA cluster shape for multicast; defaults to (1, 1, 1).
• ​a_swizzle (TensorMapSwizzle): Swizzle mode for the A operand shared-memory layout.
• ​b_swizzle (TensorMapSwizzle): Swizzle mode for the B operand shared-memory layout.
• ​transpose_b (Bool): Must be True; SM100 UMMA always uses transposed B.

Fields

• ​idesc (UMMAInsDescriptor[MmaOpSM100_SS._get_umma_kind[a_type]()]):
• ​mask (UInt16):

Implemented traits

AnyType, Copyable, Defaultable, Deinitable, ImplicitlyCopyable, Movable, RegisterPassable, TrivialRegisterPassable

Methods

__init__

def __init__() -> Self

make_a_desc

def make_a_desc(self, a: TileTensor[Storage=a.Storage, address_space=AddressSpace.SHARED, linear_idx_type=a.linear_idx_type]) -> MMASmemDescriptor

Build the K-major MMA descriptor for an A operand tile.

Exposed so callers that issue MMAs over several adjacent SMEM tiles (e.g. a k-group loop) can build the descriptor once and advance it by a comptime byte stride per tile, rather than rebuilding the full descriptor (base-pointer mask + bitfield inserts) for each tile.

Args:

• ​a (TileTensor[Storage=a.Storage, address_space=AddressSpace.SHARED, linear_idx_type=a.linear_idx_type]): A operand tile in shared memory.

Returns:

MMASmemDescriptor: The K-major MMA shared-memory descriptor for a.

make_b_desc

def make_b_desc(self, b: TileTensor[Storage=b.Storage, address_space=AddressSpace.SHARED, linear_idx_type=b.linear_idx_type]) -> MMASmemDescriptor

Build the K-major MMA descriptor for a B operand tile.

See make_a_desc for why this is exposed.

Args:

• ​b (TileTensor[Storage=b.Storage, address_space=AddressSpace.SHARED, linear_idx_type=b.linear_idx_type]): B operand tile in shared memory.

Returns:

MMASmemDescriptor: The K-major MMA shared-memory descriptor for b.

mma

def mma(self, a: TileTensor[Storage=a.Storage, address_space=AddressSpace.SHARED, linear_idx_type=a.linear_idx_type], b: TileTensor[Storage=b.Storage, address_space=AddressSpace.SHARED, linear_idx_type=b.linear_idx_type], c_tmem: UInt32, init_c: Bool)

Issue MMA operations over K tiles from shared memory to TMEM.

Args:

• ​a (TileTensor[Storage=a.Storage, address_space=AddressSpace.SHARED, linear_idx_type=a.linear_idx_type]): A operand tile in shared memory.
• ​b (TileTensor[Storage=b.Storage, address_space=AddressSpace.SHARED, linear_idx_type=b.linear_idx_type]): B operand tile in shared memory.
• ​c_tmem (UInt32): TMEM address for the accumulator.
• ​init_c (Bool): When True, zero-initialize the accumulator on the first K slice instead of accumulating.

mma_from_desc

def mma_from_desc(self, a_desc: MMASmemDescriptor, b_desc: MMASmemDescriptor, c_tmem: UInt32, init_c: Bool)

Issue MMA operations over K tiles from precomputed SMEM descriptors.

Identical to mma, but takes already-built A/B descriptors. This lets a k-group caller build the descriptor base once and advance it by a comptime byte stride per tile (the SM100 SMEM-descriptor base address adds linearly), avoiding a redundant full descriptor rebuild per tile.

Args:

• ​a_desc (MMASmemDescriptor): Precomputed K-major descriptor for the A operand tile.
• ​b_desc (MMASmemDescriptor): Precomputed K-major descriptor for the B operand tile.
• ​c_tmem (UInt32): TMEM address for the accumulator.
• ​init_c (Bool): When True, zero-initialize the accumulator on the first K slice instead of accumulating.

commit

def commit(self, ptr_mbar: Pointer[address_space=AddressSpace.SHARED])

wait

def wait(self)