UMMLA (vector)

Unsigned 8-bit integer matrix multiply-accumulate. This instruction multiplies the 2x8 matrix of unsigned 8-bit integer values in the first source vector by the 8x2 matrix of unsigned 8-bit integer values in the second source vector. The resulting 2x2 32-bit integer matrix product is destructively added to the 32-bit integer matrix accumulator in the destination vector. This is equivalent to performing an 8-way dot product per destination element.

From Armv8.2 to Armv8.5, this is an optional instruction. From Armv8.6 it is mandatory for implementations that include Advanced SIMD to support it. ID_AA64ISAR1_EL1.I8MM indicates whether this instruction is supported.

Vector
(FEAT_I8MM)

313029282726252423222120191817161514131211109876543210
01101110100Rm101001RnRd
UB

UMMLA <Vd>.4S, <Vn>.16B, <Vm>.16B

if !HaveInt8MatMulExt() then UNDEFINED; case B:U of when '00' op1_unsigned = FALSE; op2_unsigned = FALSE; when '01' op1_unsigned = TRUE; op2_unsigned = TRUE; when '10' op1_unsigned = TRUE; op2_unsigned = FALSE; when '11' UNDEFINED; integer n = UInt(Rn); integer m = UInt(Rm); integer d = UInt(Rd);

Assembler Symbols

<Vd>

Is the name of the SIMD&FP third source and destination register, encoded in the "Rd" field.

<Vn>

Is the name of the first SIMD&FP source register, encoded in the "Rn" field.

<Vm>

Is the name of the second SIMD&FP source register, encoded in the "Rm" field.

Operation

CheckFPAdvSIMDEnabled64(); bits(128) operand1 = V[n]; bits(128) operand2 = V[m]; bits(128) addend = V[d]; V[d] = MatMulAdd(addend, operand1, operand2, op1_unsigned, op2_unsigned);


Internal version only: isa v33.11seprel, AdvSIMD v29.05, pseudocode v2021-09_rel, sve v2021-09_rc3d ; Build timestamp: 2021-10-06T11:41

Copyright © 2010-2021 Arm Limited or its affiliates. All rights reserved. This document is Non-Confidential.