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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, this is an optional instruction. ID_AA64ISAR0_EL1.I8MM indicates whether this instruction is supported.

Vector
(Armv8.6)

313029282726252423222120191817161514131211109876543210
01101110100Rm101001RnRd
UB

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

if !HaveInt8MatMulExt() then 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, TRUE, TRUE);