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## USMMLA

Unsigned by signed integer matrix multiply-accumulate

The unsigned by signed integer matrix multiply-accumulate instruction multiplies the 2×8 matrix of unsigned 8-bit integer values held in each 128-bit segment of the first source vector by the 8×2 matrix of signed 8-bit integer values in the corresponding segment of the second source vector. The resulting 2×2 widened 32-bit integer matrix product is then destructively added to the 32-bit integer matrix accumulator held in the corresponding segment of the addend and destination vector. This is equivalent to performing an 8-way dot product per destination element.

This instruction is unpredicated.

ID_AA64ZFR0_EL1.I8MM indicates whether this instruction is implemented.

This instruction is illegal when executed in Streaming SVE mode, unless FEAT_SME_FA64 is implemented and enabled.

### SVE
(FEAT_I8MM)

31 | 30 | 29 | 28 | 27 | 26 | 25 | 24 | 23 | 22 | 21 | 20 | 19 | 18 | 17 | 16 | 15 | 14 | 13 | 12 | 11 | 10 | 9 | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0
0 | 1 | 0 | 0 | 0 | 1 | 0 | 1 | 1 | 0 | 0 | Zm | 1 | 0 | 0 | 1 | 1 | 0 | Zn | Zda
| uns<1> | uns<0> |  |  |  |  |

####

USMMLA <Zda>.S, <Zn>.B, <Zm>.B

if !HaveSVE() || !HaveInt8MatMulExt() then UNDEFINED; integer n = UInt(Zn); integer m = UInt(Zm); integer da = UInt(Zda); boolean op1_unsigned = TRUE; boolean op2_unsigned = FALSE;

### Assembler Symbols

<Zda> | Is the name of the third source and destination scalable vector register, encoded in the "Zda" field.

<Zn> | Is the name of the first source scalable vector register, encoded in the "Zn" field.

<Zm> | Is the name of the second source scalable vector register, encoded in the "Zm" field.

### Operation

CheckNonStreamingSVEEnabled(); constant integer VL = CurrentVL; constant integer segments = VL DIV 128; bits(VL) operand1 = Z[n, VL]; bits(VL) operand2 = Z[m, VL]; bits(VL) operand3 = Z[da, VL]; bits(VL) result = Zeros(VL); bits(128) op1, op2; bits(128) res, addend; for s = 0 to segments-1 op1 = Elem[operand1, s, 128]; op2 = Elem[operand2, s, 128]; addend = Elem[operand3, s, 128]; res = MatMulAdd(addend, op1, op2, op1_unsigned, op2_unsigned); Elem[result, s, 128] = res; Z[da, VL] = result;

### Operational information

This instruction might be immediately preceded in program order by a MOVPRFX instruction. The MOVPRFX instruction must conform to all of the following requirements, otherwise the behavior of the MOVPRFX and this instruction is unpredictable:

- The MOVPRFX instruction must be unpredicated.
- The MOVPRFX instruction must specify the same destination register as this instruction.
- The destination register must not refer to architectural register state referenced by any other source operand register of this instruction.

Base Instructions | SIMD&FP Instructions | SVE Instructions | SME Instructions | Index by Encoding | Shared Pseudocode | Proprietary Notice

Internal version only: isa v33.64, AdvSIMD v29.12, pseudocode v2023-06_rel, sve v2023-06_rel ; Build timestamp: 2023-07-04T19:42

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