Unsigned rounding shift right and accumulate (immediate)
This instruction shifts right by immediate each unsigned element of the source vector, inserting zeroes, and destructively adds the rounded intermediate result to the corresponding elements of the addend vector. The immediate shift amount is an unsigned value in the range 1 to number of bits per element. This instruction is unpredicated.
| 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 | tszh | 0 | tszl | imm3 | 1 | 1 | 1 | 0 | 1 | 1 | Zn | Zda | ||||||||||||
| R | U | ||||||||||||||||||||||||||||||
if !IsFeatureImplemented(FEAT_SVE2) && !IsFeatureImplemented(FEAT_SME) then EndOfDecode(Decode_UNDEF); end; let tsize : bits(4) = tszh::tszl; if tsize == '0000' then EndOfDecode(Decode_UNDEF); end; let esize : integer{} = 8 << HighestSetBitNZ(tsize); let n : integer = UInt(Zn); let da : integer = UInt(Zda); let shift : integer = (2 * esize) - UInt(tsize::imm3);
| <Zda> |
Is the name of the third source and destination scalable vector register, encoded in the "Zda" field. |
| <T> |
Is the size specifier,
encoded in
|
| <Zn> |
Is the name of the first source scalable vector register, encoded in the "Zn" field. |
| <const> |
Is the immediate shift amount, in the range 1 to number of bits per element, encoded in "tszh:tszl:imm3". |
CheckSVEEnabled(); let VL : integer{} = CurrentVL(); let elements : integer = VL DIV esize; let operand1 : bits(VL) = Z{}(n); let operand2 : bits(VL) = Z{}(da); var result : bits(VL); for e = 0 to elements-1 do let element : integer = (UInt(operand1[e*:esize]) + (1 << (shift - 1))) >> shift; result[e*:esize] = operand2[e*:esize] + element[esize-1:0]; end; Z{VL}(da) = result;
This instruction is a data-independent-time instruction as described in About PSTATE.DIT.
This instruction might be immediately preceded in program order by a MOVPRFX instruction. The MOVPRFX must conform to all of the following requirements, otherwise the behavior of the MOVPRFX and this instruction is CONSTRAINED UNPREDICTABLE:
2026-03_rel 2026-03-26 20:48:11
Copyright © 2010-2026 Arm Limited or its affiliates. All rights reserved. This document is Non-Confidential.