Signed shift right and accumulate (immediate)
This instruction shifts right by immediate each signed element of the source vector, preserving the sign bit, and destructively adds the truncated 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 | 0 | 0 | Zn | Zda | ||||||||||||
| R | U | ||||||||||||||||||||||||||||||
if !IsFeatureImplemented(FEAT_SVE2) && !IsFeatureImplemented(FEAT_SME) then EndOfDecode(Decode_UNDEF); constant bits(4) tsize = tszh:tszl; if tsize == '0000' then EndOfDecode(Decode_UNDEF); constant integer esize = 8 << HighestSetBitNZ(tsize); constant integer n = UInt(Zn); constant integer da = UInt(Zda); constant integer shift = (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(); constant integer VL = CurrentVL; constant integer elements = VL DIV esize; constant bits(VL) operand1 = Z[n, VL]; constant bits(VL) operand2 = Z[da, VL]; bits(VL) result; for e = 0 to elements-1 constant integer element = SInt(Elem[operand1, e, esize]) >> shift; Elem[result, e, esize] = Elem[operand2, e, esize] + element<esize-1:0>; Z[da, VL] = 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:
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