ASR (vectors)

Arithmetic shift right by vector (predicated)

Shift right, preserving the sign bit, active elements of the first source vector by corresponding elements of the second source vector and destructively place the results in the corresponding elements of the first source vector. The shift amount operand is a vector of unsigned elements in which all bits are significant, and not used modulo the element size. Inactive elements in the destination vector register remain unmodified.

313029282726252423222120191817161514131211109876543210
00000100size010000100PgZmZdn
RLU

ASR <Zdn>.<T>, <Pg>/M, <Zdn>.<T>, <Zm>.<T>

if !HaveSVE() && !HaveSME() then UNDEFINED; integer esize = 8 << UInt(size); integer g = UInt(Pg); integer dn = UInt(Zdn); integer m = UInt(Zm);

Assembler Symbols

<Zdn>

Is the name of the first source and destination scalable vector register, encoded in the "Zdn" field.

<T>

Is the size specifier, encoded in size:

size <T>
00 B
01 H
10 S
11 D
<Pg>

Is the name of the governing scalable predicate register P0-P7, encoded in the "Pg" field.

<Zm>

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

Operation

CheckSVEEnabled(); integer elements = VL DIV esize; bits(PL) mask = P[g]; bits(VL) operand1 = Z[dn]; bits(VL) operand2 = if AnyActiveElement(mask, esize) then Z[m] else Zeros(); bits(VL) result; for e = 0 to elements-1 if ElemP[mask, e, esize] == '1' then bits(esize) element1 = Elem[operand1, e, esize]; bits(esize) element2 = Elem[operand2, e, esize]; integer shift = Min(UInt(element2), esize); Elem[result, e, esize] = ASR(element1, shift); else Elem[result, e, esize] = Elem[operand1, e, esize]; Z[dn] = result;

Operational information

If FEAT_SVE2 is enabled or FEAT_SME is enabled, then when PSTATE.DIT is 1:

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:


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

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