Signed saturating shift left by immediate
Shift left by immediate each active signed element of the source vector, and destructively place the results in the corresponding elements of the source vector. Each result element is saturated to the N-bit element's signed integer range -2(N-1) to (2(N-1) )-1. The immediate shift amount is an unsigned value in the range 0 to number of bits per element minus 1. Inactive elements in the destination vector register remain unmodified.
| 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 | 0 | 0 | 0 | 0 | 1 | 0 | 0 | tszh | 0 | 0 | 0 | 1 | 1 | 0 | 1 | 0 | 0 | Pg | tszl | imm3 | Zdn | ||||||||||
| L | U | ||||||||||||||||||||||||||||||
if !HaveSVE2() && !HaveSME() then UNDEFINED; bits(4) tsize = tszh:tszl; integer esize; case tsize of when '0000' UNDEFINED; when '0001' esize = 8; when '001x' esize = 16; when '01xx' esize = 32; when '1xxx' esize = 64; integer g = UInt(Pg); integer dn = UInt(Zdn); integer shift = UInt(tsize:imm3) - esize;
| <Zdn> |
Is the name of the source and destination scalable vector register, encoded in the "Zdn" field. |
| <T> |
Is the size specifier,
encoded in
|
| <Pg> |
Is the name of the governing scalable predicate register P0-P7, encoded in the "Pg" field. |
| <const> |
Is the immediate shift amount, in the range 0 to number of bits per element minus 1, encoded in "tsz:imm3". |
CheckSVEEnabled(); integer elements = VL DIV esize; bits(VL) operand1 = Z[dn]; bits(PL) mask = P[g]; bits(VL) result; for e = 0 to elements-1 integer element1 = SInt(Elem[operand1, e, esize]); if ElemP[mask, e, esize] == '1' then integer res = element1 << shift; Elem[result, e, esize] = SignedSat(res, esize); else Elem[result, e, esize] = Elem[operand1, e, esize]; Z[dn] = result;
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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