Unsigned saturating shift left by immediate
Shift left by immediate each active unsigned 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 unsigned integer range 0 to (2N)-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 | 1 | 1 | 0 | 0 | Pg | tszl | imm3 | Zdn | ||||||||||
| L | U | ||||||||||||||||||||||||||||||
if !HaveSVE2() && !HaveSME() then UNDEFINED; constant bits(4) tsize = tszh:tszl; if tsize == '0000' then UNDEFINED; constant integer esize = 8 << HighestSetBit(tsize); 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 "tszh:tszl:imm3". |
CheckSVEEnabled(); constant integer VL = CurrentVL; constant integer PL = VL DIV 8; constant integer elements = VL DIV esize; bits(VL) operand1 = Z[dn, VL]; bits(PL) mask = P[g, PL]; bits(VL) result; for e = 0 to elements-1 integer element1 = UInt(Elem[operand1, e, esize]); if ActivePredicateElement(mask, e, esize) then integer res = element1 << shift; Elem[result, e, esize] = UnsignedSat(res, esize); else Elem[result, e, esize] = Elem[operand1, e, esize]; Z[dn, VL] = 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: aarchmrs v2023-12_rel, pseudocode v2023-12_rel, sve v2023-12_rel ; Build timestamp: 2023-12-15T16:46
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