Unsigned saturating shift right narrow by immediate (bottom)
Shift each unsigned integer value in the source vector elements right by an immediate value, and place the truncated results in the even-numbered half-width destination elements, while setting the odd-numbered elements to zero. Each result element is saturated to the half-width N-bit element's unsigned integer range 0 to (2N)-1. 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 | 0 | tszh | 1 | tszl | imm3 | 0 | 0 | 1 | 1 | 0 | 0 | Zn | Zd | |||||||||||
| U | R | T | |||||||||||||||||||||||||||||
if !IsFeatureImplemented(FEAT_SVE2) && !IsFeatureImplemented(FEAT_SME) then UNDEFINED; constant bits(3) tsize = tszh:tszl; if tsize == '000' then UNDEFINED; constant integer esize = 8 << HighestSetBit(tsize); constant integer n = UInt(Zn); constant integer d = UInt(Zd); constant integer shift = (2 * esize) - UInt(tsize:imm3);
| <Zd> |
Is the name of the destination scalable vector register, encoded in the "Zd" field. |
| <T> |
Is the size specifier,
encoded in
|
| <Zn> |
Is the name of the source scalable vector register, encoded in the "Zn" field. |
| <Tb> |
Is the size specifier,
encoded in
|
| <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 PL = VL DIV 8; constant integer elements = VL DIV (2 * esize); constant bits(VL) operand = Z[n, VL]; bits(VL) result; for e = 0 to elements-1 constant bits(2*esize) element = Elem[operand, e, 2*esize]; constant integer res = UInt(element) >> shift; Elem[result, 2*e + 0, esize] = UnsignedSat(res, esize); Elem[result, 2*e + 1, esize] = Zeros(esize); Z[d, VL] = result;
Internal version only: aarchmrs v2024-03_relA, pseudocode v2024-03_rel, sve v2024-03_rel ; Build timestamp: 2024-03-26T09:45
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