REV (predicate)

Reverse all elements in a predicate

This instruction reads all elements in the source predicate, reverses the order of all the elements, and places the result in the destination predicate. This instruction is unpredicated.

SVE
(FEAT_SVE || FEAT_SME)

313029282726252423222120191817161514131211109876543210
00000101size1101000100000Pn0Pd

Encoding

REV <Pd>.<T>, <Pn>.<T>

Decode for this encoding

if !IsFeatureImplemented(FEAT_SVE) && !IsFeatureImplemented(FEAT_SME) then EndOfDecode(Decode_UNDEF); end; let esize : integer{} = 8 << UInt(size); let n : integer = UInt(Pn); let d : integer = UInt(Pd);

Assembler Symbols

<Pd>

Is the name of the destination scalable predicate register, encoded in the "Pd" field.

<T>

Is the size specifier, encoded in size:

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

Is the name of the source scalable predicate register, encoded in the "Pn" field.

Operation

CheckSVEEnabled(); let VL : integer{} = CurrentVL(); let PL : integer{} = VL DIV 8; let operand : bits(PL) = P{}(n); let result : bits(PL) = Reverse{}(operand, esize DIV 8); P{PL}(d) = result;


2026-03_rel 2026-03-26 20:48:11

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