(old) htmldiff from-(new)

DECP (scalar)

Decrement scalar by count of true predicate elements.

Counts the number of true elements in the source predicate and then uses the result to decrement the scalar destination.

313029282726252423222120191817161514131211109876543210
00100101size1011011000100PmRdn

SVE

DECP <Xdn>, <Pm>.<T>

if !HaveSVE() then UNDEFINED; integer esize = 8 << UInt(size); integer m = UInt(Pm); integer dn = UInt(Rdn);

Assembler Symbols

<Xdn>

Is the 64-bit name of the source and destination general-purpose register, encoded in the "Rdn" field.

<Pm>

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

<T> Is the size specifier, encoded in size:
size<T>
00B
01H
10S
11D

Operation

CheckSVEEnabled(); integer elements = VL DIV esize; bits(64) operand1 = X[dn]; bits(PL) operand2 = P[m]; integer count = 0; for e = 0 to elements-1 if ElemP[operand2, e, esize] == '1' then count = count + 1; X[dn] = operand1 - count;

Operational information

If PSTATE.DIT is 1:


Internal version only: isa v31.05bv31.04, AdvSIMD v29.02, pseudocode v2019-12_rc3_1v2019-09_rc2_1, sve v2019-12_rc3v2019-09_rc3 ; Build timestamp: 2019-12-13T112019-09-27T17:0228

Copyright © 2010-2019 Arm Limited or its affiliates. All rights reserved. This document is Non-Confidential.

(old) htmldiff from-(new)