SQSHLU

Signed saturating shift left unsigned 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 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.

313029282726252423222120191817161514131211109876543210
00000100tszh001111100Pgtszlimm3Zdn

SVE2

SQSHLU <Zdn>.<T>, <Pg>/M, <Zdn>.<T>, #<const>

if !HaveSVE2() then UNDEFINED; bits(4) tsize = tszh:tszl; 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;

Assembler Symbols

<Zdn>

Is the name of the source and destination scalable vector register, encoded in the "Zdn" field.

<T> Is the size specifier, encoded in tszh:tszl:
tszh tszl <T>
00 00 RESERVED
00 01 B
00 1x H
01 xx S
1x xx D
<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".

Operation

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] = UnsignedSat(res, esize); else Elem[result, e, esize] = Elem[operand1, e, esize]; Z[dn] = result;

Operational information

If PSTATE.DIT is 1:

This instruction might be immediately preceded in program order by a MOVPRFX instruction that conforms to all of the following requirements, otherwise the behavior of either or both instructions is unpredictable:

The MOVPRFX instructions that can be used with this instruction are as follows:


Internal version only: isa v30.44, AdvSIMD v27.08, pseudocode v8.5-2019-06_rc2-5-g22901f2, sve v2019-06_rc4 ; Build timestamp: 2019-06-26T22:30

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