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Contiguous load first-fault signed halfwords to vector (scalar index).
Contiguous load with first-faulting behavior of signed halfwords to elements of a vector register from the memory address generated by a 64-bit scalar base and scalar index which is multiplied by 2 and added to the base address. After each element access the index value is incremented, but the index register is not updated. Inactive elements will not read Device memory or signal a fault, and are set to zero in the destination vector.
It has encodings from 2 classes: 32-bit element and 64-bit element
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 |
1 | 0 | 1 | 0 | 0 | 1 | 0 | 1 | 0 | 0 | 1 | Rm | 0 | 1 | 1 | Pg | Rn | Zt | ||||||||||||||
dtype<3:1> | dtype<0> |
if !HaveSVE() then UNDEFINED; integer t = UInt(Zt); integer n = UInt(Rn); integer m = UInt(Rm); integer g = UInt(Pg); integer esize = 32; integer msize = 16; boolean unsigned = FALSE;
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 |
1 | 0 | 1 | 0 | 0 | 1 | 0 | 1 | 0 | 0 | 0 | Rm | 0 | 1 | 1 | Pg | Rn | Zt | ||||||||||||||
dtype<3:1> | dtype<0> |
if !HaveSVE() then UNDEFINED; integer t = UInt(Zt); integer n = UInt(Rn); integer m = UInt(Rm); integer g = UInt(Pg); integer esize = 64; integer msize = 16; boolean unsigned = FALSE;
<Zt> | Is the name of the scalable vector register to be transferred, encoded in the "Zt" field. |
<Pg> | Is the name of the governing scalable predicate register P0-P7, encoded in the "Pg" field. |
<Xn|SP> | Is the 64-bit name of the general-purpose base register or stack pointer, encoded in the "Rn" field. |
<Xm> | Is the optional 64-bit name of the general-purpose offset register, defaulting to XZR, encoded in the "Rm" field. |
CheckSVEEnabled();
integer elements =CheckSVEEnabled();
integer elements = VL DIV esize;
bits(64) base;
bits(64) addr;
bits(PL) mask = P[g];
bits(VL) result;
bits(VL) orig = Z[t];
bits(msize) data;
bits(64) offset = VL DIV esize;
bits(64) base;
bits(64) addr;
bits(PL) mask = P[g];
bits(VL) result;
bits(VL) orig = Z[t];
bits(msize) data;
bits(64) offset = X[m];
constant integer mbytes = msize DIV 8;
boolean first = TRUE;
boolean fault = FALSE;
boolean faulted = FALSE;
boolean unknown = FALSE;
if HaveMTEExt() then SetTagCheckedInstruction(TRUE);
if n == 31 then
ifif n == 31 then LastActiveElement(mask, esize) >= 0 ||
ConstrainUnpredictableBool(Unpredictable_CHECKSPNONEACTIVE) then
CheckSPAlignment();
base = SP[];
else
base = X[n];
for e = 0 to elements-1
if if ElemP[mask, e, esize] == '1' then
addr = base + ElemP[mask, e, esize] == '1' then
addr = base + UInt(offset) * mbytes;
if first then
// Mem[] will not return if a fault is detected for the first active element
data = Mem[addr, mbytes, AccType_NORMAL];
first = FALSE;
else
// MemNF[] will return fault=TRUE if access is not performed for any reason
(data, fault) = MemNF[addr, mbytes, (data, fault) = MemNF[addr, mbytes, AccType_CNOTFIRST];
else
(data, fault) = ( AccType_CNOTFIRST];
else
(data, fault) = (Zeros(msize), FALSE);
// FFR elements set to FALSE following a supressed access/fault
faulted = faulted || fault;
if faulted then if faulted then
ElemFFR[e, esize] = '0';
// Value becomes CONSTRAINED UNPREDICTABLE after an FFR element is FALSE
unknown = unknown || ElemFFR[e, esize] == '0';
if unknown then
if !fault &&
ElemFFR[e, esize] = '0';
// Value becomes CONSTRAINED UNPREDICTABLE after an FFR element is FALSE
unknown = unknown || ElemFFR[e, esize] == '0';
if unknown then
if !fault && ConstrainUnpredictableBool((Unpredictable_SVELDNFDATA) thenUnpredictable_SVELDNFDATA) then
Elem[result, e, esize] = Extend(data, esize, unsigned);
elsif ConstrainUnpredictableBool((Unpredictable_SVELDNFZERO) thenUnpredictable_SVELDNFZERO) then
Elem[result, e, esize] = Zeros();
else // merge
Elem[result, e, esize] = Elem[orig, e, esize];
else
Elem[result, e, esize] = Extend(data, esize, unsigned);
offset = offset + 1;
Z[t] = result;(data, esize, unsigned);
offset = offset + 1;
Z[t] = result;
Internal version only: isa v32.03v31.05b, AdvSIMD v29.02, pseudocode v2020-03v2019-12_rc3_1, sve v2020-03_rc1v2019-12_rc3
; Build timestamp: 2020-04-15T132019-12-13T11:3302
Copyright © 2010-20202010-2019 Arm Limited or its affiliates. All rights reserved.
This document is Non-Confidential.
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