You copied the Doc URL to your clipboard.

BRKPB, BRKPBS

Break before first true condition, propagating from previous partition.

If the last active element of the first source predicate is false then set the destination predicate to all-false. Otherwise sets destination predicate elements up to but not including the first active and true source element to true, then sets subsequent elements to false. Inactive elements in the destination predicate register are set to zero. Optionally sets the First (N), None (Z), !Last (C) condition flags based on the predicate result, and the V flag to zero.

It has encodings from 2 classes: Not setting the condition flags and Setting the condition flags

Not setting the condition flags

313029282726252423222120191817161514131211109876543210
001001010000Pm11Pg0Pn1Pd
SB

Not setting the condition flags

BRKPB <Pd>.B, <Pg>/Z, <Pn>.B, <Pm>.B

if !HaveSVE() then UNDEFINED;
integer esize = 8;
integer g = UInt(Pg);
integer n = UInt(Pn);
integer m = UInt(Pm);
integer d = UInt(Pd);
boolean setflags = FALSE;

Setting the condition flags

313029282726252423222120191817161514131211109876543210
001001010100Pm11Pg0Pn1Pd
SB

Setting the condition flags

BRKPBS <Pd>.B, <Pg>/Z, <Pn>.B, <Pm>.B

if !HaveSVE() then UNDEFINED;
integer esize = 8;
integer g = UInt(Pg);
integer n = UInt(Pn);
integer m = UInt(Pm);
integer d = UInt(Pd);
boolean setflags = TRUE;

Assembler Symbols

<Pd>

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

<Pg>

Is the name of the governing scalable predicate register, encoded in the "Pg" field.

<Pn>

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

<Pm>

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

Operation

CheckSVEEnabled();
integer elements = VL DIV esize;
bits(PL) mask = P[g];
bits(PL) operand1 = P[n];
bits(PL) operand2 = P[m];
bits(PL) result;
boolean last = (LastActive(mask, operand1, 8) == '1');

for e = 0 to elements-1
    if ElemP[mask, e, 8] == '1' then
        last = last && (ElemP[operand2, e, 8] == '0');
        ElemP[result, e, 8] = if last then '1' else '0';
    else
        ElemP[result, e, 8] = '0';

if setflags then
    PSTATE.<N,Z,C,V> = PredTest(mask, result, esize);
P[d] = result;