BRKA, BRKAS

Break after first true condition

Sets destination predicate elements up to and including the first active and true source element to true, then sets subsequent elements to false. Inactive elements in the destination predicate register remain unmodified or are set to zero, depending on whether merging or zeroing predication is selected. 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
001001010001000001Pg0PnMPd
BS

BRKA <Pd>.B, <Pg>/<ZM>, <Pn>.B

if !HaveSVE() then UNDEFINED; integer esize = 8; integer g = UInt(Pg); integer n = UInt(Pn); integer d = UInt(Pd); boolean merging = (M == '1'); boolean setflags = FALSE;

Setting the condition flags

313029282726252423222120191817161514131211109876543210
001001010101000001Pg0Pn0Pd
BSM

BRKAS <Pd>.B, <Pg>/Z, <Pn>.B

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

<ZM>

Is the predication qualifier, encoded in M:

M <ZM>
0 Z
1 M
<Pn>

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

Operation

CheckSVEEnabled(); integer elements = VL DIV esize; bits(PL) mask = P[g]; bits(PL) operand = P[n]; bits(PL) operand2 = P[d]; boolean break = FALSE; bits(PL) result; for e = 0 to elements-1 boolean element = ElemP[operand, e, esize] == '1'; if ElemP[mask, e, esize] == '1' then ElemP[result, e, esize] = if !break then '1' else '0'; break = break || element; elsif merging then ElemP[result, e, esize] = ElemP[operand2, e, esize]; else ElemP[result, e, esize] = '0'; if setflags then PSTATE.<N,Z,C,V> = PredTest(mask, result, esize); P[d] = result;


Internal version only: isa v32.15, AdvSIMD v29.05, pseudocode v2021-03, sve v2021-03_rc2 ; Build timestamp: 2021-03-30T21:36

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