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
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 |
0 | 0 | 1 | 0 | 0 | 1 | 0 | 1 | 0 | 0 | 0 | 1 | 0 | 0 | 0 | 0 | 0 | 1 | Pg | 0 | Pn | M | Pd |
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
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 |
0 | 0 | 1 | 0 | 0 | 1 | 0 | 1 | 0 | 1 | 0 | 1 | 0 | 0 | 0 | 0 | 0 | 1 | Pg | 0 | Pn | 0 | Pd |
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:
|
<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;