Initialise predicate from named constraint.
Set elements of the destination predicate to true if the element number satisfies the named predicate constraint, or to false otherwise. If the constraint specifies more elements than are available at the current vector length then all elements of the destination predicate are set to false.
The named predicate constraint limits the number of active elements in a single predicate to:
* A fixed number (VL1 to VL256)
* The largest power of two (POW2)
* The largest multiple of three or four (MUL3 or MUL4)
* All available, implicitly a multiple of two (ALL).
Unspecified or out of range constraint encodings generate an empty predicate or zero element count rather than Undefined Instruction exception. 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: Flag setting and Not flag setting
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0 | 0 | 1 | 0 | 0 | 1 | 0 | 1 | size | 0 | 1 | 1 | 0 | 0 | 1 | 1 | 1 | 1 | 0 | 0 | 0 | pattern | 0 | Pd |
if !HaveSVE() then UNDEFINED; integer esize = 8 << UInt(size); integer d = UInt(Pd); boolean setflags = TRUE; bits(5) pat = pattern;
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0 | 0 | 1 | 0 | 0 | 1 | 0 | 1 | size | 0 | 1 | 1 | 0 | 0 | 0 | 1 | 1 | 1 | 0 | 0 | 0 | pattern | 0 | Pd |
if !HaveSVE() then UNDEFINED; integer esize = 8 << UInt(size); integer d = UInt(Pd); boolean setflags = FALSE; bits(5) pat = pattern;
<Pd> |
Is the name of the destination scalable predicate register, encoded in the "Pd" field. |
<T> |
Is the size specifier,
encoded in
size:
|
<pattern> |
Is the optional pattern specifier, defaulting to ALL,
encoded in
pattern:
|
CheckSVEEnabled(); integer elements = VL DIV esize; integer count = DecodePredCount(pat, esize); bits(PL) result; for e = 0 to elements-1 ElemP[result, e, esize] = if e < count then '1' else '0'; if setflags then PSTATE.<N,Z,C,V> = PredTest(result, result, esize); P[d] = result;
Release: 00rel5-manual
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