FSUBR (vectors) Floating-point reversed subtract vectors (predicated) Reversed subtract active floating-point elements of the first source vector from corresponding floating-point elements of the second source vector and destructively place the results in the corresponding elements of the first source vector. Inactive elements in the destination vector register remain unmodified. Green True True True 0 1 1 0 0 1 0 1 0 0 0 0 1 1 1 0 0 FSUBR <Zdn>.<T>, <Pg>/M, <Zdn>.<T>, <Zm>.<T> if !IsFeatureImplemented(FEAT_SVE) && !IsFeatureImplemented(FEAT_SME) then UNDEFINED; if size == '00' then UNDEFINED; constant integer esize = 8 << UInt(size); constant integer g = UInt(Pg); constant integer dn = UInt(Zdn); constant integer m = UInt(Zm); <Zdn> Is the name of the first source and destination scalable vector register, encoded in the "Zdn" field. <T> Is the size specifier, size <T> 00 RESERVED 01 H 10 S 11 D
<Pg> Is the name of the governing scalable predicate register P0-P7, encoded in the "Pg" field. <Zm> Is the name of the second source scalable vector register, encoded in the "Zm" field.
CheckSVEEnabled(); constant integer VL = CurrentVL; constant integer PL = VL DIV 8; constant integer elements = VL DIV esize; constant bits(PL) mask = P[g, PL]; constant bits(VL) operand1 = Z[dn, VL]; constant bits(VL) operand2 = if AnyActiveElement(mask, esize) then Z[m, VL] else Zeros(VL); bits(VL) result; for e = 0 to elements-1 constant bits(esize) element1 = Elem[operand1, e, esize]; if ActivePredicateElement(mask, e, esize) then constant bits(esize) element2 = Elem[operand2, e, esize]; Elem[result, e, esize] = FPSub(element2, element1, FPCR); else Elem[result, e, esize] = element1; Z[dn, VL] = result;