PRFH (scalar plus scalar) Contiguous prefetch halfwords (scalar index) Contiguous prefetch of halfword elements from the memory address generated by a 64-bit scalar base and scalar index which is multiplied by 2 and added to the base address. After each element prefetch the index value is incremented, but the index register is not updated. The predicate may be used to suppress prefetches from unwanted addresses. Green True 1 0 0 0 0 1 0 0 1 0 0 1 1 0 0 PRFH <prfop>, <Pg>, [<Xn|SP>, <Xm>, LSL #1] if !IsFeatureImplemented(FEAT_SVE) && !IsFeatureImplemented(FEAT_SME) then UNDEFINED; if Rm == '11111' then UNDEFINED; constant integer esize = 16; constant integer g = UInt(Pg); constant integer n = UInt(Rn); constant integer m = UInt(Rm); constant integer level = UInt(prfop<2:1>); constant boolean stream = (prfop<0> == '1'); constant PrefetchHint pref_hint = if prfop<3> == '0' then Prefetch_READ else Prefetch_WRITE; constant integer scale = 1; <prfop> Is the prefetch operation specifier, prfop <prfop> 0000 PLDL1KEEP 0001 PLDL1STRM 0010 PLDL2KEEP 0011 PLDL2STRM 0100 PLDL3KEEP 0101 PLDL3STRM x11x #uimm4 1000 PSTL1KEEP 1001 PSTL1STRM 1010 PSTL2KEEP 1011 PSTL2STRM 1100 PSTL3KEEP 1101 PSTL3STRM <Pg> Is the name of the governing scalable predicate register P0-P7, encoded in the "Pg" field. <Xn|SP> Is the 64-bit name of the general-purpose base register or stack pointer, encoded in the "Rn" field. <Xm> Is the 64-bit name of the general-purpose offset register, encoded in the "Rm" 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]; bits(64) base; bits(64) offset; if AnyActiveElement(mask, esize) then base = if n == 31 then SP[] else X[n, 64]; offset = X[m, 64]; for e = 0 to elements-1 if ActivePredicateElement(mask, e, esize) then constant integer eoff = UInt(offset) + e; constant bits(64) addr = base + (eoff << scale); Hint_Prefetch(addr, pref_hint, level, stream);