PRFW (scalar plus vector)

Gather prefetch words (scalar plus vector)

Gather prefetch of words from the active memory addresses generated by a 64-bit scalar base plus vector index. The index values are optionally first sign or zero-extended from 32 to 64 bits and then multiplied by 4. Inactive addresses are not prefetched from memory.

The <prfop> symbol specifies the prefetch hint as a combination of three options: access type PLD for load or PST for store; target cache level L1, L2 or L3; temporality (KEEP for temporal or STRM for non-temporal).

It has encodings from 3 classes: 32-bit scaled offset , 32-bit unpacked scaled offset and 64-bit scaled offset

32-bit scaled offset

if !HaveSVE() then UNDEFINED; integer esize = 32; integer g = UInt(Pg); integer n = UInt(Rn); integer m = UInt(Zm); integer level = UInt(prfop<2:1>); boolean stream = (prfop<0> == '1'); pref_hint = if prfop<3> == '0' then Prefetch_READ else Prefetch_WRITE; integer offs_size = 32; boolean offs_unsigned = (xs == '0'); integer scale = 2;

32-bit unpacked scaled offset

if !HaveSVE() then UNDEFINED; integer esize = 64; integer g = UInt(Pg); integer n = UInt(Rn); integer m = UInt(Zm); integer level = UInt(prfop<2:1>); boolean stream = (prfop<0> == '1'); pref_hint = if prfop<3> == '0' then Prefetch_READ else Prefetch_WRITE; integer offs_size = 32; boolean offs_unsigned = (xs == '0'); integer scale = 2;

64-bit scaled offset

if !HaveSVE() then UNDEFINED; integer esize = 64; integer g = UInt(Pg); integer n = UInt(Rn); integer m = UInt(Zm); integer level = UInt(prfop<2:1>); boolean stream = (prfop<0> == '1'); pref_hint = if prfop<3> == '0' then Prefetch_READ else Prefetch_WRITE; integer offs_size = 64; boolean offs_unsigned = TRUE; integer scale = 2;