ST1H (scalar plus vector)

Scatter store halfwords from a vector (vector index).

Scatter store of halfwords from the active elements of a vector register to the 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 optionally multiplied by 2. Inactive elements are not written to memory.

It has encodings from 6 classes: 32-bit scaled offset , 32-bit unpacked scaled offset , 32-bit unpacked unscaled offset , 32-bit unscaled offset , 64-bit scaled offset and 64-bit unscaled offset

32-bit scaled offset

313029282726252423222120191817161514131211109876543210
11100100111Zm1xs0PgRnZt

32-bit scaled offset

ST1H { <Zt>.S }, <Pg>, [<Xn|SP>, <Zm>.S, <mod> #1]

if !HaveSVE() then UNDEFINED; integer t = UInt(Zt); integer n = UInt(Rn); integer m = UInt(Zm); integer g = UInt(Pg); integer esize = 32; integer msize = 16; integer offs_size = 32; boolean offs_unsigned = xs == '0'; integer scale = 1;

32-bit unpacked scaled offset

313029282726252423222120191817161514131211109876543210
11100100101Zm1xs0PgRnZt

32-bit unpacked scaled offset

ST1H { <Zt>.D }, <Pg>, [<Xn|SP>, <Zm>.D, <mod> #1]

if !HaveSVE() then UNDEFINED; integer t = UInt(Zt); integer n = UInt(Rn); integer m = UInt(Zm); integer g = UInt(Pg); integer esize = 64; integer msize = 16; integer offs_size = 32; boolean offs_unsigned = xs == '0'; integer scale = 1;

32-bit unpacked unscaled offset

313029282726252423222120191817161514131211109876543210
11100100100Zm1xs0PgRnZt

32-bit unpacked unscaled offset

ST1H { <Zt>.D }, <Pg>, [<Xn|SP>, <Zm>.D, <mod>]

if !HaveSVE() then UNDEFINED; integer t = UInt(Zt); integer n = UInt(Rn); integer m = UInt(Zm); integer g = UInt(Pg); integer esize = 64; integer msize = 16; integer offs_size = 32; boolean offs_unsigned = xs == '0'; integer scale = 0;

32-bit unscaled offset

313029282726252423222120191817161514131211109876543210
11100100110Zm1xs0PgRnZt

32-bit unscaled offset

ST1H { <Zt>.S }, <Pg>, [<Xn|SP>, <Zm>.S, <mod>]

if !HaveSVE() then UNDEFINED; integer t = UInt(Zt); integer n = UInt(Rn); integer m = UInt(Zm); integer g = UInt(Pg); integer esize = 32; integer msize = 16; integer offs_size = 32; boolean offs_unsigned = xs == '0'; integer scale = 0;

64-bit scaled offset

313029282726252423222120191817161514131211109876543210
11100100101Zm101PgRnZt

64-bit scaled offset

ST1H { <Zt>.D }, <Pg>, [<Xn|SP>, <Zm>.D, LSL #1]

if !HaveSVE() then UNDEFINED; integer t = UInt(Zt); integer n = UInt(Rn); integer m = UInt(Zm); integer g = UInt(Pg); integer esize = 64; integer msize = 16; integer offs_size = 64; boolean offs_unsigned = TRUE; integer scale = 1;

64-bit unscaled offset

313029282726252423222120191817161514131211109876543210
11100100100Zm101PgRnZt

64-bit unscaled offset

ST1H { <Zt>.D }, <Pg>, [<Xn|SP>, <Zm>.D]

if !HaveSVE() then UNDEFINED; integer t = UInt(Zt); integer n = UInt(Rn); integer m = UInt(Zm); integer g = UInt(Pg); integer esize = 64; integer msize = 16; integer offs_size = 64; boolean offs_unsigned = TRUE; integer scale = 0;

Assembler Symbols

<Zt>

Is the name of the scalable vector register to be transferred, encoded in the "Zt" field.

<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.

<Zm>

Is the name of the offset scalable vector register, encoded in the "Zm" field.

<mod> Is the index extend and shift specifier, encoded in xs:
xs <mod>
0 UXTW
1 SXTW

Operation

CheckSVEEnabled(); integer elements = VL DIV esize; bits(64) base; bits(VL) offset = Z[m]; bits(VL) src = Z[t]; bits(PL) mask = P[g]; bits(64) addr; constant integer mbytes = msize DIV 8; if n == 31 then CheckSPAlignment(); base = SP[]; else base = X[n]; for e = 0 to elements-1 if ElemP[mask, e, esize] == '1' then integer off = Int(Elem[offset, e, esize]<offs_size-1:0>, offs_unsigned); addr = base + (off << scale); Mem[addr, mbytes, AccType_NORMAL] = Elem[src, e, esize]<msize-1:0>;


Release: 00rel5-manual

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