SUBHNT

Subtract narrow high part (top)

Subtract each vector element of the second source vector from the corresponding vector element in the first source vector, and place the most significant half of the result in the odd-numbered half-width destination elements, leaving the even-numbered elements unchanged. This instruction is unpredicated.

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01000101size1Zm011101ZnZd
SRT

SUBHNT <Zd>.<T>, <Zn>.<Tb>, <Zm>.<Tb>

if !IsFeatureImplemented(FEAT_SVE2) && !IsFeatureImplemented(FEAT_SME) then UNDEFINED; if size == '00' then UNDEFINED; constant integer esize = 8 << UInt(size); constant integer n = UInt(Zn); constant integer m = UInt(Zm); constant integer d = UInt(Zd);

Assembler Symbols

<Zd>

Is the name of the destination scalable vector register, encoded in the "Zd" field.

<T>

Is the size specifier, encoded in size:

size <T>
00 RESERVED
01 B
10 H
11 S
<Zn>

Is the name of the first source scalable vector register, encoded in the "Zn" field.

<Tb>

Is the size specifier, encoded in size:

size <Tb>
00 RESERVED
01 H
10 S
11 D
<Zm>

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

Operation

CheckSVEEnabled(); constant integer VL = CurrentVL; constant integer elements = VL DIV esize; constant bits(VL) operand1 = Z[n, VL]; constant bits(VL) operand2 = Z[m, VL]; bits(VL) result = Z[d, VL]; constant integer halfesize = esize DIV 2; for e = 0 to elements-1 constant integer element1 = UInt(Elem[operand1, e, esize]); constant integer element2 = UInt(Elem[operand2, e, esize]); constant integer res = (element1 - element2) >> halfesize; Elem[result, 2*e + 1, halfesize] = res<halfesize-1:0>; Z[d, VL] = result;

Operational information

If FEAT_SVE2 is implemented or FEAT_SME is implemented, then if PSTATE.DIT is 1:


Internal version only: aarchmrs v2024-03_relA, pseudocode v2024-03_rel, sve v2024-03_rel ; Build timestamp: 2024-03-26T09:45

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