Vector Subtract Wide subtracts the elements of a doubleword vector from the corresponding elements of a quadword vector, and places the results in another quadword vector. Before subtracting, it sign-extends or zero-extends the elements of the doubleword operand.
Depending on settings in the CPACR, NSACR, and HCPTR registers, and the Security state and PE mode in which the instruction is executed, an attempt to execute the instruction might be undefined, or trapped to Hyp mode. For more information see Enabling Advanced SIMD and floating-point support.
It has encodings from the following instruction sets: A32 ( A1 ) and T32 ( T1 ) .
| 31 | 30 | 29 | 28 | 27 | 26 | 25 | 24 | 23 | 22 | 21 | 20 | 19 | 18 | 17 | 16 | 15 | 14 | 13 | 12 | 11 | 10 | 9 | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
| 1 | 1 | 1 | 1 | 0 | 0 | 1 | U | 1 | D | != 11 | Vn | Vd | 0 | 0 | 1 | 1 | N | 0 | M | 0 | Vm | ||||||||||
| size | op | ||||||||||||||||||||||||||||||
if size == '11' then SEE "Related encodings"; if Vd<0> == '1' || (op == '1' && Vn<0> == '1') then UNDEFINED; constant unsigned = (U == '1'); constant is_vsubw = (op == '1'); constant integer esize = 8 << UInt(size); constant d = UInt(D:Vd); constant n = UInt(N:Vn); constant m = UInt(M:Vm); constant elements = 64 DIV esize;
| 15 | 14 | 13 | 12 | 11 | 10 | 9 | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | 15 | 14 | 13 | 12 | 11 | 10 | 9 | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
| 1 | 1 | 1 | U | 1 | 1 | 1 | 1 | 1 | D | != 11 | Vn | Vd | 0 | 0 | 1 | 1 | N | 0 | M | 0 | Vm | ||||||||||
| size | op | ||||||||||||||||||||||||||||||
if size == '11' then SEE "Related encodings"; if Vd<0> == '1' || (op == '1' && Vn<0> == '1') then UNDEFINED; constant unsigned = (U == '1'); constant is_vsubw = (op == '1'); constant integer esize = 8 << UInt(size); constant d = UInt(D:Vd); constant n = UInt(N:Vn); constant m = UInt(M:Vm); constant elements = 64 DIV esize;
Related encodings: See Advanced SIMD data-processing for the T32 instruction set, or Advanced SIMD data-processing for the A32 instruction set.
| <c> |
For encoding A1: see Standard assembler syntax fields. This encoding must be unconditional. |
|
For encoding T1: see Standard assembler syntax fields. |
| <q> |
| <dt> |
Is the data type for the elements of the second operand vector,
encoded in
|
| <Qd> |
Is the 128-bit name of the SIMD&FP destination register, encoded in the "D:Vd" field as <Qd>*2. |
| <Qn> |
Is the 128-bit name of the first SIMD&FP source register, encoded in the "N:Vn" field as <Qn>*2. |
| <Dm> |
Is the 64-bit name of the second SIMD&FP source register, encoded in the "M:Vm" field. |
if ConditionPassed() then EncodingSpecificOperations(); CheckAdvSIMDEnabled(); for e = 0 to elements-1 integer op1; if is_vsubw then op1 = Int(Elem[Qin[n>>1],e,2*esize], unsigned); else op1 = Int(Elem[Din[n],e,esize], unsigned); constant result = op1 - Int(Elem[Din[m],e,esize], unsigned); Elem[Q[d>>1],e,2*esize] = result<2*esize-1:0>;
If CPSR.DIT is 1 and this instruction passes its condition execution check:
Internal version only: isa v01_31, pseudocode v2024-03_rel ; Build timestamp: 2024-03-25T10:05
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