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Signed Halving Subtract. This instruction subtracts the elements in the vector in the second source SIMD&FP register from the corresponding elements in the vector in the first source SIMD&FP register, shifts each result right one bit, places each result into elements of a vector, and writes the vector to the destination SIMD&FP register.
Depending on the settings in the CPACR_EL1, CPTR_EL2, and CPTR_EL3 registers, and the current Security state and Exception level, an attempt to execute the instruction might be trapped.
Signed Halving Subtract. This instruction subtracts the elements in the vector in the second source SIMD&FP register from the corresponding elements in the vector in the first source SIMD&FP register, shifts each result right one bit, places each result into elements of a vector, and writes the vector to the destination SIMD&FP register.
Depending on the settings in the CPACR_EL1, CPTR_EL2, and CPTR_EL3 registers, and the current Security state and Exception level, an attempt to execute the instruction might be trapped.
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 |
0 | Q | 0 | 0 | 1 | 1 | 1 | 0 | size | 1 | Rm | 0 | 0 | 1 | 0 | 0 | 1 | Rn | Rd | |||||||||||||
U |
integer d = UInt(Rd); integer n = UInt(Rn); integer m = UInt(Rm); if size == '11' then UNDEFINED; integer esize = 8 << UInt(size); integer datasize = if Q == '1' then 128 else 64; integer elements = datasize DIV esize; boolean unsigned = (U == '1');
<Vd> | Is the name of the SIMD&FP destination register, encoded in the "Rd" field. |
<Vn> | Is the name of the first SIMD&FP source register, encoded in the "Rn" field. |
<Vm> | Is the name of the second SIMD&FP source register, encoded in the "Rm" field. |
CheckFPAdvSIMDEnabled64(); bits(datasize) operand1 = V[n]; bits(datasize) operand2 = V[m]; bits(datasize) result; integer element1; integer element2; integer diff; for e = 0 to elements-1 element1 = Int(Elem[operand1, e, esize], unsigned); element2 = Int(Elem[operand2, e, esize], unsigned); diff = element1 - element2; Elem[result, e, esize] = diff<esize:1>; V[d] = result;
If PSTATE.DIT is 1:
Internal version only: isa v32.13v32.12, AdvSIMD v29.05v29.04, pseudocode v2020-12v2020-09_xml, sve v2020-12v2020-09_rc3
; Build timestamp: 2020-12-16T142020-11-18T17:1723
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(old) | htmldiff from- | (new) |