Vector Absolute takes the absolute value of each element in a vector, and places the results in a second vector. The floating-point version only clears the sign bit.
Depending on settings in the CPACR, NSACR, HCPTR, and FPEXC 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 A2 ) and T32 ( T1 and T2 ) .
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| 1 | 1 | 1 | 1 | 0 | 0 | 1 | 1 | 1 | D | 1 | 1 | size | 0 | 1 | Vd | 0 | F | 1 | 1 | 0 | Q | M | 0 | Vm | |||||||
if size == '11' then UNDEFINED; if F == '1' && ((size == '01' && !IsFeatureImplemented(FEAT_FP16)) || size == '00') then UNDEFINED; if Q == '1' && (Vd<0> == '1' || Vm<0> == '1') then UNDEFINED; constant advsimd = TRUE; constant floating_point = (F == '1'); constant integer esize = 8 << UInt(size); constant elements = 64 DIV esize; constant d = UInt(D:Vd); constant m = UInt(M:Vm); constant regs = if Q == '0' then 1 else 2;
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| != 1111 | 1 | 1 | 1 | 0 | 1 | D | 1 | 1 | 0 | 0 | 0 | 0 | Vd | 1 | 0 | size | 1 | 1 | M | 0 | Vm | ||||||||||
| cond | |||||||||||||||||||||||||||||||
if FPSCR.Len != '000' || FPSCR.Stride != '00' then UNDEFINED; if size == '00' || (size == '01' && !IsFeatureImplemented(FEAT_FP16)) then UNDEFINED; if size == '01' && cond != '1110' then UNPREDICTABLE; constant advsimd = FALSE; constant integer esize = 8 << UInt(size); constant integer d = if size == '11' then UInt(D:Vd) else UInt(Vd:D); constant integer m = if size == '11' then UInt(M:Vm) else UInt(Vm:M); constant boolean floating_point = boolean UNKNOWN; constant integer regs = integer UNKNOWN; constant integer elements = integer UNKNOWN;
If size == '01' && cond != '1110', then one of the following behaviors must occur:
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| 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | D | 1 | 1 | size | 0 | 1 | Vd | 0 | F | 1 | 1 | 0 | Q | M | 0 | Vm | |||||||
if size == '11' then UNDEFINED; if F == '1' && ((size == '01' && !IsFeatureImplemented(FEAT_FP16)) || size == '00') then UNDEFINED; if F == '1' && size == '01' && InITBlock() then UNPREDICTABLE; if Q == '1' && (Vd<0> == '1' || Vm<0> == '1') then UNDEFINED; constant advsimd = TRUE; constant floating_point = (F == '1'); constant integer esize = 8 << UInt(size); constant elements = 64 DIV esize; constant d = UInt(D:Vd); constant m = UInt(M:Vm); constant regs = if Q == '0' then 1 else 2;
If F == '1' && size == '01' && InITBlock(), then one of the following behaviors must occur:
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| 1 | 1 | 1 | 0 | 1 | 1 | 1 | 0 | 1 | D | 1 | 1 | 0 | 0 | 0 | 0 | Vd | 1 | 0 | size | 1 | 1 | M | 0 | Vm | |||||||
if FPSCR.Len != '000' || FPSCR.Stride != '00' then UNDEFINED; if size == '00' || (size == '01' && !IsFeatureImplemented(FEAT_FP16)) then UNDEFINED; if size == '01' && InITBlock() then UNPREDICTABLE; constant advsimd = FALSE; constant integer esize = 8 << UInt(size); constant integer d = if size == '11' then UInt(D:Vd) else UInt(Vd:D); constant integer m = if size == '11' then UInt(M:Vm) else UInt(Vm:M); constant boolean floating_point = boolean UNKNOWN; constant integer regs = integer UNKNOWN; constant integer elements = integer UNKNOWN;
If size == '01' && InITBlock(), then one of the following behaviors must occur:
| <c> |
For encoding A1: see Standard assembler syntax fields. This encoding must be unconditional. |
|
For encoding A2, T1 and T2: see Standard assembler syntax fields. |
| <q> |
| <dt> |
Is the data type for the elements of the vectors,
encoded in
|
| <Qd> |
Is the 128-bit name of the SIMD&FP destination register, encoded in the "D:Vd" field as <Qd>*2. |
| <Qm> |
Is the 128-bit name of the SIMD&FP source register, encoded in the "M:Vm" field as <Qm>*2. |
| <Dd> |
Is the 64-bit name of the SIMD&FP destination register, encoded in the "D:Vd" field. |
| <Dm> |
Is the 64-bit name of the SIMD&FP source register, encoded in the "M:Vm" field. |
| <Sd> |
Is the 32-bit name of the SIMD&FP destination register, encoded in the "Vd:D" field. |
| <Sm> |
Is the 32-bit name of the SIMD&FP source register, encoded in the "Vm:M" field. |
if ConditionPassed() then EncodingSpecificOperations(); CheckAdvSIMDOrVFPEnabled(TRUE, advsimd); if advsimd then // Advanced SIMD instruction constant FPCR_Type fpcr = StandardFPCR(); for r = 0 to regs-1 for e = 0 to elements-1 if floating_point then Elem[D[d+r],e,esize] = FPAbs(Elem[D[m+r],e,esize], fpcr); else constant result = Abs(SInt(Elem[D[m+r],e,esize])); Elem[D[d+r],e,esize] = result<esize-1:0>; else // VFP instruction constant FPCR_Type fpcr = EffectiveFPCR(); case esize of when 16 H[d] = FPAbs(H[m], fpcr); when 32 S[d] = FPAbs(S[m], fpcr); when 64 D[d] = FPAbs(D[m], fpcr);
If CPSR.DIT is 1 and this instruction passes its condition execution check and is operating only on integer vector elements, then the following apply:
Internal version only: isa v01_32, pseudocode v2024-12_rel ; Build timestamp: 2024-12-16T10:54
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