FABS (scalar)

Floating-point Absolute value (scalar). This instruction calculates the absolute value in the SIMD&FP source register and writes the result to the SIMD&FP destination 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.

313029282726252423222120191817161514131211109876543210
00011110ftype100000110000RnRd
MSopc

Half-precision (ftype == 11)
(FEAT_FP16)

FABS <Hd>, <Hn>

Single-precision (ftype == 00)

FABS <Sd>, <Sn>

Double-precision (ftype == 01)

FABS <Dd>, <Dn>

if ftype == '10' || (ftype == '11' && !IsFeatureImplemented(FEAT_FP16)) then UNDEFINED; integer d = UInt(Rd); integer n = UInt(Rn); constant integer esize = 8 << UInt(ftype EOR '10');

Assembler Symbols

<Hd>

Is the 16-bit name of the SIMD&FP destination register, encoded in the "Rd" field.

<Hn>

Is the 16-bit name of the SIMD&FP source register, encoded in the "Rn" field.

<Sd>

Is the 32-bit name of the SIMD&FP destination register, encoded in the "Rd" field.

<Sn>

Is the 32-bit name of the SIMD&FP source register, encoded in the "Rn" field.

<Dd>

Is the 64-bit name of the SIMD&FP destination register, encoded in the "Rd" field.

<Dn>

Is the 64-bit name of the SIMD&FP source register, encoded in the "Rn" field.

Operation

CheckFPEnabled64(); boolean merge = IsMerging(FPCR); bits(128) result = if merge then V[d, 128] else 0<127:0>; bits(esize) operand = V[n, esize]; Elem[result, 0, esize] = FPAbs(operand, FPCR); V[d, 128] = result;


Internal version only: aarchmrs v2023-12_rel, pseudocode v2023-12_rel, sve v2023-12_rel ; Build timestamp: 2023-12-15T16:46

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