FNEG (scalar)
Floating-point negate (scalar)
This instruction negates the 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.
0
0
0
1
1
1
1
0
1
0
0
0
0
1
0
1
0
0
0
0
1
1
FNEG <Hd>, <Hn>
0
0
FNEG <Sd>, <Sn>
0
1
FNEG <Dd>, <Dn>
if ftype == '10' || (ftype == '11' && !IsFeatureImplemented(FEAT_FP16)) then UNDEFINED;
constant integer d = UInt(Rd);
constant integer n = UInt(Rn);
constant integer esize = 8 << UInt(ftype EOR '10');
<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.
CheckFPEnabled64();
constant bits(esize) operand = V[n, esize];
bits(128) result = if IsMerging(FPCR) then V[d, 128] else Zeros(128);
Elem[result, 0, esize] = FPNeg(operand, FPCR);
V[d, 128] = result;