FCADD

Floating-point complex add

This instruction operates on complex numbers that are represented in SIMD&FP registers as pairs of elements, with the more significant element holding the imaginary part of the number and the less significant element holding the real part of the number. Each element holds a floating-point value. It performs the following computation on the corresponding complex number element pairs from the two source registers:

• Considering the complex number from the second source register on an Argand diagram, the number is rotated counterclockwise by 90 or 270 degrees.
• The rotated complex number is added to the complex number from the first source register.

This instruction can generate a floating-point exception. Depending on the settings in FPCR, the exception results in either a flag being set in FPSR or a synchronous exception being generated. For more information, see Floating-point exceptions and exception traps.

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.

Vector
(FEAT_FCMA)

Decode for this encoding

if !IsFeatureImplemented(FEAT_FCMA) then EndOfDecode(Decode_UNDEF); if size == '00' then EndOfDecode(Decode_UNDEF); if size == '01' && !IsFeatureImplemented(FEAT_FP16) then EndOfDecode(Decode_UNDEF); if Q == '0' && size == '11' then EndOfDecode(Decode_UNDEF); constant integer d = UInt(Rd); constant integer n = UInt(Rn); constant integer m = UInt(Rm); constant integer esize = 8 << UInt(size); constant integer datasize = 64 << UInt(Q); constant integer elements = datasize DIV esize;