QN, DN, and SN
SN directives define names for Advanced SIMD and floating-point registers.
name directive expr
is the name to be assigned to the extension register.
namecannot be the same as any of the predefined names.
An expression that evaluates to a number in the range:
0-15 if you are using QN in A32/T32 Advanced SIMD code.
predefined register name, or a register name that has already been defined in a previous directive.
is any Advanced SIMD or floating-point datatype.
is only available for Advanced SIMD code.
[is a scalar index into a register.
[ are Extended
SN to allocate convenient names to extension
registers, to help you to remember what you use each one for.
QN directive defines a name for a
specified 128-bit extension register.
DN directive defines a name for a
specified 64-bit extension register.
SN directive defines a name for a
specified single-precision floating-point register.
NoteAvoid conflicting uses of the same register under different names.
You cannot specify a vector length in a
energy DN 6 ; defines energy as a symbol for ; floating-point double-precision register 6 mass SN 16 ; defines mass as a symbol for ; floating-point single-precision register 16
Extended notation examples
varA DN d1.U16 varB DN d2.U16 varC DN d3.U16 VADD varA,varB,varC ; VADD.U16 d1,d2,d3 index DN d4.U16 result QN q5.I32 VMULL result,varA,index ; VMULL.U16 q5,d1,d4