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Predeclared extension register names in AArch32 state

You can write the names of Advanced SIMD and floating-point registers either in upper case or lower case.

The following table shows the predeclared extension register names:

Table 3-3 Predeclared extension registers in AArch32 state

Register names Meaning
Q0-Q15 Advanced SIMD quadword registers
D0-D31 Advanced SIMD doubleword registers, floating-point double-precision registers
S0-S31 Floating-point single-precision registers

You can write the register names either in upper case or lower case.