Register indexes have been reduced to only support general purpose registers. There is no need to have enumerations with number suffix that expands to the exactly same value as the suffix value itself.
Constant
Description
kIdAx
Physical id of AL|AH|AX|EAX|RAX registers.
kIdCx
Physical id of CL|CH|CX|ECX|RCX registers.
kIdDx
Physical id of DL|DH|DX|EDX|RDX registers.
kIdBx
Physical id of BL|BH|BX|EBX|RBX registers.
kIdSp
Physical id of SPL|SP|ESP|RSP registers.
kIdBp
Physical id of BPL|BP|EBP|RBP registers.
kIdSi
Physical id of SIL|SI|ESI|RSI registers.
kIdDi
Physical id of DIL|DI|EDI|RDI registers.
kIdR8
Physical id of R8B|R8W|R8D|R8 registers (64-bit only).
kIdR9
Physical id of R9B|R9W|R9D|R9 registers (64-bit only).
kIdR10
Physical id of R10B|R10W|R10D|R10 registers (64-bit only).
kIdR11
Physical id of R11B|R11W|R11D|R11 registers (64-bit only).
kIdR12
Physical id of R12B|R12W|R12D|R12 registers (64-bit only).
kIdR13
Physical id of R13B|R13W|R13D|R13 registers (64-bit only).
kIdR14
Physical id of R14B|R14W|R14D|R14 registers (64-bit only).
kIdR15
Physical id of R15B|R15W|R15D|R15 registers (64-bit only).