ref: 41c790aa25a1457849e76fd748f10329e74ccd2c dir: /mbld/cpufeatures+plan9-x64.s/
TEXT bld$cpufeatures+0(SB),$0 MOVL $0x1,AX CPUID MOVL CX, AX MOVL DX, DX ROLQ $32, DX ORQ DX, AX RET