A design such that it would actually make sense for a compiler to mark code that should permit data-dependent CPU optimizations differently from code that should not.
This could be done using an opcode prefix, which would bloat code but would work perfectly. Or it could use an RFLAGS bit or a bit in MXCSR or a new register, etc.
Almost anything would be better than an MSR that is only accessible to privileged code.
This could be done using an opcode prefix, which would bloat code but would work perfectly. Or it could use an RFLAGS bit or a bit in MXCSR or a new register, etc.
Almost anything would be better than an MSR that is only accessible to privileged code.