"Segher Boessenkool" <segher@xxxxxxxxxxxxxxxxxxx> writes: > Maybe you can force GCC to avoid CR4 by using -ffixed-reg=cr4 . The option would be -ffixed-cr4. Another possibility here might be -fcall-used-cr4, assuming that the system call looks like a function call rather than, say, an inline asm. Ian </force GCC to avoid CR4 by using -ffixed-reg> -ffixed-cr4 option works, cr4 is no more used but replaced by cr3. I am still concerned if we face the same issue with cr3 as with cr4. So I am thinking of specifying -ffixed-cr2 -ffixed-cr3 -ffixed-cr4, since cr2, cr3 and cr4 are assumed non-volatile by GCC. Also, I have come across this macro CONDITIONAL_REGISTER_USAGE which modify fixed_regs and call_used_regs to 1 for each of the registers in the classes which should not be used by GCC. (http://gcc.gnu.org/onlinedocs/gccint/Register-Basics.html#Register-Basics ). But I do not have idea as how to and where to have this macro. Could any of you please help me out? - Praveen. -- View this message in context: http://old.nabble.com/Reg%3A-Restricting-optimization-and-CR-register-usage-tp29933073p29950894.html Sent from the gcc - Help mailing list archive at Nabble.com.
