Perform guaranteed tail call optimization for eligible fastcc calls.
Declared in <llvm/Target/TargetOptions.h>
unsigned int GuaranteedTailCallOpt : [object Object];This flag is enabled when -tailcallopt is specified on the commandline. When the flag is on, participating targets will perform tail call optimization on all calls which use the fastcc calling convention and which satisfy certain target-independent criteria (being at the end of a function, having the same return type as their parent function, etc.), using an alternate ABI if necessary.