On 11/19/09 12:50, H. Peter Anvin wrote:
Calling the profiler immediately at the entry point is clearly the more
sane option. It means the ABI is well-defined, stable, and independent
of what the actual function contents are. It means that ABI isn't the
normal C ABI (the __fentry__ function would have to preserve all
registers), but that's fine...
Note there are targets (even some old x86 variants) that required the
profiling calls to occur after the prologue. Unfortunately, nobody
documented *why* that was the case. Sigh.
Jeff
