PUSH and POP next to first/last register use

[Sami Khawam]

Hi,

I am using a custom CPU architecture where I would 
like to place the PUSH and POP instuctions of a 
register just before the first time it is written to 
and just after the last time it is read, and not in 
the prologue / epilogue of a function.

I suppose this would require using 
REGNO_FIRST_UID(N) and REGNO_LAST_UID(N) at some 
point, however I would be very grateful if you can 
help me with it, as it seems that REGNO_FIRST_UID(N) 
is still reset to 0 when 
TARGET_ASM_FUNCTION_PROLOGUE is called.

Many Thanks,

Sami Khawam