How do I delete redundant prologue/epilogue instructions?

[Daniel Towner]

Hi all,

I'm trying to overcome an optimisation problem in my port of gcc. When 
the prologue and epilogue are generated as RTL lists, the compiler 
notices that certain registers are live, and emits save/restore 
sequences for them, with the appropriate stack adjustments. Later on, 
register renaming is able to change the registers used by the function 
from callee-save to caller-save, removing any need for the 
save/restore/stack adjust code in the prologue/epilogue. However, the 
instructions which perform these operations are still emitted.

How do I delete these redundant instructions? Can anyone point me at 
another port which solves this problem?

thanks,

dan.

============================================================================
Daniel Towner
picoChip Designs Ltd., Riverside Buildings, 108, Walcot Street, BATH,
BA1 5BG
[EMAIL PROTECTED]
07786 702589