Initial shrink-wrapping patch

Ian Lance Taylor
Thu Oct 6 06:41:00 GMT 2011

Bernd Schmidt <> writes:

> This appears to be because the split prologue contains a jump, which
> means the find_many_sub_blocks call reorders the block numbers, and our
> indices into bb_flags are off.
> I'm testing the following patch, but it won't finish today - feel free
> to test and check it in, or to just disable shrink-wrapping with split
> prologues.

Thinking about it I think this is the wrong approach.  The -fsplit-stack
code by definition has to wrap the entire function and it can not modify
any callee-saved registers.  We should do shrink wrapping before
-fsplit-stack, not the other way around.


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