RFA: ia64 prologue skipping patch

[J. Johnston]

ChangeLog entry modified as asked.  Patch checked in.  Thanks.

-- Jeff J.

Kevin Buettner wrote:
> On May 14,  7:47pm, J. Johnston wrote:
> 
>>Subject: RFA: ia64 prologue skipping patch
>>
>>The attached patch revises the ia64 prologue skipping code.  It does a number of
>>things:
>>
>>   1. increases the number of instructions to look at in a prologue
>>   2. allows looking in leaf functions
>>   3. recognizes indirect input register references (one level only)
>>   4. attempts to trust the lim_pc value
>>
>>Number 1 was increased to handle some testsuite cases where the number of
>>parameters was quite high (e.g. 9 parameters).  No tuning was involved.
>>
>>Number 4 has the biggest effect.  The line table info is more accurate except
>>in the case of optimized code.
>>
>>Ok to commit?
> 
> 
> Okay  (But fix the formatting of your ChangeLog entry - the lines are too
> long.)
> 
> 
>>2003-05-14  Jeff Johnston  <jjohnstn@redhat.com>
>>
>>	* ia64-tdep.c: Increase max_skip_non_prologue_insns to 40.
>>	(examine_prologue): Support looking through leaf functions, knowing
>>	they start with mov r2,r12.  Support skipping over indirect stores of the input
>>	registers.  Upon hitting a non-nop branch instruction or predicated instruction,
>>	bail out by setting lim_pc to the current pc value in the loop.  At the end,
>>	if the lim_pc value is still beyond our calculated value and we have trust_limit set,
>>	use the lim_pc value.
> 
> 
> Kevin
>