[Bug debug/48866] gcc hangs when -g is set

[aoliva at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48866

Alexandre Oliva <aoliva at gcc dot gnu.org> changed:

           What    |Removed                     |Added
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  Attachment #24189|0                           |1
        is obsolete|                            |

--- Comment #9 from Alexandre Oliva <aoliva at gcc dot gnu.org> 2011-05-06 22:18:16 UTC ---
Created attachment 24202
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=24202
Avoid too-complex value exprs by keeping unreplaced replaceable expansions in
natural order

This alternate patch implements (with minor changes) the plan described in
comment 8, that should improve debuggability and limit the complexity of debug
values generated by the expander to about the maximum complexity of an insn. 
It successfully undoes the code movement of TER for code generated that is not
combined into other stmts.  force_reg for a subsequent insn is still regarded
as combination, although I have plans to move that up as well.  Using the
suggested target for an assignment is regarded as combination, and it must
remain that way to avoid moving the assignment before the initialization of the
target.

This has so far passed compare after bootstrap-debug on x86_64-linux-gnu;
testing it more thoroughly now.  Will add comments before posting it to the
list.