[PATCH] Modify TER to not propagate expressions across call

[Pat Haugen]

  The following patch tries to limit TER such that it will not propagate 
expressions across calls, which can extend lifetimes across calls and 
result in suboptimal code due to additional save/restore of registers. I 
tried allowing just BUILT_IN_MD builtins to be bypassed, but that still 
didn't catch things like sqrt/powf which were seen in 435.gromacs 
benchmark, so resorted to all builtins (no worse than what was being 
done before).

Bootstrap/regtested on powerpc64-linux with no new regressions.  OK for 
mainline?


2010-09-10  Pat Haugen <pthaugen@us.ibm.com>

     * tree-ssa-ter.c (temp_expr_table_d): Add call_cnt field.
     (new_temp_expr_table): Allocate call_cnt vector.
     (free_temp_expr_table): Free it.
     (process_replaceable): Add call_cnt parm and set in vector.
     (find_replaceable_in_bb): Skip replacement if def/use span a call.
     (debug_ter): Dump call_cnt value, remove stderr uses.

-Pat


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