[Bug rtl-optimization/24319] [4.3/4.4/4.5 regression] amd64 register spill error with -fschedule-insns

[lucier at math dot purdue dot edu]

------- Comment #20 from lucier at math dot purdue dot edu  2009-09-02 16:52 -------
Vlad:

Thank you for your reply.

The times I reported are for "-fschedule-insns" without "-fpressure-sched".

The times with the addition of "-fpressure-sched" are not much greater than
with "-fschedule-insns" by itself:

With -fschedule-insns

 scheduling            :  22.89 (41%) usr   0.02 ( 2%) sys  22.93 (40%) wall   
2125 kB ( 1%) ggc
 integrated RA         :   9.15 (16%) usr   0.06 ( 6%) sys   9.21 (16%) wall   
5488 kB ( 3%) ggc
 scheduling 2          :   0.60 ( 1%) usr   0.00 ( 0%) sys   0.62 ( 1%) wall   
 422 kB ( 0%) ggc
 TOTAL                 :  55.67             0.93            56.66            
180793 kB

with -fschedule-insns -fsched-pressure

 scheduling            :  23.31 (42%) usr   0.02 ( 2%) sys  23.36 (41%) wall   
2125 kB ( 1%) ggc
 integrated RA         :   9.18 (16%) usr   0.04 ( 4%) sys   9.22 (16%) wall   
5517 kB ( 3%) ggc
 scheduling 2          :   0.58 ( 1%) usr   0.01 ( 1%) sys   0.58 ( 1%) wall   
 251 kB ( 0%) ggc
 TOTAL                 :  55.77             1.00            56.89            
179606 kB

and with neither -fschedule-insns nor -fsched-pressure:

 integrated RA         :   6.40 (21%) usr   0.05 ( 5%) sys   6.41 (21%) wall   
5087 kB ( 3%) ggc
 scheduling 2          :   0.58 ( 2%) usr   0.01 ( 1%) sys   0.60 ( 2%) wall   
 244 kB ( 0%) ggc
 TOTAL                 :  29.84             0.98            30.83            
176587 kB

So pre--register allocation instruction scheduling even without the new
register pressure--aware algorithm takes quite a bit of time.

I'll try to build a profiled gcc, and then if I find something I'll put it in a
new PR.

Brad


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=24319