[Bug c++/60976] New: Compilation with G++ 4.9.0 is 2-3 times slower than with 4.8.2
astellar at ro dot ru
Sat Apr 26 15:36:00 GMT 2014
Bug ID: 60976
Summary: Compilation with G++ 4.9.0 is 2-3 times slower than
Assignee: unassigned at gcc dot gnu.org
Reporter: astellar at ro dot ru
Created attachment 32686
g++ -v output for 4.8.2
Hello. After test upgrade from 4.8.2 to 4.9.0 I've noticed that compilation
takes significantly more time than before. g++ -v output for both compilers is
I've compiled the same file from internal project with following switches.
Debug build here, but it's the same problem with release flags:
-std=gnu++11 -fvisibility=hidden -Wall -Wextra -Winit-self -Winvalid-pch
-Wfatal-errors -Woverloaded-virtual -fvisibility-inlines-hidden -O0 -g -pipe
Full ftime-report output for both compilers is in attachments. From what I see,
these steps take significantly more time than before:
- phase lang. deferred : 1.22 usr for 4.8.2, 4.08 usr for 4.9.0;
- template instantiation : 1.44 usr for 4.8.2, 5.59 usr for 4.9.0.
Some other numbers are higher too, but these 2 have the largest increase. I'm
not sure how to create a reduced test case from this project, but I will try
something on Monday.
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