http://gcc.gnu.org/bugzilla/show_bug.cgi?id=60976
Bug ID: 60976 Summary: Compilation with G++ 4.9.0 is 2-3 times slower than with 4.8.2 Product: gcc Version: 4.9.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: c++ Assignee: unassigned at gcc dot gnu.org Reporter: astellar at ro dot ru Created attachment 32686 --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=32686&action=edit 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 in attachments. 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 -fsanitize=address -ftime-report 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.