[Bug c++/61183] New: Large memory usage with smallish C++ templates (> 16GB)

[Bug c++/61183] New: Large memory usage with smallish C++ templates (> 16GB)

[giovannibajo at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61183

            Bug ID: 61183
           Summary: Large memory usage with smallish C++ templates (>
                    16GB)
           Product: gcc
           Version: 4.9.1
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: giovannibajo at gmail dot com

I'm unable to compile the attached code with GCC 4.9.0, at -O0 even without -g,
because of RAM exhaustion (16GB). LLVM 3.4svn is able to compile the program in
about 2 minutes with a peak at 2GB (even at -O3 -g).

The code is actually quite small, and relies to template + always_inline to
basically generate large functions with 99% of dead code (can be proven dead
with some constant propagation). Probably being more aggressive in some early
pass (after early inlining) should fix the compilation problem.

Original code here for further analysys:
https://raw.githubusercontent.com/rasky/cz80/master/z80.cpp

[Bug c++/61183] Large memory usage with smallish C++ templates (> 16GB)

[giovannibajo at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61183

--- Comment #1 from Giovanni Bajo <giovannibajo at gmail dot com> ---
Created attachment 32794
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=32794&action=edit
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