[Bug c++/90851] New: -O3 overflow

[zhonghao at pku dot org.cn]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=90851

            Bug ID: 90851
           Summary: -O3 overflow
           Product: gcc
           Version: 10.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: zhonghao at pku dot org.cn
  Target Milestone: ---

My gcc is 10.0.0, and the code is:


struct S { S (); S (int); ~S (); int i; };
struct A { S s[100000]; };

void
foo ()
{
 A a = {{}};
}


It takes several minutes to compile the code. With the following parameters:
g++ -Os | g++ -O3 | gcc -Os | gcc -O3 |, I got a overflow:

cc1plus: out of memory allocating 65536 bytes after a total of 58655244288
bytes