[Bug c++/81846] New: [arm] constexpr ICE: in cxx_eval_constant_expression, at cp/constexpr.c:4556

["nsz at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81846

            Bug ID: 81846
           Summary: [arm] constexpr ICE: in cxx_eval_constant_expression,
                    at cp/constexpr.c:4556
           Product: gcc
           Version: 8.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: nsz at gcc dot gnu.org
  Target Milestone: ---

following c++14 code fails to compile with ice on arm targets:

class A {
public:
    constexpr A() {
        return;
    }
};

A mwi;

$ arm-none-linux-gnueabihf-g++ -S foo.cpp
foo.cpp:8:3:   in constexpr expansion of ‘mwi.A::A()’
foo.cpp:8:3: internal compiler error: in cxx_eval_constant_expression, at
cp/constexpr.c:4556
 A mwi;
   ^~~
...

the assert is

 4554    case GOTO_EXPR:                            
 4555      *jump_target = TREE_OPERAND (t, 0);      
 4556      gcc_assert (breaks (jump_target) || continues (jump_target));
 4557      break;                                   

the -tree-original output is unexpected on arm:

;; Function constexpr A::A() (null)
;; enabled by -tree-original


{
  // predicted unlikely by goto predictor.;
  goto <D.5928>;
}
<D.5928>:;
return this;


e.g. on aarch64 it's:

;; Function constexpr A::A() (null)
;; enabled by -tree-original


{
  return;
}