On 5/4/24 5:58 PM, Andrew Pinski wrote:
In C++ sometimes you have a deconstructor function which is "empty", like for an
example with unions or with arrays. The front-end might not know it is empty
either
so this should be done on during optimization.o
To implement it I added it to DCE where we mark if a statement is necessary or
not.
Bootstrapped and tested on x86_64-linux-gnu with no regressions.
Changes since v1:
* v2: Add support for __aeabi_atexit for arm-*eabi. Add extra comments.
Add cxa_atexit-5.C testcase for -fPIC case.
* v3: Fix testcases for the __aeabi_atexit (forgot to do in the v2).
PR tree-optimization/19661
gcc/ChangeLog:
* tree-ssa-dce.cc (is_cxa_atexit): New function.
(is_removable_cxa_atexit_call): New function.
(mark_stmt_if_obviously_necessary): Don't mark removable
cxa_at_exit calls.
(mark_all_reaching_defs_necessary_1): Likewise.
(propagate_necessity): Likewise.
gcc/testsuite/ChangeLog:
* g++.dg/tree-ssa/cxa_atexit-1.C: New test.
* g++.dg/tree-ssa/cxa_atexit-2.C: New test.
* g++.dg/tree-ssa/cxa_atexit-3.C: New test.
* g++.dg/tree-ssa/cxa_atexit-4.C: New test.
* g++.dg/tree-ssa/cxa_atexit-5.C: New test.
* g++.dg/tree-ssa/cxa_atexit-6.C: New test.
OK
jeff
