An aarch64 toolchain built with --enable-default-pie fails
gcc.target/aarch64/sme/nonlocal_goto_[123].c because the register
allocator ends up resetting equivalences, so it concludes it needs to
preserve a rematerializable function invariant across a call instead
of rematerializing it.
Allow function invariant equivalences to remain when the other
circumstances that may require their removal don't apply.
Tested on aarch64-linux-gnu with --enable-default-pie --enable-host-pie,
but I note this is not a complete fix for the problem, and I'm not
confident it's safe. Does this look ok to install?
for gcc/ChangeLog
* ira.cc (setup_reg_equiv): Retain function invariant
equivalences.
---
gcc/ira.cc | 3 +++
1 file changed, 3 insertions(+)
diff --git a/gcc/ira.cc b/gcc/ira.cc
index 4eebc9c4c50fb..79cf9a413cfb2 100644
--- a/gcc/ira.cc
+++ b/gcc/ira.cc
@@ -4278,6 +4278,9 @@ setup_reg_equiv (void)
continue;
}
}
+ else if (function_invariant_p (x))
+ /* Leave ira_reg_equiv alone. */
+ continue;
}
ira_reg_equiv[i].defined_p = false;
ira_reg_equiv[i].caller_save_p = false;
--
Alexandre Oliva, happy hacker https://blog.lx.oliva.nom.br/
Free Software Activist FSFLA co-founder GNU Toolchain Engineer
More tolerance and less prejudice are key for inclusion and diversity.
Excluding neuro-others for not behaving ""normal"" is *not* inclusive!
