https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99271
--- Comment #3 from CVS Commits <cvs-commit at gcc dot gnu.org> --- The releases/gcc-10 branch has been updated by Richard Earnshaw <rearn...@gcc.gnu.org>: https://gcc.gnu.org/g:1b3bb23a576e6a864f540e3bea5097f47fea507c commit r10-9398-g1b3bb23a576e6a864f540e3bea5097f47fea507c Author: Richard Earnshaw <rearn...@arm.com> Date: Mon Feb 22 15:00:53 2021 +0000 arm: force use of r4 for __gnu_cmse_nonsecure_call when !FPCXT [PR99271] Commit r10-6017 relaxed the constraint on thumb2 calls to __gnu_cmse_nonsecure_call to allow any register for the call address. Although the initial code expansion continues to use r4 with the FPCXT extension is not enabled, the change was unsafe because subsequent optimizations could use the additional freedom to change which register was being used. To fix this we need to split the output patterns in the machine description to use distinct recognizers: one with the additional freedom when FPCXT is enabled an another that retains the original restrictions when the extension is not available. gcc: PR target/99271 * config/arm/thumb2.md (nonsecure_call_reg_thumb2_fpcxt): New pattern. (nonsecure_call_value_reg_thumb2_fpcxt): Likewise. (nonsecure_call_reg_thumb2): Restrict to using r4 for the callee address and disable when the FPCXT is not available. (nonsecure_call_value_reg_thumb2): Likewise. gcc/testsuite: * gcc.target/arm/cmse/cmse-18.c: New test.
