Fix function pointer tail calls in armv8-M.base
Summary:
The compiler fails with the following error message:
fatal error: error in backend: ran out of registers during
register allocation
Tail call optimization for Armv8-M.base fails to meet all the required
constraints when handling calls to function pointers where the
arguments take up r0-r3. This is because the pointer to the
function to be called can only be stored in r0-r3, but these are
all occupied by arguments. This patch makes sure that tail call
optimization does not try to handle this type of calls.
Reviewers: chill, MatzeB, olista01, rengolin, efriedma
Reviewed By: olista01, efriedma
Subscribers: efriedma, aemerson, javed.absar, llvm-commits, kristof.beyls
Differential Revision: https://reviews.llvm.org/D40706
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@319664
91177308-0d34-0410-b5e6-
96231b3b80d8