https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103762
--- Comment #12 from CVS Commits <cvs-commit at gcc dot gnu.org> --- The master branch has been updated by H.J. Lu <h...@gcc.gnu.org>: https://gcc.gnu.org/g:9407058a430316db5299bc7867e4a31f900cd197 commit r12-6122-g9407058a430316db5299bc7867e4a31f900cd197 Author: H.J. Lu <hjl.to...@gmail.com> Date: Sun Dec 19 08:47:03 2021 -0800 ix86: Don't use the 'm' constraint for x86_64_general_operand The 'm' constraint is defined with define_memory_constraint which allows LRA to convert the operand to the form '(mem (reg X))', where X is a base register. To prevent LRA from generating '(mem (reg X))' from a register: 1. Add a 'BM' constraint which is similar to the 'm' constraint, but is defined with define_constraint. 2. Add a 'm' mode attribute which is mapped to the 'm' constraint for general_operand and the 'BM' constraint for x86_64_general_operand. 3. Replace the 'm' constraint on <general_operand> with the '<m>' constraint. 4. Replace the 'm' constraint on x86_64_general_operand with the 'BM' constraint. gcc/ PR target/103762 * config/i386/constraints.md (BM): New constraint. * config/i386/i386.md (m): New mode attribute. Replace the 'm' constraint on <general_operand> with the '<m>' constraint. Replace the 'm' constraint on x86_64_general_operand with the 'BM' constraint. gcc/testsuite/ * gcc.target/i386/pr103762-1a.c: New test. * gcc.target/i386/pr103762-1b.c: Likewise. * gcc.target/i386/pr103762-1c.c: Likewise.