The following patch is for https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104971
The PR was already fixed by Jakub but his patch did not fix a latent LRA bug mentioned in the PR comments. The current patch fixes the latent bug.
The patch was successfully bootstrapped and tested on x86-64 and aarch64.
commit 33904327c92bd914d4e0e076be12dc0a6b453c2d Author: Vladimir N. Makarov <vmaka...@redhat.com> Date: Fri Mar 25 12:22:08 2022 -0400 [PR104971] LRA: check live hard regs to remove a dead insn LRA removes insn modifying sp for given PR test set. We should also have checked living hard regs to prevent this. The patch fixes this. gcc/ChangeLog: PR middle-end/104971 * lra-lives.cc (process_bb_lives): Check hard_regs_live for hard regs to clear remove_p flag. diff --git a/gcc/lra-lives.cc b/gcc/lra-lives.cc index 796f00629b4..a755464ee81 100644 --- a/gcc/lra-lives.cc +++ b/gcc/lra-lives.cc @@ -724,7 +724,10 @@ process_bb_lives (basic_block bb, int &curr_point, bool dead_insn_p) bool remove_p = true; for (reg = curr_id->regs; reg != NULL; reg = reg->next) - if (reg->type != OP_IN && sparseset_bit_p (pseudos_live, reg->regno)) + if (reg->type != OP_IN + && (reg->regno < FIRST_PSEUDO_REGISTER + ? TEST_HARD_REG_BIT (hard_regs_live, reg->regno) + : sparseset_bit_p (pseudos_live, reg->regno))) { remove_p = false; break;