[committed,PR104971] LRA: check live hard regs to remove a dead insn
Commit Message
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 <vmakarov@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.
@@ -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;