[pushed,RA,PR110215] Ignore conflicts for some pseudos from insns throwing a final exception
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Commit Message
The following patch solves
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110215
The patch was successfully tested and bootstrapped on x86-64, aarch64,
and ppc64le.
It is difficult to make a stable test for the PR. So there is not test
in the patch.
commit 154c69039571c66b3a6d16ecfa9e6ff22942f59f
Author: Vladimir N. Makarov <vmakarov@redhat.com>
Date: Fri Jun 16 11:12:32 2023 -0400
RA: Ignore conflicts for some pseudos from insns throwing a final exception
IRA adds conflicts to the pseudos from insns can throw exceptions
internally even if the exception code is final for the function and
the pseudo value is not used in the exception code. This results in
spilling a pseudo in a loop (see
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110215).
The following patch fixes the problem.
PR rtl-optimization/110215
gcc/ChangeLog:
* ira-lives.cc: Include except.h.
(process_bb_node_lives): Ignore conflicts from cleanup exceptions
when the pseudo does not live at the exception landing pad.
@@ -34,6 +34,7 @@ along with GCC; see the file COPYING3. If not see
#include "ira-int.h"
#include "sparseset.h"
#include "function-abi.h"
+#include "except.h"
/* The code in this file is similar to one in global but the code
works on the allocno basis and creates live ranges instead of
@@ -1383,14 +1384,24 @@ process_bb_node_lives (ira_loop_tree_node_t loop_tree_node)
SET_HARD_REG_SET (OBJECT_CONFLICT_HARD_REGS (obj));
SET_HARD_REG_SET (OBJECT_TOTAL_CONFLICT_HARD_REGS (obj));
}
- if (can_throw_internal (insn))
+ eh_region r;
+ eh_landing_pad lp;
+ rtx_code_label *landing_label;
+ basic_block landing_bb;
+ if (can_throw_internal (insn)
+ && (r = get_eh_region_from_rtx (insn)) != NULL
+ && (lp = gen_eh_landing_pad (r)) != NULL
+ && (landing_label = lp->landing_pad) != NULL
+ && (landing_bb = BLOCK_FOR_INSN (landing_label)) != NULL
+ && (r->type != ERT_CLEANUP
+ || bitmap_bit_p (df_get_live_in (landing_bb),
+ ALLOCNO_REGNO (a))))
{
- OBJECT_CONFLICT_HARD_REGS (obj)
- |= callee_abi.mode_clobbers (ALLOCNO_MODE (a));
- OBJECT_TOTAL_CONFLICT_HARD_REGS (obj)
- |= callee_abi.mode_clobbers (ALLOCNO_MODE (a));
+ HARD_REG_SET new_conflict_regs
+ = callee_abi.mode_clobbers (ALLOCNO_MODE (a));
+ OBJECT_CONFLICT_HARD_REGS (obj) |= new_conflict_regs;
+ OBJECT_TOTAL_CONFLICT_HARD_REGS (obj) |= new_conflict_regs;
}
-
if (sparseset_bit_p (allocnos_processed, num))
continue;
sparseset_set_bit (allocnos_processed, num);