https://gcc.gnu.org/g:c68bd7e8023f65d1dc23237f5a04a863344b1264
commit r15-916-gc68bd7e8023f65d1dc23237f5a04a863344b1264
Author: Hans-Peter Nilsson <h...@axis.com>
Date: Thu May 30 01:57:39 2024 +0200
Revert "resource.cc: Replace calls to find_basic_block with cfgrtl
BLOCK_FOR_INSN"
This reverts commit 933ab59c59bdc1ac9e3ca3a56527836564e1821b.
Diff:
---
gcc/resource.cc | 66 ++++++++++++++++++++++++++++++++++++++++++++++++---------
1 file changed, 56 insertions(+), 10 deletions(-)
diff --git a/gcc/resource.cc b/gcc/resource.cc
index 0d8cde93570..06fcfd3e44c 100644
--- a/gcc/resource.cc
+++ b/gcc/resource.cc
@@ -28,7 +28,6 @@ along with GCC; see the file COPYING3. If not see
#include "tm_p.h"
#include "regs.h"
#include "emit-rtl.h"
-#include "cfgrtl.h"
#include "resource.h"
#include "insn-attr.h"
#include "function-abi.h"
@@ -76,6 +75,7 @@ static HARD_REG_SET current_live_regs;
static HARD_REG_SET pending_dead_regs;
static void update_live_status (rtx, const_rtx, void *);
+static int find_basic_block (rtx_insn *, int);
static rtx_insn *next_insn_no_annul (rtx_insn *);
/* Utility function called from mark_target_live_regs via note_stores.
@@ -113,6 +113,46 @@ update_live_status (rtx dest, const_rtx x, void *data
ATTRIBUTE_UNUSED)
CLEAR_HARD_REG_BIT (pending_dead_regs, i);
}
}
+
+/* Find the number of the basic block with correct live register
+ information that starts closest to INSN. Return -1 if we couldn't
+ find such a basic block or the beginning is more than
+ SEARCH_LIMIT instructions before INSN. Use SEARCH_LIMIT = -1 for
+ an unlimited search.
+
+ The delay slot filling code destroys the control-flow graph so,
+ instead of finding the basic block containing INSN, we search
+ backwards toward a BARRIER where the live register information is
+ correct. */
+
+static int
+find_basic_block (rtx_insn *insn, int search_limit)
+{
+ /* Scan backwards to the previous BARRIER. Then see if we can find a
+ label that starts a basic block. Return the basic block number. */
+ for (insn = prev_nonnote_insn (insn);
+ insn && !BARRIER_P (insn) && search_limit != 0;
+ insn = prev_nonnote_insn (insn), --search_limit)
+ ;
+
+ /* The closest BARRIER is too far away. */
+ if (search_limit == 0)
+ return -1;
+
+ /* The start of the function. */
+ else if (insn == 0)
+ return ENTRY_BLOCK_PTR_FOR_FN (cfun)->next_bb->index;
+
+ /* See if any of the upcoming CODE_LABELs start a basic block. If we reach
+ anything other than a CODE_LABEL or note, we can't find this code. */
+ for (insn = next_nonnote_insn (insn);
+ insn && LABEL_P (insn);
+ insn = next_nonnote_insn (insn))
+ if (BLOCK_FOR_INSN (insn))
+ return BLOCK_FOR_INSN (insn)->index;
+
+ return -1;
+}
/* Similar to next_insn, but ignores insns in the delay slots of
an annulled branch. */
@@ -674,8 +714,7 @@ mark_target_live_regs (rtx_insn *insns, rtx
target_maybe_return, struct resource
}
if (b == -1)
- b = BLOCK_FOR_INSN (target)->index;
- gcc_assert (b != -1);
+ b = find_basic_block (target, param_max_delay_slot_live_search);
if (target_hash_table != NULL)
{
@@ -683,7 +722,7 @@ mark_target_live_regs (rtx_insn *insns, rtx
target_maybe_return, struct resource
{
/* If the information is up-to-date, use it. Otherwise, we will
update it below. */
- if (b == tinfo->block && tinfo->bb_tick == bb_ticks[b])
+ if (b == tinfo->block && b != -1 && tinfo->bb_tick == bb_ticks[b])
{
res->regs = tinfo->live_regs;
return;
@@ -866,6 +905,7 @@ void
init_resource_info (rtx_insn *epilogue_insn)
{
int i;
+ basic_block bb;
/* Indicate what resources are required to be valid at the end of the current
function. The condition code never is and memory always is.
@@ -935,8 +975,10 @@ init_resource_info (rtx_insn *epilogue_insn)
target_hash_table = XCNEWVEC (struct target_info *, TARGET_HASH_PRIME);
bb_ticks = XCNEWVEC (int, last_basic_block_for_fn (cfun));
- /* Set the BLOCK_FOR_INSN for each insn. */
- compute_bb_for_insn ();
+ /* Set the BLOCK_FOR_INSN of each label that starts a basic block. */
+ FOR_EACH_BB_FN (bb, cfun)
+ if (LABEL_P (BB_HEAD (bb)))
+ BLOCK_FOR_INSN (BB_HEAD (bb)) = bb;
}
/* Free up the resources allocated to mark_target_live_regs (). This
@@ -945,6 +987,8 @@ init_resource_info (rtx_insn *epilogue_insn)
void
free_resource_info (void)
{
+ basic_block bb;
+
if (target_hash_table != NULL)
{
int i;
@@ -971,7 +1015,9 @@ free_resource_info (void)
bb_ticks = NULL;
}
- free_bb_for_insn ();
+ FOR_EACH_BB_FN (bb, cfun)
+ if (LABEL_P (BB_HEAD (bb)))
+ BLOCK_FOR_INSN (BB_HEAD (bb)) = NULL;
}
/* Clear any hashed information that we have stored for INSN. */
@@ -1017,10 +1063,10 @@ clear_hashed_info_until_next_barrier (rtx_insn *insn)
void
incr_ticks_for_insn (rtx_insn *insn)
{
- int b = BLOCK_FOR_INSN (insn)->index;
- gcc_assert (b != -1);
+ int b = find_basic_block (insn, param_max_delay_slot_live_search);
- bb_ticks[b]++;
+ if (b != -1)
+ bb_ticks[b]++;
}
/* Add TRIAL to the set of resources used at the end of the current
