https://gcc.gnu.org/g:0b830664e62baeb3ff35bf79dbeaf0211251bd9b
commit 0b830664e62baeb3ff35bf79dbeaf0211251bd9b
Author: Ondřej Machota <ondrejmach...@gmail.com>
Date: Tue Apr 29 09:44:32 2025 +0200
rtl-ssa-dce: use sbitmap
Diff:
---
gcc/dce.cc | 70 ++++++++++++++++++++++++++++----------------------------------
1 file changed, 32 insertions(+), 38 deletions(-)
diff --git a/gcc/dce.cc b/gcc/dce.cc
index 4f35875988cf..3bc5bdb4d56c 100644
--- a/gcc/dce.cc
+++ b/gcc/dce.cc
@@ -1318,30 +1318,6 @@ public:
} // namespace
-struct offset_bitmap
-{
-private:
- const int m_offset;
- sbitmap m_bitmap;
-
-public:
- offset_bitmap (size_t size, int offset)
- : m_offset{offset}, m_bitmap{sbitmap_alloc (size)}
- {}
-
- offset_bitmap (int min_index, int max_index)
- : offset_bitmap (size_t (max_index - min_index + 1), -min_index)
- {}
-
- void clear_bit (int index) { bitmap_clear_bit (m_bitmap, index + m_offset); }
-
- void set_bit (int index) { bitmap_set_bit (m_bitmap, index + m_offset); }
-
- bool get_bit (int index) { return bitmap_bit_p (m_bitmap, index + m_offset);
}
-
- ~offset_bitmap () { sbitmap_free (m_bitmap); }
-};
-
class rtl_ssa_dce
{
public:
@@ -1360,8 +1336,9 @@ private:
void reset_dead_debug ();
void sweep ();
- offset_bitmap mm_marked;
- offset_bitmap mm_marked_phis;
+ int phi_min, real_max, artificial_min;
+ sbitmap mm_marked;
+ sbitmap mm_marked_phis;
std::unordered_set<insn_info *> m_marked;
std::unordered_set<phi_info *> m_marked_phis;
};
@@ -1511,8 +1488,7 @@ rtl_ssa_dce::mark_prelive_insn (insn_info *insn,
auto_vec<set_info *> &worklist)
if (dump_file)
fprintf (dump_file, "Insn %d marked as prelive\n", insn->uid ());
- mm_marked.set_bit(insn->uid());
- m_marked.emplace (insn);
+ bitmap_set_bit (mm_marked, insn->uid ());
// debug instruction are not added to worklist not to wake up possibly dead
// instructions
if (insn->is_debug_insn ())
@@ -1558,24 +1534,22 @@ rtl_ssa_dce::mark ()
// Skip already visited visited instructions.
auto uid = insn->uid ();
- if ((m_marked.count (insn) > 0) && !insn->is_phi ())
+ if (bitmap_bit_p (mm_marked, uid) && !insn->is_phi ())
continue;
- m_marked.emplace (insn);
- mm_marked.set_bit(uid);
+ bitmap_set_bit (mm_marked, uid);
use_array uses = insn->uses ();
if (insn->is_phi ())
{
- phi_info *pi = static_cast<phi_info *> (set);
- auto pi_uid = pi->uid ();
+ phi_info *phi = static_cast<phi_info *> (set);
+ auto phi_uid = pi->uid ();
// Skip already visited phi node.
- if (m_marked_phis.count (pi) > 0)
+ if (bitmap_bit_p(mm_marked_phis, phi_uid))
continue;
- mm_marked_phis.set_bit(pi_uid);
- m_marked_phis.emplace (pi);
- uses = pi->inputs ();
+ mm_marked_phis.set_bit(phi_uid);
+ uses = phi->inputs ();
}
if (dump_file)
@@ -1601,6 +1575,7 @@ rtl_ssa_dce::reset_dead_debug_insn (insn_info *insn)
if (dump_file)
fprintf (dump_file, "Resetting debug insn: %d\n", insn->uid ());
+ bitmap_clear_bit (mm_marked, insn->uid ());
insn_change change (insn);
change.new_uses = {};
INSN_VAR_LOCATION_LOC (insn->rtl ()) = gen_rtx_UNKNOWN_VAR_LOC ();
@@ -1624,7 +1599,12 @@ rtl_ssa_dce::reset_dead_debug ()
// TODO : use iterate_safely?
for (use_info *use : insn->uses ())
{
- insn_info *parent_insn = use->def ()->insn ();
+ insn_info *parent_insn = use->def ()->insn (); // TODO : check for
nullptr
+ sbitmap marked = parent_insn->is_phi () ? mm_marked_phis : mm_marked;
+ int uid = parent_insn->is_phi () ? as_a<phi_info *> (use->def ())->uid ()
? parent_insn->uid ();
+ if (!bitmap_bit_p (marked, uid)) {
+ // ...
+ }
if ((parent_insn->is_phi ()
&& m_marked_phis.count (as_a<phi_info *> (use->def ())) == 0)
|| (!parent_insn->is_phi () && m_marked.count (parent_insn) == 0))
@@ -1679,6 +1659,18 @@ rtl_ssa_dce::execute (function *fn)
// internal compiler error: gcc.c-torture/execute/20040811-1.c -
// rtl_ssa::function_info::add_phi_nodes
crtl->ssa = new rtl_ssa::function_info (fn);
+ for (insn_info *insn : crtl->ssa->all_insns ())
+ {
+ artificial_min = std::min (artificial_min, insn->uid ());
+ real_max = std::min (real_max, insn->uid ());
+ }
+
+ for (ebb_info *ebb : crtl->ssa->ebbs ())
+ for (phi_info *phi : ebb->phis ())
+ phi_min = std::min (phi_min, phi->uid ());
+
+ mm_marked = sbitmap_alloc(real_max - artificial_min + 1);
+ mm_marked_phis = sbitmap_alloc(-phi_min);
if (dump_file)
dump (dump_file, crtl->ssa);
@@ -1709,6 +1701,8 @@ rtl_ssa_dce::execute (function *fn)
if (crtl->ssa->perform_pending_updates ())
cleanup_cfg (0);
+ sbitmap_free(mm_marked);
+ sbitmap_free(mm_marked_phis);
delete crtl->ssa;
crtl->ssa = nullptr;
}
