https://gcc.gnu.org/g:e18885b07e47e933aa12ee5bbbaa29b0628ec609
commit e18885b07e47e933aa12ee5bbbaa29b0628ec609
Author: Ondřej Machota <ondrejmach...@gmail.com>
Date: Tue Apr 29 14:31:10 2025 +0200
rtl-ssa-dce: use sbitmap completed
Diff:
---
gcc/dce.cc | 113 ++++++++++++++++++++++++++++++++++---------------------------
1 file changed, 63 insertions(+), 50 deletions(-)
diff --git a/gcc/dce.cc b/gcc/dce.cc
index 3bc5bdb4d56c..67c9ad577e67 100644
--- a/gcc/dce.cc
+++ b/gcc/dce.cc
@@ -1336,11 +1336,10 @@ private:
void reset_dead_debug ();
void sweep ();
- int phi_min, real_max, artificial_min;
+ int offset;
+
sbitmap mm_marked;
sbitmap mm_marked_phis;
- std::unordered_set<insn_info *> m_marked;
- std::unordered_set<phi_info *> m_marked_phis;
};
bool
@@ -1488,7 +1487,7 @@ 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 ());
- bitmap_set_bit (mm_marked, insn->uid ());
+ bitmap_set_bit (mm_marked, insn->uid () + offset);
// debug instruction are not added to worklist not to wake up possibly dead
// instructions
if (insn->is_debug_insn ())
@@ -1533,7 +1532,7 @@ rtl_ssa_dce::mark ()
continue;
// Skip already visited visited instructions.
- auto uid = insn->uid ();
+ auto uid = insn->uid () + offset;
if (bitmap_bit_p (mm_marked, uid) && !insn->is_phi ())
continue;
@@ -1543,12 +1542,12 @@ rtl_ssa_dce::mark ()
if (insn->is_phi ())
{
phi_info *phi = static_cast<phi_info *> (set);
- auto phi_uid = pi->uid ();
+ auto phi_uid = phi->uid ();
// Skip already visited phi node.
if (bitmap_bit_p(mm_marked_phis, phi_uid))
continue;
- mm_marked_phis.set_bit(phi_uid);
+ bitmap_set_bit (mm_marked_phis, phi_uid);
uses = phi->inputs ();
}
@@ -1575,7 +1574,7 @@ 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 ());
+ // bitmap_clear_bit (mm_marked, insn->uid () + offset);
insn_change change (insn);
change.new_uses = {};
INSN_VAR_LOCATION_LOC (insn->rtl ()) = gen_rtx_UNKNOWN_VAR_LOC ();
@@ -1599,19 +1598,18 @@ rtl_ssa_dce::reset_dead_debug ()
// TODO : use iterate_safely?
for (use_info *use : insn->uses ())
{
- insn_info *parent_insn = use->def ()->insn (); // TODO : check for
nullptr
+ def_info *def = use->def ();
+ insn_info *parent_insn = def->insn ();
+ // Is this check needed?
+ if (parent_insn == nullptr)
+ continue;
+ // If we depend on a dead instruction, clear current instruction uses.
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 ();
+ int uid = parent_insn->is_phi () ? static_cast<phi_info *> (def)->uid () :
parent_insn->uid () + offset;
if (!bitmap_bit_p (marked, uid)) {
- // ...
+ reset_dead_debug_insn (insn);
+ break;
}
- 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))
- {
- reset_dead_debug_insn (insn);
- break;
- }
}
}
}
@@ -1627,7 +1625,7 @@ rtl_ssa_dce::sweep ()
for (insn_info *insn : crtl->ssa->nondebug_insns ())
{
// Artificial or marked insns should not be deleted.
- if (insn->is_artificial () || m_marked.count (insn) > 0)
+ if (insn->is_artificial () || bitmap_bit_p (mm_marked, insn->uid () +
offset))
continue;
if (dump_file)
@@ -1652,6 +1650,8 @@ rtl_ssa_dce::sweep ()
fprintf (dump_file, "DCE: finish sweep phase\n");
}
+#include <iostream>
+
unsigned int
rtl_ssa_dce::execute (function *fn)
{
@@ -1659,18 +1659,32 @@ 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);
+ int real_max = 0, artificial_min = 0;
+ std::size_t count = 0;
for (insn_info *insn : crtl->ssa->all_insns ())
{
artificial_min = std::min (artificial_min, insn->uid ());
- real_max = std::min (real_max, insn->uid ());
+ real_max = std::max (real_max, insn->uid ());
+ count++;
}
+ offset = -artificial_min;
+ // std::cout << "real_max: " << real_max << '\n';
+ // std::cout << "artificial_min: " << artificial_min << '\n';
+ // std::cout << "total: " << real_max - artificial_min + 3 << '\n';
+ // std::cout << "Offset: " << offset << '\n';
+ // std::cout << "count: " << count << '\n';
+
+ unsigned int phi_node_max = 0;
for (ebb_info *ebb : crtl->ssa->ebbs ())
for (phi_info *phi : ebb->phis ())
- phi_min = std::min (phi_min, phi->uid ());
+ phi_node_max = std::max (phi_node_max, phi->uid ());
- mm_marked = sbitmap_alloc(real_max - artificial_min + 1);
- mm_marked_phis = sbitmap_alloc(-phi_min);
+ // std::cout << "phi_node_max: " << phi_node_max << '\n';
+ mm_marked = sbitmap_alloc(real_max - artificial_min + 3);
+ bitmap_clear(mm_marked);
+ mm_marked_phis = sbitmap_alloc(phi_node_max + 1);
+ bitmap_clear(mm_marked_phis);
if (dump_file)
dump (dump_file, crtl->ssa);
@@ -1705,6 +1719,7 @@ rtl_ssa_dce::execute (function *fn)
sbitmap_free(mm_marked_phis);
delete crtl->ssa;
crtl->ssa = nullptr;
+ return 0;
}
// mark instructions that depend on a dead phi
@@ -1720,7 +1735,7 @@ rtl_ssa_dce::propagate_dead_phis ()
{
for (phi_info *phi : ebb->phis ())
{
- if (marked_phis.count (phi) > 0)
+ if (bitmap_bit_p (mm_marked_phis, phi->uid ()))
continue;
worklist.safe_push (phi);
@@ -1739,8 +1754,7 @@ rtl_ssa_dce::propagate_dead_phis ()
if (dump_file)
fprintf (dump_file, "Debug insns %d depends on dead phi.\n",
insn->uid ());
- m_marked.erase (insn);
- mm_marked.clear_bit(insn->uid());
+ bitmap_clear_bit (mm_marked, insn->uid ());
// debug instructions dont have chains
continue;
}
@@ -1748,12 +1762,12 @@ rtl_ssa_dce::propagate_dead_phis ()
// mark
if (insn->is_phi ())
{
- gcc_assert (m_marked_phis.count (static_cast<phi_info *> (set)) == 0);
+ gcc_assert (!bitmap_bit_p(mm_marked_phis, static_cast<phi_info *>
(set)->uid ()));
visited_dead_phis.emplace (static_cast<phi_info *> (set));
}
else
{
- gcc_assert (m_marked.count (insn) == 0);
+ gcc_assert (!bitmap_bit_p (mm_marked, insn->uid () + offset));
depends_on_dead_phi.emplace (insn);
}
@@ -1819,28 +1833,27 @@ test (insn_info *insn)
// make dval available in the following iteration
}
-static auto_vec<insn_change>
-wip (std::unordered_set<insn_info *> &marked,
- std::unordered_set<phi_info *> &marked_phis)
-{
- std::unordered_set<insn_info *> depends_on_dead_phi
- = propagate_dead_phis (marked, marked_phis);
- for (insn_info *insn : crtl->ssa->all_insns ())
- {
- if (insn->is_phi ()) // insn->is_artificial() ??
- continue;
-
- // skip marked instructions
- if (marked.count (insn) > 0) // debug instruction are still alive
- continue;
-
- // we cannot create debug instruction if we depend on a dead phi
- if (depends_on_dead_phi.count (insn) > 0)
- continue;
-
- // insn is nondebug and dead
- }
-}
+// static auto_vec<insn_change>
+// wip (std::unordered_set<insn_info *> &marked,
+// std::unordered_set<phi_info *> &marked_phis)
+// {
+// std::unordered_set<insn_info *> depends_on_dead_phi = propagate_dead_phis
();
+// for (insn_info *insn : crtl->ssa->all_insns ())
+// {
+// if (insn->is_phi ()) // insn->is_artificial() ??
+// continue;
+
+// // skip marked instructions
+// if (marked.count (insn) > 0) // debug instruction are still alive
+// continue;
+
+// // we cannot create debug instruction if we depend on a dead phi
+// if (depends_on_dead_phi.count (insn) > 0)
+// continue;
+
+// // insn is nondebug and dead
+// }
+// }
rtl_opt_pass *
make_pass_fast_rtl_dce (gcc::context *ctxt)
