https://gcc.gnu.org/g:e5a639732d48e976af0466bb3721d0e0df3da8da
commit e5a639732d48e976af0466bb3721d0e0df3da8da
Author: Ondřej Machota <ondrejmach...@gmail.com>
Date: Thu Jul 10 18:08:51 2025 +0200
rtl-ssa-dce: format code
Diff:
---
gcc/dce.cc | 61 +++++++++++++++++++++++++++++++------------------------------
1 file changed, 31 insertions(+), 30 deletions(-)
diff --git a/gcc/dce.cc b/gcc/dce.cc
index 67fb42541d84..4691901f56d6 100644
--- a/gcc/dce.cc
+++ b/gcc/dce.cc
@@ -1386,6 +1386,7 @@ private:
sbitmap m_marked_phis;
};
+// Return true if INSN cannot be deleted.
bool
rtl_ssa_dce::is_rtx_pattern_prelive (const_rtx insn)
{
@@ -1393,7 +1394,7 @@ rtl_ssa_dce::is_rtx_pattern_prelive (const_rtx insn)
{
case PREFETCH:
case UNSPEC:
- case TRAP_IF: /* testsuite/gcc.c-torture/execute/20020418-1.c */
+ case TRAP_IF:
return true;
default:
@@ -1401,7 +1402,7 @@ rtl_ssa_dce::is_rtx_pattern_prelive (const_rtx insn)
}
}
-// Return true if an call INSN can be deleted
+// Return true if an call INSN can be deleted.
bool
rtl_ssa_dce::can_delete_call (const_rtx insn)
{
@@ -1418,6 +1419,7 @@ rtl_ssa_dce::can_delete_call (const_rtx insn)
&& cfun->can_delete_dead_exceptions && insn_nothrow_p (insn);
}
+// Return true if rtx INSN is prelive.
bool
rtl_ssa_dce::is_rtx_prelive (const_rtx insn)
{
@@ -1461,33 +1463,34 @@ rtl_ssa_dce::is_rtx_prelive (const_rtx insn)
}
}
+// Return true if INSN is prelive - cannot be deleted.
bool
rtl_ssa_dce::is_prelive (insn_info *insn)
{
// Bb head and end contain artificial uses that we need to mark as prelive.
// Debug instructions are also prelive, however, they are not added to the
- // worklist
+ // worklist.
if (insn->is_bb_head () || insn->is_bb_end () || insn->is_debug_insn ())
return true;
- // Phi instructions are never prelive
+ // Phi instructions are never prelive.
if (insn->is_artificial ())
return false;
- gcc_assert (insn->is_real ());
+ gcc_checking_assert (insn->is_real ());
for (def_info *def : insn->defs ())
{
- // The purpose of this pass is not to eliminate memory stores...
+ // The purpose of this pass is not to eliminate memory stores.
if (def->is_mem ())
return true;
gcc_checking_assert (def->is_reg ());
- // We should not delete the frame pointer because of the dward2frame pass
+ // We should not delete the frame pointer because of the dward2frame
pass.
if (frame_pointer_needed && def->regno () == HARD_FRAME_POINTER_REGNUM)
return true;
- // Skip clobbers, they are handled inside is_rtx_prelive
+ // Skip clobbers, they are handled inside is_rtx_prelive.
if (def->kind () == access_kind::CLOBBER)
continue;
@@ -1509,7 +1512,7 @@ rtl_ssa_dce::is_prelive (insn_info *insn)
// Mark SET as visited and return true if SET->insn() is not nullptr and SET
// has not been visited. Otherwise return false.
bool
-rtl_ssa_dce::mark_if_not_visited (const set_info *set)
+rtl_ssa_dce::mark_if_not_visited (set_info *set)
{
insn_info *insn = set->insn ();
if (!insn)
@@ -1517,20 +1520,20 @@ rtl_ssa_dce::mark_if_not_visited (const set_info *set)
if (insn->is_phi ())
{
- const phi_info *phi = static_cast<const phi_info *> (set);
- auto uid = phi->uid ();
+ phi_info *phi = static_cast<phi_info *> (set);
+ unsigned int uid = phi->uid ();
if (bitmap_bit_p (m_marked_phis, uid))
return false;
bitmap_set_bit (m_marked_phis, uid);
if (dump_file)
- fprintf (dump_file, "Phi node %d:%d marked as live\n", set->regno (),
+ fprintf (dump_file, "Phi node %d in insn %d marked as live\n", uid,
insn->uid ());
}
else
{
- auto uid = insn->uid ();
+ unsigned int uid = insn->uid ();
if (m_marked.get_bit (uid))
return false;
@@ -1550,8 +1553,6 @@ rtl_ssa_dce::append_not_visited_sets (auto_vec<set_info
*> &worklist,
{
for (use_info *use : uses)
{
- // This seems to be a good idea, however there is a problem is
- // process_uses_of_deleted_def
if (use->only_occurs_in_notes ())
continue;
@@ -1562,27 +1563,23 @@ rtl_ssa_dce::append_not_visited_sets (auto_vec<set_info
*> &worklist,
if (!mark_if_not_visited (parent_set))
continue;
- // mark_if_not_visited will return false if insn is nullptr
- // insn_info *insn = parent_set->insn ();
- // gcc_checking_assert (insn);
-
- // if (dump_file)
- // fprintf (dump_file, "Adding insn %d to worklist\n", insn->uid ());
worklist.safe_push (parent_set);
}
}
-// Mark INSN and add its uses to WORKLIST if INSN is not a debug instruction
+// Mark INSN and add its uses to WORKLIST if INSN is not a debug instruction.
void
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 ());
- // A phi node will never be prelive.
+ // A phi instruction will never be prelive.
+ gcc_checking_assert(!insn->is_phi ());
+
m_marked.set_bit (insn->uid ());
// Debug instruction are not added to worklist. They would wake up possibly
- // dead instructions
+ // dead instructions.
if (insn->is_debug_insn ())
return;
@@ -1590,7 +1587,7 @@ rtl_ssa_dce::mark_prelive_insn (insn_info *insn,
auto_vec<set_info *> &worklist)
append_not_visited_sets (worklist, uses);
}
-// Scans all instructions and marks all which are prelive
+// Scan over all instructions and mark all prelive instructions.
auto_vec<set_info *>
rtl_ssa_dce::mark_prelive ()
{
@@ -1607,6 +1604,7 @@ rtl_ssa_dce::mark_prelive ()
return worklist;
}
+// Mark prelive instructions and then mark their dependencies.
void
rtl_ssa_dce::mark ()
{
@@ -1619,7 +1617,7 @@ rtl_ssa_dce::mark ()
set_info *set = worklist.pop ();
insn_info *insn = set->insn ();
- // a set without an insn will not be added to the worklist
+ // A set without an insn will not be added to the worklist.
gcc_checking_assert (insn);
use_array uses = insn->uses ();
@@ -1633,7 +1631,7 @@ rtl_ssa_dce::mark ()
}
}
-// Clear debug_insn uses and set gen_rtx_UNKNOWN_VAR_LOC
+// Clear debug_insn uses and set gen_rtx_UNKNOWN_VAR_LOC.
void
rtl_ssa_dce::reset_dead_debug_insn (insn_info *insn)
{
@@ -1662,14 +1660,17 @@ rtl_ssa_dce::reset_dead_debug ()
for (use_info *use : insn->uses ())
{
def_info *def = use->def ();
+ if (!def) // Should not happen for debug insn use...
+ continue;
+
insn_info *parent_insn = def->insn ();
- if (parent_insn == nullptr)
+ if (!parent_insn)
continue;
- // If we depend on a dead instruction, clear current instruction uses.
+ // If INSN depends on a dead instruction, clear its uses and reset it.
bool is_parent_marked = false;
if (parent_insn->is_phi ())
{
- auto phi = static_cast<phi_info *> (def);
+ phi_info *phi = static_cast<phi_info *> (def);
is_parent_marked = bitmap_bit_p (m_marked_phis, phi->uid ());
}
else
