https://gcc.gnu.org/g:90bbab8cdb9d7ecf9be135ee8c23289789700e70
commit 90bbab8cdb9d7ecf9be135ee8c23289789700e70
Author: Ondřej Machota <ondrejmach...@gmail.com>
Date: Fri Mar 21 13:42:25 2025 +0100
rtl-ssa-dce: change prelive conditions for mem
Diff:
---
gcc/dce.cc | 92 ++++++++++++++++++++++++++++++++++++--------------------------
1 file changed, 53 insertions(+), 39 deletions(-)
diff --git a/gcc/dce.cc b/gcc/dce.cc
index bd70c9588497..a769c1387346 100644
--- a/gcc/dce.cc
+++ b/gcc/dce.cc
@@ -1306,10 +1306,6 @@ public:
} // namespace
-// We should mark stack registers
-// use HARD_FRAME_POINTER_REGNUM, REGNO_PTR_FRAME_P
-// muzeme mit parallel, ktery ma napr. dva single sety, nebo asm statement
-// pouzit note_pattern_stores nebo note_stores
bool sets_global_register(rtx_insn* insn) {
rtx set = single_set(insn);
if (!set)
@@ -1442,14 +1438,24 @@ bool is_rtx_insn_prelive(rtx_insn *insn) {
// return true;
rtx body = PATTERN(insn);
- if (GET_CODE(body) == CLOBBER) //
gcc/gcc/testsuite/gcc.c-torture/compile/20000605-1.c
- return true;
+ switch (GET_CODE(body)) {
+ case CLOBBER: // gcc/gcc/testsuite/gcc.c-torture/compile/20000605-1.c
+ case USE:
+ case VAR_LOCATION:
+ case PREFETCH: // This and following case might be removed since they are
part of deletable_insn_p_1
+ case TRAP_IF:
+ case UNSPEC:
+ return true;
- if (GET_CODE(body) == PREFETCH)
- return true;
+ case PARALLEL:
+ for (int i = XVECLEN (body, 0) - 1; i >= 0; i--)
+ if (!deletable_insn_p_1 (XVECEXP (body, 0, i)))
+ return true;
+ return false;
- if (GET_CODE(body) == USE || GET_CODE(body) == TRAP_IF || GET_CODE(body) ==
UNSPEC)
- return true;
+ default:
+ return !deletable_insn_p_1 (body);
+ }
// See deletable_insn_p_1 for UNSPEC. TRAP_IF is caught by
may_trap_or_fault_p
@@ -1495,27 +1501,25 @@ bool is_prelive(insn_info *insn)
for (auto&& __def : insn->defs()) {
def_info * def = __def;
- if (!def->is_reg()) {
- continue;
+ // The purpose of this pass is not to eliminate stores to memory...
+ if (def->is_mem()) { // TODO : clobbered memory?
+ return true;
}
- // this ignore clobbers, which is probably fine
+ gcc_assert(def->is_reg());
+ // this ignores clobbers, which is probably fine
if (def->kind() == access_kind::SET
&& (HARD_REGISTER_NUM_P(def->regno())
- || (def->regno() == REGNO (pic_offset_table_rtx)
- && REGNO (pic_offset_table_rtx) >= FIRST_PSEUDO_REGISTER))
+ || ( pic_offset_table_rtx != nullptr
+ && def->regno() == REGNO (pic_offset_table_rtx)
+ && REGNO (pic_offset_table_rtx) >= FIRST_PSEUDO_REGISTER))
) {
- // We might try to write something like def->regno() == REGNO
(pic_offset_table_rtx) ...
- // TODO : else if (DF_REF_REG (def) == pic_offset_table_rtx && REGNO
(pic_offset_table_rtx) >= FIRST_PSEUDO_REGISTER)
- // std::cerr << "hello, dear hard register! regno: " << def->regno() <<
"\n";
+ // std::cerr << "hard reg marked: " << def->regno() << "in " <<
insn->uid() << "\n";
// debug(rtl);
return true;
}
}
- // auto res = is_rtx_insn_prelive(rtl);
- //std::cerr << "Trying to mark insn: " << insn->uid() << " as prelive: " <<
res << '\n';
-
return is_rtx_insn_prelive(rtl);
}
@@ -1539,7 +1543,9 @@ rtl_ssa_dce_prelive(std::unordered_set<insn_info *>
&marked)
{
next = insn->next_any_insn();
if (is_prelive(insn))
- rtl_ssa_dce_mark_live(insn, worklist, marked);
+ {
+ // std::cout << "insn is prelive: " << insn->uid() << '\n';
+ rtl_ssa_dce_mark_live(insn, worklist, marked);}
// if (insn->can_be_optimized () || insn->is_debug_insn ())
// if (fwprop_insn (insn, fwprop_addr_p))
@@ -1639,6 +1645,9 @@ rtl_ssa_dce_sweep(std::unordered_set<insn_info *> marked)
// which will hopefully have constructor for array_slice<insn_info *>
auto attempt = crtl->ssa->new_change_attempt ();
// std::cerr << "Change attempt created successfully" << std::endl;
+ for (auto && insn : crtl->ssa->all_insns()) {
+
+ }
for (insn_info *insn = crtl->ssa->first_insn(); insn; insn = next)
{
if (dump_file)
@@ -1646,22 +1655,24 @@ rtl_ssa_dce_sweep(std::unordered_set<insn_info *>
marked)
fprintf(dump_file, "Insn: %d\n", insn->uid());
}
next = insn->next_any_insn();
- if (!(marked.count(insn) > 0))
+ if (marked.count(insn) > 0)
{
- if (dump_file)
- {
- fprintf(dump_file, " Sweeping insn %d\n", insn->uid());
- }
+ continue;
+ }
+
+ if (dump_file)
+ {
+ fprintf(dump_file, " Sweeping insn %d\n", insn->uid());
+ }
- // Skip artificial insns (or uid() < 0)
- if (insn->is_real())
- {
- // std::cerr << "Insn: " << insn->uid() << " will be deleted\n";
- auto change = insn_change::delete_insn(insn);
- // crtl->ssa->possibly_queue_changes(change);
- to_delete.safe_push(change);
- // crtl->ssa->change_insn(change);
- }
+ // Skip artificial insns (or uid() < 0)
+ if (insn->is_real())
+ {
+ // std::cerr << "\033[32m" << "Insn: " << insn->uid() << " will be
deleted" << "\033[0m \n";
+ auto change = insn_change::delete_insn(insn);
+ // crtl->ssa->possibly_queue_changes(change);
+ to_delete.safe_push(change);
+ // crtl->ssa->change_insn(change);
}
}
@@ -1711,13 +1722,16 @@ rtl_ssa_dce()
{
rtl_ssa_dce_init();
// debug(crtl->ssa);
+ // for (rtx_insn * insn = get_insns (); insn != nullptr; insn =
next_insn(insn)) {
+ // debug(insn);
+ // }l
- //std::cerr << "Next phase: prelive + mark: \n";
std::unordered_set<insn_info *> marked = rtl_ssa_dce_mark();
- // std::cerr << "Marking done\n";
rtl_ssa_dce_sweep(marked);
- // std::cerr << "Sweeping done\n";
rtl_ssa_dce_done();
+ if (delete_trivially_dead_insns(get_insns (), max_reg_num ())) {
+ std::cerr << "\033[31m" << "rtl_ssa_dce did not delete everything :(" <<
"\033[0m" << "\n";
+ }
return 0;
}
