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Check equivalencies when calculating range on entry.

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When propagating on-entry values in the cache, checking if any equivalence
has a known value can improve results.  No new calculations are made.
Only queries via dominators which do not populate the cache are checked.

	PR tree-optimization/106474
	gcc/
	* gimple-range-cache.cc (ranger_cache::fill_block_cache): Query
	range of equivalences that may contribute to the range.

	gcc/testsuite/
	* g++.dg/pr106474.C: New.
This commit is contained in:
Andrew MacLeod 2022-07-29 12:05:38 -04:00
parent 5df04a7aa8
commit 87dd4c8c83
2 changed files with 60 additions and 1 deletions
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45
gcc/gimple-range-cache.cc
View file

@ -1211,13 +1211,56 @@ ranger_cache::fill_block_cache (tree name, basic_block bb, basic_block def_bb)
// Check if a dominators can supply the range.
if (range_from_dom (block_result, name, bb, RFD_FILL))
{
m_on_entry.set_bb_range (name, bb, block_result);
if (DEBUG_RANGE_CACHE)
{
fprintf (dump_file, "Filled from dominator! : ");
block_result.dump (dump_file);
fprintf (dump_file, "\n");
}
// See if any equivalences can refine it.
if (m_oracle)
{
unsigned i;
bitmap_iterator bi;
// Query equivalences in read-only mode.
const_bitmap equiv = m_oracle->equiv_set (name, bb);
EXECUTE_IF_SET_IN_BITMAP (equiv, 0, i, bi)
{
if (i == SSA_NAME_VERSION (name))
continue;
tree equiv_name = ssa_name (i);
basic_block equiv_bb = gimple_bb (SSA_NAME_DEF_STMT (equiv_name));
// Check if the equiv has any ranges calculated.
if (!m_gori.has_edge_range_p (equiv_name))
continue;
// Check if the equiv definition dominates this block
if (equiv_bb == bb ||
(equiv_bb && !dominated_by_p (CDI_DOMINATORS, bb, equiv_bb)))
continue;
Value_Range equiv_range (TREE_TYPE (equiv_name));
if (range_from_dom (equiv_range, equiv_name, bb, RFD_READ_ONLY))
{
if (block_result.intersect (equiv_range))
{
if (DEBUG_RANGE_CACHE)
{
fprintf (dump_file, "Equivalence update! : ");
print_generic_expr (dump_file, equiv_name, TDF_SLIM);
fprintf (dump_file, "had range : ");
equiv_range.dump (dump_file);
fprintf (dump_file, " refining range to :");
block_result.dump (dump_file);
fprintf (dump_file, "\n");
}
}
}
}
}
m_on_entry.set_bb_range (name, bb, block_result);
gcc_checking_assert (m_workback.length () == 0);
return;
}

16
gcc/testsuite/g++.dg/pr106474.C Normal file
View file

@ -0,0 +1,16 @@
/* { dg-do compile } */
/* { dg-options "-O2 -fdump-tree-evrp " } */
void foo();
static void __attribute__ ((noinline)) DCEMarker0_() {foo ();}
void f(bool s, bool c) {
if ((!c == !s) && !c) {
if (s) {
DCEMarker0_();
}
}
}
// With equivalences, vrp should be able to remove all IFs.
/* { dg-final { scan-tree-dump-not "goto" "evrp" } } */