https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101256
Bug ID: 101256
Summary: [12 Regression] Wrong code with -O3 since
r12-1841-g9fe9c45ae33a2df7
Product: gcc
Version: 12.0
Status: UNCONFIRMED
Keywords: wrong-code
Severity: normal
Priority: P3
Component: tree-optimization
Assignee: unassigned at gcc dot gnu.org
Reporter: marxin at gcc dot gnu.org
CC: pinskia at gcc dot gnu.org
Target Milestone: ---
Created attachment 51081
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=51081&action=edit
test-case
It's a yarpgen test case and it's not easily reducible.
However, with the following patch:
diff --git a/gcc/dbgcnt.def b/gcc/dbgcnt.def
index 93e7b4fd30e..6186b5533ca 100644
--- a/gcc/dbgcnt.def
+++ b/gcc/dbgcnt.def
@@ -158,6 +158,7 @@ DEBUG_COUNTER (dom_unreachable_edges)
DEBUG_COUNTER (dse)
DEBUG_COUNTER (dse1)
DEBUG_COUNTER (dse2)
+DEBUG_COUNTER (edge_range)
DEBUG_COUNTER (gcse2_delete)
DEBUG_COUNTER (gimple_unroll)
DEBUG_COUNTER (global_alloc_at_func)
diff --git a/gcc/tree-ssa-phiopt.c b/gcc/tree-ssa-phiopt.c
index ab12e85569d..21741504038 100644
--- a/gcc/tree-ssa-phiopt.c
+++ b/gcc/tree-ssa-phiopt.c
@@ -50,6 +50,7 @@ along with GCC; see the file COPYING3. If not see
#include "gimple-fold.h"
#include "internal-fn.h"
#include "gimple-range.h"
+#include "dbgcnt.h"
static unsigned int tree_ssa_phiopt_worker (bool, bool, bool);
static bool two_value_replacement (basic_block, basic_block, edge, gphi *,
@@ -413,7 +414,8 @@ replace_phi_edge_with_variable (basic_block cond_block,
&& EDGE_COUNT (gimple_bb (phi)->preds) == 2
&& INTEGRAL_TYPE_P (TREE_TYPE (phi_result))
&& !SSA_NAME_RANGE_INFO (new_tree)
- && SSA_NAME_RANGE_INFO (phi_result))
+ && SSA_NAME_RANGE_INFO (phi_result)
+ && dbg_cnt(edge_range))
duplicate_ssa_name_range_info (new_tree,
SSA_NAME_RANGE_TYPE (phi_result),
SSA_NAME_RANGE_INFO (phi_result));
One can reduce it to:
$ g++ driver.cpp -c && g++ func.cpp -O3 -c -fdbg-cnt=edge_range:52-52 && gcc
func.o driver.o && ./a.out
***dbgcnt: lower limit 52 reached for edge_range.***
***dbgcnt: upper limit 52 reached for edge_range.***
a.out: driver.cpp:3609: void checksum(): Assertion `var_303 == (unsigned
char)240' failed.
Aborted (core dumped)
