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re PR tree-optimization/79432 (ICE: verify_ssa failed)

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2017-02-14  Richard Biener  <rguenther@suse.de>

	PR middle-end/79432
	* tree-into-ssa.c (insert_phi_nodes): When the function can
	have abnormal edges rewrite SSA names with broken use-def
	dominance out of SSA and register them for PHI insertion.

	* gcc.dg/torture/pr79432.c: New testcase.

From-SVN: r245417
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Richard Biener 2017-02-14 07:58:12 +00:00 • committed by Richard Biener
parent ee75687bc6
commit 977472e8c6
4 changed files with 85 additions and 0 deletions
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7
gcc/ChangeLog
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@ -1,3 +1,10 @@
2017-02-14 Richard Biener <rguenther@suse.de>
PR middle-end/79432
* tree-into-ssa.c (insert_phi_nodes): When the function can
have abnormal edges rewrite SSA names with broken use-def
dominance out of SSA and register them for PHI insertion.
2017-02-13 Martin Sebor <msebor@redhat.com>
PR middle-end/79496

5
gcc/testsuite/ChangeLog
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@ -1,3 +1,8 @@
2017-02-14 Richard Biener <rguenther@suse.de>
PR middle-end/79432
* gcc.dg/torture/pr79432.c: New testcase.
2017-02-13 Martin Sebor <msebor@redhat.com>
PR middle-end/79496

20
gcc/testsuite/gcc.dg/torture/pr79432.c Normal file
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@ -0,0 +1,20 @@
/* { dg-do compile } */
int fn1 (void);
int __attribute__((returns_twice)) vfork (void);
void fn2 ()
{
int a;
a = fn1() + 2 + (vfork() + 1 + vfork());
}
void fn3 ()
{
int a;
a = fn1() + 1 + vfork();
}
void fn4 ()
{
int a;
a = fn1() + vfork();
}

53
gcc/tree-into-ssa.c
View file

@ -1066,6 +1066,59 @@ insert_phi_nodes (bitmap_head *dfs)
timevar_push (TV_TREE_INSERT_PHI_NODES);
/* When the gimplifier introduces SSA names it cannot easily avoid
situations where abnormal edges added by CFG construction break
the use-def dominance requirement. For this case rewrite SSA
names with broken use-def dominance out-of-SSA and register them
for PHI insertion. We only need to do this if abnormal edges
can appear in the function. */
tree name;
if (cfun->calls_setjmp
|| cfun->has_nonlocal_label)
FOR_EACH_SSA_NAME (i, name, cfun)
{
gimple *def_stmt = SSA_NAME_DEF_STMT (name);
if (SSA_NAME_IS_DEFAULT_DEF (name))
continue;
basic_block def_bb = gimple_bb (def_stmt);
imm_use_iterator it;
gimple *use_stmt;
bool need_phis = false;
FOR_EACH_IMM_USE_STMT (use_stmt, it, name)
{
basic_block use_bb = gimple_bb (use_stmt);
if (use_bb != def_bb
&& ! dominated_by_p (CDI_DOMINATORS, use_bb, def_bb))
need_phis = true;
}
if (need_phis)
{
tree var = create_tmp_reg (TREE_TYPE (name));
use_operand_p use_p;
FOR_EACH_IMM_USE_STMT (use_stmt, it, name)
{
basic_block use_bb = gimple_bb (use_stmt);
FOR_EACH_IMM_USE_ON_STMT (use_p, it)
SET_USE (use_p, var);
update_stmt (use_stmt);
set_livein_block (var, use_bb);
set_rewrite_uses (use_stmt, true);
bitmap_set_bit (interesting_blocks, use_bb->index);
}
def_operand_p def_p;
ssa_op_iter dit;
FOR_EACH_SSA_DEF_OPERAND (def_p, def_stmt, dit, SSA_OP_DEF)
if (DEF_FROM_PTR (def_p) == name)
SET_DEF (def_p, var);
update_stmt (def_stmt);
set_def_block (var, def_bb, false);
set_register_defs (def_stmt, true);
bitmap_set_bit (interesting_blocks, def_bb->index);
release_ssa_name (name);
}
}
auto_vec<var_info *> vars (var_infos->elements ());
FOR_EACH_HASH_TABLE_ELEMENT (*var_infos, info, var_info_p, hi)
if (info->info.need_phi_state != NEED_PHI_STATE_NO)