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riscv-gcc-1
Commit 92261ce0 by Jakub Jelinek Committed by Jakub Jelinek
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re PR tree-optimization/56490 (-Wall triggering infinite loop) 

	PR tree-optimization/56490
	* params.def (PARAM_UNINIT_CONTROL_DEP_ATTEMPTS): New param.
	* tree-ssa-uninit.c: Include params.h.
	(compute_control_dep_chain): Add num_calls argument, return false
	if it exceed PARAM_UNINIT_CONTROL_DEP_ATTEMPTS param, pass
	num_calls to recursive call.
	(find_predicates): Change dep_chain into normal array,
	cur_chain into auto_vec<edge, MAX_CHAIN_LEN + 1>, add num_calls
	variable and adjust compute_control_dep_chain caller.
	(find_def_preds): Likewise.

From-SVN: r207988
parent aa6ef874
Showing with 43 additions and 37 deletions
gcc/ChangeLog
2014-02-21 Jakub Jelinek <jakub@redhat.com>
PR tree-optimization/56490
* params.def (PARAM_UNINIT_CONTROL_DEP_ATTEMPTS): New param.
* tree-ssa-uninit.c: Include params.h.
(compute_control_dep_chain): Add num_calls argument, return false
if it exceed PARAM_UNINIT_CONTROL_DEP_ATTEMPTS param, pass
num_calls to recursive call.
(find_predicates): Change dep_chain into normal array,
cur_chain into auto_vec<edge, MAX_CHAIN_LEN + 1>, add num_calls
variable and adjust compute_control_dep_chain caller.
(find_def_preds): Likewise.
2014-02-21 Thomas Schwinge <thomas@codesourcery.com>
* gimple-pretty-print.c (dump_gimple_omp_for) [flags & TDF_RAW]
......
gcc/params.def
......@@ -1078,6 +1078,12 @@ DEFPARAM (PARAM_ASAN_USE_AFTER_RETURN,
"asan-use-after-return",
"Enable asan builtin functions protection",
1, 0, 1)
DEFPARAM (PARAM_UNINIT_CONTROL_DEP_ATTEMPTS,
"uninit-control-dep-attempts",
"Maximum number of nested calls to search for control dependencies "
"during uninitialized variable analysis",
1000, 1, 0)
/*
Local variables:
......
gcc/tree-ssa-uninit.c
......@@ -44,6 +44,7 @@ along with GCC; see the file COPYING3. If not see
#include "hashtab.h"
#include "tree-pass.h"
#include "diagnostic-core.h"
#include "params.h"
/* This implements the pass that does predicate aware warning on uses of
possibly uninitialized variables. The pass first collects the set of
......@@ -390,8 +391,8 @@ find_control_equiv_block (basic_block bb)
/* Computes the control dependence chains (paths of edges)
for DEP_BB up to the dominating basic block BB (the head node of a
chain should be dominated by it). CD_CHAINS is pointer to a
dynamic array holding the result chains. CUR_CD_CHAIN is the current
chain should be dominated by it). CD_CHAINS is pointer to an
array holding the result chains. CUR_CD_CHAIN is the current
chain being computed. *NUM_CHAINS is total number of chains. The
function returns true if the information is successfully computed,
return false if there is no control dependence or not computed. */
......@@ -400,7 +401,8 @@ static bool
compute_control_dep_chain (basic_block bb, basic_block dep_bb,
vec<edge> *cd_chains,
size_t *num_chains,
vec<edge> *cur_cd_chain)
vec<edge> *cur_cd_chain,
int *num_calls)
{
edge_iterator ei;
edge e;
......@@ -411,6 +413,10 @@ compute_control_dep_chain (basic_block bb, basic_block dep_bb,
if (EDGE_COUNT (bb->succs) < 2)
return false;
if (*num_calls > PARAM_VALUE (PARAM_UNINIT_CONTROL_DEP_ATTEMPTS))
return false;
++*num_calls;
/* Could use a set instead. */
cur_chain_len = cur_cd_chain->length ();
if (cur_chain_len > MAX_CHAIN_LEN)
......@@ -450,7 +456,7 @@ compute_control_dep_chain (basic_block bb, basic_block dep_bb,
/* Now check if DEP_BB is indirectly control dependent on BB. */
if (compute_control_dep_chain (cd_bb, dep_bb, cd_chains,
num_chains, cur_cd_chain))
num_chains, cur_cd_chain, num_calls))
{
found_cd_chain = true;
break;
......@@ -595,14 +601,12 @@ find_predicates (pred_chain_union *preds,
basic_block use_bb)
{
size_t num_chains = 0, i;
vec<edge> *dep_chains = 0;
vec<edge> cur_chain = vNULL;
int num_calls = 0;
vec<edge> dep_chains[MAX_NUM_CHAINS];
auto_vec<edge, MAX_CHAIN_LEN + 1> cur_chain;
bool has_valid_pred = false;
basic_block cd_root = 0;
typedef vec<edge> vec_edge_heap;
dep_chains = XCNEWVEC (vec_edge_heap, MAX_NUM_CHAINS);
/* First find the closest bb that is control equivalent to PHI_BB
that also dominates USE_BB. */
cd_root = phi_bb;
......@@ -615,19 +619,13 @@ find_predicates (pred_chain_union *preds,
break;
}
compute_control_dep_chain (cd_root, use_bb,
dep_chains, &num_chains,
&cur_chain);
compute_control_dep_chain (cd_root, use_bb, dep_chains, &num_chains,
&cur_chain, &num_calls);
has_valid_pred
= convert_control_dep_chain_into_preds (dep_chains,
num_chains,
preds);
/* Free individual chain */
cur_chain.release ();
= convert_control_dep_chain_into_preds (dep_chains, num_chains, preds);
for (i = 0; i < num_chains; i++)
dep_chains[i].release ();
free (dep_chains);
return has_valid_pred;
}
......@@ -694,16 +692,13 @@ static bool
find_def_preds (pred_chain_union *preds, gimple phi)
{
size_t num_chains = 0, i, n;
vec<edge> *dep_chains = 0;
vec<edge> cur_chain = vNULL;
vec<edge> dep_chains[MAX_NUM_CHAINS];
auto_vec<edge, MAX_CHAIN_LEN + 1> cur_chain;
vec<edge> def_edges = vNULL;
bool has_valid_pred = false;
basic_block phi_bb, cd_root = 0;
pointer_set_t *visited_phis;
typedef vec<edge> vec_edge_heap;
dep_chains = XCNEWVEC (vec_edge_heap, MAX_NUM_CHAINS);
phi_bb = gimple_bb (phi);
/* First find the closest dominating bb to be
the control dependence root */
......@@ -722,37 +717,29 @@ find_def_preds (pred_chain_union *preds, gimple phi)
for (i = 0; i < n; i++)
{
size_t prev_nc, j;
int num_calls = 0;
edge opnd_edge;
opnd_edge = def_edges[i];
prev_nc = num_chains;
compute_control_dep_chain (cd_root, opnd_edge->src,
dep_chains, &num_chains,
&cur_chain);
/* Free individual chain */
cur_chain.release ();
compute_control_dep_chain (cd_root, opnd_edge->src, dep_chains,
&num_chains, &cur_chain, &num_calls);
/* Now update the newly added chains with
the phi operand edge: */
if (EDGE_COUNT (opnd_edge->src->succs) > 1)
{
if (prev_nc == num_chains
&& num_chains < MAX_NUM_CHAINS)
num_chains++;
if (prev_nc == num_chains && num_chains < MAX_NUM_CHAINS)
dep_chains[num_chains++] = vNULL;
for (j = prev_nc; j < num_chains; j++)
{
dep_chains[j].safe_push (opnd_edge);
}
}
}
has_valid_pred
= convert_control_dep_chain_into_preds (dep_chains,
num_chains,
preds);
= convert_control_dep_chain_into_preds (dep_chains, num_chains, preds);
for (i = 0; i < num_chains; i++)
dep_chains[i].release ();
free (dep_chains);
return has_valid_pred;
}
......
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