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-rw-r--r--gcc/cfgloop.h2
-rw-r--r--gcc/loop-init.c9
-rw-r--r--gcc/testsuite/gcc.dg/tree-ssa/loopclosedphi.c21
-rw-r--r--gcc/tree-cfgcleanup.h1
-rw-r--r--gcc/tree-ssa-loop.c2
-rw-r--r--gcc/tree-ssa-propagate.c72
6 files changed, 104 insertions, 3 deletions
diff --git a/gcc/cfgloop.h b/gcc/cfgloop.h
index d14689d..438b1f7 100644
--- a/gcc/cfgloop.h
+++ b/gcc/cfgloop.h
@@ -824,7 +824,7 @@ extern void init_set_costs (void);
/* Loop optimizer initialization. */
extern void loop_optimizer_init (unsigned);
-extern void loop_optimizer_finalize (function *);
+extern void loop_optimizer_finalize (function *, bool = false);
inline void
loop_optimizer_finalize ()
{
diff --git a/gcc/loop-init.c b/gcc/loop-init.c
index 401e528..ac87daf 100644
--- a/gcc/loop-init.c
+++ b/gcc/loop-init.c
@@ -33,6 +33,7 @@ along with GCC; see the file COPYING3. If not see
#include "tree-ssa-loop-niter.h"
#include "loop-unroll.h"
#include "tree-scalar-evolution.h"
+#include "tree-cfgcleanup.h"
/* Apply FLAGS to the loop state. */
@@ -133,13 +134,19 @@ loop_optimizer_init (unsigned flags)
/* Finalize loop structures. */
void
-loop_optimizer_finalize (struct function *fn)
+loop_optimizer_finalize (struct function *fn, bool clean_loop_closed_phi)
{
class loop *loop;
basic_block bb;
timevar_push (TV_LOOP_FINI);
+ if (clean_loop_closed_phi && loops_state_satisfies_p (fn, LOOP_CLOSED_SSA))
+ {
+ clean_up_loop_closed_phi (fn);
+ loops_state_clear (fn, LOOP_CLOSED_SSA);
+ }
+
if (loops_state_satisfies_p (fn, LOOPS_HAVE_RECORDED_EXITS))
release_recorded_exits (fn);
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/loopclosedphi.c b/gcc/testsuite/gcc.dg/tree-ssa/loopclosedphi.c
new file mode 100644
index 0000000..d71b757
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/tree-ssa/loopclosedphi.c
@@ -0,0 +1,21 @@
+/* { dg-do compile } */
+/* { dg-options "-O3 -fno-tree-ch -w -fdump-tree-loopdone-details" } */
+
+void
+t6 (int qz, int wh)
+{
+ int jl = wh;
+
+ while (1.0 * qz / wh < 1)
+ {
+ qz = wh * (wh + 2);
+
+ while (wh < 1)
+ jl = 0;
+ }
+
+ while (qz < 1)
+ qz = jl * wh;
+}
+
+/* { dg-final { scan-tree-dump-times "Replacing" 2 "loopdone"} } */
diff --git a/gcc/tree-cfgcleanup.h b/gcc/tree-cfgcleanup.h
index 6ff6726..9e368d6 100644
--- a/gcc/tree-cfgcleanup.h
+++ b/gcc/tree-cfgcleanup.h
@@ -26,5 +26,6 @@ extern bool cleanup_tree_cfg (unsigned = 0);
extern bool fixup_noreturn_call (gimple *stmt);
extern bool delete_unreachable_blocks_update_callgraph (cgraph_node *dst_node,
bool update_clones);
+extern unsigned clean_up_loop_closed_phi (function *);
#endif /* GCC_TREE_CFGCLEANUP_H */
diff --git a/gcc/tree-ssa-loop.c b/gcc/tree-ssa-loop.c
index 5e8365d..339a0c5 100644
--- a/gcc/tree-ssa-loop.c
+++ b/gcc/tree-ssa-loop.c
@@ -529,7 +529,7 @@ tree_ssa_loop_done (void)
{
free_numbers_of_iterations_estimates (cfun);
scev_finalize ();
- loop_optimizer_finalize ();
+ loop_optimizer_finalize (cfun, true);
return 0;
}
diff --git a/gcc/tree-ssa-propagate.c b/gcc/tree-ssa-propagate.c
index 87dbf55..354057b 100644
--- a/gcc/tree-ssa-propagate.c
+++ b/gcc/tree-ssa-propagate.c
@@ -1549,3 +1549,75 @@ propagate_tree_value_into_stmt (gimple_stmt_iterator *gsi, tree val)
else
gcc_unreachable ();
}
+
+/* Check exits of each loop in FUN, walk over loop closed PHIs in
+ each exit basic block and propagate degenerate PHIs. */
+
+unsigned
+clean_up_loop_closed_phi (function *fun)
+{
+ unsigned i;
+ edge e;
+ gphi *phi;
+ tree rhs;
+ tree lhs;
+ gphi_iterator gsi;
+ struct loop *loop;
+
+ /* Avoid possibly quadratic work when scanning for loop exits across
+ all loops of a nest. */
+ if (!loops_state_satisfies_p (LOOPS_HAVE_RECORDED_EXITS))
+ return 0;
+
+ /* Walk over loop in function. */
+ FOR_EACH_LOOP_FN (fun, loop, 0)
+ {
+ /* Check each exit edege of loop. */
+ auto_vec<edge> exits = get_loop_exit_edges (loop);
+ FOR_EACH_VEC_ELT (exits, i, e)
+ if (single_pred_p (e->dest))
+ /* Walk over loop-closed PHIs. */
+ for (gsi = gsi_start_phis (e->dest); !gsi_end_p (gsi);)
+ {
+ phi = gsi.phi ();
+ rhs = gimple_phi_arg_def (phi, 0);
+ lhs = gimple_phi_result (phi);
+
+ if (rhs && may_propagate_copy (lhs, rhs))
+ {
+ /* Dump details. */
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ {
+ fprintf (dump_file, " Replacing '");
+ print_generic_expr (dump_file, lhs, dump_flags);
+ fprintf (dump_file, "' with '");
+ print_generic_expr (dump_file, rhs, dump_flags);
+ fprintf (dump_file, "'\n");
+ }
+
+ use_operand_p use_p;
+ imm_use_iterator iter;
+ gimple *use_stmt;
+ FOR_EACH_IMM_USE_STMT (use_stmt, iter, lhs)
+ {
+ FOR_EACH_IMM_USE_ON_STMT (use_p, iter)
+ replace_exp (use_p, rhs);
+ update_stmt (use_stmt);
+
+ /* Update the invariant flag for ADDR_EXPR if replacing
+ a variable index with a constant. */
+ if (gimple_assign_single_p (use_stmt)
+ && TREE_CODE (gimple_assign_rhs1 (use_stmt))
+ == ADDR_EXPR)
+ recompute_tree_invariant_for_addr_expr (
+ gimple_assign_rhs1 (use_stmt));
+ }
+ remove_phi_node (&gsi, true);
+ }
+ else
+ gsi_next (&gsi);
+ }
+ }
+
+ return 0;
+}