diff options
Diffstat (limited to 'gcc/tree-scalar-evolution.c')
| -rw-r--r-- | gcc/tree-scalar-evolution.c | 56 |
1 files changed, 53 insertions, 3 deletions
diff --git a/gcc/tree-scalar-evolution.c b/gcc/tree-scalar-evolution.c index e749047..235edcd 100644 --- a/gcc/tree-scalar-evolution.c +++ b/gcc/tree-scalar-evolution.c @@ -1928,6 +1928,32 @@ set_instantiated_value (htab_t cache, tree version, tree val) info->chrec = val; } +/* Return the closed_loop_phi node for VAR. If there is none, return + NULL_TREE. */ + +static tree +loop_closed_phi_def (tree var) +{ + struct loop *loop; + edge exit; + tree phi; + + if (var == NULL_TREE + || TREE_CODE (var) != SSA_NAME) + return NULL_TREE; + + loop = loop_containing_stmt (SSA_NAME_DEF_STMT (var)); + exit = loop->single_exit; + if (!exit) + return NULL_TREE; + + for (phi = phi_nodes (exit->dest); phi; phi = PHI_CHAIN (phi)) + if (PHI_ARG_DEF_FROM_EDGE (phi, exit) == var) + return PHI_RESULT (phi); + + return NULL_TREE; +} + /* Analyze all the parameters of the chrec that were left under a symbolic form, with respect to LOOP. CHREC is the chrec to instantiate. If ALLOW_SUPERLOOP_CHRECS is true, replacing loop invariants with @@ -1993,9 +2019,26 @@ instantiate_parameters_1 (struct loop *loop, tree chrec, result again. */ bitmap_set_bit (already_instantiated, SSA_NAME_VERSION (chrec)); res = analyze_scalar_evolution (def_loop, chrec); - if (res != chrec_dont_know) + + /* Don't instantiate loop-closed-ssa phi nodes. */ + if (TREE_CODE (res) == SSA_NAME + && (loop_containing_stmt (SSA_NAME_DEF_STMT (res)) == NULL + || (loop_containing_stmt (SSA_NAME_DEF_STMT (res))->depth + > def_loop->depth))) + { + if (res == chrec) + res = loop_closed_phi_def (chrec); + else + res = chrec; + + if (res == NULL_TREE) + res = chrec_dont_know; + } + + else if (res != chrec_dont_know) res = instantiate_parameters_1 (loop, res, allow_superloop_chrecs, cache); + bitmap_clear_bit (already_instantiated, SSA_NAME_VERSION (chrec)); /* Store the correct value to the cache. */ @@ -2652,7 +2695,8 @@ scev_const_prop (void) continue; /* Replace the uses of the name. */ - replace_uses_by (name, ev); + if (name != ev) + replace_uses_by (name, ev); if (!ssa_names_to_remove) ssa_names_to_remove = BITMAP_ALLOC (NULL); @@ -2712,7 +2756,13 @@ scev_const_prop (void) def = analyze_scalar_evolution_in_loop (ex_loop, ex_loop, def); if (!tree_does_not_contain_chrecs (def) - || chrec_contains_symbols_defined_in_loop (def, loop->num)) + || chrec_contains_symbols_defined_in_loop (def, loop->num) + || def == PHI_RESULT (phi) + || (TREE_CODE (def) == SSA_NAME + && loop_containing_stmt (SSA_NAME_DEF_STMT (def)) + && loop_containing_stmt (phi) + && loop_containing_stmt (SSA_NAME_DEF_STMT (def)) + == loop_containing_stmt (phi))) continue; /* If computing the expression is expensive, let it remain in |