diff options
| -rw-r--r-- | gcc/value-relation.cc | 57 | ||||
| -rw-r--r-- | gcc/value-relation.h | 3 |
2 files changed, 59 insertions, 1 deletions
diff --git a/gcc/value-relation.cc b/gcc/value-relation.cc index d370f93..ac5f3f9 100644 --- a/gcc/value-relation.cc +++ b/gcc/value-relation.cc @@ -407,6 +407,24 @@ equiv_oracle::register_equiv (basic_block bb, equiv_chain *equiv_1, return b; } +// Create an equivalency set containing only SSA in its definition block. +// This is done the first time SSA is registered in an equivalency and blocks +// any DOM searches past the definition. + +void +equiv_oracle::register_initial_def (tree ssa) +{ + if (SSA_NAME_IS_DEFAULT_DEF (ssa)) + return; + basic_block bb = gimple_bb (SSA_NAME_DEF_STMT (ssa)); + gcc_checking_assert (bb && !find_equiv_dom (ssa, bb)); + + unsigned v = SSA_NAME_VERSION (ssa); + bitmap_set_bit (m_equiv_set, v); + bitmap equiv_set = BITMAP_ALLOC (&m_bitmaps); + bitmap_set_bit (equiv_set, v); + add_equiv_to_block (bb, equiv_set); +} // Register an equivalence between SSA1 and SSA2 in block BB. // The equivalence oracle maintains a vector of equivalencies indexed by basic @@ -425,6 +443,14 @@ equiv_oracle::register_relation (basic_block bb, relation_kind k, tree ssa1, unsigned v1 = SSA_NAME_VERSION (ssa1); unsigned v2 = SSA_NAME_VERSION (ssa2); + + // If this is the first time an ssa_name has an equivalency registered + // create a self-equivalency record in the def block. + if (!bitmap_bit_p (m_equiv_set, v1)) + register_initial_def (ssa1); + if (!bitmap_bit_p (m_equiv_set, v2)) + register_initial_def (ssa2); + equiv_chain *equiv_1 = find_equiv_dom (ssa1, bb); equiv_chain *equiv_2 = find_equiv_dom (ssa2, bb); @@ -456,6 +482,15 @@ equiv_oracle::register_relation (basic_block bb, relation_kind k, tree ssa1, if (!equiv_set) return; + add_equiv_to_block (bb, equiv_set); +} + +// Add an equivalency record in block BB containing bitmap EQUIV_SET. +// Note the internal caller is responible for allocating EQUIV_SET properly. + +void +equiv_oracle::add_equiv_to_block (basic_block bb, bitmap equiv_set) +{ equiv_chain *ptr; // Check if this is the first time a block has an equivalence added. @@ -786,6 +821,28 @@ relation_oracle::register_stmt (gimple *stmt, relation_kind k, tree op1, print_gimple_stmt (dump_file, stmt, 0, TDF_SLIM); } + // If an equivalence is being added between a PHI and one of its arguments + // make sure that that argument is not defined in the same block. + // This can happen along back edges and the equivalence will not be + // applicable as it would require a use before def. + if (k == EQ_EXPR && is_a<gphi *> (stmt)) + { + tree phi_def = gimple_phi_result (stmt); + gcc_checking_assert (phi_def == op1 || phi_def == op2); + tree arg = op2; + if (phi_def == op2) + arg = op1; + if (gimple_bb (stmt) == gimple_bb (SSA_NAME_DEF_STMT (arg))) + { + if (dump_file && (dump_flags & TDF_DETAILS)) + { + fprintf (dump_file, " Not registered due to "); + print_generic_expr (dump_file, arg, TDF_SLIM); + fprintf (dump_file, " being defined in the same block.\n"); + } + return; + } + } register_relation (gimple_bb (stmt), k, op1, op2); } diff --git a/gcc/value-relation.h b/gcc/value-relation.h index 574fdc9..53cefbf 100644 --- a/gcc/value-relation.h +++ b/gcc/value-relation.h @@ -146,7 +146,8 @@ private: bitmap register_equiv (basic_block bb, unsigned v, equiv_chain *equiv_1); bitmap register_equiv (basic_block bb, equiv_chain *equiv_1, equiv_chain *equiv_2); - + void register_initial_def (tree ssa); + void add_equiv_to_block (basic_block bb, bitmap equiv); }; // Summary block header for relations. |