diff options
Diffstat (limited to 'gcc/tree-into-ssa.c')
| -rw-r--r-- | gcc/tree-into-ssa.c | 98 |
1 files changed, 90 insertions, 8 deletions
diff --git a/gcc/tree-into-ssa.c b/gcc/tree-into-ssa.c index f138e5b..0db9085 100644 --- a/gcc/tree-into-ssa.c +++ b/gcc/tree-into-ssa.c @@ -1,5 +1,5 @@ /* Rewrite a program in Normal form into SSA. - Copyright (C) 2001, 2002, 2003, 2004, 2005, 2007, 2008, 2009, 2010 + Copyright (C) 2001, 2002, 2003, 2004, 2005, 2007, 2008, 2009, 2010, 2011 Free Software Foundation, Inc. Contributed by Diego Novillo <dnovillo@redhat.com> @@ -745,7 +745,17 @@ mark_def_sites (basic_block bb, gimple stmt, bitmap kills) set_rewrite_uses (stmt, false); if (is_gimple_debug (stmt)) - return; + { + FOR_EACH_SSA_USE_OPERAND (use_p, stmt, iter, SSA_OP_USE) + { + tree sym = USE_FROM_PTR (use_p); + gcc_assert (DECL_P (sym)); + set_rewrite_uses (stmt, true); + } + if (rewrite_uses_p (stmt)) + SET_BIT (interesting_blocks, bb->index); + return; + } /* If a variable is used before being set, then the variable is live across a block boundary, so mark it live-on-entry to BB. */ @@ -1279,6 +1289,73 @@ get_reaching_def (tree var) } +/* Helper function for rewrite_stmt. Rewrite uses in a debug stmt. */ + +static void +rewrite_debug_stmt_uses (gimple stmt) +{ + use_operand_p use_p; + ssa_op_iter iter; + bool update = false; + + FOR_EACH_SSA_USE_OPERAND (use_p, stmt, iter, SSA_OP_USE) + { + tree var = USE_FROM_PTR (use_p), def = NULL_TREE; + gcc_assert (DECL_P (var)); + if (var_ann (var) == NULL) + { + if (TREE_CODE (var) == PARM_DECL && single_succ_p (ENTRY_BLOCK_PTR)) + { + gimple_stmt_iterator gsi + = gsi_after_labels (single_succ (ENTRY_BLOCK_PTR)); + int lim; + /* Search a few source bind stmts at the start of first bb to + see if a DEBUG_EXPR_DECL can't be reused. */ + for (lim = 32; + !gsi_end_p (gsi) && lim > 0; + gsi_next (&gsi), lim--) + { + gimple gstmt = gsi_stmt (gsi); + if (!gimple_debug_source_bind_p (gstmt)) + break; + if (gimple_debug_source_bind_get_value (gstmt) == var) + { + def = gimple_debug_source_bind_get_var (gstmt); + if (TREE_CODE (def) == DEBUG_EXPR_DECL) + break; + else + def = NULL_TREE; + } + } + /* If not, add a new source bind stmt. */ + if (def == NULL_TREE) + { + gimple def_temp; + def = make_node (DEBUG_EXPR_DECL); + def_temp = gimple_build_debug_source_bind (def, var, NULL); + DECL_ARTIFICIAL (def) = 1; + TREE_TYPE (def) = TREE_TYPE (var); + DECL_MODE (def) = DECL_MODE (var); + gsi = gsi_after_labels (single_succ (ENTRY_BLOCK_PTR)); + gsi_insert_before (&gsi, def_temp, GSI_SAME_STMT); + } + update = true; + } + } + else + def = get_current_def (var); + if (def == NULL) + { + gimple_debug_bind_reset_value (stmt); + update_stmt (stmt); + return; + } + SET_USE (use_p, def); + } + if (update) + update_stmt (stmt); +} + /* SSA Rewriting Step 2. Rewrite every variable used in each statement in the block with its immediate reaching definitions. Update the current definition of a variable when a new real or virtual definition is found. */ @@ -1306,12 +1383,17 @@ rewrite_stmt (gimple_stmt_iterator si) /* Step 1. Rewrite USES in the statement. */ if (rewrite_uses_p (stmt)) - FOR_EACH_SSA_USE_OPERAND (use_p, stmt, iter, SSA_OP_USE) - { - tree var = USE_FROM_PTR (use_p); - gcc_assert (DECL_P (var)); - SET_USE (use_p, get_reaching_def (var)); - } + { + if (is_gimple_debug (stmt)) + rewrite_debug_stmt_uses (stmt); + else + FOR_EACH_SSA_USE_OPERAND (use_p, stmt, iter, SSA_OP_USE) + { + tree var = USE_FROM_PTR (use_p); + gcc_assert (DECL_P (var)); + SET_USE (use_p, get_reaching_def (var)); + } + } /* Step 2. Register the statement's DEF operands. */ if (register_defs_p (stmt)) |