GCC 4.2.0 release.

1 files changed, 511 insertions, 0 deletions

diff --git a/contrib/gcc/tree-gimple.c b/contrib/gcc/tree-gimple.c
new file mode 100644
index 0000000..740f673
--- /dev/null
+++ b/contrib/gcc/tree-gimple.c
@@ -0,0 +1,511 @@
+/* Functions to analyze and validate GIMPLE trees.
+   Copyright (C) 2002, 2003, 2004, 2005 Free Software Foundation, Inc.
+   Contributed by Diego Novillo <dnovillo@redhat.com>
+   Rewritten by Jason Merrill <jason@redhat.com>
+
+This file is part of GCC.
+
+GCC is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 2, or (at your option)
+any later version.
+
+GCC is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with GCC; see the file COPYING.  If not, write to
+the Free Software Foundation, 51 Franklin Street, Fifth Floor,
+Boston, MA 02110-1301, USA.  */
+
+#include "config.h"
+#include "system.h"
+#include "coretypes.h"
+#include "ggc.h"
+#include "tm.h"
+#include "tree.h"
+#include "tree-gimple.h"
+#include "tree-flow.h"
+#include "output.h"
+#include "rtl.h"
+#include "expr.h"
+#include "bitmap.h"
+
+/* For the definitive definition of GIMPLE, see doc/tree-ssa.texi.  */
+
+/* Validation of GIMPLE expressions.  */
+
+/* Return true if T is a GIMPLE RHS for an assignment to a temporary.  */
+
+bool
+is_gimple_formal_tmp_rhs (tree t)
+{
+  enum tree_code code = TREE_CODE (t);
+
+  switch (TREE_CODE_CLASS (code))
+    {
+    case tcc_unary:
+    case tcc_binary:
+    case tcc_comparison:
+      return true;
+
+    default:
+      break;
+    }
+
+  switch (code)
+    {
+    case TRUTH_NOT_EXPR:
+    case TRUTH_AND_EXPR:
+    case TRUTH_OR_EXPR:
+    case TRUTH_XOR_EXPR:
+    case ADDR_EXPR:
+    case CALL_EXPR:
+    case CONSTRUCTOR:
+    case COMPLEX_EXPR:
+    case INTEGER_CST:
+    case REAL_CST:
+    case STRING_CST:
+    case COMPLEX_CST:
+    case VECTOR_CST:
+    case OBJ_TYPE_REF:
+    case ASSERT_EXPR:
+      return true;
+
+    default:
+      break;
+    }
+
+  return is_gimple_lvalue (t) || is_gimple_val (t);
+}
+
+/* Returns true iff T is a valid RHS for an assignment to a renamed
+   user -- or front-end generated artificial -- variable.  */
+
+bool
+is_gimple_reg_rhs (tree t)
+{
+  /* If the RHS of the MODIFY_EXPR may throw or make a nonlocal goto
+     and the LHS is a user variable, then we need to introduce a formal
+     temporary.  This way the optimizers can determine that the user
+     variable is only modified if evaluation of the RHS does not throw.
+
+     Don't force a temp of a non-renamable type; the copy could be
+     arbitrarily expensive.  Instead we will generate a V_MAY_DEF for
+     the assignment.  */
+
+  if (is_gimple_reg_type (TREE_TYPE (t))
+      && ((TREE_CODE (t) == CALL_EXPR && TREE_SIDE_EFFECTS (t))
+	  || tree_could_throw_p (t)))
+    return false;
+
+  return is_gimple_formal_tmp_rhs (t);
+}
+
+/* Returns true iff T is a valid RHS for an assignment to an un-renamed
+   LHS, or for a call argument.  */
+
+bool
+is_gimple_mem_rhs (tree t)
+{
+  /* If we're dealing with a renamable type, either source or dest must be
+     a renamed variable.  Also force a temporary if the type doesn't need
+     to be stored in memory, since it's cheap and prevents erroneous
+     tailcalls (PR 17526).  */
+  if (is_gimple_reg_type (TREE_TYPE (t))
+      || (TYPE_MODE (TREE_TYPE (t)) != BLKmode
+	  && (TREE_CODE (t) != CALL_EXPR
+              || ! aggregate_value_p (t, t))))
+    return is_gimple_val (t);
+  else
+    return is_gimple_formal_tmp_rhs (t);
+}
+
+/* Returns the appropriate RHS predicate for this LHS.  */
+
+gimple_predicate
+rhs_predicate_for (tree lhs)
+{
+  if (is_gimple_formal_tmp_var (lhs))
+    return is_gimple_formal_tmp_rhs;
+  else if (is_gimple_reg (lhs))
+    return is_gimple_reg_rhs;
+  else
+    return is_gimple_mem_rhs;
+}
+
+/*  Return true if T is a valid LHS for a GIMPLE assignment expression.  */
+
+bool
+is_gimple_lvalue (tree t)
+{
+  return (is_gimple_addressable (t)
+	  || TREE_CODE (t) == WITH_SIZE_EXPR
+	  /* These are complex lvalues, but don't have addresses, so they
+	     go here.  */
+	  || TREE_CODE (t) == BIT_FIELD_REF);
+}
+
+/*  Return true if T is a GIMPLE condition.  */
+
+bool
+is_gimple_condexpr (tree t)
+{
+  return (is_gimple_val (t) || COMPARISON_CLASS_P (t));
+}
+
+/*  Return true if T is something whose address can be taken.  */
+
+bool
+is_gimple_addressable (tree t)
+{
+  return (is_gimple_id (t) || handled_component_p (t)
+	  || INDIRECT_REF_P (t));
+}
+
+/* Return true if T is function invariant.  Or rather a restricted
+   form of function invariant.  */
+
+bool
+is_gimple_min_invariant (tree t)
+{
+  switch (TREE_CODE (t))
+    {
+    case ADDR_EXPR:
+      return TREE_INVARIANT (t);
+
+    case INTEGER_CST:
+    case REAL_CST:
+    case STRING_CST:
+    case COMPLEX_CST:
+    case VECTOR_CST:
+      return true;
+
+    default:
+      return false;
+    }
+}
+
+/* Return true if T looks like a valid GIMPLE statement.  */
+
+bool
+is_gimple_stmt (tree t)
+{
+  enum tree_code code = TREE_CODE (t);
+
+  switch (code)
+    {
+    case NOP_EXPR:
+      /* The only valid NOP_EXPR is the empty statement.  */
+      return IS_EMPTY_STMT (t);
+
+    case BIND_EXPR:
+    case COND_EXPR:
+      /* These are only valid if they're void.  */
+      return TREE_TYPE (t) == NULL || VOID_TYPE_P (TREE_TYPE (t));
+
+    case SWITCH_EXPR:
+    case GOTO_EXPR:
+    case RETURN_EXPR:
+    case LABEL_EXPR:
+    case CASE_LABEL_EXPR:
+    case TRY_CATCH_EXPR:
+    case TRY_FINALLY_EXPR:
+    case EH_FILTER_EXPR:
+    case CATCH_EXPR:
+    case ASM_EXPR:
+    case RESX_EXPR:
+    case PHI_NODE:
+    case STATEMENT_LIST:
+    case OMP_PARALLEL:
+    case OMP_FOR:
+    case OMP_SECTIONS:
+    case OMP_SECTION:
+    case OMP_SINGLE:
+    case OMP_MASTER:
+    case OMP_ORDERED:
+    case OMP_CRITICAL:
+    case OMP_RETURN:
+    case OMP_CONTINUE:
+      /* These are always void.  */
+      return true;
+
+    case CALL_EXPR:
+    case MODIFY_EXPR:
+      /* These are valid regardless of their type.  */
+      return true;
+
+    default:
+      return false;
+    }
+}
+
+/* Return true if T is a variable.  */
+
+bool
+is_gimple_variable (tree t)
+{
+  return (TREE_CODE (t) == VAR_DECL
+	  || TREE_CODE (t) == PARM_DECL
+	  || TREE_CODE (t) == RESULT_DECL
+	  || TREE_CODE (t) == SSA_NAME);
+}
+
+/*  Return true if T is a GIMPLE identifier (something with an address).  */
+
+bool
+is_gimple_id (tree t)
+{
+  return (is_gimple_variable (t)
+	  || TREE_CODE (t) == FUNCTION_DECL
+	  || TREE_CODE (t) == LABEL_DECL
+	  || TREE_CODE (t) == CONST_DECL
+	  /* Allow string constants, since they are addressable.  */
+	  || TREE_CODE (t) == STRING_CST);
+}
+
+/* Return true if TYPE is a suitable type for a scalar register variable.  */
+
+bool
+is_gimple_reg_type (tree type)
+{
+  return !AGGREGATE_TYPE_P (type);
+}
+
+/* Return true if T is a non-aggregate register variable.  */
+
+bool
+is_gimple_reg (tree t)
+{
+  if (TREE_CODE (t) == SSA_NAME)
+    t = SSA_NAME_VAR (t);
+
+  if (MTAG_P (t))
+    return false;
+
+  if (!is_gimple_variable (t))
+    return false;
+
+  if (!is_gimple_reg_type (TREE_TYPE (t)))
+    return false;
+
+  /* A volatile decl is not acceptable because we can't reuse it as
+     needed.  We need to copy it into a temp first.  */
+  if (TREE_THIS_VOLATILE (t))
+    return false;
+
+  /* We define "registers" as things that can be renamed as needed,
+     which with our infrastructure does not apply to memory.  */
+  if (needs_to_live_in_memory (t))
+    return false;
+
+  /* Hard register variables are an interesting case.  For those that
+     are call-clobbered, we don't know where all the calls are, since
+     we don't (want to) take into account which operations will turn
+     into libcalls at the rtl level.  For those that are call-saved,
+     we don't currently model the fact that calls may in fact change
+     global hard registers, nor do we examine ASM_CLOBBERS at the tree
+     level, and so miss variable changes that might imply.  All around,
+     it seems safest to not do too much optimization with these at the
+     tree level at all.  We'll have to rely on the rtl optimizers to
+     clean this up, as there we've got all the appropriate bits exposed.  */
+  if (TREE_CODE (t) == VAR_DECL && DECL_HARD_REGISTER (t))
+    return false;
+
+  /* Complex values must have been put into ssa form.  That is, no 
+     assignments to the individual components.  */
+  if (TREE_CODE (TREE_TYPE (t)) == COMPLEX_TYPE)
+    return DECL_COMPLEX_GIMPLE_REG_P (t);
+
+  return true;
+}
+
+
+/* Returns true if T is a GIMPLE formal temporary variable.  */
+
+bool
+is_gimple_formal_tmp_var (tree t)
+{
+  if (TREE_CODE (t) == SSA_NAME)
+    return true;
+
+  return TREE_CODE (t) == VAR_DECL && DECL_GIMPLE_FORMAL_TEMP_P (t);
+}
+
+/* Returns true if T is a GIMPLE formal temporary register variable.  */
+
+bool
+is_gimple_formal_tmp_reg (tree t)
+{
+  /* The intent of this is to get hold of a value that won't change.
+     An SSA_NAME qualifies no matter if its of a user variable or not.  */
+  if (TREE_CODE (t) == SSA_NAME)
+    return true;
+
+  /* We don't know the lifetime characteristics of user variables.  */
+  if (!is_gimple_formal_tmp_var (t))
+    return false;
+
+  /* Finally, it must be capable of being placed in a register.  */
+  return is_gimple_reg (t);
+}
+
+/* Return true if T is a GIMPLE variable whose address is not needed.  */
+
+bool
+is_gimple_non_addressable (tree t)
+{
+  if (TREE_CODE (t) == SSA_NAME)
+    t = SSA_NAME_VAR (t);
+
+  return (is_gimple_variable (t) && ! needs_to_live_in_memory (t));
+}
+
+/* Return true if T is a GIMPLE rvalue, i.e. an identifier or a constant.  */
+
+bool
+is_gimple_val (tree t)
+{
+  /* Make loads from volatiles and memory vars explicit.  */
+  if (is_gimple_variable (t)
+      && is_gimple_reg_type (TREE_TYPE (t))
+      && !is_gimple_reg (t))
+    return false;
+
+  /* FIXME make these decls.  That can happen only when we expose the
+     entire landing-pad construct at the tree level.  */
+  if (TREE_CODE (t) == EXC_PTR_EXPR || TREE_CODE (t) == FILTER_EXPR)
+    return 1;
+
+  return (is_gimple_variable (t) || is_gimple_min_invariant (t));
+}
+
+/* Similarly, but accept hard registers as inputs to asm statements.  */
+
+bool
+is_gimple_asm_val (tree t)
+{
+  if (TREE_CODE (t) == VAR_DECL && DECL_HARD_REGISTER (t))
+    return true;
+
+  return is_gimple_val (t);
+}
+
+/* Return true if T is a GIMPLE minimal lvalue.  */
+
+bool
+is_gimple_min_lval (tree t)
+{
+  return (is_gimple_id (t)
+	  || TREE_CODE (t) == INDIRECT_REF);
+}
+
+/* Return true if T is a typecast operation.  */
+
+bool
+is_gimple_cast (tree t)
+{
+  return (TREE_CODE (t) == NOP_EXPR
+	  || TREE_CODE (t) == CONVERT_EXPR
+          || TREE_CODE (t) == FIX_TRUNC_EXPR
+          || TREE_CODE (t) == FIX_CEIL_EXPR
+          || TREE_CODE (t) == FIX_FLOOR_EXPR
+          || TREE_CODE (t) == FIX_ROUND_EXPR);
+}
+
+/* Return true if T is a valid op0 of a CALL_EXPR.  */
+
+bool
+is_gimple_call_addr (tree t)
+{
+  return (TREE_CODE (t) == OBJ_TYPE_REF
+	  || is_gimple_val (t));
+}
+
+/* If T makes a function call, return the corresponding CALL_EXPR operand.
+   Otherwise, return NULL_TREE.  */
+
+tree
+get_call_expr_in (tree t)
+{
+  if (TREE_CODE (t) == MODIFY_EXPR)
+    t = TREE_OPERAND (t, 1);
+  if (TREE_CODE (t) == WITH_SIZE_EXPR)
+    t = TREE_OPERAND (t, 0);
+  if (TREE_CODE (t) == CALL_EXPR)
+    return t;
+  return NULL_TREE;
+}
+
+/* Given a memory reference expression T, return its base address.
+   The base address of a memory reference expression is the main
+   object being referenced.  For instance, the base address for
+   'array[i].fld[j]' is 'array'.  You can think of this as stripping
+   away the offset part from a memory address.
+
+   This function calls handled_component_p to strip away all the inner
+   parts of the memory reference until it reaches the base object.  */
+
+tree
+get_base_address (tree t)
+{
+  while (handled_component_p (t))
+    t = TREE_OPERAND (t, 0);
+  
+  if (SSA_VAR_P (t)
+      || TREE_CODE (t) == STRING_CST
+      || TREE_CODE (t) == CONSTRUCTOR
+      || INDIRECT_REF_P (t))
+    return t;
+  else
+    return NULL_TREE;
+}
+
+void
+recalculate_side_effects (tree t)
+{
+  enum tree_code code = TREE_CODE (t);
+  int len = TREE_CODE_LENGTH (code);
+  int i;
+
+  switch (TREE_CODE_CLASS (code))
+    {
+    case tcc_expression:
+      switch (code)
+	{
+	case INIT_EXPR:
+	case MODIFY_EXPR:
+	case VA_ARG_EXPR:
+	case PREDECREMENT_EXPR:
+	case PREINCREMENT_EXPR:
+	case POSTDECREMENT_EXPR:
+	case POSTINCREMENT_EXPR:
+	  /* All of these have side-effects, no matter what their
+	     operands are.  */
+	  return;
+
+	default:
+	  break;
+	}
+      /* Fall through.  */
+
+    case tcc_comparison:  /* a comparison expression */
+    case tcc_unary:       /* a unary arithmetic expression */
+    case tcc_binary:      /* a binary arithmetic expression */
+    case tcc_reference:   /* a reference */
+      TREE_SIDE_EFFECTS (t) = TREE_THIS_VOLATILE (t);
+      for (i = 0; i < len; ++i)
+	{
+	  tree op = TREE_OPERAND (t, i);
+	  if (op && TREE_SIDE_EFFECTS (op))
+	    TREE_SIDE_EFFECTS (t) = 1;
+	}
+      break;
+
+    default:
+      /* Can never be used with non-expressions.  */
+      gcc_unreachable ();
+   }
+}