| 123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154 | diff -Nur gcc-4.8.2.orig/gcc/tree-ssa-forwprop.c gcc-4.8.2/gcc/tree-ssa-forwprop.c--- gcc-4.8.2.orig/gcc/tree-ssa-forwprop.c	2013-02-25 16:31:31.000000000 +0100+++ gcc-4.8.2/gcc/tree-ssa-forwprop.c	2014-03-22 19:37:04.797991879 +0100@@ -688,6 +688,130 @@      recompute_tree_invariant_for_addr_expr (gimple_assign_rhs1 (stmt)); } + /* DEF_RHS contains the address of the 0th element in an array.	 +    USE_STMT uses type of DEF_RHS to compute the address of an	 +    arbitrary element within the array.  The (variable) byte offset	 +    of the element is contained in OFFSET.	 + 	 +    We walk back through the use-def chains of OFFSET to verify that	 +    it is indeed computing the offset of an element within the array	 +    and extract the index corresponding to the given byte offset.	 + 	 +    We then try to fold the entire address expression into a form	 +    &array[index].	 + 	 +    If we are successful, we replace the right hand side of USE_STMT	 +    with the new address computation.  */	 + 	 + static bool	 + forward_propagate_addr_into_variable_array_index (tree offset,	 +                                                   tree def_rhs,	 +                                                   gimple_stmt_iterator *use_stmt_gsi)	 + {	 +   tree index, tunit;	 +   gimple offset_def, use_stmt = gsi_stmt (*use_stmt_gsi);	 +   tree new_rhs, tmp;	 + 	 +   if (TREE_CODE (TREE_OPERAND (def_rhs, 0)) == ARRAY_REF)	 +     tunit = TYPE_SIZE_UNIT (TREE_TYPE (TREE_TYPE (def_rhs)));	 +   else if (TREE_CODE (TREE_TYPE (TREE_OPERAND (def_rhs, 0))) == ARRAY_TYPE)	 +     tunit = TYPE_SIZE_UNIT (TREE_TYPE (TREE_TYPE (TREE_TYPE (def_rhs))));	 +   else	 +     return false;	 +   if (!host_integerp (tunit, 1))	 +     return false;	 + 	 +   /* Get the offset's defining statement.  */	 +   offset_def = SSA_NAME_DEF_STMT (offset);	 + 	 +   /* Try to find an expression for a proper index.  This is either a	 +      multiplication expression by the element size or just the ssa name we came	 +      along in case the element size is one. In that case, however, we do not	 +      allow multiplications because they can be computing index to a higher	 +      level dimension (PR 37861). */	 +   if (integer_onep (tunit))	 +     {	 +       if (is_gimple_assign (offset_def)	 +           && gimple_assign_rhs_code (offset_def) == MULT_EXPR)	 +         return false;	 + 	 +       index = offset;	 +     }	 +   else	 +     {	 +       /* The statement which defines OFFSET before type conversion	 +          must be a simple GIMPLE_ASSIGN.  */	 +       if (!is_gimple_assign (offset_def))	 +         return false;	 + 	 +       /* The RHS of the statement which defines OFFSET must be a	 +          multiplication of an object by the size of the array elements.	 +          This implicitly verifies that the size of the array elements	 +          is constant.  */	 +      if (gimple_assign_rhs_code (offset_def) == MULT_EXPR	 +          && TREE_CODE (gimple_assign_rhs2 (offset_def)) == INTEGER_CST	 +          && tree_int_cst_equal (gimple_assign_rhs2 (offset_def), tunit))	 +        {	 +          /* The first operand to the MULT_EXPR is the desired index.  */	 +          index = gimple_assign_rhs1 (offset_def);	 +        }	 +      /* If we have idx * tunit + CST * tunit re-associate that.  */	 +      else if ((gimple_assign_rhs_code (offset_def) == PLUS_EXPR	 +                || gimple_assign_rhs_code (offset_def) == MINUS_EXPR)	 +               && TREE_CODE (gimple_assign_rhs1 (offset_def)) == SSA_NAME	 +               && TREE_CODE (gimple_assign_rhs2 (offset_def)) == INTEGER_CST	 +               && (tmp = div_if_zero_remainder (EXACT_DIV_EXPR,	 +                                                gimple_assign_rhs2 (offset_def),	 +                                                tunit)) != NULL_TREE)	 +        {	 +          gimple offset_def2 = SSA_NAME_DEF_STMT (gimple_assign_rhs1 (offset_def));	 +          if (is_gimple_assign (offset_def2)	 +              && gimple_assign_rhs_code (offset_def2) == MULT_EXPR	 +              && TREE_CODE (gimple_assign_rhs2 (offset_def2)) == INTEGER_CST	 +              && tree_int_cst_equal (gimple_assign_rhs2 (offset_def2), tunit))	 +            {	 +              index = fold_build2 (gimple_assign_rhs_code (offset_def),	 +                                   TREE_TYPE (offset),	 +                                   gimple_assign_rhs1 (offset_def2), tmp);	 +            }	 +          else	 +            return false;	 +        }	 +      else	 +         return false;	 +     }	 + 	 +   /* Replace the pointer addition with array indexing.  */	 +   index = force_gimple_operand_gsi (use_stmt_gsi, index, true, NULL_TREE,	 +                                     true, GSI_SAME_STMT);	 +   if (TREE_CODE (TREE_OPERAND (def_rhs, 0)) == ARRAY_REF)	 +     {	 +       new_rhs = unshare_expr (def_rhs);	 +       TREE_OPERAND (TREE_OPERAND (new_rhs, 0), 1) = index;	 +     }	 +   else	 +     {	 +       new_rhs = build4 (ARRAY_REF, TREE_TYPE (TREE_TYPE (TREE_TYPE (def_rhs))),	 +                         unshare_expr (TREE_OPERAND (def_rhs, 0)),	 +                         index, integer_zero_node, NULL_TREE);	 +       new_rhs = build_fold_addr_expr (new_rhs);	 +       if (!useless_type_conversion_p (TREE_TYPE (gimple_assign_lhs (use_stmt)),	 +                                       TREE_TYPE (new_rhs)))	 +         {	 +           new_rhs = force_gimple_operand_gsi (use_stmt_gsi, new_rhs, true,	 +                                               NULL_TREE, true, GSI_SAME_STMT);	 +           new_rhs = fold_convert (TREE_TYPE (gimple_assign_lhs (use_stmt)),	 +                                   new_rhs);	 +         }	 +     }	 +   gimple_assign_set_rhs_from_tree (use_stmt_gsi, new_rhs);	 +   fold_stmt (use_stmt_gsi);	 +   tidy_after_forward_propagate_addr (gsi_stmt (*use_stmt_gsi));	 +   return true;	 + }	 +++ /* NAME is a SSA_NAME representing DEF_RHS which is of the form    ADDR_EXPR <whatever>. @@ -977,6 +1101,19 @@       tidy_after_forward_propagate_addr (use_stmt);       return true;     }+   /* Try to optimize &x[0] p+ OFFSET where OFFSET is defined by	 +      converting a multiplication of an index by the size of the	 +      array elements, then the result is converted into the proper	 +      type for the arithmetic.  */	 +   if (TREE_CODE (rhs2) == SSA_NAME	 +       && (TREE_CODE (array_ref) != ARRAY_REF	 +           || integer_zerop (TREE_OPERAND (array_ref, 1)))	 +       && useless_type_conversion_p (TREE_TYPE (name), TREE_TYPE (def_rhs))	 +       /* Avoid problems with IVopts creating PLUS_EXPRs with a	 +          different type than their operands.  */	 +       && useless_type_conversion_p (TREE_TYPE (lhs), TREE_TYPE (def_rhs)))	 +     return forward_propagate_addr_into_variable_array_index (rhs2, def_rhs,	 +                                                              use_stmt_gsi);	     return false; }
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