From 108f6c2f4efe0141c859eeb52fae610b8806ffc8 Mon Sep 17 00:00:00 2001 From: Richard Guenther Date: Tue, 31 Mar 2009 13:16:36 +0000 Subject: tree.h (div_if_zero_remainder): Declare. 2009-03-31 Richard Guenther * tree.h (div_if_zero_remainder): Declare. * fold-const.c (div_if_zero_remainder): Export. * tree-ssa-forwprop.c (forward_propagate_addr_into_variable_array_index): Handle constant array index addition outside of the variable index. * gcc.dg/tree-ssa/forwprop-12.c: New testcase. From-SVN: r145343 --- gcc/tree-ssa-forwprop.c | 48 ++++++++++++++++++++++++++++++++++++++---------- 1 file changed, 38 insertions(+), 10 deletions(-) (limited to 'gcc/tree-ssa-forwprop.c') diff --git a/gcc/tree-ssa-forwprop.c b/gcc/tree-ssa-forwprop.c index 859d6fe..044f843 100644 --- a/gcc/tree-ssa-forwprop.c +++ b/gcc/tree-ssa-forwprop.c @@ -618,8 +618,13 @@ forward_propagate_addr_into_variable_array_index (tree offset, tree def_rhs, gimple_stmt_iterator *use_stmt_gsi) { - tree index; + tree index, tunit; gimple offset_def, use_stmt = gsi_stmt (*use_stmt_gsi); + tree tmp; + + tunit = TYPE_SIZE_UNIT (TREE_TYPE (TREE_TYPE (def_rhs))); + if (!host_integerp (tunit, 1)) + return false; /* Get the offset's defining statement. */ offset_def = SSA_NAME_DEF_STMT (offset); @@ -629,7 +634,7 @@ forward_propagate_addr_into_variable_array_index (tree offset, 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 (TYPE_SIZE_UNIT (TREE_TYPE (TREE_TYPE (def_rhs))))) + if (integer_onep (tunit)) { if (is_gimple_assign (offset_def) && gimple_assign_rhs_code (offset_def) == MULT_EXPR) @@ -648,18 +653,41 @@ forward_propagate_addr_into_variable_array_index (tree offset, multiplication of an object by the size of the array elements. This implicitly verifies that the size of the array elements is constant. */ - offset = gimple_assign_rhs1 (offset_def); - if (gimple_assign_rhs_code (offset_def) != MULT_EXPR - || TREE_CODE (gimple_assign_rhs2 (offset_def)) != INTEGER_CST - || !simple_cst_equal (gimple_assign_rhs2 (offset_def), - TYPE_SIZE_UNIT (TREE_TYPE (TREE_TYPE (def_rhs))))) + 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 (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; - - /* The first operand to the MULT_EXPR is the desired index. */ - index = offset; } /* Replace the pointer addition with array indexing. */ + index = force_gimple_operand_gsi (use_stmt_gsi, index, true, NULL_TREE, + true, GSI_SAME_STMT); gimple_assign_set_rhs_from_tree (use_stmt_gsi, unshare_expr (def_rhs)); use_stmt = gsi_stmt (*use_stmt_gsi); TREE_OPERAND (TREE_OPERAND (gimple_assign_rhs1 (use_stmt), 0), 1) -- cgit v1.1