diff options
Diffstat (limited to 'gcc/gimplify.c')
| -rw-r--r-- | gcc/gimplify.c | 27 |
1 files changed, 27 insertions, 0 deletions
diff --git a/gcc/gimplify.c b/gcc/gimplify.c index 698aefcfc45..c1d05b52756 100644 --- a/gcc/gimplify.c +++ b/gcc/gimplify.c @@ -1617,6 +1617,7 @@ canonicalize_addr_expr (tree *expr_p) static enum gimplify_status gimplify_conversion (tree *expr_p) { + tree tem; gcc_assert (TREE_CODE (*expr_p) == NOP_EXPR || TREE_CODE (*expr_p) == CONVERT_EXPR); @@ -1627,6 +1628,17 @@ gimplify_conversion (tree *expr_p) if (tree_ssa_useless_type_conversion (*expr_p)) *expr_p = TREE_OPERAND (*expr_p, 0); + /* Attempt to avoid NOP_EXPR by producing reference to a subtype. + For example this fold (subclass *)&A into &A->subclass avoiding + a need for statement. */ + if (TREE_CODE (*expr_p) == NOP_EXPR + && POINTER_TYPE_P (TREE_TYPE (*expr_p)) + && POINTER_TYPE_P (TREE_TYPE (TREE_OPERAND (*expr_p, 0))) + && (tem = maybe_fold_offset_to_reference + (TREE_OPERAND (*expr_p, 0), + integer_zero_node, TREE_TYPE (TREE_TYPE (*expr_p))))) + *expr_p = build_fold_addr_expr_with_type (tem, TREE_TYPE (*expr_p)); + /* If we still have a conversion at the toplevel, then canonicalize some constructs. */ if (TREE_CODE (*expr_p) == NOP_EXPR || TREE_CODE (*expr_p) == CONVERT_EXPR) @@ -5859,6 +5871,21 @@ gimplify_expr (tree *expr_p, tree *pre_p, tree *post_p, ret = GS_ALL_DONE; break; + case PLUS_EXPR: + /* Convert ((type *)A)+offset into &A->field_of_type_and_offset. + The second is gimple immediate saving a need for extra statement. + */ + if (POINTER_TYPE_P (TREE_TYPE (*expr_p)) + && TREE_CODE (TREE_OPERAND (*expr_p, 1)) == INTEGER_CST + && (tmp = maybe_fold_offset_to_reference + (TREE_OPERAND (*expr_p, 0), TREE_OPERAND (*expr_p, 1), + TREE_TYPE (TREE_TYPE (*expr_p))))) + { + *expr_p = build_fold_addr_expr_with_type (tmp, + TREE_TYPE (*expr_p)); + break; + } + /* FALLTHRU */ default: switch (TREE_CODE_CLASS (TREE_CODE (*expr_p))) { |