Re: [PATCH] Partial Transition fix attempt

[Richard Guenther <richard dot guenther at gmail dot com>]

On Wed, Mar 21, 2012 at 6:44 PM, redbrain <redbrain@gcc.gnu.org> wrote:
> in tree-mudflap.c to change usage of fold_conver to build_int_cst http://gcc.gnu.org/wiki/Partial_Transitions. I am not 100% sure this is correct but maybe someone can shed some light.

Doesn't look ok - how do you know you even have constants here?
Remember that fold_convert
handles non-constants just fine.

Richard.

> ---
> ?gcc/tree-mudflap.c | ? 38 ++++++++++++++++++++------------------
> ?1 files changed, 20 insertions(+), 18 deletions(-)
>
> diff --git a/gcc/tree-mudflap.c b/gcc/tree-mudflap.c
> index e4f6ec0..684b7b4 100644
> --- a/gcc/tree-mudflap.c
> +++ b/gcc/tree-mudflap.c
> @@ -567,8 +567,7 @@ mf_build_check_statement_for (tree base, tree limit,
>
> ? /* Build: __mf_base = (uintptr_t) <base address expression>. ?*/
> ? seq = gimple_seq_alloc ();
> - ?t = fold_convert_loc (location, mf_uintptr_type,
> - ? ? ? ? ? ? ? ? ? ? ? unshare_expr (base));
> + ?t = build_int_cst_type (mf_uintptr_type, TREE_INT_CST_LOW (unshare_expr (base)));
> ? t = force_gimple_operand (t, &stmts, false, NULL_TREE);
> ? gimple_seq_add_seq (&seq, stmts);
> ? g = gimple_build_assign (mf_base, t);
> @@ -576,8 +575,7 @@ mf_build_check_statement_for (tree base, tree limit,
> ? gimple_seq_add_stmt (&seq, g);
>
> ? /* Build: __mf_limit = (uintptr_t) <limit address expression>. ?*/
> - ?t = fold_convert_loc (location, mf_uintptr_type,
> - ? ? ? ? ? ? ? ? ? ? ? unshare_expr (limit));
> + ?t = build_int_cst_type (mf_uintptr_type, TREE_INT_CST_LOW (unshare_expr (limit)));
> ? t = force_gimple_operand (t, &stmts, false, NULL_TREE);
> ? gimple_seq_add_seq (&seq, stmts);
> ? g = gimple_build_assign (mf_limit, t);
> @@ -853,18 +851,21 @@ mf_xform_derefs_1 (gimple_stmt_iterator *iter, tree *tp,
> ? ? ? ? ? ?if (elt)
> ? ? ? ? ? ? ?elt = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (elt)),
> ? ? ? ? ? ? ? ? ? ? ? ? ? ?elt);
> - ? ? ? ? ? ?addr = fold_convert_loc (location, ptr_type_node, elt ? elt : base);
> + ? ? ? ? ? addr = build_int_cst_type (ptr_type_node, elt ? TREE_INT_CST_LOW (elt) :
> + ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?TREE_INT_CST_LOW (base));
> ? ? ? ? ? ? addr = fold_build_pointer_plus_loc (location,
> ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?addr, byte_position (field));
> ? ? ? ? ? }
> ? ? ? ? else
> ? ? ? ? ? addr = build1 (ADDR_EXPR, build_pointer_type (type), t);
> -
> +
> ? ? ? ? limit = fold_build2_loc (location, MINUS_EXPR, mf_uintptr_type,
> - ? ? ? ? ? ? ? ? ? ? ? ? ? ? fold_build2_loc (location, PLUS_EXPR, mf_uintptr_type,
> - ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? fold_convert (mf_uintptr_type, addr),
> - ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? size),
> - ? ? ? ? ? ? ? ? ? ? ? ? ? ? integer_one_node);
> + ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?fold_build2_loc (location, PLUS_EXPR, mf_uintptr_type,
> + ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? build_int_cst_type (mf_uintptr_type,
> + ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? TREE_INT_CST_LOW (addr)),
> +
> + ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? size),
> + ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?integer_one_node);
> ? ? ? }
> ? ? ? break;
>
> @@ -908,17 +909,17 @@ mf_xform_derefs_1 (gimple_stmt_iterator *iter, tree *tp,
> ? ? ? ? ? return;
>
> ? ? ? ? bpu = bitsize_int (BITS_PER_UNIT);
> - ? ? ? ?ofs = fold_convert (bitsizetype, TREE_OPERAND (t, 2));
> + ? ? ? ofs = build_int_cst_type (bitsizetype, TREE_INT_CST_LOW (TREE_OPERAND (t, 2)));
> ? ? ? ? rem = size_binop_loc (location, TRUNC_MOD_EXPR, ofs, bpu);
> ? ? ? ? ofs = size_binop_loc (location, TRUNC_DIV_EXPR, ofs, bpu);
>
> - ? ? ? ?size = fold_convert (bitsizetype, TREE_OPERAND (t, 1));
> + ? ? ? ?size = build_int_cst_type (bitsizetype, TREE_INT_CST_LOW (TREE_OPERAND (t, 1)));
> ? ? ? ? size = size_binop_loc (location, PLUS_EXPR, size, rem);
> ? ? ? ? size = size_binop_loc (location, CEIL_DIV_EXPR, size, bpu);
> - ? ? ? ?size = fold_convert (sizetype, size);
> + ? ? ? ?size = build_int_cst_type (sizetype, TREE_INT_CST_LOW (size));
>
> ? ? ? ? addr = TREE_OPERAND (TREE_OPERAND (t, 0), 0);
> - ? ? ? ?addr = fold_convert (ptr_type_node, addr);
> + ? ? ? ?addr = build_int_cst_type (ptr_type_node, TREE_INT_CST_LOW (addr));
> ? ? ? ? addr = fold_build_pointer_plus_loc (location, addr, ofs);
>
> ? ? ? ? base = addr;
> @@ -1048,8 +1049,8 @@ mx_register_decls (tree decl, gimple_seq seq, location_t location)
>
> ? ? ? ? ?/* Variable-sized objects should have sizes already been
> ? ? ? ? ? ? gimplified when we got here. */
> - ? ? ? ? size = fold_convert (size_type_node,
> - ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?TYPE_SIZE_UNIT (TREE_TYPE (decl)));
> + ? ? ? ? size = build_int_cst_type (size_type_node,
> + ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?TREE_INT_CST_LOW (TYPE_SIZE_UNIT (TREE_TYPE (decl))));
> ? ? ? ? ?gcc_assert (is_gimple_val (size));
>
>
> @@ -1233,11 +1234,12 @@ mudflap_register_call (tree obj, tree object_size, tree varname)
> ? tree arg, call_stmt;
>
> ? arg = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (obj)), obj);
> - ?arg = fold_convert (ptr_type_node, arg);
> + ?arg = build_int_cst_type (ptr_type_node, TREE_INT_CST_LOW (arg));
>
> ? call_stmt = build_call_expr (mf_register_fndecl, 4,
> ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? arg,
> - ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?fold_convert (size_type_node, object_size),
> + ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?build_int_cst_type (size_type_node,
> + ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?TREE_INT_CST_LOW (object_size)),
> ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? /* __MF_TYPE_STATIC */
> ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? build_int_cst (integer_type_node, 4),
> ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? varname);
> --
> 1.7.5.4
>