Hi!
When looking at __builtin_clear_padding today, I've noticed that
it is quite wasteful to extend the original user one argument to 3,
2 is enough. We need to encode the original type of the first argument
because pointer conversions are useless in GIMPLE, and we need to record
a boolean whether it is for -ftrivial-auto-var-init=* or not.
But for recording the type we don't need the value (we've always used
zero) and for recording the boolean we don't need the type (we've always
used integer_type_node).
So, this patch merges the two into one.
Ok for trunk if it passes full bootstrap/regtest?
2022-02-11 Jakub Jelinek <ja...@redhat.com>
* tree.cc (build_common_builtin_nodes): Fix up formatting in
__builtin_clear_padding decl creation.
* gimplify.cc (gimple_add_padding_init_for_auto_var): Encode
for_auto_init in the value of 2nd BUILT_IN_CLEAR_PADDING
argument rather than in 3rd argument.
(gimplify_call_expr): Likewise. Fix up comment formatting.
* gimple-fold.cc (gimple_fold_builtin_clear_padding): Expect
2 arguments instead of 3, take for_auto_init from the value
of 2nd argument.
--- gcc/tree.cc.jj 2022-02-11 00:19:22.436063200 +0100
+++ gcc/tree.cc 2022-02-11 12:15:00.929134203 +0100
@@ -9520,7 +9520,7 @@ build_common_builtin_nodes (void)
local_define_builtin ("__builtin_clear_padding", ftype,
BUILT_IN_CLEAR_PADDING,
"__builtin_clear_padding",
- ECF_LEAF | ECF_NOTHROW);
+ ECF_LEAF | ECF_NOTHROW);
}
if (!builtin_decl_explicit_p (BUILT_IN_UNREACHABLE)
--- gcc/gimplify.cc.jj 2022-02-11 00:19:22.305064981 +0100
+++ gcc/gimplify.cc 2022-02-11 12:17:22.679180223 +0100
@@ -1804,7 +1804,6 @@ gimple_add_padding_init_for_auto_var (tr
gimple_seq *seq_p)
{
tree addr_of_decl = NULL_TREE;
- bool for_auto_init = true;
tree fn = builtin_decl_explicit (BUILT_IN_CLEAR_PADDING);
if (is_vla)
@@ -1821,11 +1820,8 @@ gimple_add_padding_init_for_auto_var (tr
addr_of_decl = build_fold_addr_expr (decl);
}
- gimple *call = gimple_build_call (fn,
- 3, addr_of_decl,
- build_zero_cst (TREE_TYPE (addr_of_decl)),
- build_int_cst (integer_type_node,
- (int) for_auto_init));
+ gimple *call = gimple_build_call (fn, 2, addr_of_decl,
+ build_one_cst (TREE_TYPE (addr_of_decl)));
gimplify_seq_add_stmt (seq_p, call);
}
@@ -3536,15 +3532,12 @@ gimplify_call_expr (tree *expr_p, gimple
{
/* Remember the original type of the argument in an internal
dummy second argument, as in GIMPLE pointer conversions are
- useless. also mark this call as not for automatic initialization
- in the internal dummy third argument. */
+ useless. Also mark this call as not for automatic
+ initialization in the internal dummy third argument. */
p = CALL_EXPR_ARG (*expr_p, 0);
- bool for_auto_init = false;
*expr_p
- = build_call_expr_loc (EXPR_LOCATION (*expr_p), fndecl, 3, p,
- build_zero_cst (TREE_TYPE (p)),
- build_int_cst (integer_type_node,
- (int) for_auto_init));
+ = build_call_expr_loc (EXPR_LOCATION (*expr_p), fndecl, 2, p,
+ build_zero_cst (TREE_TYPE (p)));
return GS_OK;
}
break;
--- gcc/gimple-fold.cc.jj 2022-02-11 00:18:54.799439055 +0100
+++ gcc/gimple-fold.cc 2022-02-11 12:13:27.869417000 +0100
@@ -4879,10 +4879,10 @@ gimple_fold_builtin_clear_padding (gimpl
gcc_assert (gimple_call_num_args (stmt) == 3);
tree ptr = gimple_call_arg (stmt, 0);
tree typearg = gimple_call_arg (stmt, 1);
- /* the 3rd argument of __builtin_clear_padding is to distinguish whether
- this call is made by the user or by the compiler for automatic variable
- initialization. */
- bool for_auto_init = (bool) TREE_INT_CST_LOW (gimple_call_arg (stmt, 2));
+ /* The 2nd argument of __builtin_clear_padding's value is used to
+ distinguish whether this call is made by the user or by the compiler
+ for automatic variable initialization. */
+ bool for_auto_init = (bool) TREE_INT_CST_LOW (typearg);
tree type = TREE_TYPE (TREE_TYPE (typearg));
location_t loc = gimple_location (stmt);
clear_padding_struct buf;
Jakub
