> 2015-05-01 Eric Botcazou <ebotca...@adacore.com>
>
> * expr.c (expand_expr_real_1) <SSA_NAME>: Try to substitute constants
> on the RHS of expressions.
> * gimple-expr.h (is_gimple_constant): Reorder.
Bummer. This breaks C++ debugging:
+FAIL: gdb.cp/class2.exp: print alpha at marker return 0
+FAIL: gdb.cp/class2.exp: print beta at marker return 0
+FAIL: gdb.cp/class2.exp: print * aap at marker return 0
+FAIL: gdb.cp/class2.exp: print * bbp at marker return 0
+FAIL: gdb.cp/class2.exp: print * abp at marker return 0, s-p-o off
+FAIL: gdb.cp/class2.exp: print * (B *) abp at marker return 0
+FAIL: gdb.cp/class2.exp: p acp
+FAIL: gdb.cp/class2.exp: p acp->c1
+FAIL: gdb.cp/class2.exp: p acp->c2
because C++ is apparently relying on the assignment to the anonymous return
object to preserve the debug info attached to a return statement.
Would you be OK with a slight variation of your earlier idea, i.e. calling
fold_stmt with a specific valueizer from fold_marked_statements instead of the
implicit no_follow_ssa_edges in the inliner? Something like:
tree
follow_anonymous_single_use_edges (tree val)
{
if (TREE_CODE (val) == SSA_NAME
&& (!SSA_NAME_VAR (val) || DECL_IGNORED_P (SSA_NAME_VAR (var)))
&& has_single_use (val))
return val
return NULL_TREE;
}
--
Eric Botcazou
