On Tue, 13 Jan 2015, Jakub Jelinek wrote:
> On Tue, Jan 13, 2015 at 02:04:26PM +0100, Richard Biener wrote:
> > The following removes -fvar-tracking-assignments from being eligible
> > to the optimization attribute/pragma which fixes LTO operation for
> > mixed inputs (LTO just drops debug stmts if the flag is false).
> >
> > In theory we could also fix inlining to do that when inlining
> > debug stmts into a non-VTA function but I think allowing this
> > kind of per-function IL flags is just silly.
>
> I actually think it makes sense to disable -fvar-tracking-assignments
> just for specific function, e.g. when it is known to be too expensive
> on some large function you don't care about debug info quality too much,
> while you still don't want to disable it on the whole TU level, because
> you have other functions (e.g. small ones) you still want to be able to
> debug often with good coverage.
>
> So if this is fixable in the inliner and/or LTO in-streamer that would be
> my preference.
The following seems to work (for the testcase). Testing coverage
of this mode will of course be bad.
Richard.
2015-01-13 Richard Biener <rguent...@suse.de>
PR lto/64415
* tree-inline.c (insert_debug_decl_map): Check destination
function MAY_HAVE_DEBUG_STMTS.
(insert_init_debug_bind): Likewise.
(insert_init_stmt): Remove redundant check.
(remap_gimple_stmt): Drop debug stmts if the destination
function has var-tracking assignments disabled.
* gcc.dg/lto/pr64415_0.c: New testcase.
* gcc.dg/lto/pr64415_1.c: Likewise.
Index: gcc/testsuite/gcc.dg/lto/pr64415_0.c
===================================================================
--- gcc/testsuite/gcc.dg/lto/pr64415_0.c (revision 0)
+++ gcc/testsuite/gcc.dg/lto/pr64415_0.c (working copy)
@@ -0,0 +1,13 @@
+/* { dg-lto-do link } */
+/* { dg-require-effective-target fpic } */
+/* { dg-lto-options { { -O -flto -fpic } } } */
+/* { dg-extra-ld-options { -shared } } */
+
+extern void bar(char *, int);
+
+extern char *baz;
+
+void foo()
+{
+ bar(baz, 0);
+}
Index: gcc/testsuite/gcc.dg/lto/pr64415_1.c
===================================================================
--- gcc/testsuite/gcc.dg/lto/pr64415_1.c (revision 0)
+++ gcc/testsuite/gcc.dg/lto/pr64415_1.c (working copy)
@@ -0,0 +1,17 @@
+/* { dg-options "-g" } */
+
+extern int n;
+
+void bar(char *, int);
+
+inline void bar(char *s, int i)
+{
+ char *p = s;
+
+#ifdef V1
+ if (i)
+#else
+ if (n)
+#endif
+ *s = 0;
+}
Index: gcc/tree-inline.c
===================================================================
--- gcc/tree-inline.c (revision 219520)
+++ gcc/tree-inline.c (working copy)
@@ -192,7 +192,7 @@ insert_debug_decl_map (copy_body_data *i
if (!gimple_in_ssa_p (id->src_cfun))
return;
- if (!MAY_HAVE_DEBUG_STMTS)
+ if (!opt_for_fn (id->dst_fn, flag_var_tracking_assignments))
return;
if (!target_for_debug_bind (key))
@@ -1348,6 +1348,10 @@ remap_gimple_stmt (gimple stmt, copy_bod
bool skip_first = false;
gimple_seq stmts = NULL;
+ if (is_gimple_debug (stmt)
+ && !opt_for_fn (id->dst_fn, flag_var_tracking_assignments))
+ return stmts;
+
/* Begin by recognizing trees that we'll completely rewrite for the
inlining context. Our output for these trees is completely
different from out input (e.g. RETURN_EXPR is deleted, and morphs
@@ -3007,7 +3011,7 @@ insert_init_debug_bind (copy_body_data *
if (!gimple_in_ssa_p (id->src_cfun))
return NULL;
- if (!MAY_HAVE_DEBUG_STMTS)
+ if (!opt_for_fn (id->dst_fn, flag_var_tracking_assignments))
return NULL;
tracked_var = target_for_debug_bind (var);
@@ -3063,7 +3067,7 @@ insert_init_stmt (copy_body_data *id, ba
gsi_insert_after (&si, init_stmt, GSI_NEW_STMT);
gimple_regimplify_operands (init_stmt, &si);
- if (!is_gimple_debug (init_stmt) && MAY_HAVE_DEBUG_STMTS)
+ if (!is_gimple_debug (init_stmt))
{
tree def = gimple_assign_lhs (init_stmt);
insert_init_debug_bind (id, bb, def, def, init_stmt);
