Improve tree-ssa-alias dump files

[Jan Hubicka]

Hi,
this patch improves debug info of modref so it is easier to track down
misoptimizations.

Bootstrapped/regtested x86_64-linux, comitted.

Honza

gcc/ChangeLog:

2020-10-10  Jan Hubicka  <hubi...@ucw.cz>

        * tree-ssa-alias.c (ref_maybe_used_by_call_p_1): Improve debug dumps.
        (call_may_clobber_ref_p_1): Improve debug dumps.

diff --git a/gcc/tree-ssa-alias.c b/gcc/tree-ssa-alias.c
index ac7e020c5e2..877e4999f0f 100644
--- a/gcc/tree-ssa-alias.c
+++ b/gcc/tree-ssa-alias.c
@@ -43,6 +43,7 @@ along with GCC; see the file COPYING3.  If not see
 #include "attr-fnspec.h"
 #include "errors.h"
 #include "dbgcnt.h"
+#include "gimple-pretty-print.h"
 
 /* Broad overview of how alias analysis on gimple works:
 
@@ -2610,13 +2611,23 @@ ref_maybe_used_by_call_p_1 (gcall *call, ao_ref *ref, 
bool tbaa_p)
                  alias_stats.modref_use_no_alias++;
                  if (dump_file && (dump_flags & TDF_DETAILS))
                    {
-                     fprintf (dump_file, "ipa-modref: in %s,"
-                              " call to %s does not use ",
-                              cgraph_node::get
-                                  (current_function_decl)->dump_name (),
+                     fprintf (dump_file,
+                              "ipa-modref: call stmt ");
+                     print_gimple_stmt (dump_file, call, 0);
+                     fprintf (dump_file,
+                              "ipa-modref: call to %s does not use ",
                               node->dump_name ());
-                     print_generic_expr (dump_file, ref->ref);
-                     fprintf (dump_file, " %i->%i\n",
+                     if (!ref->ref && ref->base)
+                       {
+                         fprintf (dump_file, "base: ");
+                         print_generic_expr (dump_file, ref->base);
+                       }
+                     else if (ref->ref)
+                       {
+                         fprintf (dump_file, "ref: ");
+                         print_generic_expr (dump_file, ref->ref);
+                       }
+                     fprintf (dump_file, " alias sets: %i->%i\n",
                               ao_ref_base_alias_set (ref),
                               ao_ref_alias_set (ref));
                    }
@@ -3035,13 +3046,22 @@ call_may_clobber_ref_p_1 (gcall *call, ao_ref *ref, 
bool tbaa_p)
                  if (dump_file && (dump_flags & TDF_DETAILS))
                    {
                      fprintf (dump_file,
-                              "ipa-modref: in %s, "
-                              "call to %s does not clobber ",
-                              cgraph_node::get
-                                 (current_function_decl)->dump_name (),
+                              "ipa-modref: call stmt ");
+                     print_gimple_stmt (dump_file, call, 0);
+                     fprintf (dump_file,
+                              "ipa-modref: call to %s does not clobber ",
                               node->dump_name ());
-                     print_generic_expr (dump_file, ref->ref);
-                     fprintf (dump_file, " %i->%i\n",
+                     if (!ref->ref && ref->base)
+                       {
+                         fprintf (dump_file, "base: ");
+                         print_generic_expr (dump_file, ref->base);
+                       }
+                     else if (ref->ref)
+                       {
+                         fprintf (dump_file, "ref: ");
+                         print_generic_expr (dump_file, ref->ref);
+                       }
+                     fprintf (dump_file, " alias sets: %i->%i\n",
                               ao_ref_base_alias_set (ref),
                               ao_ref_alias_set (ref));
                    }