[PATCH] Fix missing profiles with PGO (PR tree-optimization/83051).

[Martin Liška]

Hello.

Following ICE can be seen when we have -fprofile-generate or -fprofile-use w/ 
missing
gcda file. I hope the proper fix is to check for reliable profile.

Patch can bootstrap on ppc64le-redhat-linux and survives regression tests.

Ready to be installed?
Martin

gcc/ChangeLog:

2018-01-19  Martin Liska  <mli...@suse.cz>

        PR tree-optimization/83051
        * predict.c (handle_missing_profiles): Consider profile only
        if it's reliable.

gcc/testsuite/ChangeLog:

2018-01-19  Martin Liska  <mli...@suse.cz>

        PR tree-optimization/83051
        * gcc.dg/torture/pr83055.c: New test.
---
 gcc/predict.c                          |  2 +-
 gcc/testsuite/gcc.dg/torture/pr83055.c | 13 +++++++++++++
 2 files changed, 14 insertions(+), 1 deletion(-)
 create mode 100644 gcc/testsuite/gcc.dg/torture/pr83055.c



diff --git a/gcc/predict.c b/gcc/predict.c
index 4c1e4489b55..c5144e49c8d 100644
--- a/gcc/predict.c
+++ b/gcc/predict.c
@@ -3357,7 +3357,7 @@ handle_missing_profiles (void)
       if (!(node->count == profile_count::zero ()))
         continue;
       for (e = node->callers; e; e = e->next_caller)
-	if (e->count.initialized_p () && e->count > 0)
+	if (e->count.initialized_p () && e->count.reliable_p ())
 	  {
             call_count = call_count + e->count;
 
diff --git a/gcc/testsuite/gcc.dg/torture/pr83055.c b/gcc/testsuite/gcc.dg/torture/pr83055.c
new file mode 100644
index 00000000000..9bc71c6cddf
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/torture/pr83055.c
@@ -0,0 +1,13 @@
+/* { dg-do compile } */
+/* { dg-additional-options "-fprofile-generate" } */
+
+void __attribute__ ((__cold__)) a (void);
+void b (void);
+void __attribute__ ((noinline)) c (void) { a (); }
+
+void
+d (void)
+{
+  b ();
+  c ();
+}