[PATCH] Fix PR78306

[Richard Biener <rguenther@suse.de>]

Appearantly for some unknown reason we refuse to inline anything into
functions calling cilk_spawn.  That breaks fortified headers and
all other always-inline function calls (intrinsics come to my mind as 
well).

Bootstrapped and tested on x86_64-unknown-linux-gnu, ok for trunk?

Thanks,
Richard.

2016-11-15  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/78306
	* ipa-inline-analysis.c (initialize_inline_failed): Do not
	inhibit inlining if function calls cilk_spawn.
	(can_inline_edge_p): Likewise.

	* gcc.dg/cilk-plus/pr78306.c: New testcase.

Index: gcc/ipa-inline-analysis.c
===================================================================
--- gcc/ipa-inline-analysis.c	(revision 242408)
+++ gcc/ipa-inline-analysis.c	(working copy)
@@ -1507,9 +1507,6 @@ initialize_inline_failed (struct cgraph_
     e->inline_failed = CIF_BODY_NOT_AVAILABLE;
   else if (callee->local.redefined_extern_inline)
     e->inline_failed = CIF_REDEFINED_EXTERN_INLINE;
-  else if (cfun && fn_contains_cilk_spawn_p (cfun))
-    /* We can't inline if the function is spawing a function.  */
-    e->inline_failed = CIF_CILK_SPAWN;
   else
     e->inline_failed = CIF_FUNCTION_NOT_CONSIDERED;
   gcc_checking_assert (!e->call_stmt_cannot_inline_p
Index: gcc/ipa-inline.c
===================================================================
--- gcc/ipa-inline.c	(revision 242408)
+++ gcc/ipa-inline.c	(working copy)
@@ -368,11 +368,6 @@ can_inline_edge_p (struct cgraph_edge *e
       e->inline_failed = CIF_FUNCTION_NOT_INLINABLE;
       inlinable = false;
     }
-  else if (inline_summaries->get (caller)->contains_cilk_spawn)
-    {
-      e->inline_failed = CIF_CILK_SPAWN;
-      inlinable = false;
-    }
   /* Don't inline a function with mismatched sanitization attributes. */
   else if (!sanitize_attrs_match_for_inline_p (caller->decl, callee->decl))
     {
Index: gcc/testsuite/gcc.dg/cilk-plus/pr78306.c
===================================================================
--- gcc/testsuite/gcc.dg/cilk-plus/pr78306.c	(revision 0)
+++ gcc/testsuite/gcc.dg/cilk-plus/pr78306.c	(working copy)
@@ -0,0 +1,30 @@
+/* { dg-do run } */
+/* { dg-options "-O2 -fcilkplus" } */
+
+#define _FORTIFY_SOURCE=2
+#include <cilk/cilk.h>
+#include <string.h>
+#include <malloc.h>
+
+int sum(int low, int high)
+{
+  if(low == high) {
+    return low;
+  }
+
+  int mid = low + (high-low)/2;
+  int a = cilk_spawn sum(low, mid);
+  int b = sum(mid+1, high);
+
+  // Some very expensive computation here
+  int foo[64];
+  memset(foo, 0, 64*sizeof(int)); // <--- Fails
+
+  cilk_sync;
+
+  return a+b;
+}
+
+int main(void) {
+  return sum(0, 100);
+}