nvptx.c (nvptx_output_call_insn): Emit trap after no return call.

	gcc/
	* config/nvptx/nvptx.c (nvptx_output_call_insn): Emit trap after no
	return call.

	gcc/testsuite/
	* gcc.target/nvptx/abort.c: New.

From-SVN: r231368

gcc/ChangeLog

+2015-12-07  Nathan Sidwell  <nathan@acm.org>
+
+	* config/nvptx/nvptx.c (nvptx_output_call_insn): Emit trap after no
+	return call.
+
 2015-12-07  David Malcolm  <dmalcolm@redhat.com>
 
 	* pretty-print.c (text_info::set_range): Rename to...

gcc/config/nvptx/nvptx.c

@@ -1890,6 +1890,13 @@ nvptx_output_call_insn (rtx_insn *insn, rtx result, rtx callee)
     }
   fprintf (asm_out_file, ";\n");
 
+  if (find_reg_note (insn, REG_NORETURN, NULL))
+    /* No return functions confuse the PTX JIT, as it doesn't realize
+       the flow control barrier they imply.  It can seg fault if it
+       encounters what looks like an unexitable loop.  Emit a trailing
+       trap, which it does grok.  */
+    fprintf (asm_out_file, "\t\ttrap; // (noreturn)\n");
+
   return result != NULL_RTX ? "\tld.param%t0\t%0, [%%retval_in];\n\t}" : "}";
 }
 

gcc/testsuite/ChangeLog

+2015-12-07  Nathan Sidwell  <nathan@acm.org>
+
+	* gcc.target/nvptx/abort.c: New.
+
 2015-12-07  David Malcolm  <dmalcolm@redhat.com>
 
 	* gcc.dg/diagnostic-ranges-1.c: New test file.

gcc/testsuite/gcc.target/nvptx/abort.c

+/* { dg-do compile} */
+/* Annotate no return functions with a trailing 'trap'.  */
+
+extern void abort ();
+
+int main (int argc, char **argv)
+{
+  if (argc > 2)
+    abort ();
+  return 0;
+}
+
+/* { dg-final { scan-assembler "call abort;\[\r\n\t \]+trap;" } } */