[PATCH 5/8] nvptx mkoffload: pass -mgomp for OpenMP offloading

[Alexander Monakov]

This patch wires up use of alternative -mgomp multilib for OpenMP offloading
via nvptx mkoffload.  It makes OpenACC and OpenMP incompatible for
simultaneous offloading compilation, so I've added a diagnostic for that.

        * config/nvptx/mkoffload.c (main): Check that either OpenACC or OpenMP
        is selected.  Pass -mgomp to offload compiler in OpenMP case.
---
 gcc/config/nvptx/mkoffload.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/gcc/config/nvptx/mkoffload.c b/gcc/config/nvptx/mkoffload.c
index c8eed45..d876c7b 100644
--- a/gcc/config/nvptx/mkoffload.c
+++ b/gcc/config/nvptx/mkoffload.c
@@ -460,6 +460,7 @@ main (int argc, char **argv)
 
   /* Scan the argument vector.  */
   bool fopenmp = false;
+  bool fopenacc = false;
   for (int i = 1; i < argc; i++)
     {
 #define STR "-foffload-abi="
@@ -476,11 +477,15 @@ main (int argc, char **argv)
 #undef STR
       else if (strcmp (argv[i], "-fopenmp") == 0)
        fopenmp = true;
+      else if (strcmp (argv[i], "-fopenacc") == 0)
+       fopenacc = true;
       else if (strcmp (argv[i], "-save-temps") == 0)
        save_temps = true;
       else if (strcmp (argv[i], "-v") == 0)
        verbose = true;
     }
+  if (!(fopenacc ^ fopenmp))
+    fatal_error (input_location, "either -fopenacc or -fopenmp must be set");
 
   struct obstack argv_obstack;
   obstack_init (&argv_obstack);
@@ -501,6 +506,8 @@ main (int argc, char **argv)
     default:
       gcc_unreachable ();
     }
+  if (fopenmp)
+    obstack_ptr_grow (&argv_obstack, "-mgomp");
 
   for (int ix = 1; ix != argc; ix++)
     {
-- 
1.8.3.1