[nvptx] Fix Wimplicit-fallthrough in nvptx.c with -save-temps

When compiling nvptx.c using -save-temps, I ran into Wimplicit-fallthrough
warnings.

The fallthrough locations have been marked with a fallthrough comment, but
that doesn't work with -save-temps, something that has been filed as
PR78497.

Work around this by using gcc_fallthrough () in addition to the comment.

Tested by building target nvptx, copying nvptx.c compile line and adding
-save-temps.

gcc/ChangeLog:

2020-09-25  Tom de Vries  <tdevries@suse.de>

	* config/nvptx/nvptx.c (nvptx_assemble_integer, nvptx_print_operand):
	Use gcc_fallthrough ().

diff --git a/gcc/config/nvptx/nvptx.c b/gcc/config/nvptx/nvptx.c
index 54b1fdf..de82f9a 100644 (file)
--- a/gcc/config/nvptx/nvptx.c
+++ b/gcc/config/nvptx/nvptx.c
@@ -2101,7 +2101,7 @@ nvptx_assemble_integer (rtx x, unsigned int size, int ARG_UNUSED (aligned_p))
       val = INTVAL (XEXP (x, 1));
       x = XEXP (x, 0);
       gcc_assert (GET_CODE (x) == SYMBOL_REF);
-      /* FALLTHROUGH */
+      gcc_fallthrough (); /* FALLTHROUGH */
 
     case SYMBOL_REF:
       gcc_assert (size == init_frag.size);
@@ -2603,7 +2603,7 @@ nvptx_print_operand (FILE *file, rtx x, int code)
     {
     case 'A':
       x = XEXP (x, 0);
-      /* FALLTHROUGH.  */
+      gcc_fallthrough (); /* FALLTHROUGH. */
 
     case 'D':
       if (GET_CODE (x) == CONST)