nvptx: Add '__builtin_stack_save()', '__builtin_stack_restore()' test case [PR65181]

Documenting the status quo.

	PR target/65181
	gcc/testsuite/
	* gcc.target/nvptx/__builtin_stack_save___builtin_stack_restore-1.c:
	Add.

1 files changed, 32 insertions, 0 deletions

diff --git a/gcc/testsuite/gcc.target/nvptx/__builtin_stack_save___builtin_stack_restore-1.c b/gcc/testsuite/gcc.target/nvptx/__builtin_stack_save___builtin_stack_restore-1.c
new file mode 100644
index 0000000..294014d
--- /dev/null
+++ b/gcc/testsuite/gcc.target/nvptx/__builtin_stack_save___builtin_stack_restore-1.c
@@ -0,0 +1,32 @@
+/* Document what we do for '__builtin_stack_save()', '__builtin_stack_restore()'.  */
+
+/* { dg-do compile }
+   TODO We can't 'assemble' this -- it's invalid PTX code.  */
+/* { dg-options {-O3 -mno-soft-stack} } */
+/* { dg-additional-options -save-temps } */
+/* { dg-final { check-function-bodies {** } {} } } */
+
+void *p;
+
+void f(void)
+{
+  p = __builtin_stack_save();
+  asm volatile ("" : : : "memory");
+  __builtin_stack_restore(p);
+  asm volatile ("" : : : "memory");
+}
+/*
+** f:
+** \.visible \.func f
+** {
+** 		st\.global\.u64	\[p\], %stack;
+** 	ret;
+*/
+
+/* The concept of a '%stack' pointer doesn't apply like this for
+   '-mno-soft-stack': PTX "native" stacks (TODO).
+
+   { dg-final { scan-assembler-not {%stack} { xfail *-*-* } } } */
+
+/* As these are an internal-use built-in function, we don't bother with
+   emitting proper error diagnostics.  */