rs6000: add effective-target test ppc_mma_hw

Add a test for dejagnu to determine if execution of MMA instructions is
supported in the test environment. Add an execution test to make sure
that __builtin_cpu_supports("mma") is true if we can execute MMA
instructions.

2020-07-13  Aaron Sawdey  <acsawdey@linux.ibm.com>

gcc/testsuite/

	* lib/target-supports.exp (check_ppc_mma_hw_available):
	New function.
	(is-effective-target): Add ppc_mma_hw.
	(is-effective-target-keyword): Add ppc_mma_hw.
	* gcc.target/powerpc/mma-supported.c: New file.
	* gcc.target/powerpc/mma-single-test.c: Require ppc_mma_hw.
	* gcc.target/powerpc/mma-double-test.c: Require ppc_mma_hw.

(cherry picked from commit 305ab735bd40b52a451851fa6e2177f184eb05d4)

gcc/testsuite/gcc.target/powerpc/mma-double-test.c

 /* { dg-do run } */
 /* { dg-require-effective-target power10_hw } */
+/* { dg-require-effective-target ppc_mma_hw } */
 /* { dg-options "-mdejagnu-cpu=power10 -O2" } */
 
 #include <stdio.h>

gcc/testsuite/gcc.target/powerpc/mma-single-test.c

 /* { dg-do run } */
 /* { dg-require-effective-target power10_hw } */
+/* { dg-require-effective-target ppc_mma_hw } */
 /* { dg-options "-mdejagnu-cpu=power10 -O2" } */
 
 #include <stdio.h>

gcc/testsuite/gcc.target/powerpc/mma-supported.c

+/* { dg-do run } */
+/* { dg-require-effective-target ppc_mma_hw } */
+/* { dg-options "-mdejagnu-cpu=power10 -O2" } */
+
+/* This test will only run when the ppc_mma_hw test passes.  If that
+   test passes, then we expect to see that mma feature is supported.
+   If this is not the case, then the test environment has problems. */
+
+#include <stdio.h>
+#include <stdlib.h>
+
+int
+main (int argc, char *argv[])
+{
+#ifdef __BUILTIN_CPU_SUPPORTS__
+  if ( !__builtin_cpu_supports ("mma"))
+    {
+#ifdef DEBUG      
+      printf ("Error: __builtin_cpu_supports says mma not supported, but ppc_mma_hw test passed.\n");
+#endif
+      abort();
+    }
+#endif
+  exit (0);
+}

gcc/testsuite/lib/target-supports.exp

@@ -2235,6 +2235,31 @@ proc check_power10_hw_available { } {
     }]
 }
 
+# Return 1 if the target supports executing MMA instructions, 0 otherwise.
+# Cache the result.  It is assumed that if a simulator does not support the
+# MMA instructions, that it will generate an error and this test will fail.
+
+proc check_ppc_mma_hw_available { } {
+    return [check_cached_effective_target ppc_mma_hw_available {
+	check_runtime_nocache ppc_mma_hw_available {
+	    #include <altivec.h>
+	    typedef double v4sf_t __attribute__ ((vector_size (16)));
+
+	    int main()
+	    {
+		__vector_quad acc0;
+		v4sf_t result[4];
+		result[0][0] = 1.0;
+		__builtin_mma_xxsetaccz (&acc0);
+		__builtin_mma_disassemble_acc (result, &acc0);
+		if (result[0][0] != 0.0)
+		   return 1;
+		return 0;
+	    }
+	} "-mcpu=power10"
+    }]
+}
+
 # Return 1 if the target supports executing __float128 on PowerPC via software
 # emulation, 0 otherwise.  Cache the result.
 
@@ -7803,6 +7828,7 @@ proc is-effective-target { arg } {
 	  "ppc_float128_hw" { set selected [check_ppc_float128_hw_available] }
 	  "ppc_recip_hw"   { set selected [check_ppc_recip_hw_available] }
 	  "ppc_cpu_supports_hw" { set selected [check_ppc_cpu_supports_hw_available] }
+	  "ppc_mma_hw"     { set selected [check_ppc_mma_hw_available] }
 	  "dfp_hw"         { set selected [check_dfp_hw_available] }
 	  "htm_hw"         { set selected [check_htm_hw_available] }
 	  "named_sections" { set selected [check_named_sections_available] }
@@ -7833,6 +7859,7 @@ proc is-effective-target-keyword { arg } {
 	  "ppc_float128_sw" { return 1 }
 	  "ppc_float128_hw" { return 1 }
 	  "ppc_recip_hw"   { return 1 }
+	  "ppc_mma_hw"     { return 1 }
 	  "dfp_hw"         { return 1 }
 	  "htm_hw"         { return 1 }
 	  "named_sections" { return 1 }