PowerPC: PowerPC tests: Add prefixed/pcrel tests

2020-06-09  Michael Meissner  <meissner@linux.ibm.com>

gcc/testsuite/
	* lib/target-supports.exp (check_effective_target_powerpc_pcrel): New.
	(check_effective_target_powerpc_prefixed_addr): New.

(cherry picked from commit 6e52b2297ecce1243c00d76b3f079b71016b8ffa)

gcc/testsuite/lib/target-supports.exp

@@ -2170,6 +2170,25 @@ proc check_p9vector_hw_available { } {
     }]
 }
 
+# Return 1 if the PowerPC target generates PC-relative instructions
+# automatically for targets that support PC-relative instructions.
+proc check_effective_target_powerpc_pcrel { } {
+    return [check_no_messages_and_pattern powerpc_pcrel \
+	{\mpla\M} assembly {
+	    static unsigned short s;
+	    unsigned short *p_foo (void) { return &s; }
+	} {-O2 -mcpu=power10}]
+}
+
+# Return 1 if the PowerPC target generates prefixed instructions automatically
+# for targets that support prefixed instructions.
+proc check_effective_target_powerpc_prefixed_addr { } {
+    return [check_no_messages_and_pattern powerpc_prefixed_addr \
+	{\mplwz\M} assembly {
+	    unsigned int foo (unsigned int *p) { return p[0x12345]; }
+	} {-O2 -mcpu=power10}]
+}
+
 # Return 1 if the target supports executing power9 modulo instructions, 0
 # otherwise.  Cache the result.