commit 60ff013998de8aa168e01b7b1c1743bcbdee99b1

Author: Will Schmidt <will_schmidt@vnet.ibm.com>

Date:   Thu Aug 12 15:41:50 2021 -0500

    Hi

      This reworks the modulo operation as seen in

    valgrind/none/tests/ppc64/test_isa_3_1_common.c:

    initialize_source_registers().   Due to a GCC issue (PR101882), we

    will try to avoid a modulo operation with both input and outputs set to

    a hard register.

      In this case, we can apply the modulo operation to the args[] array

    value used to initialize the ra value.

diff --git a/none/tests/ppc64/test_isa_3_1_common.c b/none/tests/ppc64/test_isa_3_1_common.c

index 8222a857fc..7c3dc6f009 100644

--- a/none/tests/ppc64/test_isa_3_1_common.c

+++ b/none/tests/ppc64/test_isa_3_1_common.c

@@ -2261,12 +2261,17 @@ void initialize_source_registers () {

       if (has_rb)  rb = 2*vrbi;

       /* note special case for is_insert_double, see set_up_iterators () */

       if (has_ra)  ra = 4*vrai;

       if (is_insert_double) {

 	 /* For an insert_double, the results are undefined

-	    for ra > 8, so modulo those into a valid range. */

-	 ra = ra % 9;

+	    for ra > 8, so modulo those into a valid range.

+	    Since ra is defined as a hard register, and due to gcc

+	    issue (PR101882) where a modulo operation fails with

+	    both input and output regs set to a hard register, this

+	    assignment references the args[] array again, versus

+	    ra = ra % 9;.  */

+	 ra = args[vrai] % 9;

       }

    }

    if (uses_buffer) {

       if (has_rb) {