[gcc(refs/users/meissner/heads/work095)] Make -mblock-ops-vector-pair option valid as an ISA option.

[Michael Meissner <meissner@gcc.gnu.org>]

https://gcc.gnu.org/g:470d2ec504ae0ea968d6491a12298e800de91adb

commit 470d2ec504ae0ea968d6491a12298e800de91adb
Author: Michael Meissner <meissner@linux.ibm.com>
Date:   Thu Jul 21 17:46:51 2022 -0400

    Make -mblock-ops-vector-pair option valid as an ISA option.
    
    I needed to turn off using load vector pair and store vector pair
    instructions on the power10 for performance reasons.  It is likely that in
    future machines, we will want to enable these instructions for block moves
    and copies.  This patch adds the -mblock-ops-vector-pair option mask to
    POWERPC_MASKS so that it is automatically set and cleared as we change the
    target cpu.
    
    2022-07-21   Michael Meissner  <meissner@linux.ibm.com>
    
    gcc/
    
            * config/rs6000/rs6000-cpus.def (POWERPC_MASKS): Add
            OPTION_MASK_BLOCK_OPS_VECTOR_PAIR.
            * config/rs6000/rs6000.opt (-mblock-ops-vector-pair): Add a
            comment.

Diff:
---
 gcc/config/rs6000/rs6000-cpus.def | 1 +
 gcc/config/rs6000/rs6000.opt      | 2 ++
 2 files changed, 3 insertions(+)

diff --git a/gcc/config/rs6000/rs6000-cpus.def b/gcc/config/rs6000/rs6000-cpus.def
index c3825bcccd8..6ac6c526342 100644
--- a/gcc/config/rs6000/rs6000-cpus.def
+++ b/gcc/config/rs6000/rs6000-cpus.def
@@ -122,6 +122,7 @@
 
 /* Mask of all options to set the default isa flags based on -mcpu=<xxx>.  */
 #define POWERPC_MASKS		(OPTION_MASK_ALTIVEC			\
+				 | OPTION_MASK_BLOCK_OPS_VECTOR_PAIR	\
 				 | OPTION_MASK_CMPB			\
 				 | OPTION_MASK_CRYPTO			\
 				 | OPTION_MASK_DFP			\
diff --git a/gcc/config/rs6000/rs6000.opt b/gcc/config/rs6000/rs6000.opt
index 4931d781c4e..39d6925b8f2 100644
--- a/gcc/config/rs6000/rs6000.opt
+++ b/gcc/config/rs6000/rs6000.opt
@@ -324,6 +324,8 @@ mblock-ops-unaligned-vsx
 Target Mask(BLOCK_OPS_UNALIGNED_VSX) Var(rs6000_isa_flags)
 Generate unaligned VSX load/store for inline expansion of memcpy/memmove.
 
+; Not set on power10 by default due to performance reasons, but it could be set
+; in future processors.
 mblock-ops-vector-pair
 Target Undocumented Mask(BLOCK_OPS_VECTOR_PAIR) Var(rs6000_isa_flags)
 Generate unaligned VSX vector pair load/store for inline expansion of memcpy/memmove.