[Power9] Add exploitation of non-permuting memory ops

This patch corresponds to review:
https://reviews.llvm.org/D19825

The new lxvx/stxvx instructions do not require the swaps to line the elements
up correctly. In order to select them over the lxvd2x/lxvw4x instructions which
require swaps, the patterns for the old instruction have a predicate that
ensures they won't be selected on Power9 and newer CPUs.

llvm-svn: 282143

1 files changed, 3 insertions, 0 deletions

diff --git a/llvm/lib/Target/PowerPC/PPCSubtarget.h b/llvm/lib/Target/PowerPC/PPCSubtarget.h
index f58c7c10c8b..d80a9ad8d34 100644
--- a/llvm/lib/Target/PowerPC/PPCSubtarget.h
+++ b/llvm/lib/Target/PowerPC/PPCSubtarget.h
@@ -277,6 +277,9 @@ public:
   bool hasFloat128() const { return HasFloat128; }
   bool isISA3_0() const { return IsISA3_0; }
   bool useLongCalls() const { return UseLongCalls; }
+  bool needsSwapsForVSXMemOps() const {
+    return hasVSX() && isLittleEndian() && !hasP9Vector();
+  }
 
   POPCNTDKind hasPOPCNTD() const { return HasPOPCNTD; }