[GlobalISel] Restrict G_MERGE_VALUES capability and replace with new opcodes.

This patch restricts the capability of G_MERGE_VALUES, and uses the new
G_BUILD_VECTOR and G_CONCAT_VECTORS opcodes instead in the appropriate places.

This patch also includes AArch64 support for selecting G_BUILD_VECTOR of <4 x s32>
and <2 x s64> vectors.

Differential Revisions: https://reviews.llvm.org/D53629

llvm-svn: 348788

1 files changed, 2 insertions, 0 deletions

diff --git a/llvm/lib/CodeGen/GlobalISel/Legalizer.cpp b/llvm/lib/CodeGen/GlobalISel/Legalizer.cpp
index a05ee38169d..9f4d2aa8e4a 100644
--- a/llvm/lib/CodeGen/GlobalISel/Legalizer.cpp
+++ b/llvm/lib/CodeGen/GlobalISel/Legalizer.cpp
@@ -65,6 +65,8 @@ static bool isArtifact(const MachineInstr &MI) {
   case TargetOpcode::G_SEXT:
   case TargetOpcode::G_MERGE_VALUES:
   case TargetOpcode::G_UNMERGE_VALUES:
+  case TargetOpcode::G_CONCAT_VECTORS:
+  case TargetOpcode::G_BUILD_VECTOR:
     return true;
   }
 }