Implement SystemZRegisterInfo::getMatchingSuperRegClass to enable cross-class joins.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@130857 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 14 insertions, 0 deletions

diff --git a/lib/Target/SystemZ/SystemZRegisterInfo.cpp b/lib/Target/SystemZ/SystemZRegisterInfo.cpp
index 28f94f4b6c..18b82f3a6c 100644
--- a/lib/Target/SystemZ/SystemZRegisterInfo.cpp
+++ b/lib/Target/SystemZ/SystemZRegisterInfo.cpp
@@ -58,6 +58,20 @@ BitVector SystemZRegisterInfo::getReservedRegs(const MachineFunction &MF) const
   return Reserved;
 }
 
+const TargetRegisterClass*
+SystemZRegisterInfo::getMatchingSuperRegClass(const TargetRegisterClass *A,
+                                              const TargetRegisterClass *B,
+                                              unsigned Idx) const {
+  switch(Idx) {
+  // Exact sub-classes don't exist for the other sub-register indexes.
+  default: return 0;
+  case SystemZ::subreg_32bit:
+    if (B == SystemZ::ADDR32RegisterClass)
+      return A->getSize() == 8 ? SystemZ::ADDR64RegisterClass : 0;
+    return A;
+  }
+}
+
 void SystemZRegisterInfo::
 eliminateCallFramePseudoInstr(MachineFunction &MF, MachineBasicBlock &MBB,
                               MachineBasicBlock::iterator I) const {