Lower BR_JT on the XCore to a jump into a series of jump instructions.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@96942 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 13 insertions, 0 deletions

diff --git a/lib/Target/XCore/XCoreInstrInfo.cpp b/lib/Target/XCore/XCoreInstrInfo.cpp
index 5a548449d8..722e7470f0 100644
--- a/lib/Target/XCore/XCoreInstrInfo.cpp
+++ b/lib/Target/XCore/XCoreInstrInfo.cpp
@@ -145,6 +145,11 @@ static inline bool IsCondBranch(unsigned BrOpc) {
   return IsBRF(BrOpc) || IsBRT(BrOpc);
 }
 
+static inline bool IsBR_JT(unsigned BrOpc) {
+  return BrOpc == XCore::BR_JT
+      || BrOpc == XCore::BR_JT32;
+}
+
 /// GetCondFromBranchOpc - Return the XCore CC that matches 
 /// the correspondent Branch instruction opcode.
 static XCore::CondCode GetCondFromBranchOpc(unsigned BrOpc) 
@@ -271,6 +276,14 @@ XCoreInstrInfo::AnalyzeBranch(MachineBasicBlock &MBB, MachineBasicBlock *&TBB,
     return false;
   }
 
+  // Likewise if it ends with a branch table followed by an unconditional branch.
+  if (IsBR_JT(SecondLastInst->getOpcode()) && IsBRU(LastInst->getOpcode())) {
+    I = LastInst;
+    if (AllowModify)
+      I->eraseFromParent();
+    return true;
+  }
+
   // Otherwise, can't handle this.
   return true;
 }