[Hexagon] Adding functionality for duplexing. Duplexing is a way to compress commonly used pairs of instructions in order to reduce code size. The test case duplex.ll normally would be 8 bytes, assign register to 0 and jump to link register. After duplexing this is only 4 bytes. This also tests the HexagonMCShuffler code path which is used to make sure duplexed instructions still follow slot requirements.

llvm-svn: 239095

1 files changed, 7 insertions, 2 deletions

diff --git a/llvm/lib/Target/Hexagon/HexagonAsmPrinter.cpp b/llvm/lib/Target/Hexagon/HexagonAsmPrinter.cpp
index 48113610c80..e9bb1006201 100644
--- a/llvm/lib/Target/Hexagon/HexagonAsmPrinter.cpp
+++ b/llvm/lib/Target/Hexagon/HexagonAsmPrinter.cpp
@@ -20,6 +20,7 @@
 #include "HexagonTargetMachine.h"
 #include "MCTargetDesc/HexagonInstPrinter.h"
 #include "MCTargetDesc/HexagonMCInstrInfo.h"
+#include "MCTargetDesc/HexagonMCShuffler.h"
 #include "llvm/ADT/SmallString.h"
 #include "llvm/ADT/SmallVector.h"
 #include "llvm/ADT/StringExtras.h"
@@ -199,9 +200,13 @@ void HexagonAsmPrinter::EmitInstruction(const MachineInstr *MI) {
     HexagonLowerToMC(MI, MCB, *this);
     HexagonMCInstrInfo::padEndloop(MCB);
   }
+  // Examine the packet and convert pairs of instructions to duplex
+  // instructions when possible.
+  MCInst InstBundlePreDuplex = MCInst(MCB);
+  SmallVector<DuplexCandidate, 8> possibleDuplexes;
+  possibleDuplexes = HexagonMCInstrInfo::getDuplexPossibilties(*Subtarget->getInstrInfo(), MCB);
+  HexagonMCShuffle(*Subtarget->getInstrInfo(), *Subtarget, OutStreamer->getContext(), MCB, possibleDuplexes);
   EmitToStreamer(*OutStreamer, MCB);
-
-  return;
 }
 
 extern "C" void LLVMInitializeHexagonAsmPrinter() {