[Hexagon] Allow redefinition with immediates for hw loop conversion

Normally, if the registers holding the induction variable's bounds
are redefined inside of the loop's body, the loop cannot be converted
to a hardware loop. However, if the redefining instruction is actually
loading an immediate value into the register, this conversion is both
possible and legal (since the immediate itself will be used in the
loop setup in the preheader).

llvm-svn: 316218

1 files changed, 2 insertions, 0 deletions

diff --git a/llvm/lib/Target/Hexagon/HexagonTargetMachine.cpp b/llvm/lib/Target/Hexagon/HexagonTargetMachine.cpp
index 6d7518a5ff3..a66e212a765 100644
--- a/llvm/lib/Target/Hexagon/HexagonTargetMachine.cpp
+++ b/llvm/lib/Target/Hexagon/HexagonTargetMachine.cpp
@@ -126,6 +126,7 @@ namespace llvm {
   void initializeHexagonEarlyIfConversionPass(PassRegistry&);
   void initializeHexagonExpandCondsetsPass(PassRegistry&);
   void initializeHexagonGenMuxPass(PassRegistry&);
+  void initializeHexagonHardwareLoopsPass(PassRegistry&);
   void initializeHexagonLoopIdiomRecognizePass(PassRegistry&);
   void initializeHexagonVectorLoopCarriedReusePass(PassRegistry&);
   void initializeHexagonNewValueJumpPass(PassRegistry&);
@@ -184,6 +185,7 @@ extern "C" void LLVMInitializeHexagonTarget() {
   initializeHexagonConstExtendersPass(PR);
   initializeHexagonEarlyIfConversionPass(PR);
   initializeHexagonGenMuxPass(PR);
+  initializeHexagonHardwareLoopsPass(PR);
   initializeHexagonLoopIdiomRecognizePass(PR);
   initializeHexagonVectorLoopCarriedReusePass(PR);
   initializeHexagonNewValueJumpPass(PR);