[Hexagon] Implement target feature +reserved-r19

llvm-svn: 326364

3 files changed, 8 insertions, 0 deletions

diff --git a/llvm/lib/Target/Hexagon/Hexagon.td b/llvm/lib/Target/Hexagon/Hexagon.td
index e1f3dec59f7..cacf9fb9d13 100644
--- a/llvm/lib/Target/Hexagon/Hexagon.td
+++ b/llvm/lib/Target/Hexagon/Hexagon.td
@@ -55,6 +55,8 @@ def FeatureMemNoShuf: SubtargetFeature<"mem_noshuf", "HasMemNoShuf", "false",
       "Supports mem_noshuf feature">;
 def FeatureDuplex : SubtargetFeature<"duplex", "EnableDuplex", "true",
       "Enable generation of duplex instruction">;
+def FeatureReservedR19: SubtargetFeature<"reserved-r19", "ReservedR19",
+      "true", "Reserve register R19">;
 
 //===----------------------------------------------------------------------===//
 // Hexagon Instruction Predicate Definitions.
diff --git a/llvm/lib/Target/Hexagon/HexagonRegisterInfo.cpp b/llvm/lib/Target/Hexagon/HexagonRegisterInfo.cpp
index 9c16b77a90d..3754a04f501 100644
--- a/llvm/lib/Target/Hexagon/HexagonRegisterInfo.cpp
+++ b/llvm/lib/Target/Hexagon/HexagonRegisterInfo.cpp
@@ -171,6 +171,9 @@ BitVector HexagonRegisterInfo::getReservedRegs(const MachineFunction &MF)
   Reserved.set(Hexagon::C8);
   Reserved.set(Hexagon::USR_OVF);
 
+  if (MF.getSubtarget<HexagonSubtarget>().hasReservedR19())
+    Reserved.set(Hexagon::R19);
+
   for (int x = Reserved.find_first(); x >= 0; x = Reserved.find_next(x))
     markSuperRegs(Reserved, x);
 
diff --git a/llvm/lib/Target/Hexagon/HexagonSubtarget.h b/llvm/lib/Target/Hexagon/HexagonSubtarget.h
index af93f20d97f..c1e46e3f208 100644
--- a/llvm/lib/Target/Hexagon/HexagonSubtarget.h
+++ b/llvm/lib/Target/Hexagon/HexagonSubtarget.h
@@ -52,6 +52,8 @@ class HexagonSubtarget : public HexagonGenSubtargetInfo {
 
   bool HasMemNoShuf = false;
   bool EnableDuplex = false;
+  bool ReservedR19 = false;
+
 public:
   Hexagon::ArchEnum HexagonArchVersion;
   Hexagon::ArchEnum HexagonHVXVersion = Hexagon::ArchEnum::V4;
@@ -152,6 +154,7 @@ public:
   bool useHVX128BOps() const { return useHVXOps() && UseHVX128BOps; }
   bool useHVX64BOps() const { return useHVXOps() && UseHVX64BOps; }
   bool hasMemNoShuf() const { return HasMemNoShuf; }
+  bool hasReservedR19() const { return ReservedR19; }
   bool useLongCalls() const { return UseLongCalls; }
   bool usePredicatedCalls() const;