Start pushing changes for Mips Fast-Isel

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@206505 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Target/Mips/CMakeLists.txt

@@ -26,6 +26,7 @@ add_llvm_target(MipsCodeGen
   MipsCodeEmitter.cpp
   MipsConstantIslandPass.cpp
   MipsDelaySlotFiller.cpp
+  MipsFastISel.cpp
   MipsJITInfo.cpp
   MipsInstrInfo.cpp
   MipsISelDAGToDAG.cpp

lib/Target/Mips/MipsFastISel.cpp

@@ -0,0 +1,28 @@
+//===-- MipsastISel.cpp - Mips FastISel implementation
+//---------------------===//
+
+#include "llvm/CodeGen/FunctionLoweringInfo.h"
+#include "llvm/CodeGen/FastISel.h"
+#include "llvm/Target/TargetLibraryInfo.h"
+#include "MipsISelLowering.h"
+
+using namespace llvm;
+
+namespace {
+
+class MipsFastISel final : public FastISel {
+
+public:
+  explicit MipsFastISel(FunctionLoweringInfo &funcInfo,
+                        const TargetLibraryInfo *libInfo)
+      : FastISel(funcInfo, libInfo) {}
+  bool TargetSelectInstruction(const Instruction *I) override { return false; }
+};
+}
+
+namespace llvm {
+FastISel *Mips::createFastISel(FunctionLoweringInfo &funcInfo,
+                               const TargetLibraryInfo *libInfo) {
+  return new MipsFastISel(funcInfo, libInfo);
+}
+}

lib/Target/Mips/MipsISelLowering.cpp

@@ -50,6 +50,11 @@ NoZeroDivCheck("mno-check-zero-division", cl::Hidden,
                cl::desc("MIPS: Don't trap on integer division by zero."),
                cl::init(false));
 
+cl::opt<bool>
+EnableMipsFastISel("mips-fast-isel", cl::Hidden,
+  cl::desc("Allow mips-fast-isel to be used"),
+  cl::init(false));
+
 static const MCPhysReg O32IntRegs[4] = {
   Mips::A0, Mips::A1, Mips::A2, Mips::A3
 };
@@ -396,6 +401,15 @@ const MipsTargetLowering *MipsTargetLowering::create(MipsTargetMachine &TM) {
   return llvm::createMipsSETargetLowering(TM);
 }
 
+// Create a fast isel object.
+FastISel *
+MipsTargetLowering::createFastISel(FunctionLoweringInfo &funcInfo,
+                                  const TargetLibraryInfo *libInfo) const {
+  if (!EnableMipsFastISel)
+    return TargetLowering::createFastISel(funcInfo, libInfo);
+  return Mips::createFastISel(funcInfo, libInfo);
+}
+
 EVT MipsTargetLowering::getSetCCResultType(LLVMContext &, EVT VT) const {
   if (!VT.isVector())
     return MVT::i32;

lib/Target/Mips/MipsISelLowering.h

@@ -218,6 +218,11 @@ namespace llvm {
 
     static const MipsTargetLowering *create(MipsTargetMachine &TM);
 
+    /// createFastISel - This method returns a target specific FastISel object,
+    /// or null if the target does not support "fast" ISel.
+    FastISel *createFastISel(FunctionLoweringInfo &funcInfo,
+                             const TargetLibraryInfo *libInfo) const override;
+
     virtual MVT getScalarShiftAmountTy(EVT LHSTy) const { return MVT::i32; }
 
     virtual void LowerOperationWrapper(SDNode *N,
@@ -608,6 +613,11 @@ namespace llvm {
   /// Create MipsTargetLowering objects.
   const MipsTargetLowering *createMips16TargetLowering(MipsTargetMachine &TM);
   const MipsTargetLowering *createMipsSETargetLowering(MipsTargetMachine &TM);
+
+  namespace Mips {
+    FastISel *createFastISel(FunctionLoweringInfo &funcInfo,
+                             const TargetLibraryInfo *libInfo);
+  }
 }
 
 #endif // MipsISELLOWERING_H