Add a basic TargetARM32 skeleton which knows nothing.

src/IceTargetLoweringARM32.h

Index: src/IceTargetLoweringARM32.h
diff --git a/src/IceTargetLoweringARM32.h b/src/IceTargetLoweringARM32.h
new file mode 100644
index 0000000000000000000000000000000000000000..05913a74580e5bca88a955fb9b1cb59135d36a36
--- /dev/null
+++ b/src/IceTargetLoweringARM32.h
@@ -0,0 +1,141 @@
+//===- subzero/src/IceTargetLoweringARM32.h - ARM32 lowering ----*- C++ -*-===//
+//
+//                        The Subzero Code Generator
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file declares the TargetLoweringARM32 class, which implements the
+// TargetLowering interface for the ARM 32-bit architecture.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef SUBZERO_SRC_ICETARGETLOWERINGARM32_H
+#define SUBZERO_SRC_ICETARGETLOWERINGARM32_H
+
+#include "IceDefs.h"
+#include "IceRegistersARM32.h"
+#include "IceTargetLowering.h"
+
+namespace Ice {
+
+class TargetARM32 : public TargetLowering {
+  TargetARM32() = delete;
+  TargetARM32(const TargetARM32 &) = delete;
+  TargetARM32 &operator=(const TargetARM32 &) = delete;
+
+public:
+  static TargetARM32 *create(Cfg *Func) { return new TargetARM32(Func); }

[Jim Stichnoth, 2015/04/17 19:16:02]

Just noticed that TargetFoo::create() and TargetLowering::createLowering()
should probably be returning std::unique_ptr<TargetLowering>, similar to what
TargetDataLowering does.

Maybe add a TODO here for later?

[jvoung (off chromium), 2015/04/21 17:05:30]

Done.

+
+  void translateOm1() override;
+  void translateO2() override;
+  bool doBranchOpt(Inst *I, const CfgNode *NextNode) override;
+
+  SizeT getNumRegisters() const override { return RegARM32::Reg_NUM; }
+  Variable *getPhysicalRegister(SizeT RegNum, Type Ty = IceType_void) override;
+  IceString getRegName(SizeT RegNum, Type Ty) const override;
+  llvm::SmallBitVector getRegisterSet(RegSetMask Include,
+                                      RegSetMask Exclude) const override;
+  const llvm::SmallBitVector &getRegisterSetForType(Type Ty) const override {
+    return TypeToRegisterSet[Ty];
+  }
+  bool hasFramePointer() const override { return UsesFramePointer; }
+  SizeT getFrameOrStackReg() const override {
+    return UsesFramePointer ? RegARM32::Reg_fp : RegARM32::Reg_sp;
+  }
+  size_t typeWidthInBytesOnStack(Type Ty) const override {
+    // Round up to the next multiple of 4 bytes.  In particular, i1,
+    // i8, and i16 are rounded up to 4 bytes.
+    return (typeWidthInBytes(Ty) + 3) & ~3;
+  }
+  void emitVariable(const Variable *Var) const override;
+  void lowerArguments() override;
+  void addProlog(CfgNode *Node) override;
+  void addEpilog(CfgNode *Node) override;
+  SizeT makeNextLabelNumber() { return NextLabelNumber++; }

[Jim Stichnoth, 2015/04/17 19:16:01]

Maybe this should be lifted into the base class?

(I don't see any other methods to lift, though hasFramePointer() is borderline.)

[jvoung (off chromium), 2015/04/21 17:05:30]

Done.

+
+protected:
+  explicit TargetARM32(Cfg *Func);
+
+  void postLower() override;
+
+  void lowerAlloca(const InstAlloca *Inst) override;
+  void lowerArithmetic(const InstArithmetic *Inst) override;
+  void lowerAssign(const InstAssign *Inst) override;
+  void lowerBr(const InstBr *Inst) override;
+  void lowerCall(const InstCall *Inst) override;
+  void lowerCast(const InstCast *Inst) override;
+  void lowerExtractElement(const InstExtractElement *Inst) override;
+  void lowerFcmp(const InstFcmp *Inst) override;
+  void lowerIcmp(const InstIcmp *Inst) override;
+  void lowerIntrinsicCall(const InstIntrinsicCall *Inst) override;
+  void lowerInsertElement(const InstInsertElement *Inst) override;
+  void lowerLoad(const InstLoad *Inst) override;
+  void lowerPhi(const InstPhi *Inst) override;
+  void lowerRet(const InstRet *Inst) override;
+  void lowerSelect(const InstSelect *Inst) override;
+  void lowerStore(const InstStore *Inst) override;
+  void lowerSwitch(const InstSwitch *Inst) override;
+  void lowerUnreachable(const InstUnreachable *Inst) override;
+  void prelowerPhis() override;
+  void lowerPhiAssignments(CfgNode *Node,
+                           const AssignList &Assignments) override;
+  void doAddressOptLoad() override;
+  void doAddressOptStore() override;
+  void randomlyInsertNop(float Probability) override;
+  void makeRandomRegisterPermutation(
+      llvm::SmallVectorImpl<int32_t> &Permutation,
+      const llvm::SmallBitVector &ExcludeRegisters) const override;
+
+  // Make a call to an external helper function.
+  // TODO(jvoung): Refactor to base TargetLowering?

[Jim Stichnoth, 2015/04/17 19:16:02]

sgtm

[jvoung (off chromium), 2015/04/21 17:05:30]

Went ahead and Done it.

+  InstCall *makeHelperCall(const IceString &Name, Variable *Dest,
+                           SizeT MaxSrcs) {
+    const bool HasTailCall = false;
+    Constant *CallTarget = Ctx->getConstantExternSym(Name);
+    InstCall *Call =
+        InstCall::create(Func, MaxSrcs, Dest, CallTarget, HasTailCall);
+    return Call;
+  }
+  static Type stackSlotType();
+
+  bool UsesFramePointer;
+  bool NeedsStackAlignment;
+  llvm::SmallBitVector TypeToRegisterSet[IceType_NUM];
+  llvm::SmallBitVector ScratchRegs;
+  llvm::SmallBitVector RegsUsed;
+  SizeT NextLabelNumber;
+  VarList PhysicalRegisters[IceType_NUM];
+  static IceString RegNames[];
+
+private:
+  ~TargetARM32() override {}
+};
+
+class TargetDataARM32 : public TargetDataLowering {
+  TargetDataARM32() = delete;
+  TargetDataARM32(const TargetDataARM32 &) = delete;
+  TargetDataARM32 &operator=(const TargetDataARM32 &) = delete;
+
+public:
+  static TargetDataLowering *create(GlobalContext *Ctx) {
+    return new TargetDataARM32(Ctx);
+  }
+
+  void lowerGlobals(std::unique_ptr<VariableDeclarationList> Vars) const final;
+  void lowerConstants() const final;
+
+protected:
+  explicit TargetDataARM32(GlobalContext *Ctx);
+
+private:
+  void lowerGlobal(const VariableDeclaration &Var) const;
+  ~TargetDataARM32() override {}
+  template <typename T> static void emitConstantPool(GlobalContext *Ctx);
+};
+
+} // end of namespace Ice
+
+#endif // SUBZERO_SRC_ICETARGETLOWERINGARM32_H