ARM: Assign "actuals" at call site to the appropriate GPR/stack slot.

src/IceInstARM32.h

 //===- subzero/src/IceInstARM32.h - ARM32 machine instructions --*- 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 InstARM32 and OperandARM32 classes and
@@ skipping 240 matching lines @@
 class InstARM32 : public InstTarget {
   InstARM32() = delete;
   InstARM32(const InstARM32 &) = delete;
   InstARM32 &operator=(const InstARM32 &) = delete;
 
 public:
   enum InstKindARM32 {
     k__Start = Inst::Target,
     Adc,
     Add,
+    Adjuststack,
     And,
     Asr,
     Bic,
     Br,
     Call,
     Cmp,
     Eor,
     Ldr,
     Lsl,
     Lsr,
@@ skipping 328 matching lines @@
   static bool classof(const Inst *Inst) { return isClassof(Inst, Br); }
 
 private:
   InstARM32Br(Cfg *Func, const CfgNode *TargetTrue, const CfgNode *TargetFalse,
               CondARM32::Cond Predicate);
   ~InstARM32Br() override {}
   const CfgNode *TargetTrue;
   const CfgNode *TargetFalse;
 };
 
+// AdjustStack instruction - subtracts SP by the given amount and
+// updates the stack offset during code emission.

[Jim Stichnoth, 2015/06/18 19:47:33]

It would be helpful to document what appears at first glance to be a redundancy
between Amount and SrcAmount.  (It took me some digging to realize it was
because a large Amount has to be copied into a register.

I look forward to seeing the test of a non-Constant SrcAmount. :)

[jvoung (off chromium), 2015/06/18 21:18:30]

Yep -- okay done.
Ah yes =)

+class InstARM32AdjustStack : public InstARM32 {
+  InstARM32AdjustStack() = delete;
+  InstARM32AdjustStack(const InstARM32AdjustStack &) = delete;
+  InstARM32AdjustStack &operator=(const InstARM32AdjustStack &) = delete;
+
+public:
+  static InstARM32AdjustStack *create(Cfg *Func, Variable *SP, SizeT Amount,
+                                      Operand *SrcAmount) {
+    return new (Func->allocate<InstARM32AdjustStack>())
+        InstARM32AdjustStack(Func, SP, Amount, SrcAmount);
+  }
+  void emit(const Cfg *Func) const override;
+  void emitIAS(const Cfg *Func) const override;
+  void dump(const Cfg *Func) const override;
+  static bool classof(const Inst *Inst) { return isClassof(Inst, Adjuststack); }
+
+private:
+  InstARM32AdjustStack(Cfg *Func, Variable *SP, SizeT Amount,
+                       Operand *SrcAmount);
+  SizeT Amount;

[Jim Stichnoth, 2015/06/18 19:47:33]

const?

[jvoung (off chromium), 2015/06/18 21:18:30]

Done.

+};
+
 // Call instruction (bl/blx).  Arguments should have already been pushed.
 // Technically bl and the register form of blx can be predicated, but we'll
 // leave that out until needed.
 class InstARM32Call : public InstARM32 {
   InstARM32Call() = delete;
   InstARM32Call(const InstARM32Call &) = delete;
   InstARM32Call &operator=(const InstARM32Call &) = delete;
 
 public:
   static InstARM32Call *create(Cfg *Func, Variable *Dest, Operand *CallTarget) {
@@ skipping 209 matching lines @@
 // Declare partial template specializations of emit() methods that
 // already have default implementations.  Without this, there is the
 // possibility of ODR violations and link errors.
 
 template <> void InstARM32Movw::emit(const Cfg *Func) const;
 template <> void InstARM32Movt::emit(const Cfg *Func) const;
 
 } // end of namespace Ice
 
 #endif // SUBZERO_SRC_ICEINSTARM32_H