[turbofan] Tests and fixes for ARM64 load/store with immediate offset.

src/arm64/assembler-arm64.h

Index: src/arm64/assembler-arm64.h
diff --git a/src/arm64/assembler-arm64.h b/src/arm64/assembler-arm64.h
index f01cbaf08946d89a93136971267f0c938add07f9..986167658ddee36661aca4da2c1215ba8e786b81 100644
--- a/src/arm64/assembler-arm64.h
+++ b/src/arm64/assembler-arm64.h
@@ -1850,6 +1850,9 @@ class Assembler : public AssemblerBase {
   inline static Instr ImmBarrierType(int imm2);
   inline static LSDataSize CalcLSDataSize(LoadStoreOp op);
 
+  static bool IsImmLSUnscaled(ptrdiff_t offset);

[Benedikt Meurer, 2014/09/09 05:02:36]

Why ptrdiff_t here? It looks like you really want to use int64_t. ptrdiff_t
should only be used for distance between pointers to the same array.

+  static bool IsImmLSScaled(ptrdiff_t offset, LSDataSize size);
+
   // Move immediates encoding.
   inline static Instr ImmMoveWide(uint64_t imm);
   inline static Instr ShiftMoveWide(int64_t shift);
@@ -1933,8 +1936,6 @@ class Assembler : public AssemblerBase {
   void LoadStore(const CPURegister& rt,
                  const MemOperand& addr,
                  LoadStoreOp op);
-  static bool IsImmLSUnscaled(ptrdiff_t offset);
-  static bool IsImmLSScaled(ptrdiff_t offset, LSDataSize size);
 
   void LoadStorePair(const CPURegister& rt, const CPURegister& rt2,
                      const MemOperand& addr, LoadStorePairOp op);