Subzero ARM: lowerArguments (GPR), basic legalize(), and lowerRet(i32, i64).

src/IceInst.cpp

Index: src/IceInst.cpp
diff --git a/src/IceInst.cpp b/src/IceInst.cpp
index b06f6dfa12449039c441670c016b7641ed0672ba..0e6be75ffd8b6a3dd34aa2427c5eada0ff106461 100644
--- a/src/IceInst.cpp
+++ b/src/IceInst.cpp
@@ -873,4 +873,20 @@ void InstTarget::dump(const Cfg *Func) const {
   Inst::dump(Func);
 }
 
+bool checkForRedundantAssign(const Variable *Dest, const Operand *Source) {
+  const auto SrcVar = llvm::dyn_cast<const Variable>(Source);
+  if (!SrcVar)
+    return false;
+  if (Dest->hasReg() && Dest->getRegNum() == SrcVar->getRegNum()) {
+    // TODO: On x86-64, instructions like "mov eax, eax" are used to
+    // clear the upper 32 bits of rax.  We need to recognize and
+    // preserve these.
+    return true;
+  }
+  if (!Dest->hasReg() && !SrcVar->hasReg() &&
+      Dest->getStackOffset() == SrcVar->getStackOffset())
+    return true;
+  return false;
+}
+
 } // end of namespace Ice