Add NOP to ARM IR lowering.

src/IceInstARM32.cpp

Index: src/IceInstARM32.cpp
diff --git a/src/IceInstARM32.cpp b/src/IceInstARM32.cpp
index 6b9c5a0ab545e4fb4f66b07bfa0f88bac954a908..025f71fb8daccd6882ba825247794c853a28b145 100644
--- a/src/IceInstARM32.cpp
+++ b/src/IceInstARM32.cpp
@@ -1094,6 +1094,9 @@ InstARM32Vabs::InstARM32Vabs(Cfg *Func, Variable *Dest, Variable *Src,
 InstARM32Dmb::InstARM32Dmb(Cfg *Func)
     : InstARM32Pred(Func, InstARM32::Dmb, 0, nullptr, CondARM32::AL) {}
 
+InstARM32Nop::InstARM32Nop(Cfg *Func)

[Jim Stichnoth, 2016/02/08 18:17:50]

Should nop (and dmb above) be inserted into the list more alphabetically?

[Karl, 2016/02/09 21:10:01]

Really? Where do you see sorting? For the most part, I have no idea how this
file was sorted. However, I will at least sort this short list of constructors.

+    : InstARM32Pred(Func, InstARM32::Nop, 0, nullptr, CondARM32::AL) {}
+
 // ======================== Dump routines ======================== //
 
 // Two-addr ops
@@ -2298,6 +2301,27 @@ void InstARM32Dmb::dump(const Cfg *Func) const {
                                       "sy";
 }
 
+void InstARM32Nop::emit(const Cfg *Func) const {
+  if (!BuildDefs::dump())
+    return;
+  assert(getSrcSize() == 0);
+  Func->getContext()->getStrEmit() << "\t"
+                                   << "nop";
+}
+
+void InstARM32Nop::emitIAS(const Cfg *Func) const {
+  assert(getSrcSize() == 0);
+  Func->getAssembler<ARM32::AssemblerARM32>()->nop();
+}
+
+void InstARM32Nop::dump(const Cfg *Func) const {
+  if (!BuildDefs::dump())
+    return;
+  assert(getSrcSize() == 0);
+  Func->getContext()->getStrDump() << "\t"

[Jim Stichnoth, 2016/02/08 18:17:50]

dump() doesn't usually prepend a tab character.

[Karl, 2016/02/09 21:10:01]

Done.

+                                   << "nop";
+}
+
 void OperandARM32Mem::emit(const Cfg *Func) const {
   if (!BuildDefs::dump())
     return;