Initial Subzero WASM prototype.

src/IceCfgNode.cpp

Index: src/IceCfgNode.cpp
diff --git a/src/IceCfgNode.cpp b/src/IceCfgNode.cpp
index 212f742c53959789acaf5a036fd548303ea96eff..2b06ef80170f9680f3c06121a27a4fff67bff939 100644
--- a/src/IceCfgNode.cpp
+++ b/src/IceCfgNode.cpp
@@ -39,17 +39,35 @@ IceString CfgNode::getName() const {
 
 // Adds an instruction to either the Phi list or the regular instruction list.
 // Validates that all Phis are added before all regular instructions.
-void CfgNode::appendInst(Inst *Instr) {
+void CfgNode::appendInst(Inst *Instr, bool AllowPhisAnywhere) {
   ++InstCountEstimate;
+
+  if (auto Dest = Instr->getDest()) {

[Jim Stichnoth, 2016/03/29 17:49:57]

auto *
here and below

[Eric Holk, 2016/03/29 22:58:07]

Done.

+    Dest->setDefNode(this);
+  }
+
+  if (auto Br = llvm::dyn_cast<InstBr>(Instr)) {
+    if (auto N = Br->getTargetTrue()) {
+      N->addInEdge(this);
+      addOutEdge(N);
+    }
+    if (auto N = Br->getTargetFalse()) {
+      N->addInEdge(this);
+      addOutEdge(N);
+    }
+  }
+
   if (auto *Phi = llvm::dyn_cast<InstPhi>(Instr)) {
-    if (!Insts.empty()) {
+    if (!AllowPhisAnywhere && !Insts.empty()) {
       Func->setError("Phi instruction added to the middle of a block");
+      assert(false);

[JF, 2016/03/28 18:17:13]

llvm_unreachable

[Jim Stichnoth, 2016/03/29 17:49:57]

actually just remove the assert.

[Eric Holk, 2016/03/29 19:54:08]

Actually, I didn't mean to keep this assert here anyway, so I just removed it.

Done.

       return;
     }
     Phis.push_back(Phi);
   } else {
     Insts.push_back(Instr);
   }
+  Instr->setCfgNode(this);
 }
 
 namespace {
@@ -83,6 +101,8 @@ void CfgNode::computePredecessors() {
 }
 
 void CfgNode::computeSuccessors() {
+  OutEdges.clear();
+  InEdges.clear();
   OutEdges = Insts.rbegin()->getTerminatorEdges();
 }
 
@@ -874,7 +894,7 @@ void CfgNode::contractIfEmpty() {
   // Make sure there is actually a successor to repoint in-edges to.
   if (OutEdges.empty())
     return;
-  assert(OutEdges.size() == 1);
+  assert(OutEdges.size() == 1 || OutEdges[0] == OutEdges[1]);
   // Don't try to delete a self-loop.
   if (OutEdges[0] == this)
     return;