Initial Subzero WASM prototype.

src/IceCfg.cpp

Index: src/IceCfg.cpp
diff --git a/src/IceCfg.cpp b/src/IceCfg.cpp
index 85be8b9e46040b97dd0f0788bed327cfe888cfcc..da6cdf22886ab44c85761173eeb5fbc3a3394c29 100644
--- a/src/IceCfg.cpp
+++ b/src/IceCfg.cpp
@@ -239,6 +239,22 @@ void Cfg::translate() {
     getContext()->dumpTimers();
 }
 
+void Cfg::fixPhiNodes() {
+  for (auto *Node : Nodes) {
+    // Fix all the phi edges since WASM can't tell how to make them correctly at
+    // the beginning.
+    assert(Node);
+    const auto &InEdges = Node->getInEdges();
+    for (auto &Inst : Node->getPhis()) {

[Jim Stichnoth, 2016/04/01 01:46:43]

I would use "auto *Instr" here.

[Eric Holk, 2016/04/01 19:15:01]

I changed it to `auto &Instr`. It seems the instructions are stored by value in
the list of phis, so I `auto *` doesn't work.

+      auto *Phi = llvm::cast<InstPhi>(&Inst);
+      assert(Phi);
+      for (SizeT i = 0; i < InEdges.size(); ++i) {
+        Phi->setLabel(i, InEdges[i]);
+      }
+    }
+  }
+}
+
 void Cfg::computeInOutEdges() {
   // Compute the out-edges.
   for (CfgNode *Node : Nodes)
@@ -396,7 +412,8 @@ void Cfg::reorderNodes() {
       // in-edge if the predecessor node was contracted). If this changes in
       // the future, rethink the strategy.
       assert(Node->getInEdges().size() >= 1);
-      assert(Node->getOutEdges().size() == 1);
+      assert(Node->getOutEdges().size() == 1 ||

[Jim Stichnoth, 2016/04/01 01:46:43]

This assert shows up at least a couple times, and it's not obvious at first
glance what the condition represents.  How about a helper bool function with a
self-documenting name?

[Eric Holk, 2016/04/01 19:15:01]

Done.

+             Node->getOutEdges()[0] == Node->getOutEdges()[1]);
 
       // If it's a (non-critical) edge where the successor has a single
       // in-edge, then place it before the successor.