ART: Build SSA form when try/catch is present

This patch implements support for try/catch in the SsaBuilder.
Values of locals are propagated from throwing sites inside try
blocks to their respective catch blocks and phis ("catch phis")
are created when necessary.

Change-Id: I0736565c2c4ff3f9f0924b6e3a785a50023f875a

1 files changed, 11 insertions, 0 deletions

diff --git a/compiler/optimizing/ssa_phi_elimination.cc b/compiler/optimizing/ssa_phi_elimination.cc
index 2f2e2d1fab..917341a1e7 100644
--- a/compiler/optimizing/ssa_phi_elimination.cc
+++ b/compiler/optimizing/ssa_phi_elimination.cc
@@ -114,6 +114,12 @@ void SsaRedundantPhiElimination::Run() {
       continue;
     }
 
+    if (phi->InputCount() == 0) {
+      DCHECK(phi->IsCatchPhi());
+      DCHECK(phi->IsDead());
+      continue;
+    }
+
     // Find if the inputs of the phi are the same instruction.
     HInstruction* candidate = phi->InputAt(0);
     // A loop phi cannot have itself as the first phi. Note that this
@@ -137,6 +143,11 @@ void SsaRedundantPhiElimination::Run() {
       continue;
     }
 
+    // The candidate may not dominate a phi in a catch block.
+    if (phi->IsCatchPhi() && !candidate->StrictlyDominates(phi)) {
+      continue;
+    }
+
     if (phi->IsInLoop()) {
       // Because we're updating the users of this phi, we may have new
       // phis candidate for elimination if this phi is in a loop. Add phis that