Fix register allocator

core/src/main/java/org/teavm/ast/decompilation/Decompiler.java

@@ -48,6 +48,7 @@ import org.teavm.model.MethodReference;
 import org.teavm.model.Program;
 import org.teavm.model.TextLocation;
 import org.teavm.model.TryCatchBlock;
+import org.teavm.model.instructions.AssignInstruction;
 import org.teavm.model.instructions.BinaryBranchingInstruction;
 import org.teavm.model.instructions.BranchingInstruction;
 import org.teavm.model.instructions.JumpInstruction;
@@ -299,13 +300,24 @@ public class Decompiler {
         if (exceptionHandlers[block.getIndex()]) {
             return false;
         }
-        if (block.instructionCount() != 1 || block.getExceptionVariable() != null) {
+        if (block.getExceptionVariable() != null) {
             return false;
         }
         Instruction instruction = block.getLastInstruction();
-        return instruction instanceof JumpInstruction
+        if (!(instruction instanceof JumpInstruction)
-                || instruction instanceof BranchingInstruction
+                && !(instruction instanceof BranchingInstruction)
-                || instruction instanceof BinaryBranchingInstruction;
+                && !(instruction instanceof BinaryBranchingInstruction)) {
+            return false;
+        }
+
+        while (instruction.getPrevious() != null) {
+            instruction = instruction.getPrevious();
+            if (!(instruction instanceof AssignInstruction)) {
+                return false;
+            }
+        }
+
+        return true;
     }
 
     private void closeExpiredBookmarks(StatementGenerator generator, List<TryCatchBlock> tryCatchBlocks) {

core/src/main/java/org/teavm/model/util/InterferenceGraphBuilder.java

@@ -27,24 +27,10 @@ class InterferenceGraphBuilder {
         }
         UsageExtractor useExtractor = new UsageExtractor();
         DefinitionExtractor defExtractor = new DefinitionExtractor();
-        TransitionExtractor succExtractor = new TransitionExtractor();
-        List<List<Incoming>> outgoings = ProgramUtils.getPhiOutputs(program);
-        BitSet live = new BitSet();
         for (int i = 0; i < program.basicBlockCount(); ++i) {
             BasicBlock block = program.basicBlockAt(i);
-            block.getLastInstruction().acceptVisitor(succExtractor);
 
-            BitSet liveOut = liveness.liveOut(i);
+            BitSet live = liveness.liveOut(i);
-            live.clear();
-            for (int j = 0; j < liveOut.length(); ++j) {
-                if (liveOut.get(j)) {
-                    live.set(j);
-                }
-            }
-
-            for (Incoming outgoing : outgoings.get(i)) {
-                live.set(outgoing.getValue().getIndex());
-            }
 
             for (Instruction insn = block.getLastInstruction(); insn != null; insn = insn.getPrevious()) {
                 insn.acceptVisitor(useExtractor);
@@ -69,18 +55,6 @@ class InterferenceGraphBuilder {
                 }
             }
 
-            BitSet liveIn = liveness.liveIn(i);
-            live.clear();
-            for (int j = 0; j < liveOut.length(); ++j) {
-                if (liveIn.get(j)) {
-                    live.set(j);
-                }
-            }
-
-            for (Phi phi : block.getPhis()) {
-                live.set(phi.getReceiver().getIndex());
-            }
-
             for (Phi phi : block.getPhis()) {
                 connect(nodes, phi.getReceiver().getIndex(), live);
             }

core/src/main/java/org/teavm/model/util/RegisterAllocator.java

@@ -32,6 +32,7 @@ import org.teavm.model.MethodReference;
 import org.teavm.model.Phi;
 import org.teavm.model.Program;
 import org.teavm.model.ProgramReader;
+import org.teavm.model.TextLocation;
 import org.teavm.model.Variable;
 import org.teavm.model.instructions.AssignInstruction;
 import org.teavm.model.instructions.JumpInstruction;
@@ -188,41 +189,22 @@ public class RegisterAllocator {
         DefinitionExtractor definitionExtractor = new DefinitionExtractor();
         List<Instruction> nextInstructions = new ArrayList<>();
         for (BasicBlock block : program.getBasicBlocks()) {
+            for (Phi phi : block.getPhis()) {
+                addExceptionHandlingCopies(catchIncomingsByVariable, phi.getReceiver(), block,
+                        program, block.getFirstInstruction().getLocation(), nextInstructions);
+            }
+
+            if (!nextInstructions.isEmpty()) {
+                block.addFirstAll(nextInstructions);
+                nextInstructions.clear();
+            }
+
             for (Instruction instruction : block) {
                 instruction.acceptVisitor(definitionExtractor);
                 Variable[] definedVariables = definitionExtractor.getDefinedVariables();
                 for (Variable definedVariable : definedVariables) {
-                    if (definedVariable.getIndex() >= catchIncomingsByVariable.size()) {
+                    addExceptionHandlingCopies(catchIncomingsByVariable, definedVariable, block,
-                        continue;
+                            program, instruction.getLocation(), nextInstructions);
-                    }
-                    List<Incoming> catchIncomings = catchIncomingsByVariable.get(definedVariable.getIndex());
-                    if (catchIncomings == null) {
-                        continue;
-                    }
-
-                    Incoming incoming = null;
-                    for (Iterator<Incoming> iter = catchIncomings.iterator(); iter.hasNext();) {
-                        if (iter.next().getValue() == definedVariable) {
-                            iter.remove();
-                            break;
-                        }
-                    }
-                    if (incoming == null) {
-                        continue;
-                    }
-
-                    Variable copy = program.createVariable();
-                    copy.setLabel(incoming.getPhi().getReceiver().getLabel());
-                    copy.setDebugName(incoming.getPhi().getReceiver().getDebugName());
-
-                    AssignInstruction copyInstruction = new AssignInstruction();
-                    copyInstruction.setReceiver(copy);
-                    copyInstruction.setAssignee(incoming.getValue());
-                    copyInstruction.setLocation(instruction.getLocation());
-
-                    incoming.setValue(copy);
-
-                    nextInstructions.add(copyInstruction);
                 }
 
                 if (!nextInstructions.isEmpty()) {
@@ -242,18 +224,48 @@ public class RegisterAllocator {
                 Variable copy = program.createVariable();
                 copy.setLabel(incoming.getPhi().getReceiver().getLabel());
                 copy.setDebugName(incoming.getPhi().getReceiver().getDebugName());
-                incoming.setValue(copy);
 
                 AssignInstruction copyInstruction = new AssignInstruction();
                 copyInstruction.setReceiver(copy);
                 copyInstruction.setAssignee(incoming.getValue());
                 copyInstruction.setLocation(block.getFirstInstruction().getLocation());
+                incoming.setValue(copy);
 
                 block.addFirst(copyInstruction);
             }
         }
     }
 
+    private void addExceptionHandlingCopies(List<List<Incoming>> catchIncomingsByVariable, Variable definedVariable,
+            BasicBlock block, Program program, TextLocation location, List<Instruction> nextInstructions) {
+        if (definedVariable.getIndex() >= catchIncomingsByVariable.size()) {
+            return;
+        }
+        List<Incoming> catchIncomings = catchIncomingsByVariable.get(definedVariable.getIndex());
+        if (catchIncomings == null) {
+            return;
+        }
+
+        for (Iterator<Incoming> iter = catchIncomings.iterator(); iter.hasNext();) {
+            Incoming incoming = iter.next();
+            if (incoming.getSource() == block) {
+                Variable copy = program.createVariable();
+                copy.setLabel(incoming.getPhi().getReceiver().getLabel());
+                copy.setDebugName(incoming.getPhi().getReceiver().getDebugName());
+
+                AssignInstruction copyInstruction = new AssignInstruction();
+                copyInstruction.setReceiver(copy);
+                copyInstruction.setAssignee(incoming.getValue());
+                copyInstruction.setLocation(location);
+
+                incoming.setValue(copy);
+                nextInstructions.add(copyInstruction);
+
+                iter.remove();
+            }
+        }
+    }
+
     private void insertCopy(Incoming incoming, Map<BasicBlock, BasicBlock> blockMap) {
         Phi phi = incoming.getPhi();
         Program program = phi.getBasicBlock().getProgram();

core/src/main/resources/org/teavm/backend/c/runtime.c

@@ -276,9 +276,9 @@ void teavm_outOfMemory() {
 
 static char16_t* teavm_utf16ToUtf32(char16_t* source, char32_t* target) {
     char16_t c = *source;
-    if (c & 0xFC00 == 0xD800) {
+    if ((c & 0xFC00) == 0xD800) {
         char16_t n = *(source + 1);
-        if (n & 0xFC00 == 0xDC00) {
+        if ((n & 0xFC00) == 0xDC00) {
             *target = (((c & ~0xFC00) << 10) | (n & ~0xFC00)) + 0x10000;
             return source + 2;
         }

tests/src/test/java/org/teavm/vm/VMTest.java

@@ -90,6 +90,7 @@ public class VMTest {
         int a = 23;
         try {
             a = Integer.parseInt("not a number");
+            fail("Exception not thrown");
         } catch (NumberFormatException e) {
             // do nothing
         }