--- a/graal/com.oracle.graal.compiler/src/com/oracle/graal/compiler/alloc/LinearScan.java	Tue Mar 12 17:26:53 2013 +0100
+++ b/graal/com.oracle.graal.compiler/src/com/oracle/graal/compiler/alloc/LinearScan.java	Tue Mar 12 17:27:18 2013 +0100
@@ -282,7 +282,6 @@
      * @return the created interval
      */
     Interval createInterval(Value operand) {
-        assert isProcessed(operand);
         assert isLegal(operand);
         int operandNumber = operandNumber(operand);
         Interval interval = new Interval(operand, operandNumber);
@@ -1951,12 +1950,6 @@
                 throw new GraalInternalError("");
             }
 
-            if (!isProcessed(i1.location())) {
-                TTY.println("Can not have an Interval for an ignored register " + i1.location());
-                TTY.println(i1.logString(this));
-                throw new GraalInternalError("");
-            }
-
             if (i1.first() == Range.EndMarker) {
                 TTY.println("Interval %d has no Range", i1.operandNumber);
                 TTY.println(i1.logString(this));

--- a/graal/com.oracle.graal.hotspot.amd64/src/com/oracle/graal/hotspot/amd64/AMD64HotSpotRegisterConfig.java	Tue Mar 12 17:26:53 2013 +0100
+++ b/graal/com.oracle.graal.hotspot.amd64/src/com/oracle/graal/hotspot/amd64/AMD64HotSpotRegisterConfig.java	Tue Mar 12 17:27:18 2013 +0100
@@ -33,15 +33,12 @@
 import com.oracle.graal.api.meta.*;
 import com.oracle.graal.graph.*;
 import com.oracle.graal.hotspot.*;
+import com.oracle.graal.phases.*;
 
 // @formatter:off
 public class AMD64HotSpotRegisterConfig implements RegisterConfig {
 
-    private final Register[] allocatable = {
-        rax, rbx, rcx, rdx, /*rsp,*/ rbp, rsi, rdi, r8, r9, /* r10, */r11, r12, r13, r14, /*r15, */
-        xmm0, xmm1, xmm2,  xmm3,  xmm4,  xmm5,  xmm6,  xmm7,
-        xmm8, xmm9, xmm10, xmm11, xmm12, xmm13, xmm14, xmm15
-    };
+    private final Register[] allocatable = initAllocatable();
 
     private final EnumMap<RegisterFlag, Register[]> categorized = Register.categorize(allocatable);
 
@@ -68,6 +65,34 @@
 
     private final CalleeSaveLayout csl;
 
+    private static Register findRegister(String name, Register[] all) {
+        for (Register reg : all) {
+            if (reg.name.equals(name)) {
+                return reg;
+            }
+        }
+        throw new IllegalArgumentException("register " + name + " is not allocatable");
+    }
+
+    private static Register[] initAllocatable() {
+        Register[] allocatable = {
+                        rax, rbx, rcx, rdx, /*rsp,*/ rbp, rsi, rdi, r8, r9, /* r10, */r11, r12, r13, r14, /*r15, */
+                        xmm0, xmm1, xmm2,  xmm3,  xmm4,  xmm5,  xmm6,  xmm7,
+                        xmm8, xmm9, xmm10, xmm11, xmm12, xmm13, xmm14, xmm15
+                    };
+
+        if (GraalOptions.RegisterPressure != null) {
+            String[] names = GraalOptions.RegisterPressure.split(",");
+            Register[] regs = new Register[names.length];
+            for (int i = 0; i < names.length; i++) {
+                regs[i] = findRegister(names[i], allocatable);
+            }
+            return regs;
+        }
+
+        return allocatable;
+    }
+
     public AMD64HotSpotRegisterConfig(HotSpotVMConfig config, boolean globalStubConfig) {
         if (config.windowsOs) {
             javaGeneralParameterRegisters = new Register[] {rdx, r8, r9, rdi, rsi, rcx};

--- a/graal/com.oracle.graal.phases.common/src/com/oracle/graal/phases/common/GuardLoweringPhase.java	Tue Mar 12 17:26:53 2013 +0100
+++ b/graal/com.oracle.graal.phases.common/src/com/oracle/graal/phases/common/GuardLoweringPhase.java	Tue Mar 12 17:27:18 2013 +0100
@@ -59,12 +59,19 @@
                 BeginNode trueSuccessor;
                 BeginNode falseSuccessor;
                 DeoptimizeNode deopt = graph.add(new DeoptimizeNode(guard.action(), guard.reason()));
+                BeginNode deoptBranch = BeginNode.begin(deopt);
+                Loop loop = block.getLoop();
+                while (loop != null) {
+                    LoopExitNode exit = graph.add(new LoopExitNode(loop.loopBegin()));
+                    graph.addBeforeFixed(deopt, exit);
+                    loop = loop.parent;
+                }
                 if (guard.negated()) {
-                    trueSuccessor = BeginNode.begin(deopt);
+                    trueSuccessor = deoptBranch;
                     falseSuccessor = fastPath;
                 } else {
                     trueSuccessor = fastPath;
-                    falseSuccessor = BeginNode.begin(deopt);
+                    falseSuccessor = deoptBranch;
                 }
                 IfNode ifNode = graph.add(new IfNode(guard.condition(), trueSuccessor, falseSuccessor, trueSuccessor == fastPath ? 1 : 0));
                 guard.replaceAndDelete(fastPath);

--- a/graal/com.oracle.graal.phases/src/com/oracle/graal/phases/GraalOptions.java	Tue Mar 12 17:26:53 2013 +0100
+++ b/graal/com.oracle.graal.phases/src/com/oracle/graal/phases/GraalOptions.java	Tue Mar 12 17:27:18 2013 +0100
@@ -148,6 +148,9 @@
     public static boolean ExitVMOnBailout                    = ____;
     public static boolean ExitVMOnException                  = true;
 
+    // Register allocator debugging
+    public static String  RegisterPressure                   = null;
+
     // Code generator settings
     public static boolean ConditionalElimination             = true;
     public static boolean CullFrameStates                    = ____;

--- a/mx/commands.py	Tue Mar 12 17:26:53 2013 +0100
+++ b/mx/commands.py	Tue Mar 12 17:27:18 2013 +0100
@@ -818,6 +818,10 @@
         tasks.append(t.stop())
 
         _vmbuild = 'product'
+        t = Task('BootstrapWithRegisterPressure:product')
+        vm(['-G:RegisterPressure=rbx,r11,r14,xmm3,xmm11,xmm14', '-esa', '-version'])
+        tasks.append(t.stop())
+        
         originalVm = _vm
         _vm = 'server' # hosted mode
         t = Task('UnitTests:hosted-product')