diff --git a/libraries/llvm/rts.ll b/libraries/llvm/rts.ll
index cb961d517..301b7b543 100644
--- a/libraries/llvm/rts.ll
+++ b/libraries/llvm/rts.ll
@@ -74,7 +74,7 @@
 ; This is used for two purposes:
 ;   - a refied first-class list of stacks (cyclic linked-list)
 ;   - as part of an intrusive linked-list of stacks (meta stack)
-%StackValue = type { %ReferenceCount, %Memory, %Prompt, i1, %Stack }
+%StackValue = type { %ReferenceCount, %Memory, %Prompt, %Stack }
 
 
 
@@ -336,7 +336,7 @@ define private %Stack @reset(%Stack %oldStack) {
 
     %stack.0 = insertvalue %StackValue zeroinitializer, %Memory %stackMemory, 1
     %stack.1 = insertvalue %StackValue %stack.0, %Prompt %prompt, 2
-    %stack.2 = insertvalue %StackValue %stack.1, %Stack %oldStack, 4
+    %stack.2 = insertvalue %StackValue %stack.1, %Stack %oldStack, 3
 
     store %StackValue %stack.2, %Stack %stack
 
@@ -347,59 +347,55 @@ define private %Stack @reset(%Stack %oldStack) {
 }
 
 define private void @updatePrompts(%Stack %stack) {
-    %dirtyBit_pointer = getelementptr %StackValue, %Stack %stack, i64 0, i32 3
-    %dirtyBit = load i1, ptr %dirtyBit_pointer
-    br i1 %dirtyBit, label %continue, label %done
+    %prompt_pointer = getelementptr %StackValue, %Stack %stack, i64 0, i32 2
+    %prompt = load %Prompt, ptr %prompt_pointer
+    %stack_pointer = getelementptr %PromptValue, %Prompt %prompt, i64 0, i32 1
+    %promptStack = load %Stack, ptr %stack_pointer
+    %isThis = icmp eq %Stack %promptStack, %stack
+    br i1 %isThis, label %done, label %continue
 
 done:
     ret void
 
 continue:
-    %prompt_pointer = getelementptr %StackValue, %Stack %stack, i64 0, i32 2
-    %prompt = load %Prompt, ptr %prompt_pointer
-    %stack_pointer = getelementptr %PromptValue, %Prompt %prompt, i64 0, i32 1
-    %promptStack = load %Stack, ptr %stack_pointer
     %isOccupied = icmp ne %Stack %promptStack, null
     br i1 %isOccupied, label %displace, label %update
 
 displace:
-    call void @displace(%Stack %promptStack)
+    call void @displace(%Stack %promptStack, %Stack %promptStack)
     br label %update
 
 update:
     store %Stack %stack, ptr %stack_pointer
-    store i1 0, ptr %dirtyBit_pointer
 
-    %next_pointer = getelementptr %StackValue, %Stack %stack, i64 0, i32 4
+    %next_pointer = getelementptr %StackValue, %Stack %stack, i64 0, i32 3
     %next = load %Stack, ptr %next_pointer
     tail call void @updatePrompts(%Stack %next)
     ret void
 }
 
-define void @displace(%Stack %stack) {
+define void @displace(%Stack %stack, %Stack %end) {
     %prompt_pointer = getelementptr %StackValue, %Stack %stack, i64 0, i32 2
-    %next_pointer = getelementptr %StackValue, %Stack %stack, i64 0, i32 4
-    %dirtyBit_pointer = getelementptr %StackValue, %Stack %stack, i64 0, i32 3
-    %dirtyBit = load i1, ptr %dirtyBit_pointer
-    br i1 %dirtyBit, label %done, label %continue
-
-done:
-    ret void
-
-continue:
+    %next_pointer = getelementptr %StackValue, %Stack %stack, i64 0, i32 3
     %prompt = load %Prompt, ptr %prompt_pointer
     %stack_pointer = getelementptr %PromptValue, %Prompt %prompt, i64 0, i32 1
     store %Stack null, ptr %stack_pointer
-    store i1 1, ptr %dirtyBit_pointer
 
     %next = load %Stack, ptr %next_pointer
-    tail call void @displace(%Stack %next)
+    %isEnd = icmp eq %Stack %next, %end
+    br i1 %isEnd, label %done, label %continue
+
+done:
+    ret void
+
+continue:
+    tail call void @displace(%Stack %next, %Stack %end)
     ret void
 }
 
 define %Stack @resume(%Resumption %resumption, %Stack %oldStack) {
     %uniqueResumption = call %Resumption @uniqueStack(%Resumption %resumption)
-    %rest_pointer = getelementptr %StackValue, %Resumption %uniqueResumption, i64 0, i32 4
+    %rest_pointer = getelementptr %StackValue, %Resumption %uniqueResumption, i64 0, i32 3
     %start = load %Stack, ptr %rest_pointer
     call void @updatePrompts(%Stack %start)
 
@@ -411,7 +407,7 @@ define %Stack @resume(%Resumption %resumption, %Stack %oldStack) {
 define private {%Resumption, %Stack} @shift(%Stack %stack, %Prompt %prompt) {
     %resumpion_pointer = getelementptr %PromptValue, %Prompt %prompt, i64 0, i32 1
     %resumption = load %Stack, ptr %resumpion_pointer
-    %next_pointer = getelementptr %StackValue, %Stack %resumption, i64 0, i32 4
+    %next_pointer = getelementptr %StackValue, %Stack %resumption, i64 0, i32 3
     %next = load %Stack, ptr %next_pointer
 
     store %Stack %stack, ptr %next_pointer
@@ -427,31 +423,7 @@ define private void @eraseMemory(%Memory %memory) {
     ret void
 }
 
-define private void @forEachObject(ptr %elementPointer, ptr %end, ptr %f) alwaysinline {
-    %done = icmp uge ptr %elementPointer, %end
-    br i1 %done, label %return, label %erase
-
-erase:
-    %element = load %Pos, ptr %elementPointer
-    call void %f(%Pos %element)
-
-    %nextElementPointer = getelementptr %Pos, ptr %elementPointer, i64 1
-    tail call void @forEachObject(ptr %nextElementPointer, ptr %end, ptr %f)
-    ret void
-
-return:
-    ret void
-}
-
-define void @erasePrompt(%Prompt %prompt, i1 %dirtyBit) alwaysinline {
-    br i1 %dirtyBit, label %continue, label %clearPrompt
-
-clearPrompt:
-    %stack_pointer = getelementptr %PromptValue, %Prompt %prompt, i64 0, i32 1
-    store %Stack null, ptr %stack_pointer
-    br label %continue
-
-continue:
+define void @erasePrompt(%Prompt %prompt) alwaysinline {
     %referenceCount_pointer = getelementptr %PromptValue, %Prompt %prompt, i64 0, i32 0
     %referenceCount = load %ReferenceCount, ptr %referenceCount_pointer
     switch %ReferenceCount %referenceCount, label %decrement [%ReferenceCount 0, label %free]
@@ -477,16 +449,17 @@ define void @sharePrompt(%Prompt %prompt) alwaysinline {
 define private %Stack @underflowStack(%Stack %stack) {
     %stackMemory = getelementptr %StackValue, %Stack %stack, i64 0, i32 1
     %stackPrompt = getelementptr %StackValue, %Stack %stack, i64 0, i32 2
-    %stackDirtyBit = getelementptr %StackValue, %Stack %stack, i64 0, i32 3
-    %stackRest = getelementptr %StackValue, %Stack %stack, i64 0, i32 4
+    %stackRest = getelementptr %StackValue, %Stack %stack, i64 0, i32 3
 
     %memory = load %Memory, ptr %stackMemory
     %prompt = load %Prompt, ptr %stackPrompt
     %rest = load %Stack, ptr %stackRest
-    %dirtyBit = load i1, ptr %stackDirtyBit
+
+    %promptStack_pointer = getelementptr %PromptValue, %Prompt %prompt, i64 0, i32 1
+    store %Stack null, ptr %promptStack_pointer
 
     call void @eraseMemory(%Memory %memory)
-    call void @erasePrompt(%Prompt %prompt, i1 false)
+    call void @erasePrompt(%Prompt %prompt)
     call void @free(%Stack %stack)
 
     ret %Stack %rest
@@ -537,7 +510,7 @@ done:
 copy:
     %newOldReferenceCount = sub %ReferenceCount %referenceCount, 1
     store %ReferenceCount %newOldReferenceCount, ptr %referenceCount_pointer
-    %stack_pointer = getelementptr %StackValue, %Resumption %resumption, i64 0, i32 4
+    %stack_pointer = getelementptr %StackValue, %Resumption %resumption, i64 0, i32 3
     %stack = load %Stack, ptr %stack_pointer
 
     %size = ptrtoint ptr getelementptr (%StackValue, ptr null, i64 1) to i64
@@ -551,7 +524,7 @@ loop:
 
     %stackMemory = getelementptr %StackValue, %Stack %old, i64 0, i32 1
     %stackPrompt = getelementptr %StackValue, %Stack %old, i64 0, i32 2
-    %stackRest = getelementptr %StackValue, %Stack %old, i64 0, i32 4
+    %stackRest = getelementptr %StackValue, %Stack %old, i64 0, i32 3
 
     %memory = load %Memory, ptr %stackMemory
     %prompt = load %Prompt, ptr %stackPrompt
@@ -560,8 +533,7 @@ loop:
     %newStackReferenceCounter = getelementptr %StackValue, %Stack %newStack, i64 0, i32 0
     %newStackMemory = getelementptr %StackValue, %Stack %newStack, i64 0, i32 1
     %newStackPrompt = getelementptr %StackValue, %Stack %newStack, i64 0, i32 2
-    %newStackDirtyBit = getelementptr %StackValue, %Stack %newStack, i64 0, i32 3
-    %newStackRest = getelementptr %StackValue, %Stack %newStack, i64 0, i32 4
+    %newStackRest = getelementptr %StackValue, %Stack %newStack, i64 0, i32 3
 
     %newMemory = call %Memory @copyMemory(%Memory %memory)
 
@@ -573,7 +545,6 @@ loop:
     store %ReferenceCount 0, ptr %newStackReferenceCounter
     store %Memory %newMemory, ptr %newStackMemory
     store %Prompt %prompt, ptr %newStackPrompt
-    store i1 1, ptr %newStackDirtyBit
 
     %isEnd = icmp eq %Stack %old, %resumption
     br i1 %isEnd, label %stop, label %next
@@ -607,7 +578,7 @@ define void @eraseResumption(%Resumption %resumption) alwaysinline {
     ret void
 
     free:
-    %stack_pointer = getelementptr %StackValue, %Resumption %resumption, i64 0, i32 4
+    %stack_pointer = getelementptr %StackValue, %Resumption %resumption, i64 0, i32 3
     %stack = load %Stack, ptr %stack_pointer
     store %Stack null, ptr %stack_pointer
     call void @eraseStack(%Stack %stack)
@@ -617,17 +588,25 @@ define void @eraseResumption(%Resumption %resumption) alwaysinline {
 define void @eraseStack(%Stack %stack) alwaysinline {
     %stackPointer_pointer = getelementptr %StackValue, %Stack %stack, i64 0, i32 1, i32 0
     %prompt_pointer = getelementptr %StackValue, %Stack %stack, i64 0, i32 2
-    %dirtyBit_pointer = getelementptr %StackValue, %Stack %stack, i64 0, i32 3
-    %rest_pointer = getelementptr %StackValue, %Stack %stack, i64 0, i32 4
+    %rest_pointer = getelementptr %StackValue, %Stack %stack, i64 0, i32 3
 
     %stackPointer = load %StackPointer, ptr %stackPointer_pointer
     %prompt = load %Stack, ptr %prompt_pointer
-    %dirtyBit = load i1, ptr %dirtyBit_pointer
     %rest = load %Stack, ptr %rest_pointer
 
+    %promptStack_pointer = getelementptr %PromptValue, %Prompt %prompt, i64 0, i32 1
+    %promptStack = load %Stack, ptr %promptStack_pointer
+    %isThisStack = icmp eq %Stack %promptStack, %stack
+    br i1 %isThisStack, label %clearPrompt, label %free
+
+clearPrompt:
+    store %Stack null, ptr %promptStack_pointer
+    br label %free
+
+free:
     call void @free(%Stack %stack)
     call void @eraseFrames(%StackPointer %stackPointer)
-    call void @erasePrompt(%Prompt %prompt, i1 %dirtyBit)
+    call void @erasePrompt(%Prompt %prompt)
 
     %isNull = icmp eq %Stack %rest, null
     br i1 %isNull, label %done, label %next