diff --git a/transform/testdata/interrupt.ll b/transform/testdata/interrupt.ll
index 1436827b..f4d2e022 100644
--- a/transform/testdata/interrupt.ll
+++ b/transform/testdata/interrupt.ll
@@ -1,39 +1,39 @@
 target datalayout = "e-m:e-p:32:32-Fi8-i64:64-v128:64:128-a:0:32-n32-S64"
 target triple = "armv7em-none-eabi"
 
-%machine.UART = type { %machine.RingBuffer* }
+%machine.UART = type { ptr }
 %machine.RingBuffer = type { [128 x %"runtime/volatile.Register8"], %"runtime/volatile.Register8", %"runtime/volatile.Register8" }
 %"runtime/volatile.Register8" = type { i8 }
-%"runtime/interrupt.handle" = type { i8*, i32, %"runtime/interrupt.Interrupt" }
+%"runtime/interrupt.handle" = type { ptr, i32, %"runtime/interrupt.Interrupt" }
 %"runtime/interrupt.Interrupt" = type { i32 }
 
-@"runtime/interrupt.$interrupt2" = private unnamed_addr constant %"runtime/interrupt.handle" { i8* bitcast (%machine.UART* @machine.UART0 to i8*), i32 ptrtoint (void (i32, i8*)* @"(*machine.UART).handleInterrupt$bound" to i32), %"runtime/interrupt.Interrupt" { i32 2 } }
-@machine.UART0 = internal global %machine.UART { %machine.RingBuffer* @"machine$alloc.335" }
+@"runtime/interrupt.$interrupt2" = private unnamed_addr constant %"runtime/interrupt.handle" { ptr @machine.UART0, i32 ptrtoint (ptr @"(*machine.UART).handleInterrupt$bound" to i32), %"runtime/interrupt.Interrupt" { i32 2 } }
+@machine.UART0 = internal global %machine.UART { ptr @"machine$alloc.335" }
 @"machine$alloc.335" = internal global %machine.RingBuffer zeroinitializer
 
-declare void @"runtime/interrupt.callHandlers"(i32, i8*) local_unnamed_addr
+declare void @"runtime/interrupt.callHandlers"(i32, ptr) local_unnamed_addr
 
-declare void @"device/arm.EnableIRQ"(i32, i8* nocapture readnone)
+declare void @"device/arm.EnableIRQ"(i32, ptr nocapture readnone)
 
-declare void @"device/arm.SetPriority"(i32, i32, i8* nocapture readnone)
+declare void @"device/arm.SetPriority"(i32, i32, ptr nocapture readnone)
 
 declare void @"runtime/interrupt.use"(%"runtime/interrupt.Interrupt")
 
-define void @runtime.initAll(i8* nocapture readnone) unnamed_addr {
+define void @runtime.initAll(ptr nocapture readnone) unnamed_addr {
 entry:
-  call void @"device/arm.SetPriority"(i32 ptrtoint (%"runtime/interrupt.handle"* @"runtime/interrupt.$interrupt2" to i32), i32 192, i8* undef)
-  call void @"device/arm.EnableIRQ"(i32 ptrtoint (%"runtime/interrupt.handle"* @"runtime/interrupt.$interrupt2" to i32), i8* undef)
-  call void @"runtime/interrupt.use"(%"runtime/interrupt.Interrupt" { i32 ptrtoint (%"runtime/interrupt.handle"* @"runtime/interrupt.$interrupt2" to i32) })
+  call void @"device/arm.SetPriority"(i32 ptrtoint (ptr @"runtime/interrupt.$interrupt2" to i32), i32 192, ptr undef)
+  call void @"device/arm.EnableIRQ"(i32 ptrtoint (ptr @"runtime/interrupt.$interrupt2" to i32), ptr undef)
+  call void @"runtime/interrupt.use"(%"runtime/interrupt.Interrupt" { i32 ptrtoint (ptr @"runtime/interrupt.$interrupt2" to i32) })
   ret void
 }
 
 define void @UARTE0_UART0_IRQHandler() {
-  call void @"runtime/interrupt.callHandlers"(i32 2, i8* undef)
+  call void @"runtime/interrupt.callHandlers"(i32 2, ptr undef)
   ret void
 }
 
 define void @NFCT_IRQHandler() {
-  call void @"runtime/interrupt.callHandlers"(i32 5, i8* undef)
+  call void @"runtime/interrupt.callHandlers"(i32 5, ptr undef)
   ret void
 }
 
@@ -45,22 +45,21 @@ entry:
   ]
 
 switch.body2:
-  call void @"runtime/interrupt.callHandlers"(i32 2, i8* undef)
+  call void @"runtime/interrupt.callHandlers"(i32 2, ptr undef)
   ret void
 
 switch.body5:
-  call void @"runtime/interrupt.callHandlers"(i32 5, i8* undef)
+  call void @"runtime/interrupt.callHandlers"(i32 5, ptr undef)
   ret void
 
 switch.done:
   ret void
 }
 
-define internal void @"(*machine.UART).handleInterrupt$bound"(i32, i8* nocapture %context) {
+define internal void @"(*machine.UART).handleInterrupt$bound"(i32, ptr nocapture %context) {
 entry:
-  %unpack.ptr = bitcast i8* %context to %machine.UART*
-  call void @"(*machine.UART).handleInterrupt"(%machine.UART* %unpack.ptr, i32 %0, i8* undef)
+  call void @"(*machine.UART).handleInterrupt"(ptr %context, i32 %0, ptr undef)
   ret void
 }
 
-declare void @"(*machine.UART).handleInterrupt"(%machine.UART* nocapture, i32, i8* nocapture readnone)
+declare void @"(*machine.UART).handleInterrupt"(ptr nocapture, i32, ptr nocapture readnone)
diff --git a/transform/testdata/interrupt.out.ll b/transform/testdata/interrupt.out.ll
index 7eb9f0a8..3663c0a3 100644
--- a/transform/testdata/interrupt.out.ll
+++ b/transform/testdata/interrupt.out.ll
@@ -1,31 +1,31 @@
 target datalayout = "e-m:e-p:32:32-Fi8-i64:64-v128:64:128-a:0:32-n32-S64"
 target triple = "armv7em-none-eabi"
 
-%machine.UART = type { %machine.RingBuffer* }
+%machine.UART = type { ptr }
 %machine.RingBuffer = type { [128 x %"runtime/volatile.Register8"], %"runtime/volatile.Register8", %"runtime/volatile.Register8" }
 %"runtime/volatile.Register8" = type { i8 }
 %"runtime/interrupt.Interrupt" = type { i32 }
 
-@machine.UART0 = internal global %machine.UART { %machine.RingBuffer* @"machine$alloc.335" }
+@machine.UART0 = internal global %machine.UART { ptr @"machine$alloc.335" }
 @"machine$alloc.335" = internal global %machine.RingBuffer zeroinitializer
 
-declare void @"runtime/interrupt.callHandlers"(i32, i8*) local_unnamed_addr
+declare void @"runtime/interrupt.callHandlers"(i32, ptr) local_unnamed_addr
 
-declare void @"device/arm.EnableIRQ"(i32, i8* nocapture readnone)
+declare void @"device/arm.EnableIRQ"(i32, ptr nocapture readnone)
 
-declare void @"device/arm.SetPriority"(i32, i32, i8* nocapture readnone)
+declare void @"device/arm.SetPriority"(i32, i32, ptr nocapture readnone)
 
 declare void @"runtime/interrupt.use"(%"runtime/interrupt.Interrupt")
 
-define void @runtime.initAll(i8* nocapture readnone %0) unnamed_addr {
+define void @runtime.initAll(ptr nocapture readnone %0) unnamed_addr {
 entry:
-  call void @"device/arm.SetPriority"(i32 2, i32 192, i8* undef)
-  call void @"device/arm.EnableIRQ"(i32 2, i8* undef)
+  call void @"device/arm.SetPriority"(i32 2, i32 192, ptr undef)
+  call void @"device/arm.EnableIRQ"(i32 2, ptr undef)
   ret void
 }
 
 define void @UARTE0_UART0_IRQHandler() {
-  call void @"(*machine.UART).handleInterrupt$bound"(i32 2, i8* bitcast (%machine.UART* @machine.UART0 to i8*))
+  call void @"(*machine.UART).handleInterrupt$bound"(i32 2, ptr @machine.UART0)
   ret void
 }
 
@@ -37,7 +37,7 @@ entry:
   ]
 
 switch.body2:                                     ; preds = %entry
-  call void @"(*machine.UART).handleInterrupt$bound"(i32 2, i8* bitcast (%machine.UART* @machine.UART0 to i8*))
+  call void @"(*machine.UART).handleInterrupt$bound"(i32 2, ptr @machine.UART0)
   ret void
 
 switch.body5:                                     ; preds = %entry
@@ -47,11 +47,10 @@ switch.done:                                      ; preds = %entry
   ret void
 }
 
-define internal void @"(*machine.UART).handleInterrupt$bound"(i32 %0, i8* nocapture %context) {
+define internal void @"(*machine.UART).handleInterrupt$bound"(i32 %0, ptr nocapture %context) {
 entry:
-  %unpack.ptr = bitcast i8* %context to %machine.UART*
-  call void @"(*machine.UART).handleInterrupt"(%machine.UART* %unpack.ptr, i32 %0, i8* undef)
+  call void @"(*machine.UART).handleInterrupt"(ptr %context, i32 %0, ptr undef)
   ret void
 }
 
-declare void @"(*machine.UART).handleInterrupt"(%machine.UART* nocapture, i32, i8* nocapture readnone)
+declare void @"(*machine.UART).handleInterrupt"(ptr nocapture, i32, ptr nocapture readnone)