coro-cps.ll

; Emulating cps call using LLVM Coroutines
; RUN: opt coro-cps.ll -O2 -enable-coroutines -S

define void @f(i32 %arg) {
entry:
  %bar.ret.addr = alloca i32
  %id = call token @llvm.coro.id(i32 0, i8* null, i8* null, i8* null)
  %size = call i32 @llvm.coro.size.i32()
  %alloc = call i8* @malloc(i32 %size)
  %hdl = call noalias i8* @llvm.coro.begin(token %id, i8* %alloc)
  call void @partA(i32 %arg)

  %tok = call token @llvm.coro.save(i8* %hdl)
  call void @cps_call_bar(i8* %hdl, i32* %bar.ret.addr, i32 41)
  %0 = call i8 @llvm.coro.suspend(token %tok, i1 false)
  switch i8 %0, label %suspend [i8 0, label %resume
                                i8 1, label %cleanup]
resume:
  %n = load i32, i32* %bar.ret.addr
  call void @partB(i32 %n)
  br label %cleanup

cleanup:
  %mem = call i8* @llvm.coro.free(token %id, i8* %hdl)
  call void @free(i8* %mem)
  br label %suspend
suspend:
  call i1 @llvm.coro.end(i8* %hdl, i1 false)
  ret void
}

define void @cps_call_bar(i8* %caller, i32* %retval.addr, i32 %n) {
  call void @partC(i32 %n)
  store i32 42, i32* %retval.addr
  call void @llvm.coro.resume(i8* %caller)
  ret void
}

; CHECK-LABEL: @main(
define i32 @main() {
entry:
  call void @f(i32 40)
  ret i32 0
}

declare i8* @malloc(i32)
declare void @free(i8*)

declare void @partA(i32)
declare void @partB(i32)
declare void @partC(i32)


declare token @llvm.coro.id(i32, i8*, i8*, i8*)
declare i32 @llvm.coro.size.i32()
declare i1 @llvm.coro.alloc(token)
declare i8* @llvm.coro.begin(token, i8*)
declare i8 @llvm.coro.suspend(token, i1)
declare i8* @llvm.coro.free(token, i8*)
declare i1 @llvm.coro.end(i8*, i1)

declare void @llvm.coro.resume(i8*)
declare void @llvm.coro.destroy(i8*)

declare token @llvm.coro.save(i8*)