llvm/test/Transforms/SCCP/ipsccp-clear-returned.ll

; if IPSCCP determines a function returns undef,
; then the "returned" attribute of input arguments
; should be cleared.

; RUN: opt < %s -passes=ipsccp -S | FileCheck %s
define i32 @main() {
; CHECK-LABEL: @main
entry:
; CHECK-NEXT: entry:
  %call = call i32 @func_return_undef(i32 returned 1)
; CHECK: call i32 @func_return_undef(i32 1)
; CHECK-NOT: returned
  ret i32 %call
; CHECK: ret i32 1
}

define internal i32 @func_return_undef(i32 returned %arg) {
; CHECK: {{define.*@func_return_undef}}
; CHECK-NOT: returned
entry:
; CHECK-NEXT: entry:
; CHECK-NEXT: {{ret.*undef}}
  ret i32 %arg
}


; The only case that users of zapped functions are non-call site
; users is that they are blockaddr users. Skip them because we
; want to remove the returned attribute for call sites

; CHECK: {{define.*@blockaddr_user}}
; CHECK-NOT: returned
define internal i32 @blockaddr_user(i1 %c, i32 returned %d) {
entry:
  br i1 %c, label %bb1, label %bb2

bb1:
  br label %branch.block

bb2:
  br label %branch.block

branch.block:
  %addr = phi i8* [blockaddress(@blockaddr_user, %target1), %bb1], [blockaddress(@blockaddr_user, %target2), %bb2]
  indirectbr i8* %addr, [label %target1, label %target2]

target1:
  br label %target2

; CHECK: ret i32 undef
target2:
  ret i32 %d
}

define i32 @call_blockaddr_user(i1 %c) {
; CHECK-LABEL: define i32 @call_blockaddr_user(
; CHECK-NEXT: %r = call i32 @blockaddr_user(i1 %c
; CHECK-NOT: returned
; CHECK-NEXT: ret i32 10
  %r = call i32 @blockaddr_user(i1 %c, i32 returned 10)
  ret i32 %r
}