llvm/test/CodeGen/WebAssembly/returned.ll

; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
; RUN: llc < %s -disable-wasm-fallthrough-return-opt -wasm-disable-explicit-locals -wasm-keep-registers | FileCheck %s

; Test that the "returned" attribute is optimized effectively.

target triple = "wasm32-unknown-unknown"

%class.Apple = type { i8 }
declare noalias ptr @_Znwm(i32)
declare ptr @_ZN5AppleC1Ev(ptr returned)
define ptr @_Z3foov() {
; CHECK-LABEL: _Z3foov:
; CHECK:         .functype _Z3foov () -> (i32)
; CHECK-NEXT:  # %bb.0: # %entry
; CHECK-NEXT:    i32.const $push0=, 1
; CHECK-NEXT:    call $push1=, _Znwm, $pop0
; CHECK-NEXT:    call $push2=, _ZN5AppleC1Ev, $pop1
; CHECK-NEXT:    return $pop2
entry:
  %call = tail call noalias ptr @_Znwm(i32 1)
  %call1 = tail call ptr @_ZN5AppleC1Ev(ptr %call)
  ret ptr %call
}

declare ptr @memcpy(ptr returned, ptr, i32)
define ptr @_Z3barPvS_l(ptr %p, ptr %s, i32 %n) {
; CHECK-LABEL: _Z3barPvS_l:
; CHECK:         .functype _Z3barPvS_l (i32, i32, i32) -> (i32)
; CHECK-NEXT:  # %bb.0: # %entry
; CHECK-NEXT:    call $push0=, memcpy, $0, $1, $2
; CHECK-NEXT:    return $pop0
entry:
  %call = tail call ptr @memcpy(ptr %p, ptr %s, i32 %n)
  ret ptr %p
}

; Test that the optimization isn't performed on constant arguments.

@global = external global i32
@addr = global ptr @global
define void @test_constant_arg() {
; CHECK-LABEL: test_constant_arg:
; CHECK:         .functype test_constant_arg () -> ()
; CHECK-NEXT:  # %bb.0:
; CHECK-NEXT:    i32.const $push0=, global
; CHECK-NEXT:    call $drop=, returns_arg, $pop0
; CHECK-NEXT:    return
  %call = call ptr @returns_arg(ptr @global)
  ret void
}
declare ptr @returns_arg(ptr returned)

; Test that the optimization isn't performed on arguments without the
; "returned" attribute.
declare i32 @do_something(i32 returned, i32, double)
declare void @do_something_with_i32(i32)
declare void @do_something_with_double(double)
define void @test_other_skipped(i32 %a, i32 %b, double %c) {
; CHECK-LABEL: test_other_skipped:
; CHECK:         .functype test_other_skipped (i32, i32, f64) -> ()
; CHECK-NEXT:  # %bb.0:
; CHECK-NEXT:    call $drop=, do_something, $0, $1, $2
; CHECK-NEXT:    call do_something_with_i32, $1
; CHECK-NEXT:    call do_something_with_double, $2
; CHECK-NEXT:    return
    %call = call i32 @do_something(i32 %a, i32 %b, double %c)
    call void @do_something_with_i32(i32 %b)
    call void @do_something_with_double(double %c)
    ret void
}

; Test that the optimization is performed on arguments other than the first.
declare i32 @do_something_else(i32, i32 returned)
define i32 @test_second_arg(i32 %a, i32 %b) {
; CHECK-LABEL: test_second_arg:
; CHECK:         .functype test_second_arg (i32, i32) -> (i32)
; CHECK-NEXT:  # %bb.0:
; CHECK-NEXT:    call $push0=, do_something_else, $0, $1
; CHECK-NEXT:    return $pop0
    %call = call i32 @do_something_else(i32 %a, i32 %b)
    ret i32 %b
}

define void @test() {
; CHECK-LABEL: test:
; CHECK:         .functype test () -> ()
; CHECK-NEXT:  # %bb.0: # %entry
; CHECK-NEXT:    global.get $push0=, __stack_pointer
; CHECK-NEXT:    i32.const $push1=, 16
; CHECK-NEXT:    i32.sub $push7=, $pop0, $pop1
; CHECK-NEXT:    local.tee $push6=, $0=, $pop7
; CHECK-NEXT:    global.set __stack_pointer, $pop6
; CHECK-NEXT:    i32.const $push4=, 12
; CHECK-NEXT:    i32.add $push5=, $0, $pop4
; CHECK-NEXT:    call $drop=, returns_arg, $pop5
; CHECK-NEXT:    i32.const $push2=, 16
; CHECK-NEXT:    i32.add $push3=, $0, $pop2
; CHECK-NEXT:    global.set __stack_pointer, $pop3
; CHECK-NEXT:    return
entry:
  %a = alloca i32
  call void @llvm.lifetime.start.p0(ptr %a)
  %ret = call ptr @returns_arg(ptr %a)
  call void @llvm.lifetime.end.p0(ptr %a)
  ret void
}