llvm/test/CodeGen/WebAssembly/unreachable.ll

; The assertions in this file were autogenerated by
; utils/update_llc_test_checks.py, but were hand-edited to add the
; "end_function" lines to prevent the tests from passing when there are
; superfluous instructions at the end of a function. You can run
; update_llc_test_checks.py again, but please keep the "end_function" lines
; intact when you commit.

; Wasm, to generate valid code, always internally sets `--trap-unreachable` to 1
; and `--no-trap-after-noreturn` to 0, and these command lines options, if
; explicitly given, are ignored. Various combinations of these options should
; have no effect and should not generate invalid code.
; RUN: llc < %s -verify-machineinstrs | FileCheck %s
; RUN: llc < %s -fast-isel -fast-isel-abort=1 -verify-machineinstrs | FileCheck %s
; RUN: llc < %s -verify-machineinstrs --trap-unreachable | FileCheck %s
; RUN: llc < %s -fast-isel -fast-isel-abort=1 -verify-machineinstrs --trap-unreachable | FileCheck %s
; RUN: llc < %s -verify-machineinstrs --trap-unreachable --no-trap-after-noreturn | FileCheck %s
; RUN: llc < %s -fast-isel -fast-isel-abort=1 -verify-machineinstrs --trap-unreachable --no-trap-after-noreturn | FileCheck %s

target triple = "wasm32-unknown-unknown"


; Test that the LLVM trap and debug trap intrinsics are lowered to wasm
; unreachable.

declare void @llvm.trap() cold noreturn nounwind
declare void @llvm.debugtrap() nounwind

define void @trap_ret_void() {
; CHECK-LABEL: trap_ret_void:
; CHECK:         .functype trap_ret_void () -> ()
; CHECK-NEXT:  # %bb.0:
; CHECK-NEXT:    unreachable
; CHECK-NEXT:    end_function
  call void @llvm.trap()
  ret void
}

define void @debugtrap_ret_void() {
; CHECK-LABEL: debugtrap_ret_void:
; CHECK:         .functype debugtrap_ret_void () -> ()
; CHECK-NEXT:  # %bb.0:
; CHECK-NEXT:    unreachable
; CHECK-NEXT:    # fallthrough-return
; CHECK-NEXT:    end_function
  call void @llvm.debugtrap()
  ret void
}

; LLVM trap followed by LLVM unreachable could become exactly one wasm
; unreachable, but two are emitted currently.
define void @trap_unreacheable() {
; CHECK-LABEL: trap_unreacheable:
; CHECK:         .functype trap_unreacheable () -> ()
; CHECK-NEXT:  # %bb.0:
; CHECK-NEXT:    unreachable
; CHECK-NEXT:    end_function
  call void @llvm.trap()
  unreachable
}


; Test that LLVM unreachable instruction is lowered to wasm unreachable when
; necessary to fulfill the wasm operand stack requirements.

declare void @ext_func()
declare i32 @ext_func_i32()
declare void @ext_never_return() noreturn

; LLVM IR's 'unreachable' is translated to Wasm 'unreachable'.
define i32 @missing_ret_unreachable() {
; CHECK-LABEL: missing_ret_unreachable:
; CHECK:         .functype missing_ret_unreachable () -> (i32)
; CHECK-NEXT:  # %bb.0:
; CHECK-NEXT:    call ext_func
; CHECK-NEXT:    unreachable
; CHECK-NEXT:    end_function
  call void @ext_func()
  unreachable
}

; This is similar to the above test, but the callee has a 'noreturn' attribute.
; There is an optimization that removes an 'unreachable' after a noreturn call,
; but Wasm backend doesn't use it and ignore `--no-trap-after-noreturn`, if
; given, to generate valid code.
define i32 @missing_ret_noreturn_unreachable() {
; CHECK-LABEL: missing_ret_noreturn_unreachable:
; CHECK:         .functype missing_ret_noreturn_unreachable () -> (i32)
; CHECK-NEXT:  # %bb.0:
; CHECK-NEXT:    call ext_never_return
; CHECK-NEXT:    unreachable
; CHECK-NEXT:    end_function
  call void @ext_never_return()
  unreachable
}

define i32 @no_crash_for_other_instruction_after_trap(ptr %p, i32 %b) {
; CHECK-LABEL: no_crash_for_other_instruction_after_trap:
; CHECK:      unreachable
; CHECK-NEXT: end_function
  %a = load i32, ptr %p
  call void @llvm.trap()
  ret i32 %a
}