llc cannot be verified defer in phi

[visualfc]

main.go

package main

func check() {}

func demo(n int) bool {
	defer check()
	var b bool
	if n == 100 {
		b = true
	} else {
		b = false
	}
	return b
}

func main() {
	demo(1)
}

ssa

func demo(n int) bool:
0:                                                                entry P:0 S:2
	defer check()
	t0 = n == 100:int                                                  bool
	if t0 goto 2 else 4
1:                                                              recover P:0 S:0
	return false:bool
2:                                                              if.then P:1 S:1
	jump 3
3:                                                              if.done P:2 S:0
	t1 = phi [2: true:bool, 4: false:bool] #b                          bool
	rundefers
	return t1
4:                                                              if.else P:1 S:1
	jump 3

main.ll

define i1 @main.demo(i64 %0) {
_llgo_0:
  %1 = load i32, ptr @__llgo_defer, align 4
  %2 = call ptr @pthread_getspecific(i32 %1)
  %3 = alloca i8, i64 152, align 1
  %4 = alloca i8, i64 40, align 1
  %5 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.Defer", ptr %4, i32 0, i32 0
  store ptr %3, ptr %5, align 8
  %6 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.Defer", ptr %4, i32 0, i32 1
  store i64 0, ptr %6, align 4
  %7 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.Defer", ptr %4, i32 0, i32 2
  store ptr %2, ptr %7, align 8
  %8 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.Defer", ptr %4, i32 0, i32 3
  store ptr blockaddress(@main.demo, %_llgo_5), ptr %8, align 8
  %9 = call i32 @pthread_setspecific(i32 %1, ptr %4)
  %10 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.Defer", ptr %4, i32 0, i32 1
  %11 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.Defer", ptr %4, i32 0, i32 3
  %12 = getelementptr inbounds %"github.com/goplus/llgo/internal/runtime.Defer", ptr %4, i32 0, i32 4
  %13 = call i32 @sigsetjmp(ptr %3, i32 0)
  %14 = icmp eq i32 %13, 0
  br i1 %14, label %_llgo_7, label %_llgo_8

_llgo_1:                                          ; preds = %_llgo_6
  ret i1 false

_llgo_2:                                          ; preds = %_llgo_7
  br label %_llgo_3

_llgo_3:                                          ; preds = %_llgo_4, %_llgo_2
  %15 = phi i1 [ true, %_llgo_2 ], [ false, %_llgo_4 ]
  store ptr blockaddress(@main.demo, %_llgo_9), ptr %12, align 8
  br label %_llgo_5

_llgo_4:                                          ; preds = %_llgo_7
  br label %_llgo_3

_llgo_5:                                          ; preds = %_llgo_8, %_llgo_3
  store ptr blockaddress(@main.demo, %_llgo_6), ptr %11, align 8
  %16 = load i64, ptr %10, align 4
  call void @main.check()
  %17 = load %"github.com/goplus/llgo/internal/runtime.Defer", ptr %4, align 8
  %18 = extractvalue %"github.com/goplus/llgo/internal/runtime.Defer" %17, 2
  %19 = call i32 @pthread_setspecific(i32 %1, ptr %18)
  %20 = load ptr, ptr %12, align 8
  indirectbr ptr %20, [label %_llgo_6, label %_llgo_9]

_llgo_6:                                          ; preds = %_llgo_8, %_llgo_5
  call void @"github.com/goplus/llgo/internal/runtime.Rethrow"(ptr %2)
  br label %_llgo_1

_llgo_7:                                          ; preds = %_llgo_0
  %21 = icmp eq i64 %0, 100
  br i1 %21, label %_llgo_2, label %_llgo_4

_llgo_8:                                          ; preds = %_llgo_0
  store ptr blockaddress(@main.demo, %_llgo_6), ptr %12, align 8
  %22 = load ptr, ptr %11, align 8
  indirectbr ptr %22, [label %_llgo_6, label %_llgo_5]

_llgo_9:                                          ; preds = %_llgo_5
  ret i1 %15
}

llc main.ll

Instruction does not dominate all uses!
  %15 = phi i1 [ true, %_llgo_2 ], [ false, %_llgo_4 ]
  ret i1 %15

[cpunion]

Related: #802