emscripten bug with volatile atomic ops.

atomic_flag_clear.pass.cpp

//===----------------------------------------------------------------------===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is dual licensed under the MIT and the University of Illinois Open
// Source Licenses. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//

// <atomic>

// struct atomic_flag

// void atomic_flag_clear(volatile atomic_flag*);
// void atomic_flag_clear(atomic_flag*);

#include <atomic>
#include <cassert>

int main()
{
    {
        std::atomic_flag f;
        f.test_and_set();
        atomic_flag_clear(&f);
        assert(f.test_and_set() == 0);
    }
    {
        volatile std::atomic_flag f;
        f.test_and_set();
        atomic_flag_clear(&f);
        assert(f.test_and_set() == 0);
    }
}

atomic_flag_clear.pass.ll

; ModuleID = 'test.bc'
target datalayout = "e-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-f32:32:32-f64:32:64-v64:64:64-v128:128:128-a0:0:64-f80:32:32-n8:16:32-S128"
target triple = "i386-pc-linux-gnu"

%"struct.std::__1::atomic_flag" = type { i8 }

@.str = private unnamed_addr constant [27 x i8] c"atomic_flag_clear.pass.cpp\00", align 1
@__PRETTY_FUNCTION__.main = private unnamed_addr constant [11 x i8] c"int main()\00", align 1
@.str1 = private unnamed_addr constant [22 x i8] c"f.test_and_set() == 0\00", align 1

define i32 @main() ssp {
entry:
  %this.addr.i52 = alloca %"struct.std::__1::atomic_flag"*, align 4
  %__m.addr.i53 = alloca i32, align 4
  %.atomictmp.i54 = alloca i8, align 1
  %.atomicdst.i55 = alloca i8, align 1
  %this.addr.i.i43 = alloca %"struct.std::__1::atomic_flag"*, align 4
  %__m.addr.i.i44 = alloca i32, align 4
  %.atomictmp.i.i45 = alloca i8, align 1
  %__o.addr.i46 = alloca %"struct.std::__1::atomic_flag"*, align 4
  %this.addr.i31 = alloca %"struct.std::__1::atomic_flag"*, align 4
  %__m.addr.i32 = alloca i32, align 4
  %.atomictmp.i33 = alloca i8, align 1
  %.atomicdst.i34 = alloca i8, align 1
  %this.addr.i.i27 = alloca %"struct.std::__1::atomic_flag"*, align 4
  %this.addr.i28 = alloca %"struct.std::__1::atomic_flag"*, align 4
  %this.addr.i14 = alloca %"struct.std::__1::atomic_flag"*, align 4
  %__m.addr.i15 = alloca i32, align 4
  %.atomictmp.i16 = alloca i8, align 1
  %.atomicdst.i17 = alloca i8, align 1
  %this.addr.i.i12 = alloca %"struct.std::__1::atomic_flag"*, align 4
  %__m.addr.i.i = alloca i32, align 4
  %.atomictmp.i.i = alloca i8, align 1
  %__o.addr.i = alloca %"struct.std::__1::atomic_flag"*, align 4
  %this.addr.i10 = alloca %"struct.std::__1::atomic_flag"*, align 4
  %__m.addr.i = alloca i32, align 4
  %.atomictmp.i = alloca i8, align 1
  %.atomicdst.i = alloca i8, align 1
  %this.addr.i.i = alloca %"struct.std::__1::atomic_flag"*, align 4
  %this.addr.i = alloca %"struct.std::__1::atomic_flag"*, align 4
  %retval = alloca i32, align 4
  %f = alloca %"struct.std::__1::atomic_flag", align 1
  %f2 = alloca %"struct.std::__1::atomic_flag", align 1
  store i32 0, i32* %retval
  store %"struct.std::__1::atomic_flag"* %f, %"struct.std::__1::atomic_flag"** %this.addr.i, align 4
  %this1.i = load %"struct.std::__1::atomic_flag"** %this.addr.i
  store %"struct.std::__1::atomic_flag"* %this1.i, %"struct.std::__1::atomic_flag"** %this.addr.i.i, align 4
  %this1.i.i = load %"struct.std::__1::atomic_flag"** %this.addr.i.i
  store %"struct.std::__1::atomic_flag"* %f, %"struct.std::__1::atomic_flag"** %this.addr.i52, align 4
  store i32 5, i32* %__m.addr.i53, align 4
  %this1.i56 = load %"struct.std::__1::atomic_flag"** %this.addr.i52
  %__a_.i57 = getelementptr inbounds %"struct.std::__1::atomic_flag"* %this1.i56, i32 0, i32 0
  %0 = load i32* %__m.addr.i53, align 4
  store i8 1, i8* %.atomictmp.i54
  switch i32 %0, label %monotonic.i58 [
    i32 1, label %acquire.i59
    i32 2, label %acquire.i59
    i32 3, label %release.i60
    i32 4, label %acqrel.i61
    i32 5, label %seqcst.i62
  ]

monotonic.i58:                                    ; preds = %entry
  %1 = load i8* %.atomictmp.i54, align 1
  %2 = atomicrmw xchg i8* %__a_.i57, i8 %1 monotonic
  store i8 %2, i8* %.atomicdst.i55, align 1
  br label %_ZNSt3__111atomic_flag12test_and_setENS_12memory_orderE.exit64

acquire.i59:                                      ; preds = %entry, %entry
  %3 = load i8* %.atomictmp.i54, align 1
  %4 = atomicrmw xchg i8* %__a_.i57, i8 %3 acquire
  store i8 %4, i8* %.atomicdst.i55, align 1
  br label %_ZNSt3__111atomic_flag12test_and_setENS_12memory_orderE.exit64

release.i60:                                      ; preds = %entry
  %5 = load i8* %.atomictmp.i54, align 1
  %6 = atomicrmw xchg i8* %__a_.i57, i8 %5 release
  store i8 %6, i8* %.atomicdst.i55, align 1
  br label %_ZNSt3__111atomic_flag12test_and_setENS_12memory_orderE.exit64

acqrel.i61:                                       ; preds = %entry
  %7 = load i8* %.atomictmp.i54, align 1
  %8 = atomicrmw xchg i8* %__a_.i57, i8 %7 acq_rel
  store i8 %8, i8* %.atomicdst.i55, align 1
  br label %_ZNSt3__111atomic_flag12test_and_setENS_12memory_orderE.exit64

seqcst.i62:                                       ; preds = %entry
  %9 = load i8* %.atomictmp.i54, align 1
  %10 = atomicrmw xchg i8* %__a_.i57, i8 %9 seq_cst
  store i8 %10, i8* %.atomicdst.i55, align 1
  br label %_ZNSt3__111atomic_flag12test_and_setENS_12memory_orderE.exit64

_ZNSt3__111atomic_flag12test_and_setENS_12memory_orderE.exit64: ; preds = %seqcst.i62, %acqrel.i61, %release.i60, %acquire.i59, %monotonic.i58
  %11 = load i8* %.atomicdst.i55
  %tobool.i63 = trunc i8 %11 to i1
  store %"struct.std::__1::atomic_flag"* %f, %"struct.std::__1::atomic_flag"** %__o.addr.i46, align 4
  %12 = load %"struct.std::__1::atomic_flag"** %__o.addr.i46, align 4
  store %"struct.std::__1::atomic_flag"* %12, %"struct.std::__1::atomic_flag"** %this.addr.i.i43, align 4
  store i32 5, i32* %__m.addr.i.i44, align 4
  %this1.i.i47 = load %"struct.std::__1::atomic_flag"** %this.addr.i.i43
  %__a_.i.i48 = getelementptr inbounds %"struct.std::__1::atomic_flag"* %this1.i.i47, i32 0, i32 0
  %13 = load i32* %__m.addr.i.i44, align 4
  store i8 0, i8* %.atomictmp.i.i45
  switch i32 %13, label %monotonic.i.i49 [
    i32 3, label %release.i.i50
    i32 5, label %seqcst.i.i51
  ]

monotonic.i.i49:                                  ; preds = %_ZNSt3__111atomic_flag12test_and_setENS_12memory_orderE.exit64
  %14 = load i8* %.atomictmp.i.i45, align 1
  store atomic i8 %14, i8* %__a_.i.i48 monotonic, align 1
  br label %_ZNSt3__117atomic_flag_clearEPNS_11atomic_flagE.exit

release.i.i50:                                    ; preds = %_ZNSt3__111atomic_flag12test_and_setENS_12memory_orderE.exit64
  %15 = load i8* %.atomictmp.i.i45, align 1
  store atomic i8 %15, i8* %__a_.i.i48 release, align 1
  br label %_ZNSt3__117atomic_flag_clearEPNS_11atomic_flagE.exit

seqcst.i.i51:                                     ; preds = %_ZNSt3__111atomic_flag12test_and_setENS_12memory_orderE.exit64
  %16 = load i8* %.atomictmp.i.i45, align 1
  store atomic i8 %16, i8* %__a_.i.i48 seq_cst, align 1
  br label %_ZNSt3__117atomic_flag_clearEPNS_11atomic_flagE.exit

_ZNSt3__117atomic_flag_clearEPNS_11atomic_flagE.exit: ; preds = %seqcst.i.i51, %release.i.i50, %monotonic.i.i49
  store %"struct.std::__1::atomic_flag"* %f, %"struct.std::__1::atomic_flag"** %this.addr.i31, align 4
  store i32 5, i32* %__m.addr.i32, align 4
  %this1.i35 = load %"struct.std::__1::atomic_flag"** %this.addr.i31
  %__a_.i36 = getelementptr inbounds %"struct.std::__1::atomic_flag"* %this1.i35, i32 0, i32 0
  %17 = load i32* %__m.addr.i32, align 4
  store i8 1, i8* %.atomictmp.i33
  switch i32 %17, label %monotonic.i37 [
    i32 1, label %acquire.i38
    i32 2, label %acquire.i38
    i32 3, label %release.i39
    i32 4, label %acqrel.i40
    i32 5, label %seqcst.i41
  ]

monotonic.i37:                                    ; preds = %_ZNSt3__117atomic_flag_clearEPNS_11atomic_flagE.exit
  %18 = load i8* %.atomictmp.i33, align 1
  %19 = atomicrmw xchg i8* %__a_.i36, i8 %18 monotonic
  store i8 %19, i8* %.atomicdst.i34, align 1
  br label %_ZNSt3__111atomic_flag12test_and_setENS_12memory_orderE.exit

acquire.i38:                                      ; preds = %_ZNSt3__117atomic_flag_clearEPNS_11atomic_flagE.exit, %_ZNSt3__117atomic_flag_clearEPNS_11atomic_flagE.exit
  %20 = load i8* %.atomictmp.i33, align 1
  %21 = atomicrmw xchg i8* %__a_.i36, i8 %20 acquire
  store i8 %21, i8* %.atomicdst.i34, align 1
  br label %_ZNSt3__111atomic_flag12test_and_setENS_12memory_orderE.exit

release.i39:                                      ; preds = %_ZNSt3__117atomic_flag_clearEPNS_11atomic_flagE.exit
  %22 = load i8* %.atomictmp.i33, align 1
  %23 = atomicrmw xchg i8* %__a_.i36, i8 %22 release
  store i8 %23, i8* %.atomicdst.i34, align 1
  br label %_ZNSt3__111atomic_flag12test_and_setENS_12memory_orderE.exit

acqrel.i40:                                       ; preds = %_ZNSt3__117atomic_flag_clearEPNS_11atomic_flagE.exit
  %24 = load i8* %.atomictmp.i33, align 1
  %25 = atomicrmw xchg i8* %__a_.i36, i8 %24 acq_rel
  store i8 %25, i8* %.atomicdst.i34, align 1
  br label %_ZNSt3__111atomic_flag12test_and_setENS_12memory_orderE.exit

seqcst.i41:                                       ; preds = %_ZNSt3__117atomic_flag_clearEPNS_11atomic_flagE.exit
  %26 = load i8* %.atomictmp.i33, align 1
  %27 = atomicrmw xchg i8* %__a_.i36, i8 %26 seq_cst
  store i8 %27, i8* %.atomicdst.i34, align 1
  br label %_ZNSt3__111atomic_flag12test_and_setENS_12memory_orderE.exit

_ZNSt3__111atomic_flag12test_and_setENS_12memory_orderE.exit: ; preds = %seqcst.i41, %acqrel.i40, %release.i39, %acquire.i38, %monotonic.i37
  %28 = load i8* %.atomicdst.i34
  %tobool.i42 = trunc i8 %28 to i1
  %conv = zext i1 %tobool.i42 to i32
  %cmp = icmp eq i32 %conv, 0
  br i1 %cmp, label %cond.true, label %cond.false

cond.true:                                        ; preds = %_ZNSt3__111atomic_flag12test_and_setENS_12memory_orderE.exit
  br label %cond.end

cond.false:                                       ; preds = %_ZNSt3__111atomic_flag12test_and_setENS_12memory_orderE.exit
  call void @__assert_func(i8* getelementptr inbounds ([27 x i8]* @.str, i32 0, i32 0), i32 26, i8* getelementptr inbounds ([11 x i8]* @__PRETTY_FUNCTION__.main, i32 0, i32 0), i8* getelementptr inbounds ([22 x i8]* @.str1, i32 0, i32 0))
  br label %cond.end

cond.end:                                         ; preds = %cond.false, %cond.true
  store %"struct.std::__1::atomic_flag"* %f2, %"struct.std::__1::atomic_flag"** %this.addr.i28, align 4
  %this1.i29 = load %"struct.std::__1::atomic_flag"** %this.addr.i28
  store %"struct.std::__1::atomic_flag"* %this1.i29, %"struct.std::__1::atomic_flag"** %this.addr.i.i27, align 4
  %this1.i.i30 = load %"struct.std::__1::atomic_flag"** %this.addr.i.i27
  store %"struct.std::__1::atomic_flag"* %f2, %"struct.std::__1::atomic_flag"** %this.addr.i14, align 4
  store i32 5, i32* %__m.addr.i15, align 4
  %this1.i18 = load %"struct.std::__1::atomic_flag"** %this.addr.i14
  %__a_.i19 = getelementptr inbounds %"struct.std::__1::atomic_flag"* %this1.i18, i32 0, i32 0
  %29 = load i32* %__m.addr.i15, align 4
  store i8 1, i8* %.atomictmp.i16
  switch i32 %29, label %monotonic.i20 [
    i32 1, label %acquire.i21
    i32 2, label %acquire.i21
    i32 3, label %release.i22
    i32 4, label %acqrel.i23
    i32 5, label %seqcst.i24
  ]

monotonic.i20:                                    ; preds = %cond.end
  %30 = load i8* %.atomictmp.i16, align 1
  %31 = atomicrmw volatile xchg i8* %__a_.i19, i8 %30 monotonic
  store i8 %31, i8* %.atomicdst.i17, align 1
  br label %_ZNVSt3__111atomic_flag12test_and_setENS_12memory_orderE.exit26

acquire.i21:                                      ; preds = %cond.end, %cond.end
  %32 = load i8* %.atomictmp.i16, align 1
  %33 = atomicrmw volatile xchg i8* %__a_.i19, i8 %32 acquire
  store i8 %33, i8* %.atomicdst.i17, align 1
  br label %_ZNVSt3__111atomic_flag12test_and_setENS_12memory_orderE.exit26

release.i22:                                      ; preds = %cond.end
  %34 = load i8* %.atomictmp.i16, align 1
  %35 = atomicrmw volatile xchg i8* %__a_.i19, i8 %34 release
  store i8 %35, i8* %.atomicdst.i17, align 1
  br label %_ZNVSt3__111atomic_flag12test_and_setENS_12memory_orderE.exit26

acqrel.i23:                                       ; preds = %cond.end
  %36 = load i8* %.atomictmp.i16, align 1
  %37 = atomicrmw volatile xchg i8* %__a_.i19, i8 %36 acq_rel
  store i8 %37, i8* %.atomicdst.i17, align 1
  br label %_ZNVSt3__111atomic_flag12test_and_setENS_12memory_orderE.exit26

seqcst.i24:                                       ; preds = %cond.end
  %38 = load i8* %.atomictmp.i16, align 1
  %39 = atomicrmw volatile xchg i8* %__a_.i19, i8 %38 seq_cst
  store i8 %39, i8* %.atomicdst.i17, align 1
  br label %_ZNVSt3__111atomic_flag12test_and_setENS_12memory_orderE.exit26

_ZNVSt3__111atomic_flag12test_and_setENS_12memory_orderE.exit26: ; preds = %seqcst.i24, %acqrel.i23, %release.i22, %acquire.i21, %monotonic.i20
  %40 = load i8* %.atomicdst.i17
  %tobool.i25 = trunc i8 %40 to i1
  store %"struct.std::__1::atomic_flag"* %f2, %"struct.std::__1::atomic_flag"** %__o.addr.i, align 4
  %41 = load %"struct.std::__1::atomic_flag"** %__o.addr.i, align 4
  store %"struct.std::__1::atomic_flag"* %41, %"struct.std::__1::atomic_flag"** %this.addr.i.i12, align 4
  store i32 5, i32* %__m.addr.i.i, align 4
  %this1.i.i13 = load %"struct.std::__1::atomic_flag"** %this.addr.i.i12
  %__a_.i.i = getelementptr inbounds %"struct.std::__1::atomic_flag"* %this1.i.i13, i32 0, i32 0
  %42 = load i32* %__m.addr.i.i, align 4
  store i8 0, i8* %.atomictmp.i.i
  switch i32 %42, label %monotonic.i.i [
    i32 3, label %release.i.i
    i32 5, label %seqcst.i.i
  ]

monotonic.i.i:                                    ; preds = %_ZNVSt3__111atomic_flag12test_and_setENS_12memory_orderE.exit26
  %43 = load i8* %.atomictmp.i.i, align 1
  store atomic volatile i8 %43, i8* %__a_.i.i monotonic, align 1
  br label %_ZNSt3__117atomic_flag_clearEPVNS_11atomic_flagE.exit

release.i.i:                                      ; preds = %_ZNVSt3__111atomic_flag12test_and_setENS_12memory_orderE.exit26
  %44 = load i8* %.atomictmp.i.i, align 1
  store atomic volatile i8 %44, i8* %__a_.i.i release, align 1
  br label %_ZNSt3__117atomic_flag_clearEPVNS_11atomic_flagE.exit

seqcst.i.i:                                       ; preds = %_ZNVSt3__111atomic_flag12test_and_setENS_12memory_orderE.exit26
  %45 = load i8* %.atomictmp.i.i, align 1
  store atomic volatile i8 %45, i8* %__a_.i.i seq_cst, align 1
  br label %_ZNSt3__117atomic_flag_clearEPVNS_11atomic_flagE.exit

_ZNSt3__117atomic_flag_clearEPVNS_11atomic_flagE.exit: ; preds = %seqcst.i.i, %release.i.i, %monotonic.i.i
  store %"struct.std::__1::atomic_flag"* %f2, %"struct.std::__1::atomic_flag"** %this.addr.i10, align 4
  store i32 5, i32* %__m.addr.i, align 4
  %this1.i11 = load %"struct.std::__1::atomic_flag"** %this.addr.i10
  %__a_.i = getelementptr inbounds %"struct.std::__1::atomic_flag"* %this1.i11, i32 0, i32 0
  %46 = load i32* %__m.addr.i, align 4
  store i8 1, i8* %.atomictmp.i
  switch i32 %46, label %monotonic.i [
    i32 1, label %acquire.i
    i32 2, label %acquire.i
    i32 3, label %release.i
    i32 4, label %acqrel.i
    i32 5, label %seqcst.i
  ]

monotonic.i:                                      ; preds = %_ZNSt3__117atomic_flag_clearEPVNS_11atomic_flagE.exit
  %47 = load i8* %.atomictmp.i, align 1
  %48 = atomicrmw volatile xchg i8* %__a_.i, i8 %47 monotonic
  store i8 %48, i8* %.atomicdst.i, align 1
  br label %_ZNVSt3__111atomic_flag12test_and_setENS_12memory_orderE.exit

acquire.i:                                        ; preds = %_ZNSt3__117atomic_flag_clearEPVNS_11atomic_flagE.exit, %_ZNSt3__117atomic_flag_clearEPVNS_11atomic_flagE.exit
  %49 = load i8* %.atomictmp.i, align 1
  %50 = atomicrmw volatile xchg i8* %__a_.i, i8 %49 acquire
  store i8 %50, i8* %.atomicdst.i, align 1
  br label %_ZNVSt3__111atomic_flag12test_and_setENS_12memory_orderE.exit

release.i:                                        ; preds = %_ZNSt3__117atomic_flag_clearEPVNS_11atomic_flagE.exit
  %51 = load i8* %.atomictmp.i, align 1
  %52 = atomicrmw volatile xchg i8* %__a_.i, i8 %51 release
  store i8 %52, i8* %.atomicdst.i, align 1
  br label %_ZNVSt3__111atomic_flag12test_and_setENS_12memory_orderE.exit

acqrel.i:                                         ; preds = %_ZNSt3__117atomic_flag_clearEPVNS_11atomic_flagE.exit
  %53 = load i8* %.atomictmp.i, align 1
  %54 = atomicrmw volatile xchg i8* %__a_.i, i8 %53 acq_rel
  store i8 %54, i8* %.atomicdst.i, align 1
  br label %_ZNVSt3__111atomic_flag12test_and_setENS_12memory_orderE.exit

seqcst.i:                                         ; preds = %_ZNSt3__117atomic_flag_clearEPVNS_11atomic_flagE.exit
  %55 = load i8* %.atomictmp.i, align 1
  %56 = atomicrmw volatile xchg i8* %__a_.i, i8 %55 seq_cst
  store i8 %56, i8* %.atomicdst.i, align 1
  br label %_ZNVSt3__111atomic_flag12test_and_setENS_12memory_orderE.exit

_ZNVSt3__111atomic_flag12test_and_setENS_12memory_orderE.exit: ; preds = %seqcst.i, %acqrel.i, %release.i, %acquire.i, %monotonic.i
  %57 = load i8* %.atomicdst.i
  %tobool.i = trunc i8 %57 to i1
  %conv5 = zext i1 %tobool.i to i32
  %cmp6 = icmp eq i32 %conv5, 0
  br i1 %cmp6, label %cond.true7, label %cond.false8

cond.true7:                                       ; preds = %_ZNVSt3__111atomic_flag12test_and_setENS_12memory_orderE.exit
  br label %cond.end9

cond.false8:                                      ; preds = %_ZNVSt3__111atomic_flag12test_and_setENS_12memory_orderE.exit
  call void @__assert_func(i8* getelementptr inbounds ([27 x i8]* @.str, i32 0, i32 0), i32 32, i8* getelementptr inbounds ([11 x i8]* @__PRETTY_FUNCTION__.main, i32 0, i32 0), i8* getelementptr inbounds ([22 x i8]* @.str1, i32 0, i32 0))
  br label %cond.end9

cond.end9:                                        ; preds = %cond.false8, %cond.true7
  %58 = load i32* %retval
  ret i32 %58
}

declare void @__assert_func(i8*, i32, i8*, i8*)