reland [IR] make -stack-alignment= into a module attr

Relands commit 433c8d9 with fixes for
MIPS.

Similar to D102742, specifying the stack alignment via CodegenOpts means
that this flag gets dropped during LTO, unless the command line is
re-specified as a plugin opt. Instead, encode this information as a
module level attribute so that we don't have to expose this llvm
internal flag when linking the Linux kernel with LTO.

Looks like external dependencies might need a fix:
* llvm-hs/llvm-hs#345
* halide/Halide#6079

Link: ClangBuiltLinux/linux#1377

Reviewed By: tejohnson

Differential Revision: https://reviews.llvm.org/D103048

clang/lib/CodeGen/BackendUtil.cpp

@@ -530,7 +530,6 @@ static bool initTargetOptions(DiagnosticsEngine &Diags,
   Options.NoNaNsFPMath = LangOpts.NoHonorNaNs;
   Options.NoZerosInBSS = CodeGenOpts.NoZeroInitializedInBSS;
   Options.UnsafeFPMath = LangOpts.UnsafeFPMath;
-  Options.StackAlignmentOverride = CodeGenOpts.StackAlignment;
 
   Options.BBSections =
       llvm::StringSwitch<llvm::BasicBlockSection>(CodeGenOpts.BBSections)

clang/lib/CodeGen/CodeGenModule.cpp

@@ -785,6 +785,8 @@ void CodeGenModule::Release() {
   if (getCodeGenOpts().StackProtectorGuardOffset != INT_MAX)
     getModule().setStackProtectorGuardOffset(
         getCodeGenOpts().StackProtectorGuardOffset);
+  if (getCodeGenOpts().StackAlignment)
+    getModule().setOverrideStackAlignment(getCodeGenOpts().StackAlignment);
 
   getTargetCodeGenInfo().emitTargetMetadata(*this, MangledDeclNames);
 

clang/test/CodeGen/stackrealign-main.c

@@ -1,4 +1,5 @@
 // RUN: %clang_cc1 -triple i386-unknown-unknown -emit-llvm -o - -mstack-alignment=64 %s | FileCheck %s
+// RUN: %clang_cc1 -triple i386-unknown-unknown -emit-llvm -o - %s | FileCheck %s --check-prefix=DEFAULT
 
 // CHECK-LABEL: define{{.*}} void @other()
 // CHECK: [[OTHER:#[0-9]+]]
@@ -17,3 +18,5 @@ int main(int argc, char **argv) {
 // CHECK-NOT: "stackrealign"
 // CHECK: }
 // CHECK: attributes [[MAIN]] = { noinline nounwind optnone {{.*}}"stackrealign"{{.*}} }
+// CHECK: !{i32 1, !"override-stack-alignment", i32 64}
+// DEFAULT-NOT: "override-stack-alignment"

llvm/include/llvm/IR/Module.h

@@ -909,6 +909,10 @@ class Module {
   int getStackProtectorGuardOffset() const;
   void setStackProtectorGuardOffset(int Offset);
 
+  /// Get/set the stack alignment overridden from the default.
+  unsigned getOverrideStackAlignment() const;
+  void setOverrideStackAlignment(unsigned Align);
+
   /// @name Utility functions for querying and setting the build SDK version
   /// @{
 

llvm/include/llvm/Target/TargetOptions.h

@@ -201,9 +201,6 @@ namespace llvm {
     /// as their parent function, etc.), using an alternate ABI if necessary.
     unsigned GuaranteedTailCallOpt : 1;
 
-    /// StackAlignmentOverride - Override default stack alignment for target.
-    unsigned StackAlignmentOverride = 0;
-
     /// StackSymbolOrdering - When true, this will allow CodeGen to order
     /// the local stack symbols (for code size, code locality, or any other
     /// heuristics). When false, the local symbols are left in whatever order

llvm/lib/CodeGen/CommandFlags.cpp

@@ -69,7 +69,6 @@ CGOPT(bool, DontPlaceZerosInBSS)
 CGOPT(bool, EnableGuaranteedTailCallOpt)
 CGOPT(bool, DisableTailCalls)
 CGOPT(bool, StackSymbolOrdering)
-CGOPT(unsigned, OverrideStackAlignment)
 CGOPT(bool, StackRealign)
 CGOPT(std::string, TrapFuncName)
 CGOPT(bool, UseCtors)
@@ -305,11 +304,6 @@ codegen::RegisterCodeGenFlags::RegisterCodeGenFlags() {
       cl::init(true));
   CGBINDOPT(StackSymbolOrdering);
 
-  static cl::opt<unsigned> OverrideStackAlignment(
-      "stack-alignment", cl::desc("Override default stack alignment"),
-      cl::init(0));
-  CGBINDOPT(OverrideStackAlignment);
-
   static cl::opt<bool> StackRealign(
       "stackrealign",
       cl::desc("Force align the stack to the minimum alignment"),
@@ -508,7 +502,6 @@ codegen::InitTargetOptionsFromCodeGenFlags(const Triple &TheTriple) {
   Options.EnableAIXExtendedAltivecABI = getEnableAIXExtendedAltivecABI();
   Options.NoZerosInBSS = getDontPlaceZerosInBSS();
   Options.GuaranteedTailCallOpt = getEnableGuaranteedTailCallOpt();
-  Options.StackAlignmentOverride = getOverrideStackAlignment();
   Options.StackSymbolOrdering = getStackSymbolOrdering();
   Options.UseInitArray = !getUseCtors();
   Options.RelaxELFRelocations = getRelaxELFRelocations();

llvm/lib/IR/Module.cpp

@@ -721,6 +721,17 @@ void Module::setStackProtectorGuardOffset(int Offset) {
   addModuleFlag(ModFlagBehavior::Error, "stack-protector-guard-offset", Offset);
 }
 
+unsigned Module::getOverrideStackAlignment() const {
+  Metadata *MD = getModuleFlag("override-stack-alignment");
+  if (auto *CI = mdconst::dyn_extract_or_null<ConstantInt>(MD))
+    return CI->getZExtValue();
+  return 0;
+}
+
+void Module::setOverrideStackAlignment(unsigned Align) {
+  addModuleFlag(ModFlagBehavior::Error, "override-stack-alignment", Align);
+}
+
 void Module::setSDKVersion(const VersionTuple &V) {
   SmallVector<unsigned, 3> Entries;
   Entries.push_back(V.getMajor());

llvm/lib/Target/Mips/MipsCallLowering.cpp

@@ -588,8 +588,11 @@ bool MipsCallLowering::lowerCall(MachineIRBuilder &MIRBuilder,
   }
 
   unsigned NextStackOffset = CCInfo.getNextStackOffset();
-  const TargetFrameLowering *TFL = MF.getSubtarget().getFrameLowering();
-  unsigned StackAlignment = TFL->getStackAlignment();
+  unsigned StackAlignment = F.getParent()->getOverrideStackAlignment();
+  if (!StackAlignment) {
+    const TargetFrameLowering *TFL = MF.getSubtarget().getFrameLowering();
+    StackAlignment = TFL->getStackAlignment();
+  }
   NextStackOffset = alignTo(NextStackOffset, StackAlignment);
   CallSeqStart.addImm(NextStackOffset).addImm(0);
 

llvm/lib/Target/Mips/MipsTargetMachine.cpp

@@ -120,15 +120,11 @@ MipsTargetMachine::MipsTargetMachine(const Target &T, const Triple &TT,
                         getEffectiveCodeModel(CM, CodeModel::Small), OL),
       isLittle(isLittle), TLOF(std::make_unique<MipsTargetObjectFile>()),
       ABI(MipsABIInfo::computeTargetABI(TT, CPU, Options.MCOptions)),
-      Subtarget(nullptr),
-      DefaultSubtarget(TT, CPU, FS, isLittle, *this,
-                       MaybeAlign(Options.StackAlignmentOverride)),
+      Subtarget(nullptr), DefaultSubtarget(TT, CPU, FS, isLittle, *this, None),
       NoMips16Subtarget(TT, CPU, FS.empty() ? "-mips16" : FS.str() + ",-mips16",
-                        isLittle, *this,
-                        MaybeAlign(Options.StackAlignmentOverride)),
+                        isLittle, *this, None),
       Mips16Subtarget(TT, CPU, FS.empty() ? "+mips16" : FS.str() + ",+mips16",
-                      isLittle, *this,
-                      MaybeAlign(Options.StackAlignmentOverride)) {
+                      isLittle, *this, None) {
   Subtarget = &DefaultSubtarget;
   initAsmInfo();
 
@@ -197,7 +193,7 @@ MipsTargetMachine::getSubtargetImpl(const Function &F) const {
     resetTargetOptions(F);
     I = std::make_unique<MipsSubtarget>(
         TargetTriple, CPU, FS, isLittle, *this,
-        MaybeAlign(Options.StackAlignmentOverride));
+        MaybeAlign(F.getParent()->getOverrideStackAlignment()));
   }
   return I.get();
 }

llvm/lib/Target/X86/X86TargetMachine.cpp

@@ -314,8 +314,8 @@ X86TargetMachine::getSubtargetImpl(const Function &F) const {
     resetTargetOptions(F);
     I = std::make_unique<X86Subtarget>(
         TargetTriple, CPU, TuneCPU, FS, *this,
-        MaybeAlign(Options.StackAlignmentOverride), PreferVectorWidthOverride,
-        RequiredVectorWidth);
+        MaybeAlign(F.getParent()->getOverrideStackAlignment()),
+        PreferVectorWidthOverride, RequiredVectorWidth);
   }
   return I.get();
 }

llvm/test/CodeGen/Generic/ForceStackAlign.ll

@@ -1,7 +1,7 @@
 ; Check that stack alignment can be forced. Individual targets should test their
 ; specific implementation details.
 
-; RUN: llc < %s -stackrealign -stack-alignment=32 | FileCheck %s
+; RUN: llc < %s -stackrealign | FileCheck %s
 ; CHECK-LABEL: @f
 ; CHECK-LABEL: @g
 
@@ -25,3 +25,6 @@ if.then:
 }
 
 declare void @llvm.memset.p0i8.i32(i8*, i8, i32, i1) nounwind
+
+!llvm.module.flags = !{!0}
+!0 = !{i32 2, !"override-stack-alignment", i32 32}

llvm/test/CodeGen/Mips/stack-alignment.ll

@@ -1,11 +1,14 @@
-; RUN: llc -march=mipsel < %s | FileCheck %s -check-prefix=32
-; RUN: llc -march=mipsel -stack-alignment=32 < %s | FileCheck %s -check-prefix=A32-32
-; RUN: llc -march=mipsel -mattr=+fp64,+mips32r2 < %s | FileCheck %s -check-prefix=32
-; RUN: llc -march=mips64el -mcpu=mips3 < %s | FileCheck %s -check-prefix=64
-; RUN: llc -march=mips64el -mcpu=mips4 < %s | FileCheck %s -check-prefix=64
-; RUN: llc -march=mips64el -mcpu=mips64 < %s | FileCheck %s -check-prefix=64
-; RUN: llc -march=mips64el -mcpu=mips64 -stack-alignment=32 < %s | FileCheck %s -check-prefix=A32-64
+; RUN: split-file %s %t
+; RUN: cat %t/main.ll %t/_32.ll > %t/32.ll
+; RUN: llc -march=mipsel < %t/main.ll | FileCheck %s -check-prefix=32
+; RUN: llc -march=mipsel < %t/32.ll | FileCheck %s -check-prefix=A32-32
+; RUN: llc -march=mipsel -mattr=+fp64,+mips32r2 < %t/main.ll | FileCheck %s -check-prefix=32
+; RUN: llc -march=mips64el -mcpu=mips3 < %t/main.ll | FileCheck %s -check-prefix=64
+; RUN: llc -march=mips64el -mcpu=mips4 < %t/main.ll | FileCheck %s -check-prefix=64
+; RUN: llc -march=mips64el -mcpu=mips64 < %t/main.ll | FileCheck %s -check-prefix=64
+; RUN: llc -march=mips64el -mcpu=mips64 < %t/32.ll | FileCheck %s -check-prefix=A32-64
 
+;--- main.ll
 ; 32:      addiu  $sp, $sp, -8
 ; 64:      daddiu  $sp, $sp, -16
 ; A32-32:  addiu  $sp, $sp, -32
@@ -17,3 +20,6 @@ entry:
 }
 
 attributes #0 = { "frame-pointer"="all" }
+;--- _32.ll
+!llvm.module.flags = !{!0}
+!0 = !{i32 1, !"override-stack-alignment", i32 32}

llvm/test/CodeGen/X86/base-pointer-and-cmpxchg.ll

@@ -1,7 +1,7 @@
-; RUN: llc -mtriple=x86_64-apple-macosx -mattr=+cx16 -x86-use-base-pointer=true -stackrealign -stack-alignment=32  %s -o - | FileCheck --check-prefix=CHECK --check-prefix=USE_BASE --check-prefix=USE_BASE_64 %s
-; RUN: llc -mtriple=x86_64-apple-macosx -mattr=+cx16 -x86-use-base-pointer=false -stackrealign -stack-alignment=32  %s -o - | FileCheck --check-prefix=CHECK --check-prefix=DONT_USE_BASE %s
-; RUN: llc -mtriple=x86_64-linux-gnux32 -mattr=+cx16 -x86-use-base-pointer=true -stackrealign -stack-alignment=32  %s -o - | FileCheck --check-prefix=CHECK --check-prefix=USE_BASE --check-prefix=USE_BASE_32 %s
-; RUN: llc -mtriple=x86_64-linux-gnux32 -mattr=+cx16 -x86-use-base-pointer=false -stackrealign -stack-alignment=32  %s -o - | FileCheck --check-prefix=CHECK --check-prefix=DONT_USE_BASE %s
+; RUN: llc -mtriple=x86_64-apple-macosx -mattr=+cx16 -x86-use-base-pointer=true -stackrealign %s -o - | FileCheck --check-prefix=CHECK --check-prefix=USE_BASE --check-prefix=USE_BASE_64 %s
+; RUN: llc -mtriple=x86_64-apple-macosx -mattr=+cx16 -x86-use-base-pointer=false -stackrealign %s -o - | FileCheck --check-prefix=CHECK --check-prefix=DONT_USE_BASE %s
+; RUN: llc -mtriple=x86_64-linux-gnux32 -mattr=+cx16 -x86-use-base-pointer=true -stackrealign %s -o - | FileCheck --check-prefix=CHECK --check-prefix=USE_BASE --check-prefix=USE_BASE_32 %s
+; RUN: llc -mtriple=x86_64-linux-gnux32 -mattr=+cx16 -x86-use-base-pointer=false -stackrealign %s -o - | FileCheck --check-prefix=CHECK --check-prefix=DONT_USE_BASE %s
 
 ; This function uses dynamic allocated stack to force the use
 ; of a frame pointer.
@@ -49,3 +49,5 @@ tail call void asm sideeffect "nop", "~{rax},~{rcx},~{rdx},~{rsi},~{rdi},~{rbp},
   store i32 %n, i32* %idx
   ret i1 %res
 }
+!llvm.module.flags = !{!0}
+!0 = !{i32 2, !"override-stack-alignment", i32 32}

llvm/test/CodeGen/X86/base-pointer-and-mwaitx.ll

@@ -1,7 +1,11 @@
-; RUN: llc -mtriple=x86_64-pc-linux-gnu -mattr=+mwaitx -x86-use-base-pointer=true -stackrealign -stack-alignment=32  %s -o - | FileCheck --check-prefix=CHECK --check-prefix=USE_BASE_64 %s
-; RUN: llc -mtriple=x86_64-pc-linux-gnux32 -mattr=+mwaitx -x86-use-base-pointer=true -stackrealign -stack-alignment=32  %s -o - | FileCheck --check-prefix=CHECK --check-prefix=USE_BASE_32 %s
-; RUN: llc -mtriple=x86_64-pc-linux-gnu -mattr=+mwaitx -x86-use-base-pointer=true  %s -o - | FileCheck --check-prefix=CHECK --check-prefix=NO_BASE_64 %s
-; RUN: llc -mtriple=x86_64-pc-linux-gnux32 -mattr=+mwaitx -x86-use-base-pointer=true  %s -o - | FileCheck --check-prefix=CHECK --check-prefix=NO_BASE_32 %s
+; RUN: split-file %s %t
+; RUN: cat %t/main.ll %t/_align32.ll > %t/align32.ll
+; RUN: llc -mtriple=x86_64-pc-linux-gnu -mattr=+mwaitx -x86-use-base-pointer=true -stackrealign %t/align32.ll -o - | FileCheck --check-prefix=CHECK --check-prefix=USE_BASE_64 %s
+; RUN: llc -mtriple=x86_64-pc-linux-gnux32 -mattr=+mwaitx -x86-use-base-pointer=true -stackrealign %t/align32.ll -o - | FileCheck --check-prefix=CHECK --check-prefix=USE_BASE_32 %s
+; RUN: llc -mtriple=x86_64-pc-linux-gnu -mattr=+mwaitx -x86-use-base-pointer=true %t/main.ll -o - | FileCheck --check-prefix=CHECK --check-prefix=NO_BASE_64 %s
+; RUN: llc -mtriple=x86_64-pc-linux-gnux32 -mattr=+mwaitx -x86-use-base-pointer=true %t/main.ll -o - | FileCheck --check-prefix=CHECK --check-prefix=NO_BASE_32 %s
+
+;--- main.ll
 
 ; This test checks that we save and restore the base pointer (ebx or rbx) in the
 ; presence of the mwaitx intrinsic which requires to use ebx for one of its
@@ -208,3 +212,6 @@ if.end:
 ; NO_BASE_32-NEXT: {{.+$}}
 
 declare void @llvm.x86.mwaitx(i32, i32, i32) nounwind
+;--- _align32.ll
+!llvm.module.flags = !{!0}
+!0 = !{i32 2, !"override-stack-alignment", i32 32}

llvm/test/CodeGen/X86/dynamic-allocas-VLAs-stack-align.ll

@@ -0,0 +1,46 @@
+; RUN: llc < %s -stack-symbol-ordering=0 -mcpu=generic -stackrealign -mattr=+avx -mtriple=x86_64-apple-darwin10 | FileCheck %s
+; rdar://11496434
+declare void @t1_helper(i32*)
+declare void @t3_helper(i32*, i32*)
+
+; Test when forcing stack alignment
+define i32 @t8() nounwind uwtable {
+entry:
+  %a = alloca i32, align 4
+  call void @t1_helper(i32* %a) nounwind
+  %0 = load i32, i32* %a, align 4
+  %add = add nsw i32 %0, 13
+  ret i32 %add
+
+; CHECK: _t8
+; CHECK:      movq %rsp, %rbp
+; CHECK:      andq $-32, %rsp
+; CHECK-NEXT: subq $32, %rsp
+; CHECK:      movq %rbp, %rsp
+; CHECK:      popq %rbp
+}
+
+; VLAs
+define i32 @t9(i64 %sz) nounwind uwtable {
+entry:
+  %a = alloca i32, align 4
+  %vla = alloca i32, i64 %sz, align 16
+  call void @t3_helper(i32* %a, i32* %vla) nounwind
+  %0 = load i32, i32* %a, align 4
+  %add = add nsw i32 %0, 13
+  ret i32 %add
+
+; CHECK: _t9
+; CHECK: pushq %rbp
+; CHECK: movq %rsp, %rbp
+; CHECK: pushq %rbx
+; CHECK: andq $-32, %rsp
+; CHECK: subq $32, %rsp
+; CHECK: movq %rsp, %rbx
+
+; CHECK: leaq -8(%rbp), %rsp
+; CHECK: popq %rbx
+; CHECK: popq %rbp
+}
+!llvm.module.flags = !{!0}
+!0 = !{i32 2, !"override-stack-alignment", i32 32}

llvm/test/CodeGen/X86/dynamic-allocas-VLAs.ll

@@ -1,5 +1,4 @@
 ; RUN: llc < %s -stack-symbol-ordering=0 -mcpu=generic -mattr=+avx -mtriple=x86_64-apple-darwin10 | FileCheck %s
-; RUN: llc < %s -stack-symbol-ordering=0 -mcpu=generic -stackrealign -stack-alignment=32 -mattr=+avx -mtriple=x86_64-apple-darwin10 | FileCheck %s -check-prefix=FORCE-ALIGN
 ; rdar://11496434
 
 ; no VLAs or dynamic alignment
@@ -184,44 +183,3 @@ declare i8* @llvm.stacksave() nounwind
 declare void @bar(i32, i32*, %struct.struct_t* byval(%struct.struct_t) align 8)
 
 declare void @llvm.stackrestore(i8*) nounwind
-
-
-; Test when forcing stack alignment
-define i32 @t8() nounwind uwtable {
-entry:
-  %a = alloca i32, align 4
-  call void @t1_helper(i32* %a) nounwind
-  %0 = load i32, i32* %a, align 4
-  %add = add nsw i32 %0, 13
-  ret i32 %add
-
-; FORCE-ALIGN: _t8
-; FORCE-ALIGN:      movq %rsp, %rbp
-; FORCE-ALIGN:      andq $-32, %rsp
-; FORCE-ALIGN-NEXT: subq $32, %rsp
-; FORCE-ALIGN:      movq %rbp, %rsp
-; FORCE-ALIGN:      popq %rbp
-}
-
-; VLAs
-define i32 @t9(i64 %sz) nounwind uwtable {
-entry:
-  %a = alloca i32, align 4
-  %vla = alloca i32, i64 %sz, align 16
-  call void @t3_helper(i32* %a, i32* %vla) nounwind
-  %0 = load i32, i32* %a, align 4
-  %add = add nsw i32 %0, 13
-  ret i32 %add
-
-; FORCE-ALIGN: _t9
-; FORCE-ALIGN: pushq %rbp
-; FORCE-ALIGN: movq %rsp, %rbp
-; FORCE-ALIGN: pushq %rbx
-; FORCE-ALIGN: andq $-32, %rsp
-; FORCE-ALIGN: subq $32, %rsp
-; FORCE-ALIGN: movq %rsp, %rbx
-
-; FORCE-ALIGN: leaq -8(%rbp), %rsp
-; FORCE-ALIGN: popq %rbx
-; FORCE-ALIGN: popq %rbp
-}

llvm/test/CodeGen/X86/force-align-stack-alloca.ll

@@ -3,7 +3,7 @@
 ; arbitrarily force alignment up to 32-bytes for i386 hoping that this will
 ; exceed any ABI provisions.
 ;
-; RUN: llc < %s -mcpu=generic -stackrealign -stack-alignment=32 | FileCheck %s
+; RUN: llc < %s -mcpu=generic -stackrealign | FileCheck %s
 
 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-unknown-linux-gnu"
@@ -74,3 +74,6 @@ if.then:
 }
 
 declare void @llvm.memset.p0i8.i32(i8*, i8, i32, i1) nounwind
+
+!llvm.module.flags = !{!0}
+!0 = !{i32 2, !"override-stack-alignment", i32 32}

llvm/test/CodeGen/X86/hipe-cc.ll

@@ -1,4 +1,4 @@
-; RUN: llc < %s -stack-symbol-ordering=0 -tailcallopt -code-model=medium -stack-alignment=4 -mtriple=i686-linux-gnu -mcpu=pentium | FileCheck %s
+; RUN: llc < %s -stack-symbol-ordering=0 -tailcallopt -code-model=medium -mtriple=i686-linux-gnu -mcpu=pentium | FileCheck %s
 
 ; Check the HiPE calling convention works (x86-32)
 
@@ -89,3 +89,6 @@ define cc 11 { i32, i32, i32 } @tailcaller(i32 %hp, i32 %p) nounwind {
 @clos = external dso_local constant i32
 declare cc 11 void @bar(i32, i32, i32, i32, i32)
 declare cc 11 { i32, i32, i32 } @tailcallee(i32, i32, i32, i32, i32, i32)
+
+!llvm.module.flags = !{!3}
+!3 = !{i32 2, !"override-stack-alignment", i32 4}

llvm/test/CodeGen/X86/hipe-cc64.ll

@@ -1,4 +1,4 @@
-; RUN: llc < %s -stack-symbol-ordering=0 -tailcallopt -relocation-model=static -code-model=medium -stack-alignment=8 -mtriple=x86_64-linux-gnu -mcpu=opteron | FileCheck %s
+; RUN: llc < %s -stack-symbol-ordering=0 -tailcallopt -relocation-model=static -code-model=medium -mtriple=x86_64-linux-gnu -mcpu=opteron | FileCheck %s
 
 ; Check the HiPE calling convention works (x86-64)
 
@@ -100,3 +100,5 @@ define cc 11 { i64, i64, i64 } @tailcaller(i64 %hp, i64 %p) #0 {
 @clos = external constant i64
 declare cc 11 void @bar(i64, i64, i64, i64, i64, i64)
 declare cc 11 { i64, i64, i64 } @tailcallee(i64, i64, i64, i64, i64, i64, i64)
+!llvm.module.flags = !{!3}
+!3 = !{i32 2, !"override-stack-alignment", i32 8}