[CIR][CIRGen] Add dsolocal attribute to GlobalOp and FuncOp (#686)

as title. In this PR
1.   make setDSOLocal an interface function.
2. implemented shouldAssumeDSOLocal function in CIRGenModule, using the
same skeleton as shouldAssumeDSOLocal in OG's CodeGenModule.cpp.
3. added call sites of setDSOLocal within CIRGenModule, like what's in
OG's CodeGenModule.
4.  fixed printing format 
5.  LLVM lowering
6. keep CIRGenModule::setDSOLocal(mlir::Operation *Op) wrapper at call
sites, so if we make changes to interface, we don't have to touch call
sites since there are many.

We don't have LLVM test for this PR yet, and it will be addressed by the
next PR,:
**TODO in the next PR:**
1. Implement setNonAliasAttributes in CIRGenModule.cpp, which should be
called by CIRGenModule::buildGlobalFunctionDefinition. That way, we will
set dso_local correctly for all func ops who have defs in the module.
That way we should have LLVM test case in this next PR. detailed
explanation below:

Since LLVM asm printer omits dso_local in
[isImplicitDSOLocal](https://github.com/llvm/clangir/blob/main/llvm/lib/IR/AsmWriter.cpp#L3689)(),
and all we cover so far in CIR all fall into this category, we're not
able to have a LLVM test.
However, the case
[isDeclarationForLinker()](https://github.com/llvm/clangir/blob/c28908396a3ba7bda6345907233e4f5c4e53a33e/clang/lib/CodeGen/CodeGenModule.cpp#L1655)
should have a lot of test examples as all func defs should have
dso_local, We don't have it CIR is because
A to-do in our CG.
When OG is building func def, after code is generated, it will call
setDSOLocal again via
setNonAliasAttributes—>SetCommonAttributes—>setGVProperties. The key
difference is now GV is not declaration anymore. so satisfies the test
if (!GV->isDeclarationForLinker())
    return true;

https://github.com/llvm/clangir/blob/f78f9a55e7cd6b9e350556e35097616676cf1f3e/clang/lib/CodeGen/CodeGenModule.cpp#L5864
But our CG missed this step of calling setNonAliasAttributes so it won’t
give setDSOLocal another chance to get it right

https://github.com/llvm/clangir/blob/c28908396a3ba7bda6345907233e4f5c4e53a33e/clang/lib/CIR/CodeGen/CIRGenModule.cpp#L496


**TODO in the next next PR** 
2. add call to setDSOLocal in other parts of CG other than CIRGenModule.
3. implement DefaultVisibility check, didn't do in this PR as
LLVM::DefaultVisibility has no direct counterpart in
[MLIR::](mlir::SymbolTable::Visibility). Therefore, it takes care
examination of cases to see what is the best emulation of
hasDefaultVisibility in MLIR/CIR context as far as dsolocal is
concerned.

**TODO in future**
other than DefaultVisibility check, we didn't implement
canBenefitFromLocalAlias as it depends on other missing features like
setComDat.










There is a lot of cases we need to cover, so this is just the first
step!

Author: ghehg

clang/include/clang/CIR/Dialect/IR/CIROps.td

@@ -1924,6 +1924,7 @@ def GlobalOp : CIR_Op<"global",
                        // Note this can also be a FlatSymbolRefAttr
                        OptionalAttr<AnyAttr>:$initial_value,
                        UnitAttr:$constant,
+                       UnitAttr:$dsolocal,
                        OptionalAttr<I64Attr>:$alignment,
                        OptionalAttr<ASTVarDeclInterface>:$ast,
                        OptionalAttr<StrAttr>:$section
@@ -1934,6 +1935,7 @@ def GlobalOp : CIR_Op<"global",
        (`constant` $constant^)?
        $linkage
        ($tls_model^)?
+       (`dsolocal` $dsolocal^)?
        $sym_name
        custom<GlobalOpTypeAndInitialValue>($sym_type, $initial_value, $ctorRegion, $dtorRegion)
        attr-dict
@@ -2671,6 +2673,7 @@ def FuncOp : CIR_Op<"func", [
                        UnitAttr:$coroutine,
                        UnitAttr:$lambda,
                        UnitAttr:$no_proto,
+                       UnitAttr:$dsolocal,
                        DefaultValuedAttr<GlobalLinkageKind,
                                          "GlobalLinkageKind::ExternalLinkage">:$linkage,
                        ExtraFuncAttr:$extra_attrs,

clang/include/clang/CIR/Interfaces/CIROpInterfaces.h

@@ -17,6 +17,7 @@
 #include "clang/AST/Attr.h"
 #include "clang/AST/DeclTemplate.h"
 #include "clang/AST/Mangle.h"
+#include "clang/CIR/Dialect/IR/CIROpsEnums.h"
 
 namespace mlir {
 namespace cir {} // namespace cir

clang/include/clang/CIR/Interfaces/CIROpInterfaces.td

@@ -46,14 +46,35 @@ let cppNamespace = "::mlir::cir" in {
       /*defaultImplementation=*/[{ return false; }]
       >,
       InterfaceMethod<"",
+      "bool", "hasLocalLinkage", (ins), [{}],
+      /*defaultImplementation=*/[{ 
+        return mlir::cir::isLocalLinkage($_op.getLinkage()); 
+      }]
+      >,
+      InterfaceMethod<"",
+      "bool", "hasExternalWeakLinkage", (ins), [{}],
+      /*defaultImplementation=*/[{ 
+        return mlir::cir::isExternalWeakLinkage($_op.getLinkage()); 
+      }]
+      >,
+      InterfaceMethod<"",
       "bool", "isDeclarationForLinker", (ins), [{}],
       /*defaultImplementation=*/[{
         if ($_op.hasAvailableExternallyLinkage())
           return true;
         return $_op.isDeclaration();
       }]
       >,
+      InterfaceMethod<"",
+      "void", "setDSOLocal", (ins "bool":$val), [{}],
+      /*defaultImplementation=*/[{
+        $_op.setDsolocal(val);
+      }]
+      >,
     ];
+    let extraClassDeclaration = [{ 
+    bool canBenefitFromLocalAlias() const;
+  }];
   }
 
 } // namespace mlir::cir

clang/include/clang/CIR/MissingFeatures.h

@@ -48,6 +48,8 @@ struct MissingFeatures {
   static bool hiddenVisibility() { return false; }
   static bool protectedVisibility() { return false; }
   static bool addCompilerUsedGlobal() { return false; }
+  static bool supportIFuncAttr() { return false; }
+  static bool setDefaultVisibility() { return false; }
 
   // Sanitizers
   static bool reportGlobalToASan() { return false; }

clang/lib/CIR/CodeGen/CIRGenModule.cpp

@@ -364,6 +364,103 @@ bool CIRGenModule::MayBeEmittedEagerly(const ValueDecl *Global) {
   return true;
 }
 
+static bool hasDefaultVisibility(CIRGlobalValueInterface GV) {
+  // TODO: we need to have a precise definition of what is a default visibility.
+  // in the context of MILR and CIR, now we default to
+  assert(!MissingFeatures::setDefaultVisibility());
+  return true;
+}
+
+static bool shouldAssumeDSOLocal(const CIRGenModule &CGM,
+                                 CIRGlobalValueInterface GV) {
+  if (GV.hasLocalLinkage())
+    return true;
+
+  if (!hasDefaultVisibility(GV) && !GV.hasExternalWeakLinkage()) {
+    return true;
+  }
+
+  // DLLImport explicitly marks the GV as external.
+  // so it shouldn't be dso_local
+  // But we don't have the info set now
+  assert(!MissingFeatures::setDLLImportDLLExport());
+
+  const llvm::Triple &TT = CGM.getTriple();
+  const auto &CGOpts = CGM.getCodeGenOpts();
+  if (TT.isWindowsGNUEnvironment()) {
+    // In MinGW, variables without DLLImport can still be automatically
+    // imported from a DLL by the linker; don't mark variables that
+    // potentially could come from another DLL as DSO local.
+
+    // With EmulatedTLS, TLS variables can be autoimported from other DLLs
+    // (and this actually happens in the public interface of libstdc++), so
+    // such variables can't be marked as DSO local. (Native TLS variables
+    // can't be dllimported at all, though.)
+    llvm_unreachable("MinGW not supported here");
+  }
+
+  // On COFF, don't mark 'extern_weak' symbols as DSO local. If these symbols
+  // remain unresolved in the link, they can be resolved to zero, which is
+  // outside the current DSO.
+  if (TT.isOSBinFormatCOFF() && GV.hasExternalWeakLinkage())
+    return false;
+
+  // Every other GV is local on COFF.
+  // Make an exception for windows OS in the triple: Some firmware builds use
+  // *-win32-macho triples. This (accidentally?) produced windows relocations
+  // without GOT tables in older clang versions; Keep this behaviour.
+  // FIXME: even thread local variables?
+  if (TT.isOSBinFormatCOFF() || (TT.isOSWindows() && TT.isOSBinFormatMachO()))
+    return true;
+
+  // Only handle COFF and ELF for now.
+  if (!TT.isOSBinFormatELF())
+    return false;
+
+  llvm::Reloc::Model RM = CGOpts.RelocationModel;
+  const auto &LOpts = CGM.getLangOpts();
+  if (RM != llvm::Reloc::Static && !LOpts.PIE) {
+    // On ELF, if -fno-semantic-interposition is specified and the target
+    // supports local aliases, there will be neither CC1
+    // -fsemantic-interposition nor -fhalf-no-semantic-interposition. Set
+    // dso_local on the function if using a local alias is preferable (can avoid
+    // PLT indirection).
+    if (!(isa<mlir::cir::FuncOp>(GV) && GV.canBenefitFromLocalAlias())) {
+      return false;
+    }
+    return !(CGM.getLangOpts().SemanticInterposition ||
+             CGM.getLangOpts().HalfNoSemanticInterposition);
+  }
+
+  // A definition cannot be preempted from an executable.
+  if (!GV.isDeclarationForLinker())
+    return true;
+
+  // Most PIC code sequences that assume that a symbol is local cannot produce a
+  // 0 if it turns out the symbol is undefined. While this is ABI and relocation
+  // depended, it seems worth it to handle it here.
+  if (RM == llvm::Reloc::PIC_ && GV.hasExternalWeakLinkage())
+    return false;
+
+  // PowerPC64 prefers TOC indirection to avoid copy relocations.
+  if (TT.isPPC64())
+    return false;
+
+  if (CGOpts.DirectAccessExternalData) {
+    llvm_unreachable("-fdirect-access-external-data not supported");
+  }
+
+  // If we can use copy relocations we can assume it is local.
+
+  // Otherwise don't assume it is local.
+
+  return false;
+}
+
+void CIRGenModule::setDSOLocal(CIRGlobalValueInterface GV) const {
+  GV.setDSOLocal(shouldAssumeDSOLocal(*this, GV));
+}
+
 void CIRGenModule::buildGlobal(GlobalDecl GD) {
   const auto *Global = cast<ValueDecl>(GD.getDecl());
 
@@ -1272,7 +1369,6 @@ generateStringLiteral(mlir::Location loc, mlir::TypedAttr C,
   GV.setLinkageAttr(
       mlir::cir::GlobalLinkageKindAttr::get(CGM.getBuilder().getContext(), LT));
   CIRGenModule::setInitializer(GV, C);
-
   // TODO(cir)
   assert(!cir::MissingFeatures::threadLocal() && "NYI");
   assert(!cir::MissingFeatures::unnamedAddr() && "NYI");
@@ -1326,6 +1422,7 @@ CIRGenModule::getAddrOfConstantStringFromLiteral(const StringLiteral *S,
       llvm_unreachable("this should never be untyped at this point");
     GV = generateStringLiteral(loc, typedC, LT, *this, GlobalVariableName,
                                Alignment);
+    setDSOLocal(static_cast<mlir::Operation *>(GV));
     ConstantStringMap[C] = GV;
 
     assert(!cir::MissingFeatures::reportGlobalToASan() && "NYI");
@@ -1979,6 +2076,9 @@ void CIRGenModule::setGlobalVisibility(mlir::Operation *GV,
 
 void CIRGenModule::setDSOLocal(mlir::Operation *Op) const {
   assert(!MissingFeatures::setDSOLocal());
+  if (auto globalValue = dyn_cast<mlir::cir::CIRGlobalValueInterface>(Op)) {
+    setDSOLocal(globalValue);
+  }
 }
 
 void CIRGenModule::setGVProperties(mlir::Operation *Op,
@@ -2750,6 +2850,7 @@ mlir::cir::GlobalOp CIRGenModule::createOrReplaceCXXRuntimeVariable(
     assert(!MissingFeatures::setComdat());
 
   GV.setAlignmentAttr(getSize(Alignment));
+  setDSOLocal(static_cast<mlir::Operation *>(GV));
   return GV;
 }
 

clang/lib/CIR/CodeGen/CIRGenModule.h

@@ -30,6 +30,7 @@
 #include "clang/CIR/Dialect/IR/CIRDialect.h"
 #include "clang/CIR/Dialect/IR/CIROpsEnums.h"
 #include "clang/CIR/Dialect/IR/CIRTypes.h"
+#include "clang/CIR/Interfaces/CIROpInterfaces.h"
 
 #include "llvm/ADT/ScopedHashTable.h"
 #include "llvm/ADT/SmallPtrSet.h"
@@ -281,6 +282,8 @@ class CIRGenModule : public CIRGenTypeCache {
   void buildDeferredVTables();
   bool shouldOpportunisticallyEmitVTables();
 
+  void setDSOLocal(mlir::cir::CIRGlobalValueInterface GV) const;
+
   /// Return the appropriate linkage for the vtable, VTT, and type information
   /// of the given class.
   mlir::cir::GlobalLinkageKind getVTableLinkage(const CXXRecordDecl *RD);

clang/lib/CIR/Dialect/IR/CIRDialect.cpp

@@ -2116,6 +2116,9 @@ void cir::FuncOp::print(OpAsmPrinter &p) {
   if (vis != mlir::SymbolTable::Visibility::Public)
     p << vis << " ";
 
+  if (getDsolocal())
+    p << "dsolocal ";
+
   // Print function name, signature, and control.
   p.printSymbolName(getSymName());
   auto fnType = getFunctionType();
@@ -2134,6 +2137,7 @@ void cir::FuncOp::print(OpAsmPrinter &p) {
           getAliaseeAttrName(),
           getBuiltinAttrName(),
           getCoroutineAttrName(),
+          getDsolocalAttrName(),
           getExtraAttrsAttrName(),
           getFunctionTypeAttrName(),
           getGlobalCtorAttrName(),

clang/lib/CIR/Interfaces/CIROpInterfaces.cpp

@@ -7,9 +7,18 @@
 //===----------------------------------------------------------------------===//
 #include "clang/CIR/Interfaces/CIROpInterfaces.h"
 
+#include "clang/CIR/Dialect/IR/CIROpsEnums.h"
 #include "llvm/ADT/SmallVector.h"
 
 using namespace mlir::cir;
 
 /// Include the generated type qualifiers interfaces.
 #include "clang/CIR/Interfaces/CIROpInterfaces.cpp.inc"
+
+#include "clang/CIR/MissingFeatures.h"
+
+bool CIRGlobalValueInterface::canBenefitFromLocalAlias() const {
+  assert(!::cir::MissingFeatures::supportIFuncAttr());
+  assert(!::cir::MissingFeatures::setComdat());
+  return false;
+}

clang/lib/CIR/Lowering/DirectToLLVM/LowerToLLVM.cpp

@@ -1512,6 +1512,7 @@ class CIRFuncLowering : public mlir::OpConversionPattern<mlir::cir::FuncOp> {
                   mlir::ConversionPatternRewriter &rewriter) const override {
 
     auto fnType = op.getFunctionType();
+    auto isDsoLocal = op.getDsolocal();
     mlir::TypeConverter::SignatureConversion signatureConversion(
         fnType.getNumInputs());
 
@@ -1545,7 +1546,7 @@ class CIRFuncLowering : public mlir::OpConversionPattern<mlir::cir::FuncOp> {
     filterFuncAttributes(op, /*filterArgAndResAttrs=*/false, attributes);
 
     auto fn = rewriter.create<mlir::LLVM::LLVMFuncOp>(
-        Loc, op.getName(), llvmFnTy, linkage, false, mlir::LLVM::CConv::C,
+        Loc, op.getName(), llvmFnTy, linkage, isDsoLocal, mlir::LLVM::CConv::C,
         mlir::SymbolRefAttr(), attributes);
 
     rewriter.inlineRegionBefore(op.getBody(), fn.getBody(), fn.end());
@@ -1654,6 +1655,7 @@ class CIRGlobalOpLowering
     // Fetch required values to create LLVM op.
     const auto llvmType = getTypeConverter()->convertType(op.getSymType());
     const auto isConst = op.getConstant();
+    const auto isDsoLocal = op.getDsolocal();
     const auto linkage = convertLinkage(op.getLinkage());
     const auto symbol = op.getSymName();
     const auto loc = op.getLoc();
@@ -1670,7 +1672,7 @@ class CIRGlobalOpLowering
       rewriter.replaceOpWithNewOp<mlir::LLVM::GlobalOp>(
           op, llvmType, isConst, linkage, symbol, mlir::Attribute(),
           /*alignment*/ 0, /*addrSpace*/ 0,
-          /*dsoLocal*/ false, /*threadLocal*/ (bool)op.getTlsModelAttr(),
+          /*dsoLocal*/ isDsoLocal, /*threadLocal*/ (bool)op.getTlsModelAttr(),
           /*comdat*/ mlir::SymbolRefAttr(), attributes);
       return mlir::success();
     }

clang/test/CIR/CodeGen/array.cpp

@@ -40,7 +40,7 @@ void local_stringlit() {
   const char *s = "whatnow";
 }
 
-// CHECK: cir.global "private" constant internal @".str" = #cir.const_array<"whatnow\00" : !cir.array<!s8i x 8>> : !cir.array<!s8i x 8> {alignment = 1 : i64}
+// CHECK: cir.global "private" constant internal dsolocal @".str" = #cir.const_array<"whatnow\00" : !cir.array<!s8i x 8>> : !cir.array<!s8i x 8> {alignment = 1 : i64}
 // CHECK: cir.func @_Z15local_stringlitv()
 // CHECK-NEXT:  %0 = cir.alloca !cir.ptr<!s8i>, !cir.ptr<!cir.ptr<!s8i>>, ["s", init] {alignment = 8 : i64}
 // CHECK-NEXT:  %1 = cir.get_global @".str" : !cir.ptr<!cir.array<!s8i x 8>>

clang/test/CIR/CodeGen/const-array.c

@@ -4,7 +4,7 @@ void bar() {
   const int arr[1] = {1};
 }
 
-// CHECK: cir.global "private" constant internal @bar.arr = #cir.const_array<[#cir.int<1> : !s32i]> : !cir.array<!s32i x 1> {alignment = 4 : i64}
+// CHECK: cir.global "private" constant internal dsolocal @bar.arr = #cir.const_array<[#cir.int<1> : !s32i]> : !cir.array<!s32i x 1> {alignment = 4 : i64}
 // CHECK: cir.func no_proto @bar()
 // CHECK:   {{.*}} = cir.get_global @bar.arr : !cir.ptr<!cir.array<!s32i x 1>>
 

clang/test/CIR/CodeGen/coro-task.cpp

@@ -338,7 +338,7 @@ folly::coro::Task<int> go1_lambda() {
   co_return co_await task;
 }
 
-// CHECK: cir.func coroutine lambda internal private @_ZZ10go1_lambdavENK3$_0clEv{{.*}}22 extra{{.*}}{
+// CHECK: cir.func coroutine lambda internal private dsolocal @_ZZ10go1_lambdavENK3$_0clEv{{.*}}22 extra{{.*}}{
 // CHECK: cir.func coroutine @_Z10go1_lambdav() {{.*}}22 extra{{.*}}{
 
 folly::coro::Task<int> go4() {

clang/test/CIR/CodeGen/globals.cpp

@@ -49,10 +49,10 @@ int use_func() { return func<int>(); }
 // CHECK-NEXT: cir.global external @rgb = #cir.const_array<[#cir.int<0> : !u8i, #cir.int<233> : !u8i, #cir.int<33> : !u8i]> : !cir.array<!u8i x 3>
 // CHECK-NEXT: cir.global external @alpha = #cir.const_array<"abc\00" : !cir.array<!s8i x 4>> : !cir.array<!s8i x 4>
 
-// CHECK-NEXT: cir.global "private" constant internal @".str" = #cir.const_array<"example\00" : !cir.array<!s8i x 8>> : !cir.array<!s8i x 8> {alignment = 1 : i64}
+// CHECK-NEXT: cir.global "private" constant internal dsolocal @".str" = #cir.const_array<"example\00" : !cir.array<!s8i x 8>> : !cir.array<!s8i x 8> {alignment = 1 : i64}
 // CHECK-NEXT: cir.global external @s = #cir.global_view<@".str"> : !cir.ptr<!s8i>
 
-// CHECK-NEXT: cir.global "private" constant internal @".str1" = #cir.const_array<"example1\00" : !cir.array<!s8i x 9>> : !cir.array<!s8i x 9> {alignment = 1 : i64}
+// CHECK-NEXT: cir.global "private" constant internal dsolocal @".str1" = #cir.const_array<"example1\00" : !cir.array<!s8i x 9>> : !cir.array<!s8i x 9> {alignment = 1 : i64}
 // CHECK-NEXT: cir.global external @s1 = #cir.global_view<@".str1"> : !cir.ptr<!s8i>
 
 // CHECK-NEXT: cir.global external @s2 = #cir.global_view<@".str"> : !cir.ptr<!s8i>

clang/test/CIR/CodeGen/hello.c

@@ -8,7 +8,7 @@ int main (void) {
 }
 
 // CHECK: cir.func private @printf(!cir.ptr<!s8i>, ...) -> !s32i
-// CHECK: cir.global "private" constant internal @".str" = #cir.const_array<"Hello, world!\0A\00" : !cir.array<!s8i x 15>> : !cir.array<!s8i x 15> {alignment = 1 : i64}
+// CHECK: cir.global "private" constant internal dsolocal @".str" = #cir.const_array<"Hello, world!\0A\00" : !cir.array<!s8i x 15>> : !cir.array<!s8i x 15> {alignment = 1 : i64}
 // CHECK: cir.func @main() -> !s32i
 // CHECK:   %0 = cir.alloca !s32i, !cir.ptr<!s32i>, ["__retval"] {alignment = 4 : i64}
 // CHECK:   %1 = cir.get_global @printf : !cir.ptr<!cir.func<!s32i (!cir.ptr<!s8i>, ...)>>

clang/test/CIR/CodeGen/lambda.cpp

@@ -9,7 +9,7 @@ void fn() {
 //      CHECK: !ty_22anon2E222 = !cir.struct<class "anon.2" {!cir.int<u, 8>}>
 //  CHECK-DAG: module
 
-//      CHECK: cir.func lambda internal private @_ZZ2fnvENK3$_0clEv{{.*}}) extra
+//      CHECK: cir.func lambda internal private dsolocal @_ZZ2fnvENK3$_0clEv{{.*}}) extra
 
 //      CHECK:   cir.func @_Z2fnv()
 // CHECK-NEXT:     %0 = cir.alloca !ty_22anon2E222, !cir.ptr<!ty_22anon2E222>, ["a"]
@@ -21,7 +21,7 @@ void l0() {
   a();
 }
 
-// CHECK: cir.func lambda internal private @_ZZ2l0vENK3$_0clEv({{.*}}) extra
+// CHECK: cir.func lambda internal private dsolocal @_ZZ2l0vENK3$_0clEv({{.*}}) extra
 
 // CHECK: %0 = cir.alloca !cir.ptr<!ty_22anon2E422>, !cir.ptr<!cir.ptr<!ty_22anon2E422>>, ["this", init] {alignment = 8 : i64}
 // CHECK: cir.store %arg0, %0 : !cir.ptr<!ty_22anon2E422>, !cir.ptr<!cir.ptr<!ty_22anon2E422>>
@@ -99,13 +99,13 @@ int g3() {
 }
 
 // lambda operator()
-// CHECK: cir.func lambda internal private @_ZZ2g3vENK3$_0clERKi{{.*}}!s32i extra
+// CHECK: cir.func lambda internal private dsolocal @_ZZ2g3vENK3$_0clERKi{{.*}}!s32i extra
 
 // lambda __invoke()
-// CHECK:   cir.func internal private @_ZZ2g3vEN3$_08__invokeERKi
+// CHECK:   cir.func internal private dsolocal @_ZZ2g3vEN3$_08__invokeERKi
 
 // lambda operator int (*)(int const&)()
-// CHECK:   cir.func internal private @_ZZ2g3vENK3$_0cvPFiRKiEEv
+// CHECK:   cir.func internal private dsolocal @_ZZ2g3vENK3$_0cvPFiRKiEEv
 
 // CHECK: cir.func @_Z2g3v() -> !s32i
 // CHECK:     %0 = cir.alloca !s32i, !cir.ptr<!s32i>, ["__retval"] {alignment = 4 : i64}