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-rw-r--r--lib/CodeGen/ItaniumCXXABI.cpp48
-rw-r--r--test/CodeGenCXX/static-init-pnacl.cpp14
2 files changed, 43 insertions, 19 deletions
diff --git a/lib/CodeGen/ItaniumCXXABI.cpp b/lib/CodeGen/ItaniumCXXABI.cpp
index 827f1a20b6..c66e3b7426 100644
--- a/lib/CodeGen/ItaniumCXXABI.cpp
+++ b/lib/CodeGen/ItaniumCXXABI.cpp
@@ -37,7 +37,8 @@ class ItaniumCXXABI : public CodeGen::CGCXXABI {
private:
llvm::IntegerType *PtrDiffTy;
protected:
- bool IsARM;
+ bool UseARMMethodPtrABI;
+ bool UseARMGuardVarABI;
// It's a little silly for us to cache this.
llvm::IntegerType *getPtrDiffTy() {
@@ -50,8 +51,12 @@ protected:
}
public:
- ItaniumCXXABI(CodeGen::CodeGenModule &CGM, bool IsARM = false) :
- CGCXXABI(CGM), PtrDiffTy(0), IsARM(IsARM) { }
+ ItaniumCXXABI(CodeGen::CodeGenModule &CGM,
+ bool UseARMMethodPtrABI = false,
+ bool UseARMGuardVarABI = false) :
+ CGCXXABI(CGM), PtrDiffTy(0),
+ UseARMMethodPtrABI(UseARMMethodPtrABI),
+ UseARMGuardVarABI(UseARMGuardVarABI) { }
bool isZeroInitializable(const MemberPointerType *MPT);
@@ -148,7 +153,9 @@ public:
class ARMCXXABI : public ItaniumCXXABI {
public:
- ARMCXXABI(CodeGen::CodeGenModule &CGM) : ItaniumCXXABI(CGM, /*ARM*/ true) {}
+ ARMCXXABI(CodeGen::CodeGenModule &CGM) :
+ ItaniumCXXABI(CGM, /* UseARMMethodPtrABI = */ true,
+ /* UseARMGuardVarABI = */ true) {}
void BuildConstructorSignature(const CXXConstructorDecl *Ctor,
CXXCtorType T,
@@ -200,16 +207,17 @@ CodeGen::CGCXXABI *CodeGen::CreateItaniumCXXABI(CodeGenModule &CGM) {
// include the other 32-bit ARM oddities: constructor/destructor return values
// and array cookies.
case TargetCXXABI::GenericAArch64:
- return new ItaniumCXXABI(CGM, /*IsARM = */ true);
+ return new ItaniumCXXABI(CGM, /* UseARMMethodPtrABI = */ true,
+ /* UseARMGuardVarABI = */ true);
case TargetCXXABI::GenericItanium:
if (CGM.getContext().getTargetInfo().getTriple().getArch()
== llvm::Triple::le32) {
// For PNaCl, use ARM-style method pointers so that PNaCl code
// does not assume anything about the alignment of function
- // pointers. Using IsARM=true also makes guard variables 32-bit
- // instead of 64-bit, which saves a little space.
- return new ItaniumCXXABI(CGM, /*IsARM = */ true);
+ // pointers.
+ return new ItaniumCXXABI(CGM, /* UseARMMethodPtrABI = */ true,
+ /* UseARMGuardVarABI = */ false);
}
return new ItaniumCXXABI(CGM);
@@ -274,7 +282,7 @@ ItaniumCXXABI::EmitLoadOfMemberFunctionPointer(CodeGenFunction &CGF,
// Compute the true adjustment.
llvm::Value *Adj = RawAdj;
- if (IsARM)
+ if (UseARMMethodPtrABI)
Adj = Builder.CreateAShr(Adj, ptrdiff_1, "memptr.adj.shifted");
// Apply the adjustment and cast back to the original struct type
@@ -289,7 +297,7 @@ ItaniumCXXABI::EmitLoadOfMemberFunctionPointer(CodeGenFunction &CGF,
// If the LSB in the function pointer is 1, the function pointer points to
// a virtual function.
llvm::Value *IsVirtual;
- if (IsARM)
+ if (UseARMMethodPtrABI)
IsVirtual = Builder.CreateAnd(RawAdj, ptrdiff_1);
else
IsVirtual = Builder.CreateAnd(FnAsInt, ptrdiff_1);
@@ -308,7 +316,8 @@ ItaniumCXXABI::EmitLoadOfMemberFunctionPointer(CodeGenFunction &CGF,
// Apply the offset.
llvm::Value *VTableOffset = FnAsInt;
- if (!IsARM) VTableOffset = Builder.CreateSub(VTableOffset, ptrdiff_1);
+ if (!UseARMMethodPtrABI)
+ VTableOffset = Builder.CreateSub(VTableOffset, ptrdiff_1);
VTable = Builder.CreateGEP(VTable, VTableOffset);
// Load the virtual function to call.
@@ -418,7 +427,7 @@ ItaniumCXXABI::EmitMemberPointerConversion(CodeGenFunction &CGF,
}
// The this-adjustment is left-shifted by 1 on ARM.
- if (IsARM) {
+ if (UseARMMethodPtrABI) {
uint64_t offset = cast<llvm::ConstantInt>(adj)->getZExtValue();
offset <<= 1;
adj = llvm::ConstantInt::get(adj->getType(), offset);
@@ -466,7 +475,7 @@ ItaniumCXXABI::EmitMemberPointerConversion(const CastExpr *E,
}
// The this-adjustment is left-shifted by 1 on ARM.
- if (IsARM) {
+ if (UseARMMethodPtrABI) {
uint64_t offset = cast<llvm::ConstantInt>(adj)->getZExtValue();
offset <<= 1;
adj = llvm::ConstantInt::get(adj->getType(), offset);
@@ -527,7 +536,7 @@ llvm::Constant *ItaniumCXXABI::BuildMemberPointer(const CXXMethodDecl *MD,
Context.toCharUnitsFromBits(Context.getTargetInfo().getPointerWidth(0));
uint64_t VTableOffset = (Index * PointerWidth.getQuantity());
- if (IsARM) {
+ if (UseARMMethodPtrABI) {
// ARM C++ ABI 3.2.1:
// This ABI specifies that adj contains twice the this
// adjustment, plus 1 if the member function is virtual. The
@@ -561,7 +570,8 @@ llvm::Constant *ItaniumCXXABI::BuildMemberPointer(const CXXMethodDecl *MD,
llvm::Constant *addr = CGM.GetAddrOfFunction(MD, Ty);
MemPtr[0] = llvm::ConstantExpr::getPtrToInt(addr, ptrdiff_t);
- MemPtr[1] = llvm::ConstantInt::get(ptrdiff_t, (IsARM ? 2 : 1) *
+ MemPtr[1] = llvm::ConstantInt::get(ptrdiff_t,
+ (UseARMMethodPtrABI ? 2 : 1) *
ThisAdjustment.getQuantity());
}
@@ -660,7 +670,7 @@ ItaniumCXXABI::EmitMemberPointerComparison(CodeGenFunction &CGF,
// Null member function pointers on ARM clear the low bit of Adj,
// so the zero condition has to check that neither low bit is set.
- if (IsARM) {
+ if (UseARMMethodPtrABI) {
llvm::Value *One = llvm::ConstantInt::get(LPtr->getType(), 1);
// Compute (l.adj | r.adj) & 1 and test it against zero.
@@ -700,7 +710,7 @@ ItaniumCXXABI::EmitMemberPointerIsNotNull(CodeGenFunction &CGF,
// On ARM, a member function pointer is also non-null if the low bit of 'adj'
// (the virtual bit) is set.
- if (IsARM) {
+ if (UseARMMethodPtrABI) {
llvm::Constant *One = llvm::ConstantInt::get(Ptr->getType(), 1);
llvm::Value *Adj = Builder.CreateExtractValue(MemPtr, 1, "memptr.adj");
llvm::Value *VirtualBit = Builder.CreateAnd(Adj, One, "memptr.virtualbit");
@@ -1080,7 +1090,7 @@ void ItaniumCXXABI::EmitGuardedInit(CodeGenFunction &CGF,
} else {
// Guard variables are 64 bits in the generic ABI and size width on ARM
// (i.e. 32-bit on AArch32, 64-bit on AArch64).
- guardTy = (IsARM ? CGF.SizeTy : CGF.Int64Ty);
+ guardTy = (UseARMGuardVarABI ? CGF.SizeTy : CGF.Int64Ty);
}
llvm::PointerType *guardPtrTy = guardTy->getPointerTo();
@@ -1121,7 +1131,7 @@ void ItaniumCXXABI::EmitGuardedInit(CodeGenFunction &CGF,
// if (__cxa_guard_acquire(&obj_guard))
// ...
// }
- if (IsARM && !useInt8GuardVariable) {
+ if (UseARMGuardVarABI && !useInt8GuardVariable) {
llvm::Value *V = Builder.CreateLoad(guard);
llvm::Value *Test1 = llvm::ConstantInt::get(guardTy, 1);
V = Builder.CreateAnd(V, Test1);
diff --git a/test/CodeGenCXX/static-init-pnacl.cpp b/test/CodeGenCXX/static-init-pnacl.cpp
new file mode 100644
index 0000000000..65844e5d34
--- /dev/null
+++ b/test/CodeGenCXX/static-init-pnacl.cpp
@@ -0,0 +1,14 @@
+// RUN: %clang_cc1 -emit-llvm -triple=le32-unknown-nacl -o - %s | FileCheck %s
+
+int f();
+
+// Test that PNaCl uses the Itanium/x86 ABI in which the static
+// variable's guard variable is tested via "load i8 and compare with
+// zero" rather than the ARM ABI which uses "load i32 and test the
+// bottom bit".
+void g() {
+ static int a = f();
+}
+// CHECK: load atomic i8* bitcast (i64* @_ZGVZ1gvE1a to i8*) acquire
+// CHECK-NEXT: %guard.uninitialized = icmp eq i8 %0, 0
+// CHECK-NEXT: br i1 %guard.uninitialized, label %init.check, label %init.end
generated by cgit v1.2.3-18-g5258 (git 2.32.0) at 2024-11-23 16:11:21 +0000