Improve the representation of the atomic builtins in a few ways. First, we make

their call expressions synthetically have the "deduced" types based on their
first argument. We only insert conversions in the AST for arguments whose
values require conversion to match the value type expected. This keeps PR7600
closed by maintaining the return type, but avoids assertions due to unexpected
implicit casts making the type unsigned (test case added from Daniel).

The magic is moved into the codegen for the atomic builtin which inserts the
casts as needed at the IR level to raise the type to an integer suitable for
the LLVM intrinsic. This shouldn't cause any real change in functionality, but
now we can make the builtin be more truly polymorphic.

llvm-svn: 108638

1 files changed, 86 insertions, 30 deletions

diff --git a/clang/lib/CodeGen/CGBuiltin.cpp b/clang/lib/CodeGen/CGBuiltin.cpp
index fff4bacab6b..06140119321 100644
--- a/clang/lib/CodeGen/CGBuiltin.cpp
+++ b/clang/lib/CodeGen/CGBuiltin.cpp
@@ -41,6 +41,31 @@ static void EmitMemoryBarrier(CodeGenFunction &CGF,
                          C, C + 5);
 }
 
+static Value *EmitCastToInt(CodeGenFunction &CGF,
+                            const llvm::Type *ToType, Value *Val) {
+  if (Val->getType()->isPointerTy()) {
+    return CGF.Builder.CreatePtrToInt(Val, ToType);
+  }
+  assert(Val->getType()->isIntegerTy() &&
+         "Used a non-integer and non-pointer type with atomic builtin");
+  assert(Val->getType()->getScalarSizeInBits() <=
+         ToType->getScalarSizeInBits() && "Integer type too small");
+  return CGF.Builder.CreateSExtOrBitCast(Val, ToType);
+}
+
+static Value *EmitCastFromInt(CodeGenFunction &CGF, QualType ToQualType,
+                              Value *Val) {
+  const llvm::Type *ToType = CGF.ConvertType(ToQualType);
+  if (ToType->isPointerTy()) {
+    return CGF.Builder.CreateIntToPtr(Val, ToType);
+  }
+  assert(Val->getType()->isIntegerTy() &&
+         "Used a non-integer and non-pointer type with atomic builtin");
+  assert(Val->getType()->getScalarSizeInBits() >=
+         ToType->getScalarSizeInBits() && "Integer type too small");
+  return CGF.Builder.CreateTruncOrBitCast(Val, ToType);
+}
+
 // The atomic builtins are also full memory barriers. This is a utility for
 // wrapping a call to the builtins with memory barriers.
 static Value *EmitCallWithBarrier(CodeGenFunction &CGF, Value *Fn,
@@ -60,13 +85,20 @@ static Value *EmitCallWithBarrier(CodeGenFunction &CGF, Value *Fn,
 /// and the expression node.
 static RValue EmitBinaryAtomic(CodeGenFunction &CGF,
                                Intrinsic::ID Id, const CallExpr *E) {
-  Value *Args[2] = { CGF.EmitScalarExpr(E->getArg(0)),
-                     CGF.EmitScalarExpr(E->getArg(1)) };
-  const llvm::Type *ResType[2];
-  ResType[0] = CGF.ConvertType(E->getType());
-  ResType[1] = CGF.ConvertType(E->getArg(0)->getType());
-  Value *AtomF = CGF.CGM.getIntrinsic(Id, ResType, 2);
-  return RValue::get(EmitCallWithBarrier(CGF, AtomF, Args, Args + 2));
+  const llvm::Type *ValueType =
+    llvm::IntegerType::get(CGF.getLLVMContext(),
+                           CGF.getContext().getTypeSize(E->getType()));
+  const llvm::Type *PtrType = ValueType->getPointerTo();
+  const llvm::Type *IntrinsicTypes[2] = { ValueType, PtrType };
+  Value *AtomF = CGF.CGM.getIntrinsic(Id, IntrinsicTypes, 2);
+
+  Value *Args[2] = { CGF.Builder.CreateBitCast(CGF.EmitScalarExpr(E->getArg(0)),
+                                               PtrType),
+                     EmitCastToInt(CGF, ValueType,
+                                   CGF.EmitScalarExpr(E->getArg(1))) };
+  return RValue::get(EmitCastFromInt(CGF, E->getType(),
+                                     EmitCallWithBarrier(CGF, AtomF, Args,
+                                                         Args + 2)));
 }
 
 /// Utility to insert an atomic instruction based Instrinsic::ID and
@@ -75,14 +107,21 @@ static RValue EmitBinaryAtomic(CodeGenFunction &CGF,
 static RValue EmitBinaryAtomicPost(CodeGenFunction &CGF,
                                    Intrinsic::ID Id, const CallExpr *E,
                                    Instruction::BinaryOps Op) {
-  const llvm::Type *ResType[2];
-  ResType[0] = CGF.ConvertType(E->getType());
-  ResType[1] = CGF.ConvertType(E->getArg(0)->getType());
-  Value *AtomF = CGF.CGM.getIntrinsic(Id, ResType, 2);
-  Value *Args[2] = { CGF.EmitScalarExpr(E->getArg(0)),
-                     CGF.EmitScalarExpr(E->getArg(1)) };
+  const llvm::Type *ValueType =
+    llvm::IntegerType::get(CGF.getLLVMContext(),
+                           CGF.getContext().getTypeSize(E->getType()));
+  const llvm::Type *PtrType = ValueType->getPointerTo();
+  const llvm::Type *IntrinsicTypes[2] = { ValueType, PtrType };
+  Value *AtomF = CGF.CGM.getIntrinsic(Id, IntrinsicTypes, 2);
+
+  Value *Args[2] = { CGF.Builder.CreateBitCast(CGF.EmitScalarExpr(E->getArg(0)),
+                                               PtrType),
+                     EmitCastToInt(CGF, ValueType,
+                                   CGF.EmitScalarExpr(E->getArg(1))) };
   Value *Result = EmitCallWithBarrier(CGF, AtomF, Args, Args + 2);
-  return RValue::get(CGF.Builder.CreateBinOp(Op, Result, Args[1]));
+  return RValue::get(EmitCastFromInt(CGF, E->getType(),
+                                     CGF.Builder.CreateBinOp(Op, Result,
+                                                             Args[1])));
 }
 
 /// EmitFAbs - Emit a call to fabs/fabsf/fabsl, depending on the type of ValTy,
@@ -746,14 +785,23 @@ RValue CodeGenFunction::EmitBuiltinExpr(const FunctionDecl *FD,
   case Builtin::BI__sync_val_compare_and_swap_4:
   case Builtin::BI__sync_val_compare_and_swap_8:
   case Builtin::BI__sync_val_compare_and_swap_16: {
-    const llvm::Type *ResType[2];
-    ResType[0]= ConvertType(E->getType());
-    ResType[1] = ConvertType(E->getArg(0)->getType());
-    Value *AtomF = CGM.getIntrinsic(Intrinsic::atomic_cmp_swap, ResType, 2);
-    Value *Args[3] = { EmitScalarExpr(E->getArg(0)),
-                       EmitScalarExpr(E->getArg(1)),
-                       EmitScalarExpr(E->getArg(2)) };
-    return RValue::get(EmitCallWithBarrier(*this, AtomF, Args, Args + 3));
+    const llvm::Type *ValueType =
+      llvm::IntegerType::get(CGF.getLLVMContext(),
+                             CGF.getContext().getTypeSize(E->getType()));
+    const llvm::Type *PtrType = ValueType->getPointerTo();
+    const llvm::Type *IntrinsicTypes[2] = { ValueType, PtrType };
+    Value *AtomF = CGM.getIntrinsic(Intrinsic::atomic_cmp_swap,
+                                    IntrinsicTypes, 2);
+
+    Value *Args[3] = { Builder.CreateBitCast(CGF.EmitScalarExpr(E->getArg(0)),
+                                             PtrType),
+                       EmitCastToInt(CGF, ValueType,
+                                     CGF.EmitScalarExpr(E->getArg(1))),
+                       EmitCastToInt(CGF, ValueType,
+                                     CGF.EmitScalarExpr(E->getArg(2))) };
+    return RValue::get(EmitCastFromInt(CGF, E->getType(),
+                                       EmitCallWithBarrier(CGF, AtomF, Args,
+                                                           Args + 3)));
   }
 
   case Builtin::BI__sync_bool_compare_and_swap_1:
@@ -761,14 +809,22 @@ RValue CodeGenFunction::EmitBuiltinExpr(const FunctionDecl *FD,
   case Builtin::BI__sync_bool_compare_and_swap_4:
   case Builtin::BI__sync_bool_compare_and_swap_8:
   case Builtin::BI__sync_bool_compare_and_swap_16: {
-    const llvm::Type *ResType[2];
-    ResType[0]= ConvertType(E->getArg(1)->getType());
-    ResType[1] = llvm::PointerType::getUnqual(ResType[0]);
-    Value *AtomF = CGM.getIntrinsic(Intrinsic::atomic_cmp_swap, ResType, 2);
-    Value *OldVal = EmitScalarExpr(E->getArg(1));
-    Value *Args[3] = { EmitScalarExpr(E->getArg(0)),
-                       OldVal,
-                       EmitScalarExpr(E->getArg(2)) };
+    const llvm::Type *ValueType =
+      llvm::IntegerType::get(
+        CGF.getLLVMContext(),
+        CGF.getContext().getTypeSize(E->getArg(1)->getType()));
+    const llvm::Type *PtrType = ValueType->getPointerTo();
+    const llvm::Type *IntrinsicTypes[2] = { ValueType, PtrType };
+    Value *AtomF = CGM.getIntrinsic(Intrinsic::atomic_cmp_swap,
+                                    IntrinsicTypes, 2);
+
+    Value *Args[3] = { Builder.CreateBitCast(CGF.EmitScalarExpr(E->getArg(0)),
+                                             PtrType),
+                       EmitCastToInt(CGF, ValueType,
+                                     CGF.EmitScalarExpr(E->getArg(1))),
+                       EmitCastToInt(CGF, ValueType,
+                                     CGF.EmitScalarExpr(E->getArg(2))) };
+    Value *OldVal = Args[1];
     Value *PrevVal = EmitCallWithBarrier(*this, AtomF, Args, Args + 3);
     Value *Result = Builder.CreateICmpEQ(PrevVal, OldVal);
     // zext bool to int.