Reimplement the bittest intrinsic family as builtins with inline asm
We need to implement _interlockedbittestandset as a builtin for
windows.h, so we might as well do the whole family. It reduces code
duplication anyway.
Fixes PR33188, a long standing bug in our bittest implementation
encountered by Chakra.
llvm-svn: 333978
diff --git a/clang/lib/CodeGen/CGBuiltin.cpp b/clang/lib/CodeGen/CGBuiltin.cpp
index 8793f83..c6c9df4 100644
--- a/clang/lib/CodeGen/CGBuiltin.cpp
+++ b/clang/lib/CodeGen/CGBuiltin.cpp
@@ -484,6 +484,37 @@
return Builder.CreateCall(F, {Ptr, Min, NullIsUnknown});
}
+static RValue EmitBitTestIntrinsic(CodeGenFunction &CGF, const CallExpr *E,
+ char TestAnd, char Size,
+ bool Locked = false) {
+ Value *BitBase = CGF.EmitScalarExpr(E->getArg(0));
+ Value *BitPos = CGF.EmitScalarExpr(E->getArg(1));
+
+ // Build the assembly.
+ SmallString<64> Asm;
+ raw_svector_ostream AsmOS(Asm);
+ if (Locked)
+ AsmOS << "lock ";
+ AsmOS << "bt";
+ if (TestAnd)
+ AsmOS << TestAnd;
+ AsmOS << Size << " $2, ($1)\n\tsetc ${0:b}";
+
+ // Build the constraints. FIXME: We should support immediates when possible.
+ std::string Constraints = "=r,r,r,~{cc},~{flags},~{memory},~{fpsr}";
+ llvm::IntegerType *IntType = llvm::IntegerType::get(
+ CGF.getLLVMContext(),
+ CGF.getContext().getTypeSize(E->getArg(1)->getType()));
+ llvm::Type *IntPtrType = IntType->getPointerTo();
+ llvm::FunctionType *FTy =
+ llvm::FunctionType::get(CGF.Int8Ty, {IntPtrType, IntType}, false);
+
+ llvm::InlineAsm *IA =
+ llvm::InlineAsm::get(FTy, Asm, Constraints, /*SideEffects=*/true);
+ CallSite CS = CGF.Builder.CreateCall(IA, {BitBase, BitPos});
+ return RValue::get(CS.getInstruction());
+}
+
// Many of MSVC builtins are on both x64 and ARM; to avoid repeating code, we
// handle them here.
enum class CodeGenFunction::MSVCIntrin {
@@ -497,7 +528,6 @@
_InterlockedIncrement,
_InterlockedOr,
_InterlockedXor,
- _interlockedbittestandset,
__fastfail,
};
@@ -565,22 +595,6 @@
case MSVCIntrin::_InterlockedXor:
return MakeBinaryAtomicValue(*this, AtomicRMWInst::Xor, E);
- case MSVCIntrin::_interlockedbittestandset: {
- llvm::Value *Addr = EmitScalarExpr(E->getArg(0));
- llvm::Value *Bit = EmitScalarExpr(E->getArg(1));
- AtomicRMWInst *RMWI = Builder.CreateAtomicRMW(
- AtomicRMWInst::Or, Addr,
- Builder.CreateShl(ConstantInt::get(Bit->getType(), 1), Bit),
- llvm::AtomicOrdering::SequentiallyConsistent);
- // Shift the relevant bit to the least significant position, truncate to
- // the result type, and test the low bit.
- llvm::Value *Shifted = Builder.CreateLShr(RMWI, Bit);
- llvm::Value *Truncated =
- Builder.CreateTrunc(Shifted, ConvertType(E->getType()));
- return Builder.CreateAnd(Truncated,
- ConstantInt::get(Truncated->getType(), 1));
- }
-
case MSVCIntrin::_InterlockedDecrement: {
llvm::Type *IntTy = ConvertType(E->getType());
AtomicRMWInst *RMWI = Builder.CreateAtomicRMW(
@@ -2791,9 +2805,32 @@
case Builtin::BI_InterlockedXor16:
case Builtin::BI_InterlockedXor:
return RValue::get(EmitMSVCBuiltinExpr(MSVCIntrin::_InterlockedXor, E));
+
+ case Builtin::BI_bittest:
+ return EmitBitTestIntrinsic(*this, E, '\0', 'l');
+ case Builtin::BI_bittestandcomplement:
+ return EmitBitTestIntrinsic(*this, E, 'c', 'l');
+ case Builtin::BI_bittestandreset:
+ return EmitBitTestIntrinsic(*this, E, 'r', 'l');
+ case Builtin::BI_bittestandset:
+ return EmitBitTestIntrinsic(*this, E, 's', 'l');
+ case Builtin::BI_interlockedbittestandreset:
+ return EmitBitTestIntrinsic(*this, E, 'r', 'l', /*Locked=*/true);
case Builtin::BI_interlockedbittestandset:
- return RValue::get(
- EmitMSVCBuiltinExpr(MSVCIntrin::_interlockedbittestandset, E));
+ return EmitBitTestIntrinsic(*this, E, 's', 'l', /*Locked=*/true);
+
+ case Builtin::BI_bittest64:
+ return EmitBitTestIntrinsic(*this, E, '\0', 'q');
+ case Builtin::BI_bittestandcomplement64:
+ return EmitBitTestIntrinsic(*this, E, 'c', 'q');
+ case Builtin::BI_bittestandreset64:
+ return EmitBitTestIntrinsic(*this, E, 'r', 'q');
+ case Builtin::BI_bittestandset64:
+ return EmitBitTestIntrinsic(*this, E, 's', 'q');
+ case Builtin::BI_interlockedbittestandreset64:
+ return EmitBitTestIntrinsic(*this, E, 'r', 'q', /*Locked=*/true);
+ case Builtin::BI_interlockedbittestandset64:
+ return EmitBitTestIntrinsic(*this, E, 's', 'q', /*Locked=*/true);
case Builtin::BI__exception_code:
case Builtin::BI_exception_code: