PR6515: Implement __builtin_signbit and friends.
I'm reasonably sure my implementation is correct, but it would be nice if
someone could double-check.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@97864 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/CGBuiltin.cpp b/lib/CodeGen/CGBuiltin.cpp
index 8703c38..706e441 100644
--- a/lib/CodeGen/CGBuiltin.cpp
+++ b/lib/CodeGen/CGBuiltin.cpp
@@ -682,6 +682,23 @@
Value *F = CGM.getIntrinsic(Intrinsic::pow, &ArgType, 1);
return RValue::get(Builder.CreateCall2(F, Base, Exponent, "tmp"));
}
+
+ case Builtin::BI__builtin_signbit:
+ case Builtin::BI__builtin_signbitf:
+ case Builtin::BI__builtin_signbitl: {
+ LLVMContext &C = CGM.getLLVMContext();
+
+ Value *Arg = EmitScalarExpr(E->getArg(0));
+ const llvm::Type *ArgTy = Arg->getType();
+ if (ArgTy->isPPC_FP128Ty())
+ break; // FIXME: I'm not sure what the right implementation is here.
+ int ArgWidth = ArgTy->getPrimitiveSizeInBits();
+ const llvm::Type *ArgIntTy = llvm::IntegerType::get(C, ArgWidth);
+ Value *BCArg = Builder.CreateBitCast(Arg, ArgIntTy);
+ Value *ZeroCmp = llvm::Constant::getNullValue(ArgIntTy);
+ Value *Result = Builder.CreateICmpSLT(BCArg, ZeroCmp);
+ return RValue::get(Builder.CreateZExt(Result, ConvertType(E->getType())));
+ }
}
// If this is an alias for a libm function (e.g. __builtin_sin) turn it into