[checked-arithmetic builtins] Added builtins to enable users to perform checked-arithmetic in c.
This will enable users in security critical applications to perform
checked-arithmetic in a fast safe manner that is amenable to c.
Tests/an update to Language Extensions is included as well.
rdar://13421498.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@184497 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/CGBuiltin.cpp b/lib/CodeGen/CGBuiltin.cpp
index 90b8ebc..c57c767 100644
--- a/lib/CodeGen/CGBuiltin.cpp
+++ b/lib/CodeGen/CGBuiltin.cpp
@@ -1414,6 +1414,77 @@
CarryOutStore->setAlignment(CarryOutPtr.second);
return RValue::get(Sum2);
}
+ case Builtin::BI__builtin_uadd_overflow:
+ case Builtin::BI__builtin_uaddl_overflow:
+ case Builtin::BI__builtin_uaddll_overflow:
+ case Builtin::BI__builtin_usub_overflow:
+ case Builtin::BI__builtin_usubl_overflow:
+ case Builtin::BI__builtin_usubll_overflow:
+ case Builtin::BI__builtin_umul_overflow:
+ case Builtin::BI__builtin_umull_overflow:
+ case Builtin::BI__builtin_umulll_overflow:
+ case Builtin::BI__builtin_sadd_overflow:
+ case Builtin::BI__builtin_saddl_overflow:
+ case Builtin::BI__builtin_saddll_overflow:
+ case Builtin::BI__builtin_ssub_overflow:
+ case Builtin::BI__builtin_ssubl_overflow:
+ case Builtin::BI__builtin_ssubll_overflow:
+ case Builtin::BI__builtin_smul_overflow:
+ case Builtin::BI__builtin_smull_overflow:
+ case Builtin::BI__builtin_smulll_overflow: {
+
+ // We translate all of these builtins directly to the relevant llvm IR node.
+
+ // Scalarize our inputs.
+ llvm::Value *X = EmitScalarExpr(E->getArg(0));
+ llvm::Value *Y = EmitScalarExpr(E->getArg(1));
+ std::pair<llvm::Value *, unsigned> SumOutPtr =
+ EmitPointerWithAlignment(E->getArg(2));
+
+ // Decide which of the overflow intrinsics we are lowering to:
+ llvm::Intrinsic::ID IntrinsicId;
+ switch (BuiltinID) {
+ default: llvm_unreachable("Unknown security overflow builtin id.");
+ case Builtin::BI__builtin_uadd_overflow:
+ case Builtin::BI__builtin_uaddl_overflow:
+ case Builtin::BI__builtin_uaddll_overflow:
+ IntrinsicId = llvm::Intrinsic::uadd_with_overflow;
+ break;
+ case Builtin::BI__builtin_usub_overflow:
+ case Builtin::BI__builtin_usubl_overflow:
+ case Builtin::BI__builtin_usubll_overflow:
+ IntrinsicId = llvm::Intrinsic::usub_with_overflow;
+ break;
+ case Builtin::BI__builtin_umul_overflow:
+ case Builtin::BI__builtin_umull_overflow:
+ case Builtin::BI__builtin_umulll_overflow:
+ IntrinsicId = llvm::Intrinsic::umul_with_overflow;
+ break;
+ case Builtin::BI__builtin_sadd_overflow:
+ case Builtin::BI__builtin_saddl_overflow:
+ case Builtin::BI__builtin_saddll_overflow:
+ IntrinsicId = llvm::Intrinsic::sadd_with_overflow;
+ break;
+ case Builtin::BI__builtin_ssub_overflow:
+ case Builtin::BI__builtin_ssubl_overflow:
+ case Builtin::BI__builtin_ssubll_overflow:
+ IntrinsicId = llvm::Intrinsic::ssub_with_overflow;
+ break;
+ case Builtin::BI__builtin_smul_overflow:
+ case Builtin::BI__builtin_smull_overflow:
+ case Builtin::BI__builtin_smulll_overflow:
+ IntrinsicId = llvm::Intrinsic::smul_with_overflow;
+ break;
+ }
+
+
+ llvm::Value *Carry;
+ llvm::Value *Sum = EmitOverflowIntrinsic(*this, IntrinsicId, X, Y, Carry);
+ llvm::StoreInst *SumOutStore = Builder.CreateStore(Sum, SumOutPtr.first);
+ SumOutStore->setAlignment(SumOutPtr.second);
+
+ return RValue::get(Carry);
+ }
case Builtin::BI__noop:
return RValue::get(0);
}