Add objectsize intrinsic and hook it up through codegen. Doesn't
do anything than return "I don't know" at the moment.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@85189 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/SelectionDAG/SelectionDAGBuild.cpp b/lib/CodeGen/SelectionDAG/SelectionDAGBuild.cpp
index f3a0622..b220d55 100644
--- a/lib/CodeGen/SelectionDAG/SelectionDAGBuild.cpp
+++ b/lib/CodeGen/SelectionDAG/SelectionDAGBuild.cpp
@@ -4204,6 +4204,18 @@
DAG.setRoot(Result);
return 0;
}
+ case Intrinsic::objectsize: {
+ // If we don't know by now, we're never going to know.
+ ConstantInt *CI = dyn_cast<ConstantInt>(I.getOperand(2));
+
+ assert(CI && "Non-constant type in __builtin_object_size?");
+
+ if (CI->getZExtValue() < 2)
+ setValue(&I, DAG.getConstant(-1, MVT::i32));
+ else
+ setValue(&I, DAG.getConstant(0, MVT::i32));
+ return 0;
+ }
case Intrinsic::var_annotation:
// Discard annotate attributes
return 0;
diff --git a/lib/Transforms/Scalar/SimplifyLibCalls.cpp b/lib/Transforms/Scalar/SimplifyLibCalls.cpp
index e186601..575c93b 100644
--- a/lib/Transforms/Scalar/SimplifyLibCalls.cpp
+++ b/lib/Transforms/Scalar/SimplifyLibCalls.cpp
@@ -509,6 +509,27 @@
}
//===----------------------------------------------------------------------===//
+// Miscellaneous LibCall/Intrinsic Optimizations
+//===----------------------------------------------------------------------===//
+
+namespace {
+struct SizeOpt : public LibCallOptimization {
+ virtual Value *CallOptimizer(Function *Callee, CallInst *CI, IRBuilder<> &B) {
+ // TODO: We can do more with this, but delaying to here should be no change
+ // in behavior.
+ ConstantInt *Const = dyn_cast<ConstantInt>(CI->getOperand(2));
+
+ if (!Const) return 0;
+
+ if (Const->getZExtValue() < 2)
+ return Constant::getAllOnesValue(Const->getType());
+ else
+ return ConstantInt::get(Const->getType(), 0);
+ }
+};
+}
+
+//===----------------------------------------------------------------------===//
// String and Memory LibCall Optimizations
//===----------------------------------------------------------------------===//
@@ -1548,6 +1569,7 @@
// Formatting and IO Optimizations
SPrintFOpt SPrintF; PrintFOpt PrintF;
FWriteOpt FWrite; FPutsOpt FPuts; FPrintFOpt FPrintF;
+ SizeOpt ObjectSize;
bool Modified; // This is only used by doInitialization.
public:
@@ -1653,6 +1675,9 @@
Optimizations["fwrite"] = &FWrite;
Optimizations["fputs"] = &FPuts;
Optimizations["fprintf"] = &FPrintF;
+
+ // Miscellaneous
+ Optimizations["llvm.objectsize"] = &ObjectSize;
}