Faster stack-protector for Android/AArch64.
Bionic has a defined thread-local location for the stack protector
cookie. Emit a direct load instead of going through __stack_chk_guard.
llvm-svn: 265481
diff --git a/llvm/lib/CodeGen/StackProtector.cpp b/llvm/lib/CodeGen/StackProtector.cpp
index db3fef5..23ae672 100644
--- a/llvm/lib/CodeGen/StackProtector.cpp
+++ b/llvm/lib/CodeGen/StackProtector.cpp
@@ -333,24 +333,20 @@
AllocaInst *&AI, Value *&StackGuardVar) {
bool SupportsSelectionDAGSP = false;
PointerType *PtrTy = Type::getInt8PtrTy(RI->getContext());
- unsigned AddressSpace, Offset;
- if (TLI->getStackCookieLocation(AddressSpace, Offset)) {
- Constant *OffsetVal =
- ConstantInt::get(Type::getInt32Ty(RI->getContext()), Offset);
+ IRBuilder<> B(&F->getEntryBlock().front());
- StackGuardVar =
- ConstantExpr::getIntToPtr(OffsetVal, PointerType::get(PtrTy,
- AddressSpace));
- } else if (TT.isOSOpenBSD()) {
- StackGuardVar = M->getOrInsertGlobal("__guard_local", PtrTy);
- cast<GlobalValue>(StackGuardVar)
- ->setVisibility(GlobalValue::HiddenVisibility);
- } else {
- SupportsSelectionDAGSP = true;
- StackGuardVar = M->getOrInsertGlobal("__stack_chk_guard", PtrTy);
+ StackGuardVar = TLI->getStackCookieLocation(B);
+ if (!StackGuardVar) {
+ if (TT.isOSOpenBSD()) {
+ StackGuardVar = M->getOrInsertGlobal("__guard_local", PtrTy);
+ cast<GlobalValue>(StackGuardVar)
+ ->setVisibility(GlobalValue::HiddenVisibility);
+ } else {
+ SupportsSelectionDAGSP = true;
+ StackGuardVar = M->getOrInsertGlobal("__stack_chk_guard", PtrTy);
+ }
}
- IRBuilder<> B(&F->getEntryBlock().front());
AI = B.CreateAlloca(PtrTy, nullptr, "StackGuardSlot");
LoadInst *LI = B.CreateLoad(StackGuardVar, "StackGuard");
B.CreateCall(Intrinsic::getDeclaration(M, Intrinsic::stackprotector),