From ec52aaa12f57896fc806e849fa21a61603050ac4 Mon Sep 17 00:00:00 2001 From: Evan Cheng Date: Tue, 28 Feb 2012 06:42:03 +0000 Subject: Some ARM implementaions, e.g. A-series, does return stack prediction. That is, the processor keeps a return addresses stack (RAS) which stores the address and the instruction execution state of the instruction after a function-call type branch instruction. Calling a "noreturn" function with normal call instructions (e.g. bl) can corrupt RAS and causes 100% return misprediction so LLVM should use a unconditional branch instead. i.e. mov lr, pc b _foo The "mov lr, pc" is issued in order to get proper backtrace. rdar://8979299 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@151623 91177308-0d34-0410-b5e6-96231b3b80d8 --- include/llvm/Target/TargetLowering.h | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) (limited to 'include') diff --git a/include/llvm/Target/TargetLowering.h b/include/llvm/Target/TargetLowering.h index 9cfee25..4f3e432 100644 --- a/include/llvm/Target/TargetLowering.h +++ b/include/llvm/Target/TargetLowering.h @@ -1233,7 +1233,8 @@ public: LowerCallTo(SDValue Chain, Type *RetTy, bool RetSExt, bool RetZExt, bool isVarArg, bool isInreg, unsigned NumFixedArgs, CallingConv::ID CallConv, bool isTailCall, - bool isReturnValueUsed, SDValue Callee, ArgListTy &Args, + bool doesNotRet, bool isReturnValueUsed, + SDValue Callee, ArgListTy &Args, SelectionDAG &DAG, DebugLoc dl) const; /// LowerCall - This hook must be implemented to lower calls into the @@ -1245,7 +1246,7 @@ public: virtual SDValue LowerCall(SDValue /*Chain*/, SDValue /*Callee*/, CallingConv::ID /*CallConv*/, bool /*isVarArg*/, - bool &/*isTailCall*/, + bool /*doesNotRet*/, bool &/*isTailCall*/, const SmallVectorImpl &/*Outs*/, const SmallVectorImpl &/*OutVals*/, const SmallVectorImpl &/*Ins*/, -- cgit v1.1