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| author | Evan Cheng <evan.cheng@apple.com> | 2012-02-28 06:42:03 +0000 |
|---|---|---|
| committer | Evan Cheng <evan.cheng@apple.com> | 2012-02-28 06:42:03 +0000 |
| commit | 87c7b09d8d7e7f04b720d298a7194c4473a8c524 (patch) | |
| tree | bbb0ebbd77e5a544fbe06f60bbb05802170d23d1 /llvm/lib/Target/Sparc | |
| parent | ccd651cac84b0620192f0ca404a841d52ad3a387 (diff) | |
| download | bcm5719-llvm-87c7b09d8d7e7f04b720d298a7194c4473a8c524.tar.gz bcm5719-llvm-87c7b09d8d7e7f04b720d298a7194c4473a8c524.zip | |
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
llvm-svn: 151623
Diffstat (limited to 'llvm/lib/Target/Sparc')
| -rw-r--r-- | llvm/lib/Target/Sparc/SparcISelLowering.cpp | 2 | ||||
| -rw-r--r-- | llvm/lib/Target/Sparc/SparcISelLowering.h | 5 |
2 files changed, 3 insertions, 4 deletions
diff --git a/llvm/lib/Target/Sparc/SparcISelLowering.cpp b/llvm/lib/Target/Sparc/SparcISelLowering.cpp index a2a7d6c8f71..a6b63fbbb8e 100644 --- a/llvm/lib/Target/Sparc/SparcISelLowering.cpp +++ b/llvm/lib/Target/Sparc/SparcISelLowering.cpp @@ -347,7 +347,7 @@ SparcTargetLowering::LowerFormalArguments(SDValue Chain, SDValue SparcTargetLowering::LowerCall(SDValue Chain, SDValue Callee, CallingConv::ID CallConv, bool isVarArg, - bool &isTailCall, + bool doesNotRet, bool &isTailCall, const SmallVectorImpl<ISD::OutputArg> &Outs, const SmallVectorImpl<SDValue> &OutVals, const SmallVectorImpl<ISD::InputArg> &Ins, diff --git a/llvm/lib/Target/Sparc/SparcISelLowering.h b/llvm/lib/Target/Sparc/SparcISelLowering.h index 8a1886a856e..4a7c479b106 100644 --- a/llvm/lib/Target/Sparc/SparcISelLowering.h +++ b/llvm/lib/Target/Sparc/SparcISelLowering.h @@ -77,9 +77,8 @@ namespace llvm { SmallVectorImpl<SDValue> &InVals) const; virtual SDValue - LowerCall(SDValue Chain, SDValue Callee, - CallingConv::ID CallConv, bool isVarArg, - bool &isTailCall, + LowerCall(SDValue Chain, SDValue Callee, CallingConv::ID CallConv, + bool isVarArg, bool doesNotRet, bool &isTailCall, const SmallVectorImpl<ISD::OutputArg> &Outs, const SmallVectorImpl<SDValue> &OutVals, const SmallVectorImpl<ISD::InputArg> &Ins, |
