diff options
Diffstat (limited to 'lib/CodeGen/SelectionDAG/TargetLowering.cpp')
-rw-r--r-- | lib/CodeGen/SelectionDAG/TargetLowering.cpp | 42 |
1 files changed, 0 insertions, 42 deletions
diff --git a/lib/CodeGen/SelectionDAG/TargetLowering.cpp b/lib/CodeGen/SelectionDAG/TargetLowering.cpp index 21b8cce77f..3c5305d226 100644 --- a/lib/CodeGen/SelectionDAG/TargetLowering.cpp +++ b/lib/CodeGen/SelectionDAG/TargetLowering.cpp @@ -2584,45 +2584,3 @@ SDValue TargetLowering::BuildUDIV(SDNode *N, SelectionDAG &DAG, DAG.getConstant(magics.s-1, getShiftAmountTy())); } } - -/// IgnoreHarmlessInstructions - Ignore instructions between a CALL and RET -/// node that don't prevent tail call optimization. -static SDValue IgnoreHarmlessInstructions(SDValue node) { - // Found call return. - if (node.getOpcode() == ISD::CALL) return node; - // Ignore MERGE_VALUES. Will have at least one operand. - if (node.getOpcode() == ISD::MERGE_VALUES) - return IgnoreHarmlessInstructions(node.getOperand(0)); - // Ignore ANY_EXTEND node. - if (node.getOpcode() == ISD::ANY_EXTEND) - return IgnoreHarmlessInstructions(node.getOperand(0)); - if (node.getOpcode() == ISD::TRUNCATE) - return IgnoreHarmlessInstructions(node.getOperand(0)); - // Any other node type. - return node; -} - -bool TargetLowering::CheckTailCallReturnConstraints(CallSDNode *TheCall, - SDValue Ret) { - unsigned NumOps = Ret.getNumOperands(); - // ISD::CALL results:(value0, ..., valuen, chain) - // ISD::RET operands:(chain, value0, flag0, ..., valuen, flagn) - // Value return: - // Check that operand of the RET node sources from the CALL node. The RET node - // has at least two operands. Operand 0 holds the chain. Operand 1 holds the - // value. - // Also we need to check that there is no code in between the call and the - // return. Hence we also check that the incomming chain to the return sources - // from the outgoing chain of the call. - if (NumOps > 1 && - IgnoreHarmlessInstructions(Ret.getOperand(1)) == SDValue(TheCall,0) && - Ret.getOperand(0) == SDValue(TheCall, TheCall->getNumValues()-1)) - return true; - // void return: The RET node has the chain result value of the CALL node as - // input. - if (NumOps == 1 && - Ret.getOperand(0) == SDValue(TheCall, TheCall->getNumValues()-1)) - return true; - - return false; -} |