Tail call optimization improvements:
Move platform independent code (lowering of possibly overwritten
arguments, check for tail call optimization eligibility) from
target X86ISelectionLowering.cpp to TargetLowering.h and
SelectionDAGISel.cpp.
Initial PowerPC tail call implementation:
Support ppc32 implemented and tested (passes my tests and
test-suite llvm-test).
Support ppc64 implemented and half tested (passes my tests).
On ppc tail call optimization is performed if
caller and callee are fastcc
call is a tail call (in tail call position, call followed by ret)
no variable argument lists or byval arguments
option -tailcallopt is enabled
Supported:
* non pic tail calls on linux/darwin
* module-local tail calls on linux(PIC/GOT)/darwin(PIC)
* inter-module tail calls on darwin(PIC)
If constraints are not met a normal call will be emitted.
A test checking the argument lowering behaviour on x86-64 was added.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@50477 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/PowerPC/PPCISelLowering.h b/lib/Target/PowerPC/PPCISelLowering.h
index 8ea419d..d28799a 100644
--- a/lib/Target/PowerPC/PPCISelLowering.h
+++ b/lib/Target/PowerPC/PPCISelLowering.h
@@ -162,7 +162,16 @@
/// CMP_UNRESERVE = Test for equality and "unreserve" if not true. This
/// is used to implement atomic operations.
- CMP_UNRESERVE
+ CMP_UNRESERVE,
+
+ /// TAILCALL - Indicates a tail call should be taken.
+ TAILCALL,
+ /// TC_RETURN - A tail call return.
+ /// operand #0 chain
+ /// operand #1 callee (register or absolute)
+ /// operand #2 stack adjustment
+ /// operand #3 optional in flag
+ TC_RETURN
};
}
@@ -308,11 +317,27 @@
/// the offset of the target addressing mode.
virtual bool isLegalAddressImmediate(GlobalValue *GV) const;
+ /// IsEligibleForTailCallOptimization - Check whether the call is eligible
+ /// for tail call optimization. Target which want to do tail call
+ /// optimization should implement this function.
+ virtual bool IsEligibleForTailCallOptimization(SDOperand Call,
+ SDOperand Ret,
+ SelectionDAG &DAG) const;
+
private:
/// PPCAtomicLabelIndex - Keep track the number of PPC atomic labels.
///
unsigned PPCAtomicLabelIndex;
+ SDOperand getFramePointerFrameIndex(SelectionDAG & DAG) const;
+ SDOperand getReturnAddrFrameIndex(SelectionDAG & DAG) const;
+
+ SDOperand EmitTailCallLoadFPAndRetAddr(SelectionDAG & DAG,
+ int SPDiff,
+ SDOperand Chain,
+ SDOperand &LROpOut,
+ SDOperand &FPOpOut);
+
SDOperand LowerRETURNADDR(SDOperand Op, SelectionDAG &DAG);
SDOperand LowerFRAMEADDR(SDOperand Op, SelectionDAG &DAG);
SDOperand LowerConstantPool(SDOperand Op, SelectionDAG &DAG);