Last round of changes for ARM tail calls.

Not turning them on yet.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@106295 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Dale Johannesen 2010-06-18 18:13:11 +00:00
parent 2bff8abbf2
commit df50d7e238
2 changed files with 16 additions and 9 deletions

View File

@ -1101,7 +1101,7 @@ ARMTargetLowering::LowerCall(SDValue Chain, SDValue Callee,
}
} else if (VA.isRegLoc()) {
RegsToPass.push_back(std::make_pair(VA.getLocReg(), Arg));
} else {
} else if (!IsSibCall) {
assert(VA.isMemLoc());
MemOpChains.push_back(LowerMemOpCallTo(Chain, StackPtr, Arg,
@ -1357,12 +1357,6 @@ ARMTargetLowering::IsEligibleForTailCallOptimization(SDValue Callee,
// Look for obvious safe cases to perform tail call optimization that do not
// require ABI changes. This is what gcc calls sibcall.
// Can't do sibcall if stack needs to be dynamically re-aligned. PEI needs to
// emit a special epilogue.
// Not sure yet if this is true on ARM.
//?? if (RegInfo->needsStackRealignment(MF))
//?? return false;
// Do not sibcall optimize vararg calls unless the call site is not passing
// any arguments.
if (isVarArg && !Outs.empty())
@ -1373,6 +1367,19 @@ ARMTargetLowering::IsEligibleForTailCallOptimization(SDValue Callee,
if (isCalleeStructRet || isCallerStructRet)
return false;
// On Thumb, for the moment, we can only do this to functions defined in this
// compilation, or to indirect calls. A Thumb B to an ARM function is not
// easily fixed up in the linker, unlike BL.
if (Subtarget->isThumb()) {
if (GlobalAddressSDNode *G = dyn_cast<GlobalAddressSDNode>(Callee)) {
const GlobalValue *GV = G->getGlobal();
if (GV->isDeclaration() || GV->isWeakForLinker())
return false;
} else if (isa<ExternalSymbolSDNode>(Callee)) {
return false;
}
}
// If the calling conventions do not match, then we'd better make sure the
// results are returned in the same way as what the caller expects.
if (!CCMatch) {

View File

@ -1049,7 +1049,7 @@ let isCall = 1, isTerminator = 1, isReturn = 1, isBarrier = 1 in {
"@TC_RETURN","\t$dst", []>, Requires<[IsDarwin]>;
def TAILJMPd : ABXI<0b1010, (outs), (ins brtarget:$dst, variable_ops),
IIC_Br, "b\t$dst @ TAILCALL",
IIC_Br, "b.w\t$dst @ TAILCALL",
[]>, Requires<[IsDarwin]>;
def TAILJMPr : AXI<(outs), (ins tcGPR:$dst, variable_ops),
@ -1084,7 +1084,7 @@ let isCall = 1, isTerminator = 1, isReturn = 1, isBarrier = 1 in {
"@TC_RETURN","\t$dst", []>, Requires<[IsNotDarwin]>;
def TAILJMPdND : ABXI<0b1010, (outs), (ins brtarget:$dst, variable_ops),
IIC_Br, "b\t$dst @ TAILCALL",
IIC_Br, "b.w\t$dst @ TAILCALL",
[]>, Requires<[IsNotDarwin]>;
def TAILJMPrND : AXI<(outs), (ins tGPR:$dst, variable_ops),